Merge branch 'master' into split-with-empty-cols

Cargo.lock

@@ -1733,6 +1733,7 @@ dependencies = [
  "serde_ini 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_yaml 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "shellexpand 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "subprocess 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "surf 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "syntect 3.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2646,6 +2647,11 @@ dependencies = [
  "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "shellexpand"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "slab"
 version = "0.4.2"
@@ -3568,6 +3574,7 @@ dependencies = [
 "checksum serde_yaml 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)" = "38b08a9a90e5260fe01c6480ec7c811606df6d3a660415808c3c3fa8ed95b582"
 "checksum shell-words 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "39acde55a154c4cd3ae048ac78cc21c25f3a0145e44111b523279113dce0d94a"
 "checksum shell32-sys 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9ee04b46101f57121c9da2b151988283b6beb79b34f5bb29a58ee48cb695122c"
+"checksum shellexpand 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de7a5b5a9142fd278a10e0209b021a1b85849352e6951f4f914735c976737564"
 "checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 "checksum sluice 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ec70d7c3b17c262d4a18f7291c6ce62bf47170915f3b795434d3c5c49a4e59b7"
 "checksum smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)" = "ab606a9c5e214920bb66c458cd7be8ef094f813f20fe77a54cc7dbfff220d4b7"

Cargo.toml

@@ -78,6 +78,7 @@ battery = "0.7.4"
 textwrap = {version = "0.11.0", features = ["term_size"]}
 rawkey = {version = "0.1.2", optional = true }
 clipboard = {version = "0.5", optional = true }
+shellexpand = "1.0.0"
 
 [dev-dependencies]
 pretty_assertions = "0.6.1"

src/cli.rs

@@ -58,12 +58,17 @@ fn load_plugin(path: &std::path::Path, context: &mut Context) -> Result<(), Shel
 
     let mut input = String::new();
     match reader.read_line(&mut input) {
-        Ok(_) => {
+        Ok(count) => {
+            trace!("processing response ({} bytes)", count);
+
             let response = serde_json::from_str::<JsonRpc<Result<Signature, ShellError>>>(&input);
             match response {
                 Ok(jrpc) => match jrpc.params {
                     Ok(params) => {
                         let fname = path.to_string_lossy();
+
+                        trace!("processing {:?}", params);
+
                         if params.is_filter {
                             let fname = fname.to_string();
                             let name = params.name.clone();
@@ -91,7 +96,9 @@ fn load_plugin(path: &std::path::Path, context: &mut Context) -> Result<(), Shel
 
 fn load_plugins_in_dir(path: &std::path::PathBuf, context: &mut Context) -> Result<(), ShellError> {
     let re_bin = Regex::new(r"^nu_plugin_[A-Za-z_]+$")?;
-    let re_exe = Regex::new(r"^nu_plugin_[A-Za-z_]+\.exe$")?;
+    let re_exe = Regex::new(r"^nu_plugin_[A-Za-z_]+\.(exe|bat)$")?;
+
+    trace!("Looking for plugins in {:?}", path);
 
     match std::fs::read_dir(path) {
         Ok(p) => {
@@ -99,8 +106,10 @@ fn load_plugins_in_dir(path: &std::path::PathBuf, context: &mut Context) -> Resu
                 let entry = entry?;
                 let filename = entry.file_name();
                 let f_name = filename.to_string_lossy();
+
                 if re_bin.is_match(&f_name) || re_exe.is_match(&f_name) {
                     let mut load_path = path.clone();
+                    trace!("Found {:?}", f_name);
                     load_path.push(f_name.to_string());
                     load_plugin(&load_path, context)?;
                 }
@@ -121,19 +130,24 @@ fn load_plugins(context: &mut Context) -> Result<(), ShellError> {
         None => println!("PATH is not defined in the environment."),
     }
 
-    // Also use our debug output for now
-    let mut path = std::path::PathBuf::from(".");
-    path.push("target");
-    path.push("debug");
+    #[cfg(debug_assertions)]
+    {
+        // Use our debug plugins in debug mode
+        let mut path = std::path::PathBuf::from(".");
+        path.push("target");
+        path.push("debug");
+        let _ = load_plugins_in_dir(&path, context);
+    }
 
-    let _ = load_plugins_in_dir(&path, context);
+    #[cfg(not(debug_assertions))]
+    {
+        // Use our release plugins in release mode
+        let mut path = std::path::PathBuf::from(".");
+        path.push("target");
+        path.push("release");
 
-    // Also use our release output for now
-    let mut path = std::path::PathBuf::from(".");
-    path.push("target");
-    path.push("release");
-
-    let _ = load_plugins_in_dir(&path, context);
+        let _ = load_plugins_in_dir(&path, context);
+    }
 
     Ok(())
 }
@@ -162,6 +176,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             whole_stream_command(Reverse),
             whole_stream_command(Trim),
             whole_stream_command(ToArray),
+            whole_stream_command(ToBSON),
             whole_stream_command(ToCSV),
             whole_stream_command(ToJSON),
             whole_stream_command(ToTOML),
@@ -217,6 +232,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
         let _ = ansi_term::enable_ansi_support();
     }
 
+    // we are ok if history does not exist
     let _ = rl.load_history("history.txt");
 
     let ctrl_c = Arc::new(AtomicBool::new(false));
@@ -297,7 +313,9 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
         }
         ctrlcbreak = false;
     }
-    rl.save_history("history.txt")?;
+
+    // we are ok if we can not save history
+    let _ = rl.save_history("history.txt");
 
     Ok(())
 }
@@ -504,7 +522,9 @@ fn classify_command(
 
                     trace!(target: "nu::build_pipeline", "classifying {:?}", config);
 
-                    let args: hir::Call = config.parse_args(call, context.registry(), source)?;
+                    let args: hir::Call = config.parse_args(call, &context, source)?;
+
+                    trace!(target: "nu::build_pipeline", "args :: {}", args.debug(source));
 
                     Ok(ClassifiedCommand::Internal(InternalCommand {
                         command,

src/commands.rs

@@ -35,8 +35,8 @@ crate mod pick;
 crate mod plugin;
 crate mod prev;
 crate mod ps;
-crate mod reverse;
 crate mod reject;
+crate mod reverse;
 crate mod rm;
 crate mod save;
 crate mod shells;
@@ -48,6 +48,7 @@ crate mod split_row;
 crate mod table;
 crate mod tags;
 crate mod to_array;
+crate mod to_bson;
 crate mod to_csv;
 crate mod to_json;
 crate mod to_toml;
@@ -104,6 +105,7 @@ crate use split_row::SplitRow;
 crate use table::Table;
 crate use tags::Tags;
 crate use to_array::ToArray;
+crate use to_bson::ToBSON;
 crate use to_csv::ToCSV;
 crate use to_json::ToJSON;
 crate use to_toml::ToTOML;

src/commands/classified.rs

@@ -122,10 +122,11 @@ impl InternalCommand {
             self.name_span.clone(),
             context.source_map.clone(),
             self.args,
-            source,
+            &source,
             objects,
         );
 
+        let result = trace_out_stream!(target: "nu::trace_stream::internal", source: &source, "output" = result);
         let mut result = result.values;
 
         let mut stream = VecDeque::new();

src/commands/command.rs

@@ -422,6 +422,25 @@ pub enum CommandAction {
     LeaveShell,
 }
 
+impl ToDebug for CommandAction {
+    fn fmt_debug(&self, f: &mut fmt::Formatter, _source: &str) -> fmt::Result {
+        match self {
+            CommandAction::ChangePath(s) => write!(f, "action:change-path={}", s),
+            CommandAction::AddSpanSource(u, source) => {
+                write!(f, "action:add-span-source={}@{:?}", u, source)
+            }
+            CommandAction::Exit => write!(f, "action:exit"),
+            CommandAction::EnterShell(s) => write!(f, "action:enter-shell={}", s),
+            CommandAction::EnterValueShell(t) => {
+                write!(f, "action:enter-value-shell={:?}", t.debug())
+            }
+            CommandAction::PreviousShell => write!(f, "action:previous-shell"),
+            CommandAction::NextShell => write!(f, "action:next-shell"),
+            CommandAction::LeaveShell => write!(f, "action:leave-shell"),
+        }
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 pub enum ReturnSuccess {
     Value(Tagged<Value>),
@@ -430,6 +449,16 @@ pub enum ReturnSuccess {
 
 pub type ReturnValue = Result<ReturnSuccess, ShellError>;
 
+impl ToDebug for ReturnValue {
+    fn fmt_debug(&self, f: &mut fmt::Formatter, source: &str) -> fmt::Result {
+        match self {
+            Err(err) => write!(f, "{}", err.debug(source)),
+            Ok(ReturnSuccess::Value(v)) => write!(f, "{:?}", v.debug()),
+            Ok(ReturnSuccess::Action(a)) => write!(f, "{}", a.debug(source)),
+        }
+    }
+}
+
 impl From<Tagged<Value>> for ReturnValue {
     fn from(input: Tagged<Value>) -> ReturnValue {
         Ok(ReturnSuccess::Value(input))
@@ -469,7 +498,7 @@ pub trait WholeStreamCommand: Send + Sync {
         Signature {
             name: self.name().to_string(),
             positional: vec![],
-            rest_positional: true,
+            rest_positional: None,
             named: indexmap::IndexMap::new(),
             is_filter: true,
         }
@@ -491,7 +520,7 @@ pub trait PerItemCommand: Send + Sync {
         Signature {
             name: self.name().to_string(),
             positional: vec![],
-            rest_positional: true,
+            rest_positional: None,
             named: indexmap::IndexMap::new(),
             is_filter: true,
         }

src/commands/from_bson.rs

@@ -2,7 +2,7 @@ use crate::commands::WholeStreamCommand;
 use crate::object::base::OF64;
 use crate::object::{Primitive, TaggedDictBuilder, Value};
 use crate::prelude::*;
-use bson::{decode_document, Bson, spec::BinarySubtype};
+use bson::{decode_document, spec::BinarySubtype, Bson};
 
 pub struct FromBSON;
 
@@ -47,71 +47,80 @@ fn convert_bson_value_to_nu_value(v: &Bson, tag: impl Into<Tag>) -> Tagged<Value
         Bson::Boolean(b) => Value::Primitive(Primitive::Boolean(*b)).tagged(tag),
         Bson::Null => Value::Primitive(Primitive::String(String::from(""))).tagged(tag),
         Bson::RegExp(r, opts) => {
-             let mut collected = TaggedDictBuilder::new(tag);
-             collected.insert_tagged(
-                 "$regex".to_string(),
-                 Value::Primitive(Primitive::String(String::from(r))).tagged(tag),
-             );
-             collected.insert_tagged(
-                 "$options".to_string(),
-                 Value::Primitive(Primitive::String(String::from(opts))).tagged(tag),
-             );
-             collected.into_tagged_value()
+            let mut collected = TaggedDictBuilder::new(tag);
+            collected.insert_tagged(
+                "$regex".to_string(),
+                Value::Primitive(Primitive::String(String::from(r))).tagged(tag),
+            );
+            collected.insert_tagged(
+                "$options".to_string(),
+                Value::Primitive(Primitive::String(String::from(opts))).tagged(tag),
+            );
+            collected.into_tagged_value()
         }
+        // TODO: Add Int32 to nushell?
         Bson::I32(n) => Value::Primitive(Primitive::Int(*n as i64)).tagged(tag),
         Bson::I64(n) => Value::Primitive(Primitive::Int(*n as i64)).tagged(tag),
         Bson::JavaScriptCode(js) => {
-             let mut collected = TaggedDictBuilder::new(tag);
-             collected.insert_tagged(
-                 "$javascript".to_string(),
-                 Value::Primitive(Primitive::String(String::from(js))).tagged(tag),
-             );
-             collected.into_tagged_value()
+            let mut collected = TaggedDictBuilder::new(tag);
+            collected.insert_tagged(
+                "$javascript".to_string(),
+                Value::Primitive(Primitive::String(String::from(js))).tagged(tag),
+            );
+            collected.into_tagged_value()
         }
         Bson::JavaScriptCodeWithScope(js, doc) => {
-             let mut collected = TaggedDictBuilder::new(tag);
-             collected.insert_tagged(
-                 "$javascript".to_string(),
-                 Value::Primitive(Primitive::String(String::from(js))).tagged(tag),
-             );
-             collected.insert_tagged(
-                 "$scope".to_string(),
-                 convert_bson_value_to_nu_value(&Bson::Document(doc.to_owned()), tag),
-             );
-             collected.into_tagged_value()
+            let mut collected = TaggedDictBuilder::new(tag);
+            collected.insert_tagged(
+                "$javascript".to_string(),
+                Value::Primitive(Primitive::String(String::from(js))).tagged(tag),
+            );
+            collected.insert_tagged(
+                "$scope".to_string(),
+                convert_bson_value_to_nu_value(&Bson::Document(doc.to_owned()), tag),
+            );
+            collected.into_tagged_value()
         }
         Bson::TimeStamp(ts) => {
-             let mut collected = TaggedDictBuilder::new(tag);
-             collected.insert_tagged(
-                 "$timestamp".to_string(),
-                 Value::Primitive(Primitive::Int(*ts as i64)).tagged(tag),
-             );
-             collected.into_tagged_value()
+            let mut collected = TaggedDictBuilder::new(tag);
+            collected.insert_tagged(
+                "$timestamp".to_string(),
+                Value::Primitive(Primitive::Int(*ts as i64)).tagged(tag),
+            );
+            collected.into_tagged_value()
         }
         Bson::Binary(bst, bytes) => {
-             let mut collected = TaggedDictBuilder::new(tag);
-             collected.insert_tagged(
-                 "$binary_subtype".to_string(),
-                 match bst {
-                     BinarySubtype::UserDefined(u) => Value::Primitive(Primitive::Int(*u as i64)),
-                     _ => Value::Primitive(Primitive::String(binary_subtype_to_string(*bst))),
-                 }.tagged(tag)
-             );
-             collected.insert_tagged(
-                 "$binary".to_string(),
-                 Value::Binary(bytes.to_owned()).tagged(tag),
-             );
-             collected.into_tagged_value()
+            let mut collected = TaggedDictBuilder::new(tag);
+            collected.insert_tagged(
+                "$binary_subtype".to_string(),
+                match bst {
+                    BinarySubtype::UserDefined(u) => Value::Primitive(Primitive::Int(*u as i64)),
+                    _ => Value::Primitive(Primitive::String(binary_subtype_to_string(*bst))),
+                }
+                .tagged(tag),
+            );
+            collected.insert_tagged(
+                "$binary".to_string(),
+                Value::Binary(bytes.to_owned()).tagged(tag),
+            );
+            collected.into_tagged_value()
+        }
+        Bson::ObjectId(obj_id) => {
+            let mut collected = TaggedDictBuilder::new(tag);
+            collected.insert_tagged(
+                "$object_id".to_string(),
+                Value::Primitive(Primitive::String(obj_id.to_hex())).tagged(tag),
+            );
+            collected.into_tagged_value()
         }
-        Bson::ObjectId(obj_id) => Value::Primitive(Primitive::String(obj_id.to_hex())).tagged(tag),
         Bson::UtcDatetime(dt) => Value::Primitive(Primitive::Date(*dt)).tagged(tag),
         Bson::Symbol(s) => {
-             let mut collected = TaggedDictBuilder::new(tag);
-             collected.insert_tagged(
-                 "$symbol".to_string(),
-                 Value::Primitive(Primitive::String(String::from(s))).tagged(tag),
-             );
-             collected.into_tagged_value()
+            let mut collected = TaggedDictBuilder::new(tag);
+            collected.insert_tagged(
+                "$symbol".to_string(),
+                Value::Primitive(Primitive::String(String::from(s))).tagged(tag),
+            );
+            collected.into_tagged_value()
         }
     }
 }
@@ -125,7 +134,8 @@ fn binary_subtype_to_string(bst: BinarySubtype) -> String {
         BinarySubtype::Uuid => "uuid",
         BinarySubtype::Md5 => "md5",
         _ => unreachable!(),
-    }.to_string()
+    }
+    .to_string()
 }
 
 #[derive(Debug)]

src/commands/get.rs

@@ -22,33 +22,41 @@ impl WholeStreamCommand for Get {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, get)?.run()
     }
+
     fn signature(&self) -> Signature {
-        Signature::build("get").rest()
+        Signature::build("get").rest(SyntaxType::Member)
     }
 }
 
 fn get_member(path: &Tagged<String>, obj: &Tagged<Value>) -> Result<Tagged<Value>, ShellError> {
-    let mut current = obj;
+    let mut current = Some(obj);
     for p in path.split(".") {
-        match current.get_data_by_key(p) {
-            Some(v) => current = v,
-            None => {
+        if let Some(obj) = current {
+            current = match obj.get_data_by_key(p) {
+                Some(v) => Some(v),
+                None =>
                 // Before we give up, see if they gave us a path that matches a field name by itself
-                match obj.get_data_by_key(&path.item) {
-                    Some(v) => return Ok(v.clone()),
-                    None => {
-                        return Err(ShellError::labeled_error(
-                            "Unknown column",
-                            "table missing column",
-                            path.span(),
-                        ));
+                {
+                    match obj.get_data_by_key(&path.item) {
+                        Some(v) => return Ok(v.clone()),
+                        None => {
+                            return Err(ShellError::labeled_error(
+                                "Unknown column",
+                                "table missing column",
+                                path.span(),
+                            ));
+                        }
                     }
                 }
             }
         }
     }
 
-    Ok(current.clone())
+    match current {
+        Some(v) => Ok(v.clone()),
+        None => Ok(Value::nothing().tagged(obj.tag)),
+    }
+    // Ok(current.clone())
 }
 
 pub fn get(

src/commands/last.rs

@@ -44,7 +44,7 @@ fn last(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, S
             "Value is too low",
             "expected a positive integer",
             args.expect_nth(0)?.span(),
-        ))
+        ));
     }
 
     let stream = async_stream_block! {

src/commands/mkdir.rs

@@ -27,7 +27,7 @@ impl PerItemCommand for Mkdir {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("mkdir").rest()
+        Signature::build("mkdir").rest(SyntaxType::Path)
     }
 }
 

src/commands/open.rs

@@ -44,7 +44,8 @@ fn run(call_info: &CallInfo, shell_manager: &ShellManager) -> Result<OutputStrea
     {
         file => file,
     };
-    let path_str = path.as_string()?;
+    let path_buf = path.as_path()?;
+    let path_str = path_buf.display().to_string();
     let path_span = path.span();
     let name_span = call_info.name_span;
     let has_raw = call_info.args.has("raw");
@@ -426,14 +427,16 @@ pub fn parse_string_as_value(
     name_span: Span,
 ) -> Result<Tagged<Value>, ShellError> {
     match extension {
-        Some(x) if x == "csv" => crate::commands::from_csv::from_csv_string_to_value(
-            contents,
-            false,
-            contents_tag,
-        )
-        .map_err(move |_| {
-            ShellError::labeled_error("Could not open as CSV", "could not open as CSV", name_span)
-        }),
+        Some(x) if x == "csv" => {
+            crate::commands::from_csv::from_csv_string_to_value(contents, false, contents_tag)
+                .map_err(move |_| {
+                    ShellError::labeled_error(
+                        "Could not open as CSV",
+                        "could not open as CSV",
+                        name_span,
+                    )
+                })
+        }
         Some(x) if x == "toml" => {
             crate::commands::from_toml::from_toml_string_to_value(contents, contents_tag).map_err(
                 move |_| {
@@ -507,9 +510,9 @@ pub fn parse_binary_as_value(
             crate::commands::from_bson::from_bson_bytes_to_value(contents, contents_tag).map_err(
                 move |_| {
                     ShellError::labeled_error(
-                       "Could not open as BSON",
-                       "could not open as BSON",
-                       name_span,
+                        "Could not open as BSON",
+                        "could not open as BSON",
+                        name_span,
                     )
                 },
             )

src/commands/pick.rs

@@ -17,7 +17,7 @@ impl WholeStreamCommand for Pick {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pick").rest()
+        Signature::build("pick").rest(SyntaxType::Any)
     }
 
     fn run(

src/commands/plugin.rs

@@ -3,6 +3,7 @@ use crate::errors::ShellError;
 use crate::parser::registry;
 use crate::prelude::*;
 use derive_new::new;
+use log::trace;
 use serde::{self, Deserialize, Serialize};
 use std::io::prelude::*;
 use std::io::BufReader;
@@ -64,6 +65,8 @@ pub fn filter_plugin(
     args: CommandArgs,
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
+    trace!("filter_plugin :: {}", path);
+
     let args = args.evaluate_once(registry)?;
 
     let mut child = std::process::Command::new(path)
@@ -80,6 +83,8 @@ pub fn filter_plugin(
 
     let call_info = args.call_info.clone();
 
+    trace!("filtering :: {:?}", call_info);
+
     let stream = bos
         .chain(args.input.values)
         .chain(eos)
@@ -95,7 +100,14 @@ pub fn filter_plugin(
 
                 let request = JsonRpc::new("begin_filter", call_info.clone());
                 let request_raw = serde_json::to_string(&request).unwrap();
-                let _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
+                match stdin.write(format!("{}\n", request_raw).as_bytes()) {
+                    Ok(_) => {}
+                    Err(err) => {
+                        let mut result = VecDeque::new();
+                        result.push_back(Err(ShellError::unexpected(format!("{}", err))));
+                        return result;
+                    }
+                }
 
                 let mut input = String::new();
                 match reader.read_line(&mut input) {
@@ -140,7 +152,15 @@ pub fn filter_plugin(
                 let mut reader = BufReader::new(stdout);
 
                 let request: JsonRpc<std::vec::Vec<Value>> = JsonRpc::new("end_filter", vec![]);
-                let request_raw = serde_json::to_string(&request).unwrap();
+                let request_raw = match serde_json::to_string(&request) {
+                    Ok(req) => req,
+                    Err(err) => {
+                        let mut result = VecDeque::new();
+                        result.push_back(Err(ShellError::unexpected(format!("{}", err))));
+                        return result;
+                    }
+                };
+
                 let _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
 
                 let mut input = String::new();

src/commands/reject.rs

@@ -24,7 +24,7 @@ impl WholeStreamCommand for Reject {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("reject").rest()
+        Signature::build("reject").rest(SyntaxType::Member)
     }
 }
 

src/commands/save.rs

@@ -59,7 +59,7 @@ fn save(
             // If there is no filename, check the metadata for the origin filename
             if input.len() > 0 {
                 let origin = input[0].origin();
-                match origin.map(|x| source_map.get(&x)).flatten() {
+                match origin.and_then(|x| source_map.get(&x)) {
                     Some(path) => match path {
                         SpanSource::File(file) => {
                             full_path.push(Path::new(file));

src/commands/sort_by.rs

@@ -4,13 +4,19 @@ use crate::prelude::*;
 
 pub struct SortBy;
 
+#[derive(Deserialize)]
+pub struct SortByArgs {
+    rest: Vec<Tagged<String>>,
+    reverse: bool,
+}
+
 impl WholeStreamCommand for SortBy {
     fn run(
         &self,
         args: CommandArgs,
         registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        sort_by(args, registry)
+        args.process(registry, sort_by)?.run()
     }
 
     fn name(&self) -> &str {
@@ -18,43 +24,32 @@ impl WholeStreamCommand for SortBy {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("sort-by").switch("reverse")
+        Signature::build("sort-by")
+            .rest(SyntaxType::String)
+            .switch("reverse")
     }
 }
 
-fn sort_by(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
-    let args = args.evaluate_once(registry)?;
-    let (input, args) = args.parts();
+fn sort_by(
+    SortByArgs { reverse, rest }: SortByArgs,
+    mut context: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    Ok(OutputStream::new(async_stream_block! {
+        let mut vec = context.input.drain_vec().await;
 
-    let fields: Result<Vec<_>, _> = args
-        .positional
-        .iter()
-        .flatten()
-        .map(|a| a.as_string())
-        .collect();
-
-    let fields = fields?;
-
-    let output = input.values.collect::<Vec<_>>();
-
-    let reverse = args.has("reverse");
-    let output = output.map(move |mut vec| {
         let calc_key = |item: &Tagged<Value>| {
-            fields
-                .iter()
+            rest.iter()
                 .map(|f| item.get_data_by_key(f).map(|i| i.clone()))
                 .collect::<Vec<Option<Tagged<Value>>>>()
         };
         if reverse {
-            vec.sort_by_cached_key(|item| {
-                std::cmp::Reverse(calc_key(item))
-            });
+            vec.sort_by_cached_key(|item| std::cmp::Reverse(calc_key(item)));
         } else {
             vec.sort_by_cached_key(calc_key);
+        };
+
+        for item in vec {
+            yield item.into();
         }
-
-        vec.into_iter().collect::<VecDeque<_>>()
-    });
-
-    Ok(output.flatten_stream().from_input_stream())
+    }))
 }

src/commands/split_column.rs

@@ -31,7 +31,7 @@ impl WholeStreamCommand for SplitColumn {
         Signature::build("split-column")
             .required("separator", SyntaxType::Any)
             .switch("collapse-empty")
-            .rest()
+            .rest(SyntaxType::Member)
     }
 }
 

src/commands/tags.rs

@@ -38,7 +38,7 @@ fn tags(args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream,
                 dict.insert("end", Value::int(span.end as i64));
                 tags.insert_tagged("span", dict.into_tagged_value());
 
-                match origin.map(|x| source_map.get(&x)).flatten() {
+                match origin.and_then(|x| source_map.get(&x)) {
                     Some(SpanSource::File(source)) => {
                         tags.insert("origin", Value::string(source));
                     }

src/commands/to_bson.rs

@@ -0,0 +1,231 @@
+use crate::commands::WholeStreamCommand;
+use crate::object::{Dictionary, Primitive, Value};
+use crate::prelude::*;
+use bson::{encode_document, oid::ObjectId, spec::BinarySubtype, Bson, Document};
+use std::convert::TryInto;
+
+pub struct ToBSON;
+
+impl WholeStreamCommand for ToBSON {
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        to_bson(args, registry)
+    }
+
+    fn name(&self) -> &str {
+        "to-bson"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("to-bson")
+    }
+}
+
+pub fn value_to_bson_value(v: &Value) -> Bson {
+    match v {
+        Value::Primitive(Primitive::Boolean(b)) => Bson::Boolean(*b),
+        Value::Primitive(Primitive::Bytes(b)) => Bson::I64(*b as i64),
+        Value::Primitive(Primitive::Date(d)) => Bson::UtcDatetime(*d),
+        Value::Primitive(Primitive::EndOfStream) => Bson::Null,
+        Value::Primitive(Primitive::BeginningOfStream) => Bson::Null,
+        Value::Primitive(Primitive::Float(f)) => Bson::FloatingPoint(f.into_inner()),
+        Value::Primitive(Primitive::Int(i)) => Bson::I64(*i),
+        Value::Primitive(Primitive::Nothing) => Bson::Null,
+        Value::Primitive(Primitive::String(s)) => Bson::String(s.clone()),
+        Value::Primitive(Primitive::Path(s)) => Bson::String(s.display().to_string()),
+        Value::List(l) => Bson::Array(l.iter().map(|x| value_to_bson_value(x)).collect()),
+        Value::Block(_) => Bson::Null,
+        Value::Binary(b) => Bson::Binary(BinarySubtype::Generic, b.clone()),
+        Value::Object(o) => object_value_to_bson(o),
+    }
+}
+
+// object_value_to_bson handles all Objects, even those that correspond to special
+// types (things like regex or javascript code).
+fn object_value_to_bson(o: &Dictionary) -> Bson {
+    let mut it = o.entries.iter();
+    if it.len() > 2 {
+        return generic_object_value_to_bson(o);
+    }
+    match it.next() {
+        Some((regex, tagged_regex_value)) if regex == "$regex" => match it.next() {
+            Some((options, tagged_opts_value)) if options == "$options" => {
+                let r: Result<String, _> = tagged_regex_value.try_into();
+                let opts: Result<String, _> = tagged_opts_value.try_into();
+                if r.is_err() || opts.is_err() {
+                    generic_object_value_to_bson(o)
+                } else {
+                    Bson::RegExp(r.unwrap(), opts.unwrap())
+                }
+            }
+            _ => generic_object_value_to_bson(o),
+        },
+        Some((javascript, tagged_javascript_value)) if javascript == "$javascript" => {
+            match it.next() {
+                Some((scope, tagged_scope_value)) if scope == "$scope" => {
+                    let js: Result<String, _> = tagged_javascript_value.try_into();
+                    let s: Result<&Dictionary, _> = tagged_scope_value.try_into();
+                    if js.is_err() || s.is_err() {
+                        generic_object_value_to_bson(o)
+                    } else {
+                        if let Bson::Document(doc) = object_value_to_bson(s.unwrap()) {
+                            Bson::JavaScriptCodeWithScope(js.unwrap(), doc)
+                        } else {
+                            generic_object_value_to_bson(o)
+                        }
+                    }
+                }
+                None => {
+                    let js: Result<String, _> = tagged_javascript_value.try_into();
+                    if js.is_err() {
+                        generic_object_value_to_bson(o)
+                    } else {
+                        Bson::JavaScriptCode(js.unwrap())
+                    }
+                }
+                _ => generic_object_value_to_bson(o),
+            }
+        }
+        Some((timestamp, tagged_timestamp_value)) if timestamp == "$timestamp" => {
+            let ts: Result<i64, _> = tagged_timestamp_value.try_into();
+            if ts.is_err() {
+                generic_object_value_to_bson(o)
+            } else {
+                Bson::TimeStamp(ts.unwrap())
+            }
+        }
+        Some((binary_subtype, tagged_binary_subtype_value))
+            if binary_subtype == "$binary_subtype" =>
+        {
+            match it.next() {
+                Some((binary, tagged_bin_value)) if binary == "$binary" => {
+                    let bst = get_binary_subtype(tagged_binary_subtype_value);
+                    let bin: Result<Vec<u8>, _> = tagged_bin_value.try_into();
+                    if bst.is_none() || bin.is_err() {
+                        generic_object_value_to_bson(o)
+                    } else {
+                        Bson::Binary(bst.unwrap(), bin.unwrap())
+                    }
+                }
+                _ => generic_object_value_to_bson(o),
+            }
+        }
+        Some((object_id, tagged_object_id_value)) if object_id == "$object_id" => {
+            let obj_id: Result<String, _> = tagged_object_id_value.try_into();
+            if obj_id.is_err() {
+                generic_object_value_to_bson(o)
+            } else {
+                let obj_id = ObjectId::with_string(&obj_id.unwrap());
+                if obj_id.is_err() {
+                    generic_object_value_to_bson(o)
+                } else {
+                    Bson::ObjectId(obj_id.unwrap())
+                }
+            }
+        }
+        Some((symbol, tagged_symbol_value)) if symbol == "$symbol" => {
+            let sym: Result<String, _> = tagged_symbol_value.try_into();
+            if sym.is_err() {
+                generic_object_value_to_bson(o)
+            } else {
+                Bson::Symbol(sym.unwrap())
+            }
+        }
+        _ => generic_object_value_to_bson(o),
+    }
+}
+
+fn get_binary_subtype<'a>(tagged_value: &'a Tagged<Value>) -> Option<BinarySubtype> {
+    match tagged_value.item() {
+        Value::Primitive(Primitive::String(s)) => Some(match s.as_ref() {
+            "generic" => BinarySubtype::Generic,
+            "function" => BinarySubtype::Function,
+            "binary_old" => BinarySubtype::BinaryOld,
+            "uuid_old" => BinarySubtype::UuidOld,
+            "uuid" => BinarySubtype::Uuid,
+            "md5" => BinarySubtype::Md5,
+            _ => unreachable!(),
+        }),
+        Value::Primitive(Primitive::Int(i)) => Some(BinarySubtype::UserDefined(*i as u8)),
+        _ => None,
+    }
+}
+
+// generic_object_value_bson handles any Object that does not
+// correspond to a special bson type (things like regex or javascript code).
+fn generic_object_value_to_bson(o: &Dictionary) -> Bson {
+    let mut doc = Document::new();
+    for (k, v) in o.entries.iter() {
+        doc.insert(k.clone(), value_to_bson_value(v));
+    }
+    Bson::Document(doc)
+}
+
+fn shell_encode_document(
+    writer: &mut Vec<u8>,
+    doc: Document,
+    span: Span,
+) -> Result<(), ShellError> {
+    match encode_document(writer, &doc) {
+        Err(e) => Err(ShellError::labeled_error(
+            format!("Failed to encode document due to: {:?}", e),
+            "requires BSON-compatible document",
+            span,
+        )),
+        _ => Ok(()),
+    }
+}
+
+fn bson_value_to_bytes(bson: Bson, span: Span) -> Result<Vec<u8>, ShellError> {
+    let mut out = Vec::new();
+    match bson {
+        Bson::Array(a) => {
+            for v in a.into_iter() {
+                match v {
+                    Bson::Document(d) => shell_encode_document(&mut out, d, span)?,
+                    _ => {
+                        return Err(ShellError::labeled_error(
+                            format!("All top level values must be Documents, got {:?}", v),
+                            "requires BSON-compatible document",
+                            span,
+                        ))
+                    }
+                }
+            }
+        }
+        Bson::Document(d) => shell_encode_document(&mut out, d, span)?,
+        _ => {
+            return Err(ShellError::labeled_error(
+                format!("All top level values must be Documents, got {:?}", bson),
+                "requires BSON-compatible document",
+                span,
+            ))
+        }
+    }
+    Ok(out)
+}
+
+fn to_bson(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let name_span = args.name_span();
+    let out = args.input;
+
+    Ok(out
+        .values
+        .map(
+            move |a| match bson_value_to_bytes(value_to_bson_value(&a), name_span) {
+                Ok(x) => ReturnSuccess::value(Value::Binary(x).simple_spanned(name_span)),
+                _ => Err(ShellError::labeled_error_with_secondary(
+                    "Expected an object with BSON-compatible structure from pipeline",
+                    "requires BSON-compatible input: Must be Array or Object",
+                    name_span,
+                    format!("{} originates from here", a.item.type_name()),
+                    a.span(),
+                )),
+            },
+        )
+        .to_output_stream())
+}

src/commands/version.rs

@@ -5,8 +5,6 @@ use crate::parser::registry::Signature;
 use crate::prelude::*;
 use indexmap::IndexMap;
 
-const VERSION: &'static str = env!("CARGO_PKG_VERSION");
-
 pub struct Version;
 
 impl WholeStreamCommand for Version {
@@ -34,7 +32,7 @@ pub fn date(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStrea
     let mut indexmap = IndexMap::new();
     indexmap.insert(
         "version".to_string(),
-        Tagged::from_simple_spanned_item(Value::string(VERSION.to_string()), span),
+        Tagged::from_simple_spanned_item(Value::string(clap::crate_version!()), span),
     );
 
     let value = Tagged::from_simple_spanned_item(Value::Object(Dictionary::from(indexmap)), span);

src/context.rs

@@ -121,7 +121,7 @@ impl Context {
         name_span: Span,
         source_map: SourceMap,
         args: hir::Call,
-        source: Text,
+        source: &Text,
         input: InputStream,
     ) -> OutputStream {
         let command_args = self.command_args(args, input, source, source_map, name_span);
@@ -131,13 +131,13 @@ impl Context {
     fn call_info(
         &self,
         args: hir::Call,
-        source: Text,
+        source: &Text,
         source_map: SourceMap,
         name_span: Span,
     ) -> UnevaluatedCallInfo {
         UnevaluatedCallInfo {
             args,
-            source,
+            source: source.clone(),
             source_map,
             name_span,
         }
@@ -147,7 +147,7 @@ impl Context {
         &self,
         args: hir::Call,
         input: InputStream,
-        source: Text,
+        source: &Text,
         source_map: SourceMap,
         name_span: Span,
     ) -> CommandArgs {

src/errors.rs

@@ -5,6 +5,7 @@ use ansi_term::Color;
 use derive_new::new;
 use language_reporting::{Diagnostic, Label, Severity};
 use serde::{Deserialize, Serialize};
+use std::fmt;
 
 #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
 pub enum Description {
@@ -56,6 +57,12 @@ pub struct ShellError {
     cause: Option<Box<ProximateShellError>>,
 }
 
+impl ToDebug for ShellError {
+    fn fmt_debug(&self, f: &mut fmt::Formatter, source: &str) -> fmt::Result {
+        self.error.fmt_debug(f, source)
+    }
+}
+
 impl serde::de::Error for ShellError {
     fn custom<T>(msg: T) -> Self
     where
@@ -335,6 +342,7 @@ pub enum ProximateShellError {
         right: Tagged<String>,
     },
 }
+
 impl ProximateShellError {
     fn start(self) -> ShellError {
         ShellError {
@@ -344,6 +352,13 @@ impl ProximateShellError {
     }
 }
 
+impl ToDebug for ProximateShellError {
+    fn fmt_debug(&self, f: &mut fmt::Formatter, _source: &str) -> fmt::Result {
+        // TODO: Custom debug for inner spans
+        write!(f, "{:?}", self)
+    }
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ShellDiagnostic {
     crate diagnostic: Diagnostic<Span>,

src/evaluate/evaluator.rs

@@ -39,6 +39,7 @@ crate fn evaluate_baseline_expr(
 ) -> Result<Tagged<Value>, ShellError> {
     match &expr.item {
         RawExpression::Literal(literal) => Ok(evaluate_literal(expr.copy_span(*literal), source)),
+        RawExpression::FilePath(path) => Ok(Value::path(path.clone()).tagged(expr.span())),
         RawExpression::Synthetic(hir::Synthetic::String(s)) => Ok(Value::string(s).tagged_unknown()),
         RawExpression::Variable(var) => evaluate_reference(var, scope, source),
         RawExpression::ExternalCommand(external) => evaluate_external(external, scope, source),

src/format/table.rs

@@ -78,13 +78,16 @@ impl TableView {
         for head in 0..headers.len() {
             let mut current_col_max = 0;
             for row in 0..values.len() {
-                let value_length = entries[row][head].0.len();
+                let value_length = entries[row][head].0.chars().count();
                 if value_length > current_col_max {
                     current_col_max = value_length;
                 }
             }
 
-            max_per_column.push(std::cmp::max(current_col_max, headers[head].len()));
+            max_per_column.push(std::cmp::max(
+                current_col_max,
+                headers[head].chars().count(),
+            ));
         }
 
         // Different platforms want different amounts of buffer, not sure why

src/git.rs

@@ -7,15 +7,13 @@ pub fn current_branch() -> Option<String> {
         Ok(repo) => {
             let r = repo.head();
             match r {
-                Ok(r) => {
-                    match r.shorthand() {
-                        Some(s) => Some(s.to_string()),
-                        None => None,
-                    }
+                Ok(r) => match r.shorthand() {
+                    Some(s) => Some(s.to_string()),
+                    None => None,
                 },
-                _ => None
+                _ => None,
             }
-        },
-        _ => None
+        }
+        _ => None,
     }
 }

src/lib.rs

@@ -3,7 +3,6 @@
 #![feature(generators)]
 #![feature(try_trait)]
 #![feature(bind_by_move_pattern_guards)]
-#![feature(option_flattening)]
 #![feature(specialization)]
 #![feature(proc_macro_hygiene)]
 
@@ -30,6 +29,7 @@ pub use crate::commands::command::{CallInfo, ReturnSuccess, ReturnValue};
 pub use crate::context::{SourceMap, SpanSource};
 pub use crate::env::host::BasicHost;
 pub use crate::object::base::OF64;
+pub use crate::parser::hir::SyntaxType;
 pub use crate::plugin::{serve_plugin, Plugin};
 pub use crate::utils::{AbsolutePath, RelativePath};
 pub use cli::cli;

src/object/base.rs

@@ -122,10 +122,8 @@ impl Primitive {
     pub fn style(&self) -> &'static str {
         match self {
             Primitive::Bytes(0) => "c", // centre 'missing' indicator
-            Primitive::Int(_) |
-            Primitive::Bytes(_) |
-            Primitive::Float(_) => "r",
-            _ => ""
+            Primitive::Int(_) | Primitive::Bytes(_) | Primitive::Float(_) => "r",
+            _ => "",
         }
     }
 }
@@ -245,6 +243,48 @@ impl std::convert::TryFrom<&'a Tagged<Value>> for i64 {
     }
 }
 
+impl std::convert::TryFrom<&'a Tagged<Value>> for String {
+    type Error = ShellError;
+
+    fn try_from(value: &'a Tagged<Value>) -> Result<String, ShellError> {
+        match value.item() {
+            Value::Primitive(Primitive::String(s)) => Ok(s.clone()),
+            v => Err(ShellError::type_error(
+                "String",
+                value.copy_span(v.type_name()),
+            )),
+        }
+    }
+}
+
+impl std::convert::TryFrom<&'a Tagged<Value>> for Vec<u8> {
+    type Error = ShellError;
+
+    fn try_from(value: &'a Tagged<Value>) -> Result<Vec<u8>, ShellError> {
+        match value.item() {
+            Value::Binary(b) => Ok(b.clone()),
+            v => Err(ShellError::type_error(
+                "Binary",
+                value.copy_span(v.type_name()),
+            )),
+        }
+    }
+}
+
+impl std::convert::TryFrom<&'a Tagged<Value>> for &'a crate::object::Dictionary {
+    type Error = ShellError;
+
+    fn try_from(value: &'a Tagged<Value>) -> Result<&'a crate::object::Dictionary, ShellError> {
+        match value.item() {
+            Value::Object(d) => Ok(d),
+            v => Err(ShellError::type_error(
+                "Dictionary",
+                value.copy_span(v.type_name()),
+            )),
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize)]
 pub enum Switch {
     Present,
@@ -295,6 +335,7 @@ impl Value {
         }
     }
 
+    // TODO: This is basically a legacy construct, I think
     pub fn data_descriptors(&self) -> Vec<String> {
         match self {
             Value::Primitive(_) => vec![],
@@ -472,7 +513,7 @@ impl Value {
     crate fn style_leaf(&self) -> &'static str {
         match self {
             Value::Primitive(p) => p.style(),
-            _ => ""
+            _ => "",
         }
     }
 
@@ -559,6 +600,10 @@ impl Value {
         Value::Primitive(Primitive::String(s.into()))
     }
 
+    pub fn path(s: impl Into<PathBuf>) -> Value {
+        Value::Primitive(Primitive::Path(s.into()))
+    }
+
     pub fn bytes(s: impl Into<u64>) -> Value {
         Value::Primitive(Primitive::Bytes(s.into()))
     }
@@ -594,6 +639,18 @@ impl Value {
     }
 }
 
+impl Tagged<Value> {
+    crate fn as_path(&self) -> Result<PathBuf, ShellError> {
+        match self.item() {
+            Value::Primitive(Primitive::Path(path)) => Ok(path.clone()),
+            other => Err(ShellError::type_error(
+                "Path",
+                other.type_name().tagged(self.span()),
+            )),
+        }
+    }
+}
+
 crate fn select_fields(obj: &Value, fields: &[String], tag: impl Into<Tag>) -> Tagged<Value> {
     let mut out = TaggedDictBuilder::new(tag);
 

src/object/types.rs

@@ -2,7 +2,6 @@ use crate::object::base as value;
 use crate::parser::hir;
 use crate::prelude::*;
 use log::trace;
-use std::path::PathBuf;
 
 pub trait ExtractType: Sized {
     fn extract(value: &Tagged<Value>) -> Result<Self, ShellError>;
@@ -196,9 +195,9 @@ impl ExtractType for std::path::PathBuf {
 
         match &value {
             Tagged {
-                item: Value::Primitive(Primitive::String(p)),
+                item: Value::Primitive(Primitive::Path(p)),
                 ..
-            } => Ok(PathBuf::from(p)),
+            } => Ok(p.clone()),
             other => Err(ShellError::type_error("Path", other.tagged_type_name())),
         }
     }

src/parser/hir.rs

@@ -11,16 +11,22 @@ use derive_new::new;
 use getset::Getters;
 use serde::{Deserialize, Serialize};
 use std::fmt;
+use std::path::PathBuf;
 
 use crate::evaluate::Scope;
 
-crate use self::baseline_parse::{baseline_parse_single_token, baseline_parse_token_as_string};
-crate use self::baseline_parse_tokens::{baseline_parse_next_expr, SyntaxType, TokensIterator};
+crate use self::baseline_parse::{
+    baseline_parse_single_token, baseline_parse_token_as_number, baseline_parse_token_as_path,
+    baseline_parse_token_as_string,
+};
+crate use self::baseline_parse_tokens::{baseline_parse_next_expr, TokensIterator};
 crate use self::binary::Binary;
 crate use self::external_command::ExternalCommand;
 crate use self::named::NamedArguments;
 crate use self::path::Path;
 
+pub use self::baseline_parse_tokens::SyntaxType;
+
 pub fn path(head: impl Into<Expression>, tail: Vec<Tagged<impl Into<String>>>) -> Path {
     Path::new(
         head.into(),
@@ -68,6 +74,8 @@ impl ToDebug for Call {
             write!(f, "{}", named.debug(source))?;
         }
 
+        write!(f, ")")?;
+
         Ok(())
     }
 }
@@ -81,6 +89,7 @@ pub enum RawExpression {
     Block(Vec<Expression>),
     List(Vec<Expression>),
     Path(Box<Path>),
+    FilePath(PathBuf),
     ExternalCommand(ExternalCommand),
 
     #[allow(unused)]
@@ -105,6 +114,7 @@ impl RawExpression {
         match self {
             RawExpression::Literal(literal) => literal.type_name(),
             RawExpression::Synthetic(synthetic) => synthetic.type_name(),
+            RawExpression::FilePath(..) => "filepath",
             RawExpression::Variable(..) => "variable",
             RawExpression::List(..) => "list",
             RawExpression::Binary(..) => "binary",
@@ -141,6 +151,10 @@ impl Expression {
         )
     }
 
+    crate fn file_path(path: impl Into<PathBuf>, outer: impl Into<Span>) -> Expression {
+        Tagged::from_simple_spanned_item(RawExpression::FilePath(path.into()), outer.into())
+    }
+
     crate fn bare(span: impl Into<Span>) -> Expression {
         Tagged::from_simple_spanned_item(RawExpression::Literal(Literal::Bare), span.into())
     }
@@ -170,7 +184,8 @@ impl Expression {
 impl ToDebug for Expression {
     fn fmt_debug(&self, f: &mut fmt::Formatter, source: &str) -> fmt::Result {
         match self.item() {
-            RawExpression::Literal(l) => write!(f, "{:?}", l),
+            RawExpression::Literal(l) => l.tagged(self.span()).fmt_debug(f, source),
+            RawExpression::FilePath(p) => write!(f, "{}", p.display()),
             RawExpression::Synthetic(Synthetic::String(s)) => write!(f, "{:?}", s),
             RawExpression::Variable(Variable::It(_)) => write!(f, "$it"),
             RawExpression::Variable(Variable::Other(s)) => write!(f, "${}", s.slice(source)),

src/parser/hir/baseline_parse.rs

@@ -1,5 +1,7 @@
+use crate::context::Context;
 use crate::parser::{hir, RawToken, Token};
 use crate::Text;
+use std::path::PathBuf;
 
 pub fn baseline_parse_single_token(token: &Token, source: &Text) -> hir::Expression {
     match *token.item() {
@@ -15,6 +17,20 @@ pub fn baseline_parse_single_token(token: &Token, source: &Text) -> hir::Express
     }
 }
 
+pub fn baseline_parse_token_as_number(token: &Token, source: &Text) -> hir::Expression {
+    match *token.item() {
+        RawToken::Variable(span) if span.slice(source) == "it" => {
+            hir::Expression::it_variable(span, token.span())
+        }
+        RawToken::External(span) => hir::Expression::external_command(span, token.span()),
+        RawToken::Variable(span) => hir::Expression::variable(span, token.span()),
+        RawToken::Integer(int) => hir::Expression::int(int, token.span()),
+        RawToken::Size(int, unit) => hir::Expression::size(int, unit, token.span()),
+        RawToken::Bare => hir::Expression::bare(token.span()),
+        RawToken::String(span) => hir::Expression::string(span, token.span()),
+    }
+}
+
 pub fn baseline_parse_token_as_string(token: &Token, source: &Text) -> hir::Expression {
     match *token.item() {
         RawToken::Variable(span) if span.slice(source) == "it" => {
@@ -28,3 +44,32 @@ pub fn baseline_parse_token_as_string(token: &Token, source: &Text) -> hir::Expr
         RawToken::String(span) => hir::Expression::string(span, token.span()),
     }
 }
+
+pub fn baseline_parse_token_as_path(
+    token: &Token,
+    context: &Context,
+    source: &Text,
+) -> hir::Expression {
+    match *token.item() {
+        RawToken::Variable(span) if span.slice(source) == "it" => {
+            hir::Expression::it_variable(span, token.span())
+        }
+        RawToken::External(span) => hir::Expression::external_command(span, token.span()),
+        RawToken::Variable(span) => hir::Expression::variable(span, token.span()),
+        RawToken::Integer(_) => hir::Expression::bare(token.span()),
+        RawToken::Size(_, _) => hir::Expression::bare(token.span()),
+        RawToken::Bare => hir::Expression::file_path(
+            expand_path(token.span().slice(source), context),
+            token.span(),
+        ),
+        RawToken::String(span) => {
+            hir::Expression::file_path(expand_path(span.slice(source), context), token.span())
+        }
+    }
+}
+
+pub fn expand_path(string: &str, context: &Context) -> PathBuf {
+    let expanded = shellexpand::tilde_with_context(string, || context.shell_manager.homedir());
+
+    PathBuf::from(expanded.as_ref())
+}

src/parser/hir/baseline_parse_tokens.rs

@@ -1,8 +1,11 @@
+use crate::context::Context;
 use crate::errors::ShellError;
-use crate::parser::registry::CommandRegistry;
 use crate::parser::{
     hir,
-    hir::{baseline_parse_single_token, baseline_parse_token_as_string},
+    hir::{
+        baseline_parse_single_token, baseline_parse_token_as_number, baseline_parse_token_as_path,
+        baseline_parse_token_as_string,
+    },
     DelimitedNode, Delimiter, PathNode, RawToken, TokenNode,
 };
 use crate::{Span, Tag, Tagged, TaggedItem, Text};
@@ -12,8 +15,9 @@ use serde::{Deserialize, Serialize};
 
 pub fn baseline_parse_tokens(
     token_nodes: &mut TokensIterator<'_>,
-    registry: &CommandRegistry,
+    context: &Context,
     source: &Text,
+    syntax_type: SyntaxType,
 ) -> Result<Vec<hir::Expression>, ShellError> {
     let mut exprs: Vec<hir::Expression> = vec![];
 
@@ -22,7 +26,7 @@ pub fn baseline_parse_tokens(
             break;
         }
 
-        let expr = baseline_parse_next_expr(token_nodes, registry, source, SyntaxType::Any)?;
+        let expr = baseline_parse_next_expr(token_nodes, context, source, syntax_type)?;
         exprs.push(expr);
     }
 
@@ -35,7 +39,10 @@ pub enum SyntaxType {
     Any,
     List,
     Literal,
+    String,
+    Member,
     Variable,
+    Number,
     Path,
     Binary,
     Block,
@@ -44,7 +51,7 @@ pub enum SyntaxType {
 
 pub fn baseline_parse_next_expr(
     tokens: &mut TokensIterator,
-    registry: &CommandRegistry,
+    context: &Context,
     source: &Text,
     syntax_type: SyntaxType,
 ) -> Result<hir::Expression, ShellError> {
@@ -56,7 +63,7 @@ pub fn baseline_parse_next_expr(
 
     match (syntax_type, next) {
         (SyntaxType::Path, TokenNode::Token(token)) => {
-            return Ok(baseline_parse_token_as_string(token, source))
+            return Ok(baseline_parse_token_as_path(token, context, source))
         }
 
         (SyntaxType::Path, token) => {
@@ -66,10 +73,50 @@ pub fn baseline_parse_next_expr(
             ))
         }
 
-        _ => {}
+        (SyntaxType::String, TokenNode::Token(token)) => {
+            return Ok(baseline_parse_token_as_string(token, source));
+        }
+
+        (SyntaxType::String, token) => {
+            return Err(ShellError::type_error(
+                "String",
+                token.type_name().simple_spanned(token.span()),
+            ))
+        }
+
+        (SyntaxType::Number, TokenNode::Token(token)) => {
+            return Ok(baseline_parse_token_as_number(token, source));
+        }
+
+        (SyntaxType::Number, token) => {
+            return Err(ShellError::type_error(
+                "Numeric",
+                token.type_name().simple_spanned(token.span()),
+            ))
+        }
+
+        // TODO: More legit member processing
+        (SyntaxType::Member, TokenNode::Token(token)) => {
+            return Ok(baseline_parse_token_as_string(token, source));
+        }
+
+        (SyntaxType::Member, token) => {
+            return Err(ShellError::type_error(
+                "member",
+                token.type_name().simple_spanned(token.span()),
+            ))
+        }
+
+        (SyntaxType::Any, _) => {}
+        (SyntaxType::List, _) => {}
+        (SyntaxType::Literal, _) => {}
+        (SyntaxType::Variable, _) => {}
+        (SyntaxType::Binary, _) => {}
+        (SyntaxType::Block, _) => {}
+        (SyntaxType::Boolean, _) => {}
     };
 
-    let first = baseline_parse_semantic_token(next, registry, source)?;
+    let first = baseline_parse_semantic_token(next, context, source)?;
 
     let possible_op = tokens.peek();
 
@@ -88,7 +135,7 @@ pub fn baseline_parse_next_expr(
                 op.span(),
             ))
         }
-        Some(token) => baseline_parse_semantic_token(token, registry, source)?,
+        Some(token) => baseline_parse_semantic_token(token, context, source)?,
     };
 
     // We definitely have a binary expression here -- let's see if we should coerce it into a block
@@ -176,13 +223,13 @@ pub fn baseline_parse_next_expr(
 
 pub fn baseline_parse_semantic_token(
     token: &TokenNode,
-    registry: &CommandRegistry,
+    context: &Context,
     source: &Text,
 ) -> Result<hir::Expression, ShellError> {
     match token {
         TokenNode::Token(token) => Ok(baseline_parse_single_token(token, source)),
         TokenNode::Call(_call) => unimplemented!(),
-        TokenNode::Delimited(delimited) => baseline_parse_delimited(delimited, registry, source),
+        TokenNode::Delimited(delimited) => baseline_parse_delimited(delimited, context, source),
         TokenNode::Pipeline(_pipeline) => unimplemented!(),
         TokenNode::Operator(_op) => unreachable!(),
         TokenNode::Flag(_flag) => Err(ShellError::unimplemented(
@@ -191,20 +238,24 @@ pub fn baseline_parse_semantic_token(
         TokenNode::Member(_span) => unreachable!(),
         TokenNode::Whitespace(_span) => unreachable!(),
         TokenNode::Error(error) => Err(*error.item.clone()),
-        TokenNode::Path(path) => baseline_parse_path(path, registry, source),
+        TokenNode::Path(path) => baseline_parse_path(path, context, source),
     }
 }
 
 pub fn baseline_parse_delimited(
     token: &Tagged<DelimitedNode>,
-    registry: &CommandRegistry,
+    context: &Context,
     source: &Text,
 ) -> Result<hir::Expression, ShellError> {
     match token.delimiter() {
         Delimiter::Brace => {
             let children = token.children();
-            let exprs =
-                baseline_parse_tokens(&mut TokensIterator::new(children), registry, source)?;
+            let exprs = baseline_parse_tokens(
+                &mut TokensIterator::new(children),
+                context,
+                source,
+                SyntaxType::Any,
+            )?;
 
             let expr = hir::RawExpression::Block(exprs);
             Ok(Tagged::from_simple_spanned_item(expr, token.span()))
@@ -212,8 +263,12 @@ pub fn baseline_parse_delimited(
         Delimiter::Paren => unimplemented!(),
         Delimiter::Square => {
             let children = token.children();
-            let exprs =
-                baseline_parse_tokens(&mut TokensIterator::new(children), registry, source)?;
+            let exprs = baseline_parse_tokens(
+                &mut TokensIterator::new(children),
+                context,
+                source,
+                SyntaxType::Any,
+            )?;
 
             let expr = hir::RawExpression::List(exprs);
             Ok(expr.tagged(Tag::unknown_origin(token.span())))
@@ -223,10 +278,10 @@ pub fn baseline_parse_delimited(
 
 pub fn baseline_parse_path(
     token: &Tagged<PathNode>,
-    registry: &CommandRegistry,
+    context: &Context,
     source: &Text,
 ) -> Result<hir::Expression, ShellError> {
-    let head = baseline_parse_semantic_token(token.head(), registry, source)?;
+    let head = baseline_parse_semantic_token(token.head(), context, source)?;
 
     let mut tail = vec![];
 

src/parser/hir/named.rs

@@ -27,7 +27,7 @@ impl ToDebug for NamedArguments {
         for (name, value) in &self.named {
             match value {
                 NamedValue::AbsentSwitch => continue,
-                NamedValue::PresentSwitch(span) => write!(f, " {}", span.slice(source))?,
+                NamedValue::PresentSwitch(span) => write!(f, " --{}", span.slice(source))?,
                 NamedValue::AbsentValue => continue,
                 NamedValue::Value(expr) => write!(f, " --{} {}", name, expr.debug(source))?,
             }

src/parser/parse/parser.rs

@@ -540,6 +540,8 @@ fn is_start_bare_char(c: char) -> bool {
         '@' => true,
         '*' => true,
         '?' => true,
+        '~' => true,
+        '+' => true,
         _ => false,
     }
 }
@@ -557,6 +559,8 @@ fn is_bare_char(c: char) -> bool {
         '*' => true,
         '?' => true,
         '=' => true,
+        '~' => true,
+        '+' => true,
         _ => false,
     }
 }

src/parser/parse_command.rs

@@ -1,5 +1,6 @@
+use crate::context::Context;
 use crate::errors::{ArgumentError, ShellError};
-use crate::parser::registry::{CommandRegistry, NamedType, PositionalType, Signature};
+use crate::parser::registry::{NamedType, PositionalType, Signature};
 use crate::parser::{baseline_parse_tokens, CallNode};
 use crate::parser::{
     hir::{self, NamedArguments},
@@ -10,7 +11,7 @@ use log::trace;
 
 pub fn parse_command(
     config: &Signature,
-    registry: &CommandRegistry,
+    context: &Context,
     call: &Tagged<CallNode>,
     source: &Text,
 ) -> Result<hir::Call, ShellError> {
@@ -31,7 +32,7 @@ pub fn parse_command(
             .collect()
     });
 
-    match parse_command_tail(&config, registry, children, source, call.span())? {
+    match parse_command_tail(&config, context, children, source, call.span())? {
         None => Ok(hir::Call::new(Box::new(head), None, None)),
         Some((positional, named)) => Ok(hir::Call::new(Box::new(head), positional, named)),
     }
@@ -63,7 +64,7 @@ fn parse_command_head(head: &TokenNode) -> Result<hir::Expression, ShellError> {
 
 fn parse_command_tail(
     config: &Signature,
-    registry: &CommandRegistry,
+    context: &Context,
     tail: Option<Vec<TokenNode>>,
     source: &Text,
     command_span: Span,
@@ -101,7 +102,7 @@ fn parse_command_tail(
                         }
 
                         let expr =
-                            hir::baseline_parse_next_expr(tail, registry, source, *syntax_type)?;
+                            hir::baseline_parse_next_expr(tail, context, source, *syntax_type)?;
 
                         tail.restart();
                         named.insert_mandatory(name, expr);
@@ -121,7 +122,7 @@ fn parse_command_tail(
                         ));
                     }
 
-                    let expr = hir::baseline_parse_next_expr(tail, registry, source, *syntax_type)?;
+                    let expr = hir::baseline_parse_next_expr(tail, context, source, *syntax_type)?;
 
                     tail.restart();
                     named.insert_optional(name, Some(expr));
@@ -160,16 +161,17 @@ fn parse_command_tail(
             }
         }
 
-        let result = hir::baseline_parse_next_expr(tail, registry, source, arg.syntax_type())?;
+        let result = hir::baseline_parse_next_expr(tail, context, source, arg.syntax_type())?;
 
         positional.push(result);
     }
 
     trace_remaining("after positional", tail.clone(), source);
 
-    // TODO: Only do this if rest params are specified
-    let remainder = baseline_parse_tokens(tail, registry, source)?;
-    positional.extend(remainder);
+    if let Some(syntax_type) = config.rest_positional {
+        let remainder = baseline_parse_tokens(tail, context, source, syntax_type)?;
+        positional.extend(remainder);
+    }
 
     trace_remaining("after rest", tail.clone(), source);
 
@@ -180,6 +182,8 @@ fn parse_command_tail(
         positional => Some(positional),
     };
 
+    // TODO: Error if extra unconsumed positional arguments
+
     let named = match named {
         named if named.named.is_empty() => None,
         named => Some(named),

src/parser/registry.rs

@@ -74,8 +74,8 @@ pub struct Signature {
     pub name: String,
     #[new(default)]
     pub positional: Vec<PositionalType>,
-    #[new(value = "false")]
-    pub rest_positional: bool,
+    #[new(value = "None")]
+    pub rest_positional: Option<SyntaxType>,
     #[new(default)]
     pub named: IndexMap<String, NamedType>,
     #[new(value = "false")]
@@ -130,8 +130,8 @@ impl Signature {
         self
     }
 
-    pub fn rest(mut self) -> Signature {
-        self.rest_positional = true;
+    pub fn rest(mut self, ty: SyntaxType) -> Signature {
+        self.rest_positional = Some(ty);
         self
     }
 }
@@ -279,10 +279,10 @@ impl Signature {
     crate fn parse_args(
         &self,
         call: &Tagged<CallNode>,
-        registry: &CommandRegistry,
+        context: &Context,
         source: &Text,
     ) -> Result<hir::Call, ShellError> {
-        let args = parse_command(self, registry, call, source)?;
+        let args = parse_command(self, context, call, source)?;
 
         trace!("parsed args: {:?}", args);
 

src/plugins/add.rs

@@ -1,7 +1,6 @@
-use indexmap::IndexMap;
 use nu::{
-    serve_plugin, CallInfo, Plugin, PositionalType, Primitive, ReturnSuccess, ReturnValue,
-    ShellError, Signature, Tagged, Value,
+    serve_plugin, CallInfo, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError, Signature,
+    SyntaxType, Tagged, Value,
 };
 
 struct Add {
@@ -43,17 +42,12 @@ impl Add {
 
 impl Plugin for Add {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        Ok(Signature {
-            name: "add".to_string(),
-            positional: vec![
-                PositionalType::mandatory_any("Field"),
-                PositionalType::mandatory_any("Value"),
-            ],
-            is_filter: true,
-            named: IndexMap::new(),
-            rest_positional: true,
-        })
+        Ok(Signature::build("add")
+            .required("Field", SyntaxType::String)
+            .required("Value", SyntaxType::String)
+            .rest(SyntaxType::String).filter())
     }
+
     fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
         if let Some(args) = call_info.args.positional {
             match &args[0] {

src/plugins/binaryview.rs

@@ -1,9 +1,5 @@
-#![feature(option_flattening)]
 use crossterm::{cursor, terminal, Attribute, RawScreen};
-use indexmap::IndexMap;
-use nu::{
-    serve_plugin, CallInfo, NamedType, Plugin, ShellError, Signature, SpanSource, Tagged, Value,
-};
+use nu::{serve_plugin, CallInfo, Plugin, ShellError, Signature, SpanSource, Tagged, Value};
 use pretty_hex::*;
 
 struct BinaryView;
@@ -16,15 +12,7 @@ impl BinaryView {
 
 impl Plugin for BinaryView {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        let mut named = IndexMap::new();
-        named.insert("lores".to_string(), NamedType::Switch);
-        Ok(Signature {
-            name: "binaryview".to_string(),
-            positional: vec![],
-            is_filter: false,
-            named,
-            rest_positional: false,
-        })
+        Ok(Signature::build("binaryview").switch("lores"))
     }
 
     fn sink(&mut self, call_info: CallInfo, input: Vec<Tagged<Value>>) {
@@ -32,7 +20,7 @@ impl Plugin for BinaryView {
             let value_origin = v.origin();
             match v.item {
                 Value::Binary(b) => {
-                    let source = value_origin.map(|x| call_info.source_map.get(&x)).flatten();
+                    let source = value_origin.and_then(|x| call_info.source_map.get(&x));
                     let _ = view_binary(&b, source, call_info.args.has("lores"));
                 }
                 _ => {}

src/plugins/edit.rs

@@ -1,7 +1,6 @@
-use indexmap::IndexMap;
 use nu::{
-    serve_plugin, CallInfo, Plugin, PositionalType, Primitive, ReturnSuccess, ReturnValue,
-    ShellError, Signature, Tagged, Value,
+    serve_plugin, CallInfo, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError, Signature,
+    SyntaxType, Tagged, Value,
 };
 
 struct Edit {
@@ -42,17 +41,12 @@ impl Edit {
 
 impl Plugin for Edit {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        Ok(Signature {
-            name: "edit".to_string(),
-            positional: vec![
-                PositionalType::mandatory_any("Field"),
-                PositionalType::mandatory_any("Value"),
-            ],
-            is_filter: true,
-            named: IndexMap::new(),
-            rest_positional: true,
-        })
+        Ok(Signature::build("edit")
+            .required("Field", SyntaxType::String)
+            .required("Value", SyntaxType::String)
+            .filter())
     }
+
     fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
         if let Some(args) = call_info.args.positional {
             match &args[0] {

src/plugins/inc.rs

@@ -1,7 +1,6 @@
-use indexmap::IndexMap;
 use nu::{
-    serve_plugin, CallInfo, NamedType, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError,
-    Signature, Tagged, TaggedItem, Value,
+    serve_plugin, CallInfo, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError, Signature,
+    SyntaxType, Tagged, TaggedItem, Value,
 };
 
 enum Action {
@@ -116,19 +115,14 @@ impl Inc {
 
 impl Plugin for Inc {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        let mut named = IndexMap::new();
-        named.insert("major".to_string(), NamedType::Switch);
-        named.insert("minor".to_string(), NamedType::Switch);
-        named.insert("patch".to_string(), NamedType::Switch);
-
-        Ok(Signature {
-            name: "inc".to_string(),
-            positional: vec![],
-            is_filter: true,
-            named,
-            rest_positional: true,
-        })
+        Ok(Signature::build("inc")
+            .switch("major")
+            .switch("minor")
+            .switch("patch")
+            .rest(SyntaxType::String)
+            .filter())
     }
+
     fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
         if call_info.args.has("major") {
             self.for_semver(SemVerAction::Major);

src/plugins/skip.rs

@@ -1,7 +1,7 @@
 use indexmap::IndexMap;
 use nu::{
     serve_plugin, CallInfo, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError, Signature,
-    Tagged, Value,
+    SyntaxType, Tagged, Value,
 };
 
 struct Skip {
@@ -20,7 +20,7 @@ impl Plugin for Skip {
             positional: vec![],
             is_filter: true,
             named: IndexMap::new(),
-            rest_positional: true,
+            rest_positional: Some(SyntaxType::Number),
         })
     }
     fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {

src/plugins/str.rs

@@ -1,7 +1,6 @@
-use indexmap::IndexMap;
 use nu::{
-    serve_plugin, CallInfo, NamedType, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError,
-    Signature, Tagged, Value,
+    serve_plugin, CallInfo, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError, Signature,
+    SyntaxType, Tagged, Value,
 };
 use regex::Regex;
 
@@ -40,9 +39,11 @@ impl Str {
         let applied = match self.action.as_ref() {
             Some(Action::Downcase) => Value::string(input.to_ascii_lowercase()),
             Some(Action::Upcase) => Value::string(input.to_ascii_uppercase()),
-            Some(Action::ToInteger) => match input.trim().parse::<i64>() {
-                Ok(v) => Value::int(v),
-                Err(_) => Value::string(input),
+            Some(Action::ToInteger) => match input.trim() {
+                other => match other.parse::<i64>() {
+                    Ok(v) => Value::int(v),
+                    Err(_) => Value::string(input),
+                },
             },
             Some(Action::Replace(ref mode)) => match mode {
                 ReplaceAction::Direct => Value::string(self.first_param()),
@@ -138,9 +139,7 @@ impl Str {
                 Some(ref f) => {
                     let replacement = match value.item.get_data_by_path(value.tag(), f) {
                         Some(result) => self.strutils(result.map(|x| x.clone()))?,
-                        None => {
-                            return Err(ShellError::string("str could not find field to replace"))
-                        }
+                        None => return Ok(Tagged::from_item(Value::nothing(), value.tag)),
                     };
                     match value
                         .item
@@ -168,20 +167,14 @@ impl Str {
 
 impl Plugin for Str {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        let mut named = IndexMap::new();
-        named.insert("downcase".to_string(), NamedType::Switch);
-        named.insert("upcase".to_string(), NamedType::Switch);
-        named.insert("to-int".to_string(), NamedType::Switch);
-        named.insert("replace".to_string(), NamedType::Switch);
-        named.insert("find-replace".to_string(), NamedType::Switch);
-
-        Ok(Signature {
-            name: "str".to_string(),
-            positional: vec![],
-            is_filter: true,
-            named,
-            rest_positional: true,
-        })
+        Ok(Signature::build("str")
+            .switch("downcase")
+            .switch("upcase")
+            .switch("to-int")
+            .switch("replace")
+            .switch("find-replace")
+            .rest(SyntaxType::Member)
+            .filter())
     }
 
     fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {

src/plugins/sum.rs

@@ -1,4 +1,3 @@
-use indexmap::IndexMap;
 use nu::{
     serve_plugin, CallInfo, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError, Signature,
     Tag, Tagged, Value,
@@ -14,6 +13,7 @@ impl Sum {
 
     fn sum(&mut self, value: Tagged<Value>) -> Result<(), ShellError> {
         match value.item {
+            Value::Primitive(Primitive::Nothing) => Ok(()),
             Value::Primitive(Primitive::Int(i)) => {
                 match self.total {
                     Some(Tagged {
@@ -64,14 +64,9 @@ impl Sum {
 
 impl Plugin for Sum {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        Ok(Signature {
-            name: "sum".to_string(),
-            positional: vec![],
-            is_filter: true,
-            named: IndexMap::new(),
-            rest_positional: true,
-        })
+        Ok(Signature::build("sum").filter())
     }
+
     fn begin_filter(&mut self, _: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
         Ok(vec![])
     }

src/plugins/sys.rs

@@ -1,10 +1,9 @@
 use futures::executor::block_on;
 use futures::stream::StreamExt;
 use heim::{disk, memory, net};
-use indexmap::IndexMap;
 use nu::{
     serve_plugin, CallInfo, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError, Signature,
-    Tag, Tagged, TaggedDictBuilder, Value,
+    SyntaxType, Tag, Tagged, TaggedDictBuilder, Value,
 };
 use std::ffi::OsStr;
 
@@ -251,14 +250,9 @@ async fn sysinfo(tag: Tag) -> Vec<Tagged<Value>> {
 
 impl Plugin for Sys {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        Ok(Signature {
-            name: "sys".to_string(),
-            positional: vec![],
-            is_filter: true,
-            named: IndexMap::new(),
-            rest_positional: true,
-        })
+        Ok(Signature::build("sys").rest(SyntaxType::Any))
     }
+
     fn begin_filter(&mut self, callinfo: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
         Ok(block_on(sysinfo(Tag::unknown_origin(callinfo.name_span)))
             .into_iter()

src/plugins/textview.rs

@@ -1,8 +1,5 @@
-#![feature(option_flattening)]
-
 use crossterm::{cursor, terminal, RawScreen};
 use crossterm::{InputEvent, KeyEvent};
-use indexmap::IndexMap;
 use nu::{
     serve_plugin, CallInfo, Plugin, Primitive, ShellError, Signature, SourceMap, SpanSource,
     Tagged, Value,
@@ -29,13 +26,7 @@ impl TextView {
 
 impl Plugin for TextView {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        Ok(Signature {
-            name: "textview".to_string(),
-            positional: vec![],
-            is_filter: false,
-            named: IndexMap::new(),
-            rest_positional: false,
-        })
+        Ok(Signature::build("textview"))
     }
 
     fn sink(&mut self, call_info: CallInfo, input: Vec<Tagged<Value>>) {
@@ -217,7 +208,7 @@ fn view_text_value(value: &Tagged<Value>, source_map: &SourceMap) {
     let value_origin = value.origin();
     match value.item {
         Value::Primitive(Primitive::String(ref s)) => {
-            let source = value_origin.map(|x| source_map.get(&x)).flatten();
+            let source = value_origin.and_then(|x| source_map.get(&x));
 
             if let Some(source) = source {
                 let extension: Option<String> = match source {

src/plugins/tree.rs

@@ -1,5 +1,4 @@
 use derive_new::new;
-use indexmap::IndexMap;
 use nu::{serve_plugin, CallInfo, Plugin, ShellError, Signature, Tagged, Value};
 use ptree::item::StringItem;
 use ptree::output::print_tree_with;
@@ -81,13 +80,7 @@ struct TreeViewer;
 
 impl Plugin for TreeViewer {
     fn config(&mut self) -> Result<Signature, ShellError> {
-        Ok(Signature {
-            name: "tree".to_string(),
-            positional: vec![],
-            is_filter: false,
-            named: IndexMap::new(),
-            rest_positional: true,
-        })
+        Ok(Signature::build("tree"))
     }
 
     fn sink(&mut self, _call_info: CallInfo, input: Vec<Tagged<Value>>) {

src/prelude.rs

@@ -32,6 +32,25 @@ macro_rules! trace_stream {
     }};
 }
 
+#[macro_export]
+macro_rules! trace_out_stream {
+    (target: $target:tt, source: $source:expr, $desc:tt = $expr:expr) => {{
+        if log::log_enabled!(target: $target, log::Level::Trace) {
+            use futures::stream::StreamExt;
+
+            let source = $source.clone();
+
+            let objects = $expr.values.inspect(move |o| {
+                trace!(target: $target, "{} = {}", $desc, o.debug(&source));
+            });
+
+            $crate::stream::OutputStream::new(objects)
+        } else {
+            $expr
+        }
+    }};
+}
+
 crate use crate::cli::MaybeOwned;
 crate use crate::commands::command::{
     CallInfo, CommandAction, CommandArgs, ReturnSuccess, ReturnValue, RunnableContext,

src/shell/filesystem_shell.rs

@@ -72,12 +72,16 @@ impl Shell for FilesystemShell {
         "filesystem".to_string()
     }
 
+    fn homedir(&self) -> Option<PathBuf> {
+        dirs::home_dir()
+    }
+
     fn ls(&self, args: EvaluatedWholeStreamCommandArgs) -> Result<OutputStream, ShellError> {
         let cwd = self.path();
         let mut full_path = PathBuf::from(self.path());
 
         match &args.nth(0) {
-            Some(Tagged { item: value, .. }) => full_path.push(Path::new(&value.as_string()?)),
+            Some(value) => full_path.push(Path::new(&value.as_path()?)),
             _ => {}
         }
 
@@ -176,7 +180,7 @@ impl Shell for FilesystemShell {
                 }
             },
             Some(v) => {
-                let target = v.as_string()?;
+                let target = v.as_path()?;
                 let path = PathBuf::from(self.path());
                 match dunce::canonicalize(path.join(target).as_path()) {
                     Ok(p) => p,

src/shell/shell.rs

@@ -7,9 +7,11 @@ use crate::context::SourceMap;
 use crate::errors::ShellError;
 use crate::prelude::*;
 use crate::stream::OutputStream;
+use std::path::PathBuf;
 
 pub trait Shell: std::fmt::Debug {
     fn name(&self, source_map: &SourceMap) -> String;
+    fn homedir(&self) -> Option<PathBuf>;
     fn ls(&self, args: EvaluatedWholeStreamCommandArgs) -> Result<OutputStream, ShellError>;
     fn cd(&self, args: EvaluatedWholeStreamCommandArgs) -> Result<OutputStream, ShellError>;
     fn cp(&self, args: CopyArgs, name: Span, path: &str) -> Result<OutputStream, ShellError>;

src/shell/shell_manager.rs

@@ -9,6 +9,7 @@ use crate::shell::filesystem_shell::FilesystemShell;
 use crate::shell::shell::Shell;
 use crate::stream::OutputStream;
 use std::error::Error;
+use std::path::PathBuf;
 use std::sync::{Arc, Mutex};
 
 #[derive(Clone, Debug)]
@@ -102,16 +103,24 @@ impl ShellManager {
         self.set_path(self.path());
     }
 
+    pub fn homedir(&self) -> Option<PathBuf> {
+        let env = self.shells.lock().unwrap();
+
+        env[self.current_shell].homedir()
+    }
+
     pub fn ls(&self, args: EvaluatedWholeStreamCommandArgs) -> Result<OutputStream, ShellError> {
         let env = self.shells.lock().unwrap();
 
         env[self.current_shell].ls(args)
     }
+
     pub fn cd(&self, args: EvaluatedWholeStreamCommandArgs) -> Result<OutputStream, ShellError> {
         let env = self.shells.lock().unwrap();
 
         env[self.current_shell].cd(args)
     }
+
     pub fn cp(
         &self,
         args: CopyArgs,

src/shell/value_shell.rs

@@ -69,6 +69,10 @@ impl Shell for ValueShell {
         )
     }
 
+    fn homedir(&self) -> Option<PathBuf> {
+        dirs::home_dir()
+    }
+
     fn ls(&self, _args: EvaluatedWholeStreamCommandArgs) -> Result<OutputStream, ShellError> {
         Ok(self
             .members()
@@ -80,19 +84,20 @@ impl Shell for ValueShell {
         let path = match args.nth(0) {
             None => "/".to_string(),
             Some(v) => {
-                let target = v.as_string()?;
+                let target = v.as_path()?;
 
                 let mut cwd = PathBuf::from(&self.path);
-                match target {
-                    x if x == ".." => {
-                        cwd.pop();
+
+                if target == PathBuf::from("..") {
+                    cwd.pop();
+                } else {
+                    match target.to_str() {
+                        Some(target) => match target.chars().nth(0) {
+                            Some(x) if x == '/' => cwd = PathBuf::from(target),
+                            _ => cwd.push(target),
+                        },
+                        None => cwd.push(target),
                     }
-                    _ => match target.chars().nth(0) {
-                        Some(x) if x == '/' => cwd = PathBuf::from(target),
-                        _ => {
-                            cwd.push(target);
-                        }
-                    },
                 }
                 cwd.to_string_lossy().to_string()
             }

src/utils.rs

@@ -105,7 +105,10 @@ impl FileStructure {
         self.root = path.to_path_buf();
     }
 
-    pub fn paths_applying_with<F>(&mut self, to: F) -> Result<Vec<(PathBuf, PathBuf)>, Box<dyn std::error::Error>>
+    pub fn paths_applying_with<F>(
+        &mut self,
+        to: F,
+    ) -> Result<Vec<(PathBuf, PathBuf)>, Box<dyn std::error::Error>>
     where
         F: Fn((PathBuf, usize)) -> Result<(PathBuf, PathBuf), Box<dyn std::error::Error>>,
     {
@@ -155,6 +158,7 @@ impl FileStructure {
 
 #[cfg(test)]
 mod tests {
+    use pretty_assertions::assert_eq;
 
     use super::{FileStructure, Res};
     use std::path::PathBuf;
@@ -175,7 +179,8 @@ mod tests {
     fn prepares_and_decorates_source_files_for_copying() {
         let mut res = FileStructure::new();
 
-        res.walk_decorate(fixtures().as_path()).expect("Can not decorate files traversal.");
+        res.walk_decorate(fixtures().as_path())
+            .expect("Can not decorate files traversal.");
 
         assert_eq!(
             res.resources,

tests/command_ls_tests.rs

@@ -18,7 +18,7 @@ fn ls_lists_regular_files() {
     nu!(
         output,
         cwd(&full_path),
-        "ls | get name | lines| split-column \".\" | get Column2 | str Column2 --to-int | sum | echo $it"
+        r#"ls | get name | lines | split-column "." | get Column2 | str Column2 --to-int | sum | echo $it"#
     );
 
     assert_eq!(output, "30");

tests/command_mv_tests.rs

@@ -8,15 +8,13 @@ use std::path::{Path, PathBuf};
 #[test]
 fn moves_a_file() {
     let sandbox = Playground::setup_for("mv_test_1")
-        .with_files(vec![
-            EmptyFile("andres.txt"),
-        ])
+        .with_files(vec![EmptyFile("andres.txt")])
         .mkdir("expected")
         .test_dir_name();
 
     let full_path = format!("{}/{}", Playground::root(), sandbox);
     let original = format!("{}/{}", full_path, "andres.txt");
-    let expected  = format!("{}/{}", full_path, "expected/yehuda.txt");
+    let expected = format!("{}/{}", full_path, "expected/yehuda.txt");
 
     nu!(
         _output,
@@ -31,21 +29,14 @@ fn moves_a_file() {
 #[test]
 fn overwrites_if_moving_to_existing_file() {
     let sandbox = Playground::setup_for("mv_test_2")
-        .with_files(vec![
-            EmptyFile("andres.txt"),
-            EmptyFile("jonathan.txt"),
-        ])
+        .with_files(vec![EmptyFile("andres.txt"), EmptyFile("jonathan.txt")])
         .test_dir_name();
 
     let full_path = format!("{}/{}", Playground::root(), sandbox);
     let original = format!("{}/{}", full_path, "andres.txt");
-    let expected  = format!("{}/{}", full_path, "jonathan.txt");
+    let expected = format!("{}/{}", full_path, "jonathan.txt");
 
-    nu!(
-        _output,
-        cwd(&full_path),
-        "mv andres.txt jonathan.txt"
-    );
+    nu!(_output, cwd(&full_path), "mv andres.txt jonathan.txt");
 
     assert!(!h::file_exists_at(PathBuf::from(original)));
     assert!(h::file_exists_at(PathBuf::from(expected)));
@@ -58,14 +49,10 @@ fn moves_a_directory() {
         .test_dir_name();
 
     let full_path = format!("{}/{}", Playground::root(), sandbox);
-    let original_dir  = format!("{}/{}", full_path, "empty_dir");
-    let expected  = format!("{}/{}", full_path, "renamed_dir");
+    let original_dir = format!("{}/{}", full_path, "empty_dir");
+    let expected = format!("{}/{}", full_path, "renamed_dir");
 
-    nu!(
-        _output,
-        cwd(&full_path),
-        "mv empty_dir renamed_dir"
-    );
+    nu!(_output, cwd(&full_path), "mv empty_dir renamed_dir");
 
     assert!(!h::dir_exists_at(PathBuf::from(original_dir)));
     assert!(h::dir_exists_at(PathBuf::from(expected)));
@@ -74,22 +61,15 @@ fn moves_a_directory() {
 #[test]
 fn moves_the_file_inside_directory_if_path_to_move_is_existing_directory() {
     let sandbox = Playground::setup_for("mv_test_4")
-        .with_files(vec![
-            EmptyFile("jonathan.txt"),
-        ])
+        .with_files(vec![EmptyFile("jonathan.txt")])
         .mkdir("expected")
         .test_dir_name();
 
     let full_path = format!("{}/{}", Playground::root(), sandbox);
-    let original_dir   = format!("{}/{}", full_path, "jonathan.txt");
-    let expected  = format!("{}/{}", full_path, "expected/jonathan.txt");
-
-    nu!(
-        _output,
-        cwd(&full_path),
-        "mv jonathan.txt expected"
-    );
+    let original_dir = format!("{}/{}", full_path, "jonathan.txt");
+    let expected = format!("{}/{}", full_path, "expected/jonathan.txt");
 
+    nu!(_output, cwd(&full_path), "mv jonathan.txt expected");
 
     assert!(!h::file_exists_at(PathBuf::from(original_dir)));
     assert!(h::file_exists_at(PathBuf::from(expected)));
@@ -99,22 +79,15 @@ fn moves_the_file_inside_directory_if_path_to_move_is_existing_directory() {
 fn moves_the_directory_inside_directory_if_path_to_move_is_existing_directory() {
     let sandbox = Playground::setup_for("mv_test_5")
         .within("contributors")
-        .with_files(vec![
-            EmptyFile("jonathan.txt"),
-        ])
+        .with_files(vec![EmptyFile("jonathan.txt")])
         .mkdir("expected")
         .test_dir_name();
 
     let full_path = format!("{}/{}", Playground::root(), sandbox);
-    let original_dir  = format!("{}/{}", full_path, "contributors");
-    let expected  = format!("{}/{}", full_path, "expected/contributors");
-
-    nu!(
-        _output,
-        cwd(&full_path),
-        "mv contributors expected"
-    );
+    let original_dir = format!("{}/{}", full_path, "contributors");
+    let expected = format!("{}/{}", full_path, "expected/contributors");
 
+    nu!(_output, cwd(&full_path), "mv contributors expected");
 
     assert!(!h::dir_exists_at(PathBuf::from(original_dir)));
     assert!(h::file_exists_at(PathBuf::from(expected)));
@@ -124,14 +97,12 @@ fn moves_the_directory_inside_directory_if_path_to_move_is_existing_directory()
 fn moves_the_directory_inside_directory_if_path_to_move_is_nonexistent_directory() {
     let sandbox = Playground::setup_for("mv_test_6")
         .within("contributors")
-        .with_files(vec![
-            EmptyFile("jonathan.txt"),
-        ])
+        .with_files(vec![EmptyFile("jonathan.txt")])
         .mkdir("expected")
         .test_dir_name();
 
     let full_path = format!("{}/{}", Playground::root(), sandbox);
-    let original_dir   = format!("{}/{}", full_path, "contributors");
+    let original_dir = format!("{}/{}", full_path, "contributors");
 
     nu!(
         _output,
@@ -139,7 +110,10 @@ fn moves_the_directory_inside_directory_if_path_to_move_is_nonexistent_directory
         "mv contributors expected/this_dir_exists_now/los_tres_amigos"
     );
 
-    let expected  = format!("{}/{}", full_path, "expected/this_dir_exists_now/los_tres_amigos");
+    let expected = format!(
+        "{}/{}",
+        full_path, "expected/this_dir_exists_now/los_tres_amigos"
+    );
 
     assert!(!h::dir_exists_at(PathBuf::from(original_dir)));
     assert!(h::file_exists_at(PathBuf::from(expected)));
@@ -168,11 +142,7 @@ fn moves_using_path_with_wildcard() {
     let work_dir = format!("{}/{}", full_path, "work_dir");
     let expected_copies_path = format!("{}/{}", full_path, "expected");
 
-    nu!(
-        _output,
-        cwd(&work_dir),
-        "mv ../originals/*.ini ../expected"
-    );
+    nu!(_output, cwd(&work_dir), "mv ../originals/*.ini ../expected");
 
     assert!(h::files_exist_at(
         vec![
@@ -185,7 +155,6 @@ fn moves_using_path_with_wildcard() {
     ));
 }
 
-
 #[test]
 fn moves_using_a_glob() {
     let sandbox = Playground::setup_for("mv_test_8")
@@ -204,11 +173,7 @@ fn moves_using_a_glob() {
     let work_dir = format!("{}/{}", full_path, "work_dir");
     let expected_copies_path = format!("{}/{}", full_path, "expected");
 
-    nu!(
-        _output,
-        cwd(&work_dir),
-        "mv ../meals/* ../expected"
-    );
+    nu!(_output, cwd(&work_dir), "mv ../meals/* ../expected");
 
     assert!(h::dir_exists_at(PathBuf::from(meal_dir)));
     assert!(h::files_exist_at(

tests/command_open_tests.rs

@@ -28,7 +28,7 @@ fn open_can_parse_bson_1() {
     nu!(
         output,
         cwd("tests/fixtures/formats"),
-        "open sample.bson | nth 0 | get b | echo $it"
+        "open sample.bson | get root | nth 0 | get b | echo $it"
     );
 
     assert_eq!(output, "hello");
@@ -39,7 +39,7 @@ fn open_can_parse_bson_2() {
     nu!(
         output,
         cwd("tests/fixtures/formats"),
-        "open sample.bson | nth 6 | get b | get '$binary_subtype' | echo $it "
+        "open sample.bson | get root | nth 6 | get b | get '$binary_subtype' | echo $it "
     );
 
     assert_eq!(output, "function");

tests/command_rm_tests.rs

@@ -98,10 +98,7 @@ fn rm_removes_deeply_nested_directories_with_wildcard_and_recursive_flag() {
     );
 
     assert!(!h::files_exist_at(
-        vec![
-            Path::new("src/parser/parse"),
-            Path::new("src/parser/hir"),
-        ],
+        vec![Path::new("src/parser/parse"), Path::new("src/parser/hir"),],
         PathBuf::from(&full_path)
     ));
 }
@@ -150,7 +147,11 @@ fn rm_errors_if_attempting_to_delete_a_directory_with_content_without_recursive_
 
     let full_path = format!("{}/{}", Playground::root(), sandbox);
 
-    nu_error!(output, cwd(&Playground::root()), "rm rm_prevent_directory_removal_without_flag_test");
+    nu_error!(
+        output,
+        cwd(&Playground::root()),
+        "rm rm_prevent_directory_removal_without_flag_test"
+    );
 
     assert!(h::file_exists_at(PathBuf::from(full_path)));
     assert!(output.contains("is a directory"));

tests/filter_inc_tests.rs

@@ -16,14 +16,15 @@ fn can_only_apply_one() {
 
 #[test]
 fn by_one_with_field_passed() {
-    Playground::setup_for("plugin_inc_by_one_with_field_passed_test")
-        .with_files(vec![FileWithContent(
+    Playground::setup_for("plugin_inc_by_one_with_field_passed_test").with_files(vec![
+        FileWithContent(
             "sample.toml",
             r#"
                 [package]
                 edition = "2018"
             "#,
-        )]);
+        ),
+    ]);
 
     nu!(
         output,
@@ -36,14 +37,15 @@ fn by_one_with_field_passed() {
 
 #[test]
 fn by_one_with_no_field_passed() {
-    Playground::setup_for("plugin_inc_by_one_with_no_field_passed_test")
-        .with_files(vec![FileWithContent(
+    Playground::setup_for("plugin_inc_by_one_with_no_field_passed_test").with_files(vec![
+        FileWithContent(
             "sample.toml",
             r#"
                 [package]
                 contributors = "2"
             "#,
-        )]);
+        ),
+    ]);
 
     nu!(
         output,
@@ -54,17 +56,15 @@ fn by_one_with_no_field_passed() {
     assert_eq!(output, "3");
 }
 
-
 #[test]
 fn semversion_major_inc() {
-    Playground::setup_for("plugin_inc_major_semversion_test")
-        .with_files(vec![FileWithContent(
-            "sample.toml",
-            r#"
+    Playground::setup_for("plugin_inc_major_semversion_test").with_files(vec![FileWithContent(
+        "sample.toml",
+        r#"
                 [package]
                 version = "0.1.3"
             "#,
-        )]);
+    )]);
 
     nu!(
         output,
@@ -77,14 +77,13 @@ fn semversion_major_inc() {
 
 #[test]
 fn semversion_minor_inc() {
-    Playground::setup_for("plugin_inc_minor_semversion_test")
-        .with_files(vec![FileWithContent(
-            "sample.toml",
-            r#"
+    Playground::setup_for("plugin_inc_minor_semversion_test").with_files(vec![FileWithContent(
+        "sample.toml",
+        r#"
                 [package]
                 version = "0.1.3"
             "#,
-        )]);
+    )]);
 
     nu!(
         output,
@@ -97,14 +96,13 @@ fn semversion_minor_inc() {
 
 #[test]
 fn semversion_patch_inc() {
-    Playground::setup_for("plugin_inc_patch_semversion_test")
-        .with_files(vec![FileWithContent(
-            "sample.toml",
-            r#"
+    Playground::setup_for("plugin_inc_patch_semversion_test").with_files(vec![FileWithContent(
+        "sample.toml",
+        r#"
                 [package]
                 version = "0.1.3"
             "#,
-        )]);
+    )]);
 
     nu!(
         output,
@@ -117,14 +115,15 @@ fn semversion_patch_inc() {
 
 #[test]
 fn semversion_without_passing_field() {
-    Playground::setup_for("plugin_inc_semversion_without_passing_field_test")
-        .with_files(vec![FileWithContent(
+    Playground::setup_for("plugin_inc_semversion_without_passing_field_test").with_files(vec![
+        FileWithContent(
             "sample.toml",
             r#"
                 [package]
                 version = "0.1.3"
             "#,
-        )]);
+        ),
+    ]);
 
     nu!(
         output,

tests/filters_test.rs

@@ -106,6 +106,17 @@ fn can_convert_table_to_json_text_and_from_json_text_back_into_table() {
     assert_eq!(output, "markup");
 }
 
+#[test]
+fn can_convert_json_text_to_bson_and_back_into_table() {
+    nu!(
+        output,
+        cwd("tests/fixtures/formats"),
+        "open sample.bson | to-bson | from-bson | get root | nth 1 | get b | echo $it"
+    );
+
+    assert_eq!(output, "whel");
+}
+
 #[test]
 fn can_convert_table_to_toml_text_and_from_toml_text_back_into_table() {
     nu!(