First working plugin

Cargo.lock

@@ -188,9 +188,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "chrono"
-version = "0.4.6"
+version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
+ "libc 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-integer 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.93 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -202,7 +203,7 @@ name = "chrono-humanize"
 version = "0.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -210,7 +211,7 @@ name = "chrono-tz"
 version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "parse-zoneinfo 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -703,7 +704,7 @@ dependencies = [
 
 [[package]]
 name = "enum-utils"
-version = "0.1.0"
+version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "enum-utils-from-str 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1442,7 +1443,7 @@ dependencies = [
  "app_dirs 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "byte-unit 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono-humanize 0.0.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono-tz 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1452,7 +1453,7 @@ dependencies = [
  "derive_more 0.15.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "dirs 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "dunce 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "enum-utils 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "enum-utils 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "enum_derive 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-sink-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1486,7 +1487,7 @@ dependencies = [
  "serde_yaml 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "subprocess 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "sys-info 0.5.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "sysinfo 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sysinfo 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "term 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml-query 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1787,7 +1788,7 @@ name = "pretty_env_logger"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2467,7 +2468,7 @@ dependencies = [
 
 [[package]]
 name = "sysinfo"
-version = "0.8.6"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2994,7 +2995,7 @@ dependencies = [
 "checksum bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "206fdffcfa2df7cbe15601ef46c813fce0965eb3286db6b56c583b814b51c81c"
 "checksum cc 1.0.37 (registry+https://github.com/rust-lang/crates.io-index)" = "39f75544d7bbaf57560d2168f28fd649ff9c76153874db88bdbdfd839b1a7e7d"
 "checksum cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "b486ce3ccf7ffd79fdeb678eac06a9e6c09fc88d33836340becb8fffe87c5e33"
-"checksum chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "45912881121cb26fad7c38c17ba7daa18764771836b34fab7d3fbd93ed633878"
+"checksum chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "77d81f58b7301084de3b958691458a53c3f7e0b1d702f77e550b6a88e3a88abe"
 "checksum chrono-humanize 0.0.11 (registry+https://github.com/rust-lang/crates.io-index)" = "eb2ff48a655fe8d2dae9a39e66af7fd8ff32a879e8c4e27422c25596a8b5e90d"
 "checksum chrono-tz 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e0e430fad0384e4defc3dc6b1223d1b886087a8bf9b7080e5ae027f73851ea15"
 "checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
@@ -3050,7 +3051,7 @@ dependencies = [
 "checksum encoding-index-tradchinese 1.20141219.5 (registry+https://github.com/rust-lang/crates.io-index)" = "fd0e20d5688ce3cab59eb3ef3a2083a5c77bf496cb798dc6fcdb75f323890c18"
 "checksum encoding_index_tests 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a246d82be1c9d791c5dfde9a2bd045fc3cbba3fa2b11ad558f27d01712f00569"
 "checksum encoding_rs 0.8.17 (registry+https://github.com/rust-lang/crates.io-index)" = "4155785c79f2f6701f185eb2e6b4caf0555ec03477cb4c70db67b465311620ed"
-"checksum enum-utils 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "23c5d9343285feb320b4f2b0d0ba9501c11e1a19052026852d772a6e96e8de5d"
+"checksum enum-utils 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1f1ae672d9891879fb93e17ab6015c4e3bbe63fbeb23a41b9ac39ffa845b8836"
 "checksum enum-utils-from-str 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6b5669381f76d7320e122abdd4a8307f986634f6d067fb69e31179422175801a"
 "checksum enum_derive 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "406ac2a8c9eedf8af9ee1489bee9e50029278a6456c740f7454cf8a158abc816"
 "checksum env_logger 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b61fa891024a945da30a9581546e8cfaf5602c7b3f4c137a2805cf388f92075a"
@@ -3237,7 +3238,7 @@ dependencies = [
 "checksum synstructure 0.10.2 (registry+https://github.com/rust-lang/crates.io-index)" = "02353edf96d6e4dc81aea2d8490a7e9db177bf8acb0e951c24940bf866cb313f"
 "checksum syntect 3.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e80b8831c5a543192ffc3727f01cf0e57579c6ac15558e3048bfb5708892167b"
 "checksum sys-info 0.5.7 (registry+https://github.com/rust-lang/crates.io-index)" = "76d6cf7b349b6a6daaf7a3797227e2f4108c8dd398e0aca7e29b9fb239948541"
-"checksum sysinfo 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)" = "d291d07ba27acd519287ca22fb1fb024dcc4b925cddb63d69af24db153ca2c82"
+"checksum sysinfo 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c3e2cab189e59f72710e3dd5e1e0d5be0f6c5c999c326f2fdcdf3bf4483ec9fd"
 "checksum tempfile 3.0.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7dc4738f2e68ed2855de5ac9cdbe05c9216773ecde4739b2f095002ab03a13ef"
 "checksum term 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "edd106a334b7657c10b7c540a0106114feadeb4dc314513e97df481d5d966f42"
 "checksum termcolor 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "96d6098003bde162e4277c70665bd87c326f5a0c3f3fbfb285787fa482d54e6e"

Cargo.toml

@@ -1,3 +1,5 @@
+cargo-features = ["default-run"]
+
 [package]
 name = "nu"
 version = "0.1.2"
@@ -5,13 +7,14 @@ authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner
 description = "A shell for the GitHub era"
 license = "MIT"
 edition = "2018"
+default-run = "nu"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 rustyline = "5.0.0"
-sysinfo = "0.8.6"
+sysinfo = "0.9"
-chrono = { version = "0.4.6", features = ["serde"] }
+chrono = { version = "0.4.7", features = ["serde"] }
 chrono-tz = "0.5.1"
 derive-new = "0.5.6"
 prettytable-rs = "0.8.0"
@@ -56,7 +59,7 @@ reqwest = "0.9"
 roxmltree = "0.6.1"
 nom_locate = { git = "https://github.com/wycats/nom_locate.git", branch = "nom5" }
 derive_more = "0.15.0"
-enum-utils = "0.1.0"
+enum-utils = "0.1.1"
 unicode-xid = "0.1.0"
 serde_ini = "0.2.0"
 subprocess = "0.1.18"
@@ -65,3 +68,15 @@ mime = "0.3.13"
 
 [dev-dependencies]
 pretty_assertions = "0.6.1"
+
+[lib]
+name = "nu"
+path = "src/lib.rs"
+
+[[bin]]
+name = "nu_plugin_inc"
+path = "src/plugins/inc.rs"
+
+[[bin]]
+name = "nu"
+path = "src/main.rs"

src/cli.rs

@@ -64,6 +64,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             command("get", get::get),
             command("enter", enter::enter),
             command("exit", exit::exit),
+            command("inc", plugin_inc::plugin_inc),
             command("lines", lines::lines),
             command("pick", pick::pick),
             command("split-column", split_column::split_column),
@@ -170,39 +171,6 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
                     &language_reporting::DefaultConfig,
                 )
                 .unwrap();
-
-                // match err {
-                //     ShellError::Diagnostic(diag) => {
-                //         let host = context.host.lock().unwrap();
-                //         let writer = host.err_termcolor();
-                //         line.push_str(" ");
-                //         let files = crate::parser::Files::new(line);
-
-                //         language_reporting::emit(
-                //             &mut writer.lock(),
-                //             &files,
-                //             &diag.diagnostic,
-                //             &language_reporting::DefaultConfig,
-                //         )
-                //         .unwrap();
-                //     }
-
-                //     ShellError::TypeError(desc) => context
-                //         .host
-                //         .lock()
-                //         .unwrap()
-                //         .stdout(&format!("TypeError: {}", desc)),
-
-                //     ShellError::MissingProperty { subpath, .. } => context
-                //         .host
-                //         .lock()
-                //         .unwrap()
-                //         .stdout(&format!("Missing property {}", subpath)),
-
-                //     ShellError::String(_) => {
-                //         context.host.lock().unwrap().stdout(&format!("{}", err))
-                //     }
-                // }
             }
 
             LineResult::Break => {

src/commands.rs

@@ -18,6 +18,7 @@ crate mod lines;
 crate mod ls;
 crate mod open;
 crate mod pick;
+crate mod plugin_inc;
 crate mod ps;
 crate mod reject;
 crate mod save;
@@ -42,5 +43,5 @@ crate mod where_;
 crate use command::command;
 crate use config::Config;
 crate use open::Open;
-crate use where_::Where;
 crate use skip_while::SkipWhile;
+crate use where_::Where;

src/commands/command.rs

@@ -6,6 +6,7 @@ use crate::parser::{
 };
 use crate::prelude::*;
 use getset::Getters;
+use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 
 #[derive(Getters)]
@@ -51,14 +52,14 @@ pub struct SinkCommandArgs {
     pub input: Vec<Value>,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub enum CommandAction {
     ChangePath(PathBuf),
     Enter(Value),
     Exit,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub enum ReturnValue {
     Value(Value),
     Action(CommandAction),

src/commands/plugin_inc.rs

@@ -0,0 +1,97 @@
+use crate::errors::ShellError;
+use crate::parser::registry::{CommandConfig, PositionalType};
+use crate::parser::Spanned;
+use crate::prelude::*;
+use serde::{self, Deserialize, Serialize};
+use std::io::prelude::*;
+use std::io::BufReader;
+use std::io::{Read, Write};
+use subprocess::Exec;
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct JsonRpc<T> {
+    jsonrpc: String,
+    pub method: String,
+    pub params: T,
+}
+impl<T> JsonRpc<T> {
+    pub fn new<U: Into<String>>(method: U, params: T) -> Self {
+        JsonRpc {
+            jsonrpc: "2.0".into(),
+            method: method.into(),
+            params,
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "method")]
+#[allow(non_camel_case_types)]
+pub enum NuResult {
+    response { params: VecDeque<ReturnValue> },
+}
+
+pub fn plugin_inc(args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let input = args.input;
+    let args = if let Some(ref positional) = args.args.positional {
+        positional.clone()
+    } else {
+        vec![]
+    };
+
+    let stream = input
+        .map(move |v| {
+            let mut process = Exec::cmd("./target/debug/nu_plugin_inc");
+            process = process.stdout(subprocess::Redirection::Pipe);
+            process = process.stdin(subprocess::Redirection::Pipe);
+
+            let mut popen = process.popen().unwrap();
+
+            let mut stdout = popen.stdout.take().unwrap();
+            let mut stdin = popen.stdin.take().unwrap();
+            let mut reader = BufReader::new(stdout);
+
+            let request = JsonRpc::new("init", args.clone());
+            let request_raw = serde_json::to_string(&request).unwrap();
+            stdin.write(format!("{}\n", request_raw).as_bytes());
+
+            // println!("Wrote out init");
+            // println!("{:?}", v);
+            let request = JsonRpc::new("filter", v);
+            let request_raw = serde_json::to_string(&request).unwrap();
+            stdin.write(format!("{}\n", request_raw).as_bytes());
+
+            let mut input = String::new();
+            match reader.read_line(&mut input) {
+                Ok(_) => {
+                    let response = serde_json::from_str::<NuResult>(&input);
+                    match response {
+                        Ok(NuResult::response { params }) => {
+                            let request: JsonRpc<std::vec::Vec<Value>> =
+                                JsonRpc::new("quit", vec![]);
+                            let request_raw = serde_json::to_string(&request).unwrap();
+                            stdin.write(format!("{}\n", request_raw).as_bytes());
+                            params
+                        }
+                        Err(_) => {
+                            let mut result = VecDeque::new();
+                            result.push_back(ReturnValue::Value(Value::Error(Box::new(
+                                ShellError::string("Error while processing input"),
+                            ))));
+                            result
+                        }
+                    }
+                }
+                Err(x) => {
+                    let mut result = VecDeque::new();
+                    result.push_back(ReturnValue::Value(Value::Error(Box::new(
+                        ShellError::string("Error while processing input"),
+                    ))));
+                    result
+                }
+            }
+        })
+        .flatten();
+
+    Ok(stream.boxed())
+}

src/errors.rs

@@ -151,7 +151,7 @@ impl ShellError {
         }
     }
 
-    crate fn string(title: impl Into<String>) -> ShellError {
+    pub fn string(title: impl Into<String>) -> ShellError {
         ShellError::String(StringError::new(title.into(), Value::nothing()))
     }
 

src/lib.rs

@@ -0,0 +1,26 @@
+#![feature(crate_visibility_modifier)]
+#![feature(in_band_lifetimes)]
+#![feature(async_await)]
+#![feature(try_trait)]
+#![feature(bind_by_move_pattern_guards)]
+
+mod cli;
+mod commands;
+mod context;
+mod env;
+mod errors;
+mod evaluate;
+mod format;
+mod git;
+mod object;
+mod parser;
+mod prelude;
+mod shell;
+mod stream;
+
+pub use crate::commands::command::ReturnValue;
+pub use crate::parser::Spanned;
+pub use cli::cli;
+pub use errors::ShellError;
+pub use object::base::{Primitive, Value};
+pub use parser::parse::text::Text;

src/main.rs

@@ -4,26 +4,10 @@
 #![feature(try_trait)]
 #![feature(bind_by_move_pattern_guards)]
 
-mod cli;
-mod commands;
-mod context;
-mod env;
-mod errors;
-mod evaluate;
-mod format;
-mod git;
-mod object;
-mod parser;
-mod prelude;
-mod shell;
-mod stream;
-
 use clap::{App, Arg};
 use log::LevelFilter;
 use std::error::Error;
 
-crate use parser::parse::text::Text;
-
 fn main() -> Result<(), Box<dyn Error>> {
     let matches = App::new("nu shell")
         .version("0.5")
@@ -72,6 +56,6 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     builder.try_init()?;
 
-    futures::executor::block_on(crate::cli::cli())?;
+    futures::executor::block_on(nu::cli())?;
     Ok(())
 }

src/object/base.rs

@@ -398,36 +398,36 @@ impl Value {
     }
 
     #[allow(unused)]
-    crate fn block(e: hir::Expression, source: Text) -> Value {
+    pub fn block(e: hir::Expression, source: Text) -> Value {
         Value::Block(Block::new(e, source))
     }
 
-    crate fn string(s: impl Into<String>) -> Value {
+    pub fn string(s: impl Into<String>) -> Value {
         Value::Primitive(Primitive::String(s.into()))
     }
 
-    crate fn bytes(s: impl Into<u128>) -> Value {
+    pub fn bytes(s: impl Into<u128>) -> Value {
         Value::Primitive(Primitive::Bytes(s.into()))
     }
 
-    crate fn int(s: impl Into<i64>) -> Value {
+    pub fn int(s: impl Into<i64>) -> Value {
         Value::Primitive(Primitive::Int(s.into()))
     }
 
-    crate fn float(s: impl Into<OF64>) -> Value {
+    pub fn float(s: impl Into<OF64>) -> Value {
         Value::Primitive(Primitive::Float(s.into()))
     }
 
-    crate fn boolean(s: impl Into<bool>) -> Value {
+    pub fn boolean(s: impl Into<bool>) -> Value {
         Value::Primitive(Primitive::Boolean(s.into()))
     }
 
-    crate fn system_date(s: SystemTime) -> Value {
+    pub fn system_date(s: SystemTime) -> Value {
         Value::Primitive(Primitive::Date(s.into()))
     }
 
     #[allow(unused)]
-    crate fn date_from_str(s: &str) -> Result<Value, ShellError> {
+    pub fn date_from_str(s: &str) -> Result<Value, ShellError> {
         let date = DateTime::parse_from_rfc3339(s)
             .map_err(|err| ShellError::string(&format!("Date parse error: {}", err)))?;
 
@@ -437,19 +437,19 @@ impl Value {
     }
 
     #[allow(unused)]
-    crate fn system_date_result(s: Result<SystemTime, std::io::Error>) -> Value {
+    pub fn system_date_result(s: Result<SystemTime, std::io::Error>) -> Value {
         match s {
             Ok(time) => Value::Primitive(Primitive::Date(time.into())),
             Err(err) => Value::Error(Box::new(ShellError::string(format!("{}", err)))),
         }
     }
 
-    crate fn nothing() -> Value {
+    pub fn nothing() -> Value {
         Value::Primitive(Primitive::Nothing)
     }
 
     #[allow(unused)]
-    crate fn list(values: impl Into<Vec<Value>>) -> Value {
+    pub fn list(values: impl Into<Vec<Value>>) -> Value {
         Value::List(values.into())
     }
 }

src/parser.rs

@@ -12,7 +12,7 @@ crate use parse::flag::Flag;
 crate use parse::operator::Operator;
 crate use parse::parser::{nom_input, pipeline};
 crate use parse::pipeline::{Pipeline, PipelineElement};
-crate use parse::span::{Span, Spanned};
+pub use parse::span::{Span, Spanned};
 crate use parse::text::Text;
 crate use parse::token_tree::TokenNode;
 crate use parse::tokens::{RawToken, Token};

src/parser/parse/span.rs

@@ -8,8 +8,8 @@ use serde_derive::{Deserialize, Serialize};
 )]
 #[get = "crate"]
 pub struct Spanned<T> {
-    crate span: Span,
+    pub span: Span,
-    crate item: T,
+    pub item: T,
 }
 
 impl<T> std::ops::Deref for Spanned<T> {

src/plugins/inc.rs

@@ -0,0 +1,100 @@
+use nu::{Primitive, ReturnValue, ShellError, Spanned, Value};
+use serde::{Deserialize, Serialize};
+use std::io;
+
+/// A wrapper for proactive notifications to the IDE (eg. diagnostics). These must
+/// follow the JSON 2.0 RPC spec
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct JsonRpc<T> {
+    jsonrpc: String,
+    pub method: String,
+    pub params: T,
+}
+impl<T> JsonRpc<T> {
+    pub fn new<U: Into<String>>(method: U, params: T) -> Self {
+        JsonRpc {
+            jsonrpc: "2.0".into(),
+            method: method.into(),
+            params,
+        }
+    }
+}
+
+fn send_response<T: Serialize>(result: T) {
+    let response = JsonRpc::new("response", result);
+    let response_raw = serde_json::to_string(&response).unwrap();
+    println!("{}", response_raw);
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "method")]
+#[allow(non_camel_case_types)]
+pub enum NuCommand {
+    init { params: Vec<Spanned<Value>> },
+    filter { params: Value },
+    quit,
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut inc_by = 1;
+
+    loop {
+        let mut input = String::new();
+        match io::stdin().read_line(&mut input) {
+            Ok(_) => {
+                let command = serde_json::from_str::<NuCommand>(&input);
+
+                match command {
+                    Ok(NuCommand::init { params }) => {
+                        for param in params {
+                            match param {
+                                Spanned {
+                                    item: Value::Primitive(Primitive::Int(i)),
+                                    ..
+                                } => {
+                                    inc_by = i;
+                                }
+                                _ => {
+                                    send_response(ReturnValue::Value(Value::Error(Box::new(
+                                        ShellError::string("Unrecognized type in params"),
+                                    ))));
+                                }
+                            }
+                        }
+                    }
+                    Ok(NuCommand::filter { params }) => match params {
+                        Value::Primitive(Primitive::Int(i)) => {
+                            send_response(vec![ReturnValue::Value(Value::int(i + inc_by))]);
+                        }
+                        Value::Primitive(Primitive::Bytes(b)) => {
+                            send_response(vec![ReturnValue::Value(Value::bytes(
+                                b + inc_by as u128,
+                            ))]);
+                        }
+                        _ => {
+                            send_response(ReturnValue::Value(Value::Error(Box::new(
+                                ShellError::string("Unrecognized type in stream"),
+                            ))));
+                        }
+                    },
+                    Ok(NuCommand::quit) => {
+                        break;
+                    }
+                    Err(_) => {
+                        send_response(ReturnValue::Value(Value::Error(Box::new(
+                            ShellError::string("Unrecognized type in stream"),
+                        ))));
+                    }
+                }
+            }
+            Err(error) => {
+                send_response(ReturnValue::Value(Value::Error(Box::new(
+                    ShellError::string("Unrecognized type in stream"),
+                ))));
+            }
+        }
+    }
+
+    Ok(())
+}