This is part of on-going work with capabilities when working with

tables and able to work with them for data processing & viewing
purposes. At the moment, certain ways to process said tables we
are able to view a histogram of a given column.

As usage matures, we may find certain core commands that could
be used ergonomically when working with tables on Nu.

README.md

@@ -256,6 +256,7 @@ Nu adheres closely to a set of goals that make up its design philosophy. As feat
 | format pattern | Format table row data as a string following the given pattern |
 | get column-or-column-path | Open column and get data from the corresponding cells |
 | group-by column | Creates a new table with the data from the table rows grouped by the column given |
+| histogram column ...column-names | Creates a new table with a histogram based on the column name passed in, optionally give the frequency column name
 | inc (column-or-column-path) | Increment a value or version. Optionally use the column of a table |
 | insert column-or-column-path value | Insert a new column to the table |
 | last amount | Show only the last number of rows |
@@ -267,6 +268,7 @@ Nu adheres closely to a set of goals that make up its design philosophy. As feat
 | reverse | Reverses the table. |
 | skip amount | Skip a number of rows |
 | skip-while condition | Skips rows while the condition matches. |
+| split-by column | Creates a new table with the data from the inner tables splitted by the column given |
 | sort-by ...columns | Sort by the given columns |
 | str (column) | Apply string function. Optionally use the column of a table |
 | sum | Sum a column of values |

src/cli.rs

@@ -301,6 +301,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             whole_stream_command(FromYML),
             whole_stream_command(Pick),
             whole_stream_command(Get),
+            whole_stream_command(Histogram),
             per_item_command(Remove),
             per_item_command(Fetch),
             per_item_command(Open),
@@ -320,6 +321,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             per_item_command(Mkdir),
             per_item_command(Move),
             whole_stream_command(Save),
+            whole_stream_command(SplitBy),
             whole_stream_command(Table),
             whole_stream_command(Version),
             whole_stream_command(Which),
@@ -328,12 +330,10 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
         cfg_if::cfg_if! {
             if #[cfg(data_processing_primitives)] {
                 context.add_commands(vec![
-                whole_stream_command(SplitBy),
                 whole_stream_command(ReduceBy),
                 whole_stream_command(EvaluateBy),
                 whole_stream_command(TSortBy),
                 whole_stream_command(MapMaxBy),
-                whole_stream_command(Histogram),
                 ]);
             }
         }

src/commands.rs

@@ -16,6 +16,8 @@ pub(crate) mod debug;
 pub(crate) mod echo;
 pub(crate) mod enter;
 pub(crate) mod env;
+#[allow(unused)]
+pub(crate) mod evaluate_by;
 pub(crate) mod exit;
 pub(crate) mod fetch;
 pub(crate) mod first;
@@ -33,10 +35,13 @@ pub(crate) mod from_yaml;
 pub(crate) mod get;
 pub(crate) mod group_by;
 pub(crate) mod help;
+pub(crate) mod histogram;
 pub(crate) mod history;
 pub(crate) mod last;
 pub(crate) mod lines;
 pub(crate) mod ls;
+#[allow(unused)]
+pub(crate) mod map_max_by;
 pub(crate) mod mkdir;
 pub(crate) mod mv;
 pub(crate) mod next;
@@ -49,6 +54,8 @@ pub(crate) mod post;
 pub(crate) mod prepend;
 pub(crate) mod prev;
 pub(crate) mod pwd;
+#[allow(unused)]
+pub(crate) mod reduce_by;
 pub(crate) mod reject;
 pub(crate) mod reverse;
 pub(crate) mod rm;
@@ -57,20 +64,11 @@ pub(crate) mod shells;
 pub(crate) mod size;
 pub(crate) mod skip_while;
 pub(crate) mod sort_by;
-
+pub(crate) mod split_by;
-cfg_if::cfg_if! {
-    if #[cfg(data_processing_primitives)] {
-        pub(crate) mod split_by;
-        pub(crate) mod reduce_by;
-        pub(crate) mod evaluate_by;
-        pub(crate) mod t_sort_by;
-        pub(crate) mod map_max_by;
-        pub(crate) mod histogram;
-    }
-}
-
 pub(crate) mod split_column;
 pub(crate) mod split_row;
+#[allow(unused)]
+pub(crate) mod t_sort_by;
 pub(crate) mod table;
 pub(crate) mod tags;
 pub(crate) mod to_bson;
@@ -103,6 +101,8 @@ pub(crate) use debug::Debug;
 pub(crate) use echo::Echo;
 pub(crate) use enter::Enter;
 pub(crate) use env::Env;
+#[allow(unused)]
+pub(crate) use evaluate_by::EvaluateBy;
 pub(crate) use exit::Exit;
 pub(crate) use fetch::Fetch;
 pub(crate) use first::First;
@@ -122,10 +122,13 @@ pub(crate) use from_yaml::FromYML;
 pub(crate) use get::Get;
 pub(crate) use group_by::GroupBy;
 pub(crate) use help::Help;
+pub(crate) use histogram::Histogram;
 pub(crate) use history::History;
 pub(crate) use last::Last;
 pub(crate) use lines::Lines;
 pub(crate) use ls::LS;
+#[allow(unused)]
+pub(crate) use map_max_by::MapMaxBy;
 pub(crate) use mkdir::Mkdir;
 pub(crate) use mv::Move;
 pub(crate) use next::Next;
@@ -137,6 +140,8 @@ pub(crate) use post::Post;
 pub(crate) use prepend::Prepend;
 pub(crate) use prev::Previous;
 pub(crate) use pwd::PWD;
+#[allow(unused)]
+pub(crate) use reduce_by::ReduceBy;
 pub(crate) use reject::Reject;
 pub(crate) use reverse::Reverse;
 pub(crate) use rm::Remove;
@@ -145,20 +150,11 @@ pub(crate) use shells::Shells;
 pub(crate) use size::Size;
 pub(crate) use skip_while::SkipWhile;
 pub(crate) use sort_by::SortBy;
-
+pub(crate) use split_by::SplitBy;
-cfg_if::cfg_if! {
-    if #[cfg(data_processing_primitives)] {
-        pub(crate) use split_by::SplitBy;
-        pub(crate) use reduce_by::ReduceBy;
-        pub(crate) use evaluate_by::EvaluateBy;
-        pub(crate) use t_sort_by::TSortBy;
-        pub(crate) use map_max_by::MapMaxBy;
-        pub(crate) use histogram::Histogram;
-    }
-}
-
 pub(crate) use split_column::SplitColumn;
 pub(crate) use split_row::SplitRow;
+#[allow(unused)]
+pub(crate) use t_sort_by::TSortBy;
 pub(crate) use table::Table;
 pub(crate) use tags::Tags;
 pub(crate) use to_bson::ToBSON;

src/commands/histogram.rs

@@ -1,10 +1,10 @@
-use crate::commands::WholeStreamCommand;
+use crate::commands::evaluate_by::evaluate;
 use crate::commands::group_by::group;
+use crate::commands::map_max_by::map_max;
+use crate::commands::reduce_by::reduce;
 use crate::commands::t_sort_by::columns_sorted;
 use crate::commands::t_sort_by::t_sort;
-use crate::commands::evaluate_by::evaluate;
+use crate::commands::WholeStreamCommand;
-use crate::commands::reduce_by::reduce;
-use crate::commands::map_max_by::map_max;
 use crate::data::TaggedDictBuilder;
 use crate::errors::ShellError;
 use crate::prelude::*;
@@ -15,6 +15,7 @@ pub struct Histogram;
 #[derive(Deserialize)]
 pub struct HistogramArgs {
     column_name: Tagged<String>,
+    rest: Vec<Tagged<String>>,
 }
 
 impl WholeStreamCommand for Histogram {
@@ -23,11 +24,16 @@ impl WholeStreamCommand for Histogram {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("histogram").required(
+        Signature::build("histogram")
-            "column_name",
+            .required(
-            SyntaxShape::String,
+                "column_name",
-            "the name of the column to graph by",
+                SyntaxShape::String,
-        )
+                "the name of the column to graph by",
+            )
+            .rest(
+                SyntaxShape::Member,
+                "column name to give the histogram's frequency column",
+            )
     }
 
     fn usage(&self) -> &str {
@@ -44,7 +50,7 @@ impl WholeStreamCommand for Histogram {
 }
 
 pub fn histogram(
-    HistogramArgs { column_name }: HistogramArgs,
+    HistogramArgs { column_name, rest }: HistogramArgs,
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
@@ -68,13 +74,24 @@ pub fn histogram(
 
                 let mut idx = 0;
 
+                let column_names_supplied: Vec<_> = rest.iter().map(|f| f.item.clone()).collect();
+
+                let frequency_column_name = if column_names_supplied.is_empty() {
+                    "frecuency".to_string()
+                } else {
+                    column_names_supplied[0].clone()
+                };
+
+                let column = (*column_name).clone();
+
                 if let Tagged { item: Value::Table(start), .. } = datasets.get(0).unwrap() {
                     for percentage in start.into_iter() {
+
                         let mut fact = TaggedDictBuilder::new(&name);
-                        fact.insert_tagged("committer", group_labels.get(idx).unwrap().clone());
+                        fact.insert_tagged(&column, group_labels.get(idx).unwrap().clone());
 
                         if let Tagged { item: Value::Primitive(Primitive::Int(ref num)), .. } = percentage.clone() {
-                            fact.insert("activity", std::iter::repeat("*").take(num.to_i32().unwrap() as usize).collect::<String>());
+                            fact.insert(&frequency_column_name, std::iter::repeat("*").take(num.to_i32().unwrap() as usize).collect::<String>());
                         }
 
                         idx = idx + 1;
@@ -104,38 +121,36 @@ fn percentages(
         } => {
             let datasets: Vec<_> = datasets
                 .into_iter()
-                .map(|subsets| {
+                .map(|subsets| match subsets {
-                    match subsets {
+                    Tagged {
-                        Tagged {
+                        item: Value::Table(data),
-                            item: Value::Table(data),
+                        ..
-                            ..
+                    } => {
-                        } => {
+                        let data = data
-                            let data = data
+                            .into_iter()
-                                .into_iter()
+                            .map(|d| match d {
-                                .map(|d| match d {
+                                Tagged {
-                                    Tagged {
+                                    item: Value::Primitive(Primitive::Int(n)),
-                                        item: Value::Primitive(Primitive::Int(n)),
+                                    ..
-                                        ..
+                                } => {
-                                    } => {
+                                    let max = match max {
-                                        let max = match max {
+                                        Tagged {
-                                            Tagged {
+                                            item: Value::Primitive(Primitive::Int(ref maxima)),
-                                                item: Value::Primitive(Primitive::Int(ref maxima)),
+                                            ..
-                                                ..
+                                        } => maxima.to_i32().unwrap(),
-                                            } => maxima.to_i32().unwrap(),
+                                        _ => 0,
-                                            _ => 0,
+                                    };
-                                        };
 
-                                        let n = { n.to_i32().unwrap() * 100 / max };
+                                    let n = { n.to_i32().unwrap() * 100 / max };
 
-                                        Value::number(n).tagged(&tag)
+                                    Value::number(n).tagged(&tag)
-                                    }
+                                }
-                                    _ => Value::number(0).tagged(&tag),
+                                _ => Value::number(0).tagged(&tag),
-                                })
+                            })
-                                .collect::<Vec<_>>();
+                            .collect::<Vec<_>>();
-                            Value::Table(data).tagged(&tag)
+                        Value::Table(data).tagged(&tag)
-                        }
-                        _ => Value::Table(vec![]).tagged(&tag),
                     }
+                    _ => Value::Table(vec![]).tagged(&tag),
                 })
                 .collect();
 

src/commands/map_max_by.rs

@@ -81,29 +81,27 @@ pub fn map_max(
         } => {
             let datasets: Vec<_> = datasets
                 .into_iter()
-                .map(|subsets| {
+                .map(|subsets| match subsets {
-                    match subsets {
+                    Tagged {
-                        Tagged {
+                        item: Value::Table(data),
-                            item: Value::Table(data),
+                        ..
-                            ..
+                    } => {
-                        } => {
+                        let data = data.into_iter().fold(0, |acc, value| match value {
-                            let data = data.into_iter().fold(0, |acc, value| match value {
+                            Tagged {
-                                Tagged {
+                                item: Value::Primitive(Primitive::Int(n)),
-                                    item: Value::Primitive(Primitive::Int(n)),
+                                ..
-                                    ..
+                            } => {
-                                } => {
+                                if n.to_i32().unwrap() > acc {
-                                    if n.to_i32().unwrap() > acc {
+                                    n.to_i32().unwrap()
-                                        n.to_i32().unwrap()
+                                } else {
-                                    } else {
+                                    acc
-                                        acc
-                                    }
                                 }
-                                _ => acc,
+                            }
-                            });
+                            _ => acc,
-                            Value::number(data).tagged(&tag)
+                        });
-                        }
+                        Value::number(data).tagged(&tag)
-                        _ => Value::number(0).tagged(&tag),
                     }
+                    _ => Value::number(0).tagged(&tag),
                 })
                 .collect();
 

src/commands/t_sort_by.rs

@@ -57,25 +57,25 @@ fn t_sort_by(
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     Ok(OutputStream::new(async_stream! {
-            let values: Vec<Tagged<Value>> = input.values.collect().await;
+        let values: Vec<Tagged<Value>> = input.values.collect().await;
 
-            let column_grouped_by_name = if let Some(grouped_by) = group_by {
+        let column_grouped_by_name = if let Some(grouped_by) = group_by {
-                Some(grouped_by.item().clone())
+            Some(grouped_by.item().clone())
-            } else {
+        } else {
-                None
+            None
-            };
+        };
 
-            if show_columns {
+        if show_columns {
-                for label in columns_sorted(column_grouped_by_name, &values[0], &name).iter() {
+            for label in columns_sorted(column_grouped_by_name, &values[0], &name).iter() {
-                     yield ReturnSuccess::value(label.clone());
+                 yield ReturnSuccess::value(label.clone());
-                }
-            } else {
-                match t_sort(column_grouped_by_name, None, &values[0], name) {
-                    Ok(sorted) => yield ReturnSuccess::value(sorted),
-                    Err(err) => yield Err(err)
-                }
             }
-        }))
+        } else {
+            match t_sort(column_grouped_by_name, None, &values[0], name) {
+                Ok(sorted) => yield ReturnSuccess::value(sorted),
+                Err(err) => yield Err(err)
+            }
+        }
+    }))
 }
 
 pub fn columns_sorted(
@@ -125,7 +125,7 @@ pub fn columns_sorted(
 
             keys.into_iter().map(|k| k.tagged(&origin_tag)).collect()
         }
-        _ => vec![Value::string("default").tagged(&origin_tag)]
+        _ => vec![Value::string("default").tagged(&origin_tag)],
     }
 }
 

tests/commands_test.rs

@@ -31,6 +31,35 @@ fn group_by() {
     })
 }
 
+#[test]
+fn histogram() {
+    Playground::setup("histogram_test_1", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "los_tres_caballeros.csv",
+            r#"
+                first_name,last_name,rusty_at
+                Andrés,Robalino,Ecuador
+                Jonathan,Turner,Estados Unidos
+                Yehuda,Katz,Estados Unidos
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), h::pipeline(
+            r#"
+                open los_tres_caballeros.csv
+                | histogram rusty_at countries
+                | where rusty_at == "Ecuador"
+                | get countries
+                | echo $it
+            "#
+        ));
+
+        assert_eq!(actual, "**************************************************");
+        // 50%
+    })
+}
+
 #[test]
 fn group_by_errors_if_unknown_column_name() {
     Playground::setup("group_by_test_2", |dirs, sandbox| {
@@ -56,7 +85,6 @@ fn group_by_errors_if_unknown_column_name() {
     })
 }
 
-#[cfg(data_processing_primitives)]
 #[test]
 fn split_by() {
     Playground::setup("split_by_test_1", |dirs, sandbox| {
@@ -86,7 +114,6 @@ fn split_by() {
     })
 }
 
-#[cfg(data_processing_primitives)]
 #[test]
 fn split_by_errors_if_no_table_given_as_input() {
     Playground::setup("split_by_test_2", |dirs, sandbox| {