Experiment: Allow both $true/true and $false/false (#4696)

* Change true/false to keywords

* oops, clippy

* Both kinds of bools

* Add in some boolean variables

* disable py virtualenv test for now

crates/nu-cli/src/completions.rs

@@ -70,9 +70,7 @@ impl NuCompleter {
     ) -> Vec<(reedline::Span, String)> {
         let mut output = vec![];
 
-        let builtins = [
-            "$nu", "$scope", "$in", "$config", "$env", "$true", "$false", "$nothing",
-        ];
+        let builtins = ["$nu", "$scope", "$in", "$config", "$env", "$nothing"];
 
         for builtin in builtins {
             if builtin.as_bytes().starts_with(prefix) {

crates/nu-command/src/conversions/into/binary.rs

@@ -61,7 +61,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "convert a boolean to a nushell binary primitive",
-                example: "$true | into binary",
+                example: "true | into binary",
                 result: Some(Value::Binary {
                     val: i64::from(1).to_le_bytes().to_vec(),
                     span: Span::test_data(),

crates/nu-command/src/conversions/into/bool.rs

@@ -42,7 +42,7 @@ impl Command for SubCommand {
         vec![
             Example {
                 description: "Convert value to boolean in table",
-                example: "echo [[value]; ['false'] ['1'] [0] [1.0] [$true]] | into bool value",
+                example: "echo [[value]; ['false'] ['1'] [0] [1.0] [true]] | into bool value",
                 result: Some(Value::List {
                     vals: vec![
                         Value::Record {
@@ -76,7 +76,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "Convert bool to boolean",
-                example: "$true | into bool",
+                example: "true | into bool",
                 result: Some(Value::boolean(true, span)),
             },
             Example {

crates/nu-command/src/conversions/into/int.rs

@@ -75,7 +75,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "Convert bool to integer",
-                example: "[$false, $true] | into int",
+                example: "[false, true] | into int",
                 result: Some(Value::List {
                     vals: vec![Value::test_int(0), Value::test_int(1)],
                     span: Span::test_data(),

crates/nu-command/src/conversions/into/string.rs

@@ -103,7 +103,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "convert boolean to string",
-                example: "$true | into string",
+                example: "true | into string",
                 result: Some(Value::String {
                     val: "true".to_string(),
                     span: Span::test_data(),

crates/nu-command/src/core_commands/debug.rs

@@ -60,8 +60,7 @@ impl Command for Debug {
             },
             Example {
                 description: "Print the value of a table",
-                example:
-                    "echo [[version patch]; [0.1.0 $false] [0.1.1 $true] [0.2.0 $false]] | debug",
+                example: "echo [[version patch]; [0.1.0 false] [0.1.1 true] [0.2.0 false]] | debug",
                 result: Some(Value::List {
                     vals: vec![
                         Value::test_string("{version: 0.1.0, patch: false}"),

crates/nu-command/src/core_commands/let_.rs

@@ -70,7 +70,7 @@ impl Command for Let {
             },
             Example {
                 description: "Set a variable based on the condition",
-                example: "let x = if $false { -1 } else { 1 }",
+                example: "let x = if false { -1 } else { 1 }",
                 result: None,
             },
         ]

crates/nu-command/src/core_commands/tutor.rs

@@ -351,7 +351,7 @@ ls | each {|x| $x.name}
 ```
 The above will create a list of the filenames in the directory.
 ```
-if $true { echo "it's true" } { echo "it's not true" }
+if true { echo "it's true" } { echo "it's not true" }
 ```
 This `if` call will run the first block if the expression is true, or the
 second block if the expression is false.

crates/nu-command/src/dataframe/eager/filter_with.rs

@@ -28,7 +28,7 @@ impl Command for FilterWith {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Filter dataframe using a bool mask",
-            example: r#"let mask = ([$true $false] | dfr to-df);
+            example: r#"let mask = ([true false] | dfr to-df);
     [[a b]; [1 2] [3 4]] | dfr to-df | dfr filter-with $mask"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![

crates/nu-command/src/dataframe/eager/to_df.rs

@@ -86,7 +86,7 @@ impl Command for ToDataFrame {
             },
             Example {
                 description: "Takes a list of booleans and creates a dataframe",
-                example: "[$true $true $false] | dfr to-df",
+                example: "[true true false] | dfr to-df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0".to_string(),

crates/nu-command/src/dataframe/series/all_false.rs

@@ -26,7 +26,7 @@ impl Command for AllFalse {
         vec![
             Example {
                 description: "Returns true if all values are false",
-                example: "[$false $false $false] | dfr to-df | dfr all-false",
+                example: "[false false false] | dfr to-df | dfr all-false",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "all_false".to_string(),

crates/nu-command/src/dataframe/series/all_true.rs

@@ -26,7 +26,7 @@ impl Command for AllTrue {
         vec![
             Example {
                 description: "Returns true if all values are true",
-                example: "[$true $true $true] | dfr to-df | dfr all-true",
+                example: "[true true true] | dfr to-df | dfr all-true",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "all_true".to_string(),

crates/nu-command/src/dataframe/series/indexes/arg_true.rs

@@ -26,7 +26,7 @@ impl Command for ArgTrue {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns indexes where values are true",
-            example: "[$false $true $false] | dfr to-df | dfr arg-true",
+            example: "[false true false] | dfr to-df | dfr arg-true",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "arg_true".to_string(),

crates/nu-command/src/dataframe/series/masks/not.rs

@@ -28,7 +28,7 @@ impl Command for NotSeries {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Inverts boolean mask",
-            example: "[$true $false $true] | dfr to-df | dfr not",
+            example: "[true false true] | dfr to-df | dfr not",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),

crates/nu-command/src/filters/find.rs

@@ -91,7 +91,7 @@ impl Command for Find {
             },
             Example {
                 description: "Find if a service is not running",
-                example: "[[version patch]; [0.1.0 $false] [0.1.1 $true] [0.2.0 $false]] | find -p { |it| $it.patch }",
+                example: "[[version patch]; [0.1.0 false] [0.1.1 true] [0.2.0 false]] | find -p { |it| $it.patch }",
                 result: Some(Value::List {
                     vals: vec![Value::test_record(
                             vec!["version", "patch"],

crates/nu-command/src/filters/shuffle.rs

@@ -38,7 +38,7 @@ impl Command for Shuffle {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Shuffle rows randomly (execute it several times and see the difference)",
-            example: r#"echo [[version patch]; [1.0.0 $false] [3.0.1 $true] [2.0.0 $false]] | shuffle"#,
+            example: r#"echo [[version patch]; [1.0.0 false] [3.0.1 true] [2.0.0 false]] | shuffle"#,
             result: None,
         }]
     }

crates/nu-command/src/formats/to/nuon.rs

@@ -65,9 +65,9 @@ fn value_to_string(v: &Value, span: Span) -> Result<String, ShellError> {
         )),
         Value::Bool { val, .. } => {
             if *val {
-                Ok("$true".to_string())
+                Ok("true".to_string())
             } else {
-                Ok("$false".to_string())
+                Ok("false".to_string())
             }
         }
         Value::CellPath { .. } => Err(ShellError::UnsupportedInput(

crates/nu-command/src/shells/shells_.rs

@@ -79,7 +79,7 @@ impl Command for Shells {
             },
             Example {
                 description: "Show currently active shell",
-                example: r#"shells | where active == $true"#,
+                example: r#"shells | where active == true"#,
                 result: None,
             },
         ]

crates/nu-command/src/viewers/griddle.rs

@@ -169,7 +169,7 @@ prints out the list properly."#
             },
             Example {
                 description: "Render a table with 'name' column in it to a grid",
-                example: "[[name patch]; [0.1.0 $false] [0.1.1 $true] [0.2.0 $false]] | grid",
+                example: "[[name patch]; [0.1.0 false] [0.1.1 true] [0.2.0 false]] | grid",
                 result: Some(Value::String {
                     val: "0.1.0 │ 0.1.1 │ 0.2.0".to_string(),
                     span: Span::test_data(),

crates/nu-command/tests/commands/str_/into_string.rs

@@ -45,7 +45,7 @@ fn from_boolean() {
     let actual = nu!(
         cwd: ".", pipeline(
         r#"
-        echo $true | into string
+        echo true | into string
         "#
         )
     );

crates/nu-command/tests/format_conversions/nuon.rs

@@ -65,7 +65,7 @@ fn to_nuon_bool() {
     let actual = nu!(
         cwd: "tests/fixtures/formats", pipeline(
         r#"
-            $false
+            false
             | to nuon
             | from nuon
         "#

crates/nu-parser/src/parser.rs

@@ -49,6 +49,10 @@ pub fn is_math_expression_like(bytes: &[u8]) -> bool {
         return false;
     }
 
+    if bytes == b"true" || bytes == b"false" {
+        return true;
+    }
+
     let b = bytes[0];
 
     b == b'0'
@@ -3258,6 +3262,41 @@ pub fn parse_value(
         return parse_variable_expr(working_set, span);
     }
 
+    if bytes == b"true" {
+        if matches!(shape, SyntaxShape::Boolean) || matches!(shape, SyntaxShape::Any) {
+            return (
+                Expression {
+                    expr: Expr::Bool(true),
+                    span,
+                    ty: Type::Bool,
+                    custom_completion: None,
+                },
+                None,
+            );
+        } else {
+            return (
+                Expression::garbage(span),
+                Some(ParseError::Expected("non-boolean value".into(), span)),
+            );
+        }
+    } else if bytes == b"false" {
+        if matches!(shape, SyntaxShape::Boolean) || matches!(shape, SyntaxShape::Any) {
+            return (
+                Expression {
+                    expr: Expr::Bool(false),
+                    span,
+                    ty: Type::Bool,
+                    custom_completion: None,
+                },
+                None,
+            );
+        } else {
+            return (
+                Expression::garbage(span),
+                Some(ParseError::Expected("non-boolean value".into(), span)),
+            );
+        }
+    }
     match bytes[0] {
         b'$' => return parse_dollar_expr(working_set, span),
         b'(' => {
@@ -3381,7 +3420,7 @@ pub fn parse_value(
         }
         SyntaxShape::Boolean => {
             // Redundant, though we catch bad boolean parses here
-            if bytes == b"$true" || bytes == b"$false" {
+            if bytes == b"true" || bytes == b"false" {
                 (
                     Expression {
                         expr: Expr::Bool(true),
@@ -3603,6 +3642,7 @@ pub fn parse_expression(
     while pos < spans.len() {
         // Check if there is any environment shorthand
         let name = working_set.get_span_contents(spans[pos]);
+
         let split = name.split(|x| *x == b'=');
         let split: Vec<_> = split.collect();
         if split.len() == 2 && !split[0].is_empty() {