Syntax highlighting

src/parser.rs

@@ -14,7 +14,7 @@ use parser::PipelineParser;
 
 pub fn parse(input: &str, _registry: &dyn CommandRegistry) -> Result<Pipeline, ShellError> {
     let parser = PipelineParser::new();
-    let tokens = Lexer::new(input);
+    let tokens = Lexer::new(input, false);
 
     match parser.parse(tokens) {
         Ok(val) => Ok(val),

src/parser/lexer.rs

@@ -375,14 +375,15 @@ pub enum Token {
 crate struct Lexer<'source> {
     lexer: logos::Lexer<TopToken, &'source str>,
     first: bool,
-    // state: LexerState,
+    whitespace: bool, // state: LexerState
 }
 
 impl Lexer<'source> {
-    crate fn new(source: &str) -> Lexer<'_> {
+    crate fn new(source: &str, whitespace: bool) -> Lexer<'_> {
         Lexer {
             first: true,
             lexer: logos::Logos::lexer(source),
+            whitespace
             // state: LexerState::default(),
         }
     }
@@ -400,7 +401,7 @@ impl Iterator for Lexer<'source> {
                 TopToken::Error => {
                     return Some(Err(lex_error(&self.lexer.range(), self.lexer.source)))
                 }
-                TopToken::Whitespace => return self.next(),
+                TopToken::Whitespace if !self.whitespace => return self.next(),
                 other => {
                     return spanned(other.to_token()?, self.lexer.slice(), &self.lexer.range())
                 }
@@ -415,7 +416,7 @@ impl Iterator for Lexer<'source> {
 
                     match token {
                         TopToken::Error => return Some(Err(lex_error(&range, self.lexer.source))),
-                        TopToken::Whitespace => return self.next(),
+                        TopToken::Whitespace if !self.whitespace => return self.next(),
                         other => return spanned(other.to_token()?, slice, &range),
                     }
                 }
@@ -429,7 +430,7 @@ impl Iterator for Lexer<'source> {
                         AfterMemberDot::Error => {
                             return Some(Err(lex_error(&range, self.lexer.source)))
                         }
-                        AfterMemberDot::Whitespace => self.next(),
+                        AfterMemberDot::Whitespace if !self.whitespace => self.next(),
                         other => return spanned(other.to_token()?, slice, &range),
                     }
                 }
@@ -443,7 +444,7 @@ impl Iterator for Lexer<'source> {
                         AfterVariableToken::Error => {
                             return Some(Err(lex_error(&range, self.lexer.source)))
                         }
-                        AfterVariableToken::Whitespace => self.next(),
+                        AfterVariableToken::Whitespace if !self.whitespace => self.next(),
 
                         other => return spanned(other.to_token()?, slice, &range),
                     }
@@ -508,7 +509,7 @@ mod tests {
     use pretty_assertions::assert_eq;
 
     fn assert_lex(source: &str, tokens: &[TestToken<'_>]) {
-        let lex = Lexer::new(source);
+        let lex = Lexer::new(source, false);
         let mut current = 0;
 
         let expected_tokens: Vec<SpannedToken> = tokens

src/shell/helper.rs

@@ -1,15 +1,17 @@
 use crate::shell::completer::NuCompleter;
 
+use crate::parser::lexer::SpannedToken;
 use crate::prelude::*;
+use ansi_term::Color;
+use log::debug;
 use rustyline::completion::{self, Completer, FilenameCompleter};
 use rustyline::error::ReadlineError;
-use rustyline::highlight::{Highlighter, MatchingBracketHighlighter};
+use rustyline::highlight::Highlighter;
 use rustyline::hint::{Hinter, HistoryHinter};
 use std::borrow::Cow::{self, Owned};
 
 crate struct Helper {
     completer: NuCompleter,
-    highlighter: MatchingBracketHighlighter,
     hinter: HistoryHinter,
 }
 
@@ -20,7 +22,6 @@ impl Helper {
                 file_completer: FilenameCompleter::new(),
                 commands,
             },
-            highlighter: MatchingBracketHighlighter::new(),
             hinter: HistoryHinter {},
         }
     }
@@ -54,12 +55,78 @@ impl Highlighter for Helper {
         Owned("\x1b[1m".to_owned() + hint + "\x1b[m")
     }
 
-    fn highlight<'l>(&self, line: &'l str, pos: usize) -> Cow<'l, str> {
-        self.highlighter.highlight(line, pos)
+    fn highlight<'l>(&self, line: &'l str, _pos: usize) -> Cow<'l, str> {
+        let tokens = crate::parser::lexer::Lexer::new(line, true);
+        let tokens: Result<Vec<(usize, SpannedToken, usize)>, _> = tokens.collect();
+
+        match tokens {
+            Err(_) => Cow::Borrowed(line),
+            Ok(v) => {
+                let mut out = String::new();
+                let mut iter = v.iter();
+
+                let mut state = State::Command;
+
+                loop {
+                    match iter.next() {
+                        None => return Cow::Owned(out),
+                        Some((start, token, end)) => {
+                            let (style, new_state) = token_style(&token, state);
+
+                            debug!("token={:?}", token);
+                            debug!("style={:?}", style);
+                            debug!("new_state={:?}", new_state);
+
+                            state = new_state;
+                            let slice = &line[*start..*end];
+                            let styled = style.paint(slice);
+                            out.push_str(&styled.to_string());
+                        }
+                    }
+                }
+            }
+        }
     }
 
-    fn highlight_char(&self, line: &str, pos: usize) -> bool {
-        self.highlighter.highlight_char(line, pos)
+    fn highlight_char(&self, _line: &str, _pos: usize) -> bool {
+        true
+    }
+}
+
+#[derive(Debug)]
+enum State {
+    Command,
+    Flag,
+    Var,
+    Bare,
+    None,
+}
+
+fn token_style(
+    token: &crate::parser::lexer::SpannedToken,
+    state: State,
+) -> (ansi_term::Style, State) {
+    use crate::parser::lexer::Token::*;
+
+    match (state, &token.token) {
+        (State::Command, Bare) => (Color::Cyan.bold(), State::None),
+        (State::Command, Whitespace) => (Color::White.normal(), State::Command),
+
+        (State::Flag, Bare) => (Color::Black.bold(), State::None),
+
+        (State::Var, Variable) => (Color::Yellow.bold(), State::None),
+
+        (State::Bare, Dot) => (Color::Green.normal(), State::Bare),
+        (State::Bare, Member) => (Color::Green.normal(), State::Bare),
+
+        (_, Dash) | (_, DashDash) => (Color::Black.bold(), State::Flag),
+        (_, Dollar) => (Color::Yellow.bold(), State::Var),
+        (_, Bare) => (Color::Green.normal(), State::Bare),
+        (_, Member) => (Color::Cyan.normal(), State::None),
+        (_, Num) => (Color::Purple.bold(), State::None),
+        (_, DQString) | (_, SQString) => (Color::Green.normal(), State::None),
+        (_, Pipe) => (Color::White.normal(), State::Command),
+        _ => (Color::White.normal(), State::None),
     }
 }