Added keyword and operator colors and matching bracket validator to cli (#590)

Cargo.lock

@@ -99,7 +99,10 @@ dependencies = [
  "Boa",
  "colored",
  "jemallocator",
+ "lazy_static",
+ "regex",
  "rustyline",
+ "rustyline-derive",
  "serde_json",
  "structopt",
 ]
@@ -833,6 +836,16 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "rustyline-derive"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54a50e29610a5be68d4a586a5cce3bfb572ed2c2a74227e4168444b7bf4e5235"
+dependencies = [
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.5"

boa_cli/Cargo.toml

@@ -13,9 +13,12 @@ edition = "2018"
 [dependencies]
 Boa = { path = "../boa", features = ["serde"] }
 rustyline = "6.2.0"
+rustyline-derive = "0.3.1"
 structopt = "0.3.15"
 serde_json = "1.0.56"
 colored = "2.0.0"
+regex = "1"
+lazy_static = "1.4.0"
 
 [target.x86_64-unknown-linux-gnu.dependencies]
 jemallocator = "0.3.2"

boa_cli/src/main.rs

@@ -32,7 +32,18 @@ use boa::{
     syntax::ast::{node::StatementList, token::Token},
 };
 use colored::*;
-use rustyline::{config::Config, error::ReadlineError, EditMode, Editor};
+use lazy_static::lazy_static;
+use regex::{Captures, Regex};
+use rustyline::{
+    config::Config,
+    error::ReadlineError,
+    highlight::Highlighter,
+    validate::{MatchingBracketValidator, ValidationContext, ValidationResult, Validator},
+    EditMode, Editor,
+};
+use rustyline_derive::{Completer, Helper, Hinter};
+use std::borrow::Cow;
+use std::collections::HashSet;
 use std::{fs::read_to_string, path::PathBuf};
 use structopt::{clap::arg_enum, StructOpt};
 
@@ -206,10 +217,14 @@ pub fn main() -> Result<(), std::io::Error> {
             })
             .build();
 
-        let mut editor = Editor::<()>::with_config(config);
+        let mut editor = Editor::with_config(config);
         let _ = editor.load_history(CLI_HISTORY);
+        editor.set_helper(Some(RLHelper {
+            highlighter: LineHighlighter,
+            validator: MatchingBracketValidator::new(),
+        }));
 
-        let readline = "> ".cyan().bold().to_string();
+        let readline = ">> ".cyan().bold().to_string();
 
         loop {
             match editor.readline(&readline) {
@@ -243,3 +258,118 @@ pub fn main() -> Result<(), std::io::Error> {
 
     Ok(())
 }
+
+#[derive(Completer, Helper, Hinter)]
+struct RLHelper {
+    highlighter: LineHighlighter,
+    validator: MatchingBracketValidator,
+}
+
+impl Validator for RLHelper {
+    fn validate(&self, ctx: &mut ValidationContext<'_>) -> Result<ValidationResult, ReadlineError> {
+        self.validator.validate(ctx)
+    }
+
+    fn validate_while_typing(&self) -> bool {
+        self.validator.validate_while_typing()
+    }
+}
+
+impl Highlighter for RLHelper {
+    fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
+        hint.into()
+    }
+
+    fn highlight<'l>(&self, line: &'l str, pos: usize) -> Cow<'l, str> {
+        self.highlighter.highlight(line, pos)
+    }
+
+    fn highlight_candidate<'c>(
+        &self,
+        candidate: &'c str,
+        _completion: rustyline::CompletionType,
+    ) -> Cow<'c, str> {
+        self.highlighter.highlight(candidate, 0)
+    }
+
+    fn highlight_char(&self, line: &str, _: usize) -> bool {
+        !line.is_empty()
+    }
+}
+
+lazy_static! {
+    static ref KEYWORDS: HashSet<&'static str> = {
+        let mut keywords = HashSet::new();
+        keywords.insert("break");
+        keywords.insert("case");
+        keywords.insert("catch");
+        keywords.insert("class");
+        keywords.insert("const");
+        keywords.insert("continue");
+        keywords.insert("default");
+        keywords.insert("delete");
+        keywords.insert("do");
+        keywords.insert("else");
+        keywords.insert("export");
+        keywords.insert("extends");
+        keywords.insert("finally");
+        keywords.insert("for");
+        keywords.insert("function");
+        keywords.insert("if");
+        keywords.insert("import");
+        keywords.insert("instanceof");
+        keywords.insert("new");
+        keywords.insert("return");
+        keywords.insert("super");
+        keywords.insert("switch");
+        keywords.insert("this");
+        keywords.insert("throw");
+        keywords.insert("try");
+        keywords.insert("typeof");
+        keywords.insert("var");
+        keywords.insert("void");
+        keywords.insert("while");
+        keywords.insert("with");
+        keywords.insert("yield");
+        keywords.insert("await");
+        keywords.insert("enum");
+        keywords.insert("let");
+        keywords
+    };
+}
+
+struct LineHighlighter;
+
+impl Highlighter for LineHighlighter {
+    fn highlight<'l>(&self, line: &'l str, _: usize) -> Cow<'l, str> {
+        let mut coloured = line.to_string();
+
+        let reg = Regex::new(
+            r"(?x)
+            (?P<identifier>[$A-z_]+[$A-z_0-9]*) |
+            (?P<op>[+\-/*%~^!&|=<>,.;:])",
+        )
+        .unwrap();
+
+        coloured = reg
+            .replace_all(&coloured, |caps: &Captures<'_>| {
+                if let Some(cap) = caps.name("identifier") {
+                    match cap.as_str() {
+                        "true" | "false" | "null" | "Infinity" => cap.as_str().purple().to_string(),
+                        "undefined" => cap.as_str().truecolor(100, 100, 100).to_string(),
+                        identifier if KEYWORDS.contains(identifier) => {
+                            cap.as_str().yellow().bold().to_string()
+                        }
+                        _ => cap.as_str().to_string(),
+                    }
+                } else if let Some(cap) = caps.name("op") {
+                    cap.as_str().green().to_string()
+                } else {
+                    caps[0].to_string()
+                }
+            })
+            .to_string();
+
+        coloured.into()
+    }
+}