Add full support for comments in MOROS Lisp (#489)

* Add full support for Lisp comments

* Update changelog

* Update doc

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## Unreleased
+- Add full support for comments in lisp (#489)
 - Add parenthesis matching to editor (#488)
 - Upgrade smoltcp from 0.8.2 to 0.9.1 (#484)
 - Update rust to nightly-2022-12-21 (#485)

doc/lisp.md

@@ -187,3 +187,4 @@ Rewrite parts of the code and add new functions and examples.
 
 ### 0.5.0 (unpublished)
 - Rename or add aliases to many functions
+- Add full support for line and inline comments

src/usr/lisp/eval.rs

@@ -1,6 +1,5 @@
-use super::{Err, Exp, Env, Function};
+use super::{Err, Exp, Env, Function, parse_eval};
 use super::env::{env_get, env_set, function_env};
-use super::parse::parse;
 use super::expand::expand;
 use super::string;
 
@@ -130,15 +129,13 @@ fn eval_do_args(args: &[Exp], env: &mut Rc<RefCell<Env>>) -> Result<Exp, Err> {
 fn eval_load_args(args: &[Exp], env: &mut Rc<RefCell<Env>>) -> Result<Exp, Err> {
     ensure_length_eq!(args, 1);
     let path = string(&args[0])?;
-    let mut code = fs::read_to_string(&path).or(Err(Err::Reason("Could not read file".to_string())))?;
+    let mut input = fs::read_to_string(&path).or(Err(Err::Reason(format!("File not found '{}'", path))))?;
     loop {
-        let (rest, exp) = parse(&code)?;
-        let exp = expand(&exp, env)?;
-        eval(&exp, env)?;
+        let (rest, _) = parse_eval(&input, env)?;
         if rest.is_empty() {
             break;
         }
-        code = rest;
+        input = rest;
     }
     Ok(Exp::Bool(true))
 }

src/usr/lisp/mod.rs

@@ -182,16 +182,11 @@ pub fn byte(exp: &Exp) -> Result<u8, Err> {
 
 // REPL
 
-fn parse_eval(exp: &str, env: &mut Rc<RefCell<Env>>) -> Result<Exp, Err> {
-    let (_, exp) = parse(exp)?;
+fn parse_eval(input: &str, env: &mut Rc<RefCell<Env>>) -> Result<(String, Exp), Err> {
+    let (rest, exp) = parse(input)?;
     let exp = expand(&exp, env)?;
     let exp = eval(&exp, env)?;
-    Ok(exp)
-}
-
-fn strip_comments(s: &str) -> String {
-    // FIXME: This doesn't handle `#` inside a string
-    s.split('#').next().unwrap().into()
+    Ok((rest, exp))
 }
 
 fn lisp_completer(line: &str) -> Vec<String> {
@@ -221,33 +216,29 @@ fn repl(env: &mut Rc<RefCell<Env>>) -> Result<(), ExitCode> {
     prompt.history.load(history_file);
     prompt.completion.set(&lisp_completer);
 
-    while let Some(line) = prompt.input(&prompt_string) {
-        if line == "(quit)" {
+    while let Some(input) = prompt.input(&prompt_string) {
+        if input == "(quit)" {
             break;
         }
-        if line.is_empty() {
+        if input.is_empty() {
             println!();
             continue;
         }
-        match parse_eval(&line, env) {
-            Ok(res) => {
-                println!("{}\n", res);
+        match parse_eval(&input, env) {
+            Ok((_, exp)) => {
+                println!("{}\n", exp);
             }
             Err(e) => match e {
                 Err::Reason(msg) => println!("{}Error:{} {}\n", csi_error, csi_reset, msg),
             },
         }
-        prompt.history.add(&line);
+        prompt.history.add(&input);
         prompt.history.save(history_file);
     }
     Ok(())
 }
 
 pub fn main(args: &[&str]) -> Result<(), ExitCode> {
-    let line_color = Style::color("Yellow");
-    let error_color = Style::color("LightRed");
-    let reset = Style::reset();
-
     let env = &mut default_env();
 
     // Store args in env
@@ -269,37 +260,27 @@ pub fn main(args: &[&str]) -> Result<(), ExitCode> {
         if args[1] == "-h" || args[1] == "--help" {
             return help();
         }
-        let pathname = args[1];
-        if let Ok(code) = api::fs::read_to_string(pathname) {
-            let mut block = String::new();
-            let mut opened = 0;
-            let mut closed = 0;
-            for (i, line) in code.split('\n').enumerate() {
-                let line = strip_comments(line);
-                if !line.is_empty() {
-                    opened += line.matches('(').count();
-                    closed += line.matches(')').count();
-                    block.push_str(&line);
-                    if closed >= opened {
-                        if let Err(e) = parse_eval(&block, env) {
-                            match e {
-                                Err::Reason(msg) => {
-                                    eprintln!("{}Error:{} {}", error_color, reset, msg);
-                                    eprintln!();
-                                    eprintln!("  {}{}:{} {}", line_color, i, reset, line);
-                                    return Err(ExitCode::Failure);
-                                }
-                            }
+        let path = args[1];
+        if let Ok(mut input) = api::fs::read_to_string(path) {
+            loop {
+                match parse_eval(&input, env) {
+                    Ok((rest, _)) => {
+                        if rest.is_empty() {
+                            break;
                         }
-                        block.clear();
-                        opened = 0;
-                        closed = 0;
+                        input = rest;
+                    }
+                    Err(Err::Reason(msg)) => {
+                        let csi_error = Style::color("LightRed");
+                        let csi_reset = Style::reset();
+                        eprintln!("{}Error:{} {}", csi_error, csi_reset, msg);
+                        return Err(ExitCode::Failure);
                     }
                 }
             }
             Ok(())
         } else {
-            error!("File not found '{}'", pathname);
+            error!("File not found '{}'", path);
             Err(ExitCode::Failure)
         }
     }
@@ -320,7 +301,7 @@ fn test_lisp() {
 
     macro_rules! eval {
         ($e:expr) => {
-            format!("{}", parse_eval($e, env).unwrap())
+            format!("{}", parse_eval($e, env).unwrap().1)
         };
     }
 

src/usr/lisp/parse.rs

@@ -4,6 +4,7 @@ use alloc::string::String;
 use alloc::string::ToString;
 use alloc::vec;
 
+use nom::Err::Error;
 use nom::IResult;
 use nom::branch::alt;
 use nom::bytes::complete::escaped_transform;
@@ -91,7 +92,15 @@ fn parse_quasiquote(input: &str) -> IResult<&str, Exp> {
     Ok((input, Exp::List(list)))
 }
 
+use nom::sequence::pair;
+use alloc::format;
+
+fn parse_comment(input: &str) -> IResult<&str, ()> {
+    value((), pair(char('#'), is_not("\n")))(input)
+}
+
 fn parse_exp(input: &str) -> IResult<&str, Exp> {
+    let (input, _) = opt(parse_comment)(input)?;
     delimited(multispace0, alt((
         parse_num, parse_bool, parse_str, parse_list, parse_quote, parse_quasiquote, parse_unquote_splice, parse_unquote, parse_splice, parse_sym
     )), multispace0)(input)
@@ -100,6 +109,10 @@ fn parse_exp(input: &str) -> IResult<&str, Exp> {
 pub fn parse(input: &str)-> Result<(String, Exp), Err> {
     match parse_exp(input) {
         Ok((input, exp)) => Ok((input.to_string(), exp)),
-        Err(_) => Err(Err::Reason("Could not parse input".to_string())),
+        Err(Error(err)) if !err.input.is_empty() => {
+            let line = err.input.lines().next().unwrap();
+            Err(Err::Reason(format!("Could not parse '{}'", line)))
+        }
+        _ => Err(Err::Reason(format!("Could not parse input"))),
     }
 }

www/calculator.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Calculator</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Calculator</h1>

www/editor.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Editor</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Editor</h1>

www/filesystem.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Filesystem</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Filesystem</h1>

www/index.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS: Obscure Rust Operating System</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS: Obscure Rust Operating System</h1>

www/lisp.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Lisp</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Lisp</h1>
@@ -220,6 +220,7 @@ language and reading from the filesystem.</p>
 
     <ul>
     <li>Rename or add aliases to many functions</li>
+    <li>Add full support for line and inline comments</li>
     </ul>
   </body>
 </html>

www/manual.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Manual</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Manual</h1>

www/network.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Network</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Network</h1>

www/regex.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Regular Expression Engine</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Regular Expression Engine</h1>

www/shell.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Shell</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Shell</h1>

www/syscalls.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS Syscalls</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS Syscalls</h1>

www/test.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8">
     <title>MOROS</title>
-    <link rel="stylesheet" type="text/css" href="/moros.css">
+    <link rel="stylesheet" type="text/css" href="moros.css">
   </head>
   <body>
     <h1>MOROS</h1>