From 41723eb4caf581b7287f5d85944126f61b469bab Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Fri, 18 Nov 2022 20:55:44 +0100
Subject: [PATCH] Parse comments in whitespace

---
 src/ast/basic.rs    | 14 ++++++++++++--
 src/parser/basic.rs | 35 +++++++++++++++++++++++++++++------
 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/src/ast/basic.rs b/src/ast/basic.rs
index 628b459..e472e39 100644
--- a/src/ast/basic.rs
+++ b/src/ast/basic.rs
@@ -2,15 +2,25 @@ use std::fmt;
 
 use crate::span::{HasSpan, Span};
 
+#[derive(Clone)]
+pub enum Line {
+    Empty,
+    Comment(String),
+}
+
 #[derive(Clone)]
 pub struct Space {
-    pub comment: Vec<(String, Span)>,
+    pub lines: Vec<Line>,
     pub span: Span,
 }
 
 impl fmt::Debug for Space {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Space").finish()
+        if self.lines.iter().any(|l| matches!(l, Line::Comment(_))) {
+            write!(f, "space with comments")
+        } else {
+            write!(f, "space")
+        }
     }
 }
 
diff --git a/src/parser/basic.rs b/src/parser/basic.rs
index 971d558..d3cb2f1 100644
--- a/src/parser/basic.rs
+++ b/src/parser/basic.rs
@@ -1,20 +1,43 @@
 //! Corresponds to `ast::basic`.
 
 use chumsky::prelude::*;
+use chumsky::text::Character;
 
-use crate::ast::{Ident, Space};
+use crate::ast::{Ident, Line, Space};
 use crate::span::Span;
 
 pub type Error = Simple<char, Span>;
 
 // TODO https://github.com/rust-lang/rust/issues/63063
 
+pub fn inline() -> impl Parser<char, (), Error = Error> {
+    filter(|c: &char| c.is_whitespace() && *c != '\n')
+        .repeated()
+        .to(())
+}
+
+pub fn newline() -> impl Parser<char, (), Error = Error> {
+    just('\n').to(())
+}
+
+pub fn line() -> impl Parser<char, Line, Error = Error> {
+    let empty = newline().to(Line::Empty);
+
+    let comment = just('#')
+        .ignore_then(take_until(newline()))
+        .map(|(s, _)| s)
+        .collect::<String>()
+        .map(Line::Comment);
+
+    empty.or(comment)
+}
+
 pub fn space() -> impl Parser<char, Space, Error = Error> {
-    // TODO Parse comments
-    text::whitespace().map_with_span(|(), span| Space {
-        comment: vec![],
-        span,
-    })
+    inline()
+        .ignore_then(line())
+        .repeated()
+        .then_ignore(inline())
+        .map_with_span(|lines, span| Space { lines, span })
 }
 
 pub fn ident() -> impl Parser<char, Ident, Error = Error> {