Split parse into regex_parser and line_parser

README.md

@@ -31,7 +31,7 @@ line-oriented diff.
 Difftastic treats source code as a sequence of atoms or (possibly
 nested) lists.
 
-Language syntax is defined in `parse.rs`: you provide regular
+Language syntax is defined in `src/regex_parser.rs`: you provide regular
 expressions for atoms (including comments), open delimiters, and close
 delimiters.
 

src/line_parser.rs

@@ -0,0 +1,59 @@
+use typed_arena::Arena;
+
+use crate::{positions::SingleLineSpan, syntax::Syntax};
+
+/// Split `s` by lines, and treat each line as an atom.
+///
+/// This is a fallback for files that we don't know how to parse.
+pub fn parse<'a>(arena: &'a Arena<Syntax<'a>>, s: &str) -> Vec<&'a Syntax<'a>> {
+    let mut res = vec![];
+    for (i, line) in s.lines().enumerate() {
+        res.push(Syntax::new_atom(
+            arena,
+            vec![SingleLineSpan {
+                line: i.into(),
+                start_col: 0,
+                end_col: line.len(),
+            }],
+            line,
+        ));
+    }
+
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    // TODO: move assert_syntaxes to a more relevant file.
+    use crate::regex_parser::tests::assert_syntaxes;
+
+    #[test]
+    fn test_parse_lines() {
+        let arena = Arena::new();
+
+        assert_syntaxes(
+            &parse(&arena, "foo\nbar"),
+            &[
+                Syntax::new_atom(
+                    &arena,
+                    vec![SingleLineSpan {
+                        line: 0.into(),
+                        start_col: 0,
+                        end_col: 3,
+                    }],
+                    "foo",
+                ),
+                Syntax::new_atom(
+                    &arena,
+                    vec![SingleLineSpan {
+                        line: 1.into(),
+                        start_col: 0,
+                        end_col: 3,
+                    }],
+                    "bar",
+                ),
+            ],
+        );
+    }
+}

src/main.rs

@@ -1,9 +1,10 @@
 mod dijkstra;
 mod inline;
 mod intervals;
+mod line_parser;
 mod lines;
-mod parse;
 mod positions;
+mod regex_parser;
 mod side_by_side;
 mod sitter;
 mod style;
@@ -16,7 +17,6 @@ use typed_arena::Arena;
 
 use crate::dijkstra::mark_syntax;
 use crate::lines::{join_overlapping, visible_groups, MaxLine};
-use crate::parse::{from_extension, parse, parse_lines};
 use crate::syntax::{change_positions, init_info, matching_lines};
 
 fn read_or_die(path: &str) -> Vec<u8> {
@@ -113,16 +113,16 @@ fn main() {
                 sitter::parse(&arena, &rhs_src, extension),
             )
         } else {
-            match from_extension(extension) {
+            match regex_parser::from_extension(extension) {
                 Some(lang) => (
                     lang.name.clone(),
-                    parse(&arena, &lhs_src, &lang),
+                    regex_parser::parse(&arena, &lhs_src, &lang),
-                    parse(&arena, &rhs_src, &lang),
+                    regex_parser::parse(&arena, &rhs_src, &lang),
                 ),
                 None => (
                     "text".into(),
-                    parse_lines(&arena, &lhs_src),
+                    line_parser::parse(&arena, &lhs_src),
-                    parse_lines(&arena, &rhs_src),
+                    line_parser::parse(&arena, &rhs_src),
                 ),
             }
         };

src/regex_parser.rs

@@ -210,26 +210,6 @@ pub fn from_extension(extension: &OsStr) -> Option<Language> {
     }
 }
 
-/// Split `s` by lines, and treat each line as an atom.
-///
-/// This is a fallback for files that we don't know how to parse.
-pub fn parse_lines<'a>(arena: &'a Arena<Syntax<'a>>, s: &str) -> Vec<&'a Syntax<'a>> {
-    let mut res: Vec<&'a Syntax<'a>> = vec![];
-    for (i, line) in s.lines().enumerate() {
-        res.push(Syntax::new_atom(
-            arena,
-            vec![SingleLineSpan {
-                line: i.into(),
-                start_col: 0,
-                end_col: line.len(),
-            }],
-            line,
-        ));
-    }
-
-    res
-}
-
 /// Parse `s` according to `lang`.
 pub fn parse<'a>(arena: &'a Arena<Syntax<'a>>, s: &str, lang: &Language) -> Vec<&'a Syntax<'a>> {
     let nl_pos = NewlinePositions::from(s);
@@ -368,7 +348,7 @@ impl ParseState {
 }
 
 #[cfg(test)]
-mod tests {
+pub mod tests {
     use super::*;
     use crate::syntax::Syntax::*;
 
@@ -376,7 +356,7 @@ mod tests {
         from_extension(&OsStr::new("js")).unwrap()
     }
 
-    fn assert_syntaxes<'a>(actual: &[&'a Syntax<'a>], expected: &[&'a Syntax<'a>]) {
+    pub fn assert_syntaxes<'a>(actual: &[&'a Syntax<'a>], expected: &[&'a Syntax<'a>]) {
         if !syntaxes_match(actual, expected) {
             dbg!(expected, actual);
             assert!(false);
@@ -494,35 +474,6 @@ mod tests {
         true
     }
 
-    #[test]
-    fn test_parse_lines() {
-        let arena = Arena::new();
-
-        assert_syntaxes(
-            &parse_lines(&arena, "foo\nbar"),
-            &[
-                Syntax::new_atom(
-                    &arena,
-                    vec![SingleLineSpan {
-                        line: 0.into(),
-                        start_col: 0,
-                        end_col: 3,
-                    }],
-                    "foo",
-                ),
-                Syntax::new_atom(
-                    &arena,
-                    vec![SingleLineSpan {
-                        line: 1.into(),
-                        start_col: 0,
-                        end_col: 3,
-                    }],
-                    "bar",
-                ),
-            ],
-        );
-    }
-
     #[test]
     fn test_parse_integer() {
         let arena = Arena::new();