From 018ba3cd2c7bcaf7ca3080307927f28cd25e293b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20M=C3=BCller?= <neikos@neikos.email>
Date: Wed, 11 Mar 2026 10:34:17 +0100
Subject: [PATCH] Add for loop parsing
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Marcel Müller <neikos@neikos.email>
---
 src/parser/mod.rs | 85 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 69 insertions(+), 16 deletions(-)

diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index a9171f0..de0ba97 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -209,6 +209,8 @@ pub enum TokenKind {
     Invalid,
     ConditionalIf,
     ConditionalElse,
+    For,
+    In,
     End,
     Literal(TokenLiteral),
 }
@@ -295,6 +297,8 @@ impl TemplateToken {
         invalid => TokenKind::Invalid,
         conditional_if => TokenKind::ConditionalIf,
         conditional_else => TokenKind::ConditionalElse,
+        keyword_for => TokenKind::For,
+        keyword_in => TokenKind::In,
         end => TokenKind::End,
     }
 
@@ -381,14 +385,7 @@ fn parse_interpolate<'input>(input: &mut Input<'input>) -> PResult<'input, Vec<T
 fn parse_block_token<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
     trace(
         "parse_block_token",
-        alt((
-            parse_ident,
-            terminated(parse_literal, ident_terminator_check),
-            terminated(parse_condition_if, ident_terminator_check),
-            terminated(parse_condition_else, ident_terminator_check),
-            terminated(parse_end, ident_terminator_check),
-            parse_whitespace,
-        )),
+        alt((parse_ident, parse_keyword, parse_whitespace)),
     )
     .parse_next(input)
 }
@@ -431,6 +428,26 @@ fn parse_end<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken
     trace("parse_end", "end".map(TemplateToken::end)).parse_next(input)
 }
 
+fn parse_for<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace("parse_for", "for".map(TemplateToken::keyword_for)).parse_next(input)
+}
+
+fn parse_in<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    trace("parse_in", "in".map(TemplateToken::keyword_in)).parse_next(input)
+}
+
+fn parse_keyword<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
+    alt((
+        terminated(parse_literal, ident_terminator_check),
+        terminated(parse_condition_if, ident_terminator_check),
+        terminated(parse_condition_else, ident_terminator_check),
+        terminated(parse_for, ident_terminator_check),
+        terminated(parse_in, ident_terminator_check),
+        terminated(parse_end, ident_terminator_check),
+    ))
+    .parse_next(input)
+}
+
 fn parse_whitespace<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateToken> {
     trace(
         "parse_whitespace",
@@ -458,14 +475,9 @@ fn parse_ident<'input>(input: &mut Input<'input>) -> PResult<'input, TemplateTok
 }
 
 fn ident<'input>(input: &mut Input<'input>) -> PResult<'input, NomoInput> {
-    peek(not(alt((
-        parse_literal,
-        parse_condition_if,
-        parse_condition_else,
-        parse_end,
-    ))))
-    .context(ParseError::ctx().msg("Expected an ident, but found a literal instead"))
-    .parse_next(input)?;
+    peek(not(parse_keyword))
+        .context(ParseError::ctx().msg("Expected an ident, but found a literal instead"))
+        .parse_next(input)?;
 
     take_while(1.., |c: char| c.is_alphanumeric() || "_".contains(c)).parse_next(input)
 }
@@ -627,4 +639,45 @@ mod tests {
         )
         "#);
     }
+
+    #[test]
+    fn parse_for_loop() {
+        let input = "{{ for value in array }} Hi: {{= value }} {{ end }}";
+        let output = parse(input.into());
+
+        insta::assert_debug_snapshot!(output, @r#"
+        Ok(
+            ParsedTemplate {
+                tokens: [
+                    [LeftDelim]"{{" (0..2),
+                    [Whitespace]" " (2..3),
+                    [For]"for" (3..6),
+                    [Whitespace]" " (6..7),
+                    [Ident]"value" (7..12),
+                    [Whitespace]" " (12..13),
+                    [In]"in" (13..15),
+                    [Whitespace]" " (15..16),
+                    [Ident]"array" (16..21),
+                    [Whitespace]" " (21..22),
+                    [RightDelim]"}}" (22..24),
+                    [Whitespace]" " (24..25),
+                    [Content]"Hi:" (25..28),
+                    [Whitespace]" " (28..29),
+                    [LeftDelim]"{{" (29..31),
+                    [WantsOutput]"=" (31..32),
+                    [Whitespace]" " (32..33),
+                    [Ident]"value" (33..38),
+                    [Whitespace]" " (38..39),
+                    [RightDelim]"}}" (39..41),
+                    [Whitespace]" " (41..42),
+                    [LeftDelim]"{{" (42..44),
+                    [Whitespace]" " (44..45),
+                    [End]"end" (45..48),
+                    [Whitespace]" " (48..49),
+                    [RightDelim]"}}" (49..51),
+                ],
+            },
+        )
+        "#);
+    }
 }