parser: move nested_parenthesis() helper into node module

1 files changed, 49 insertions, 3 deletions

diff --git a/askama_parser/src/expr.rs b/askama_parser/src/expr.rs
index 03620e7..c5c2351 100644
--- a/askama_parser/src/expr.rs
+++ b/askama_parser/src/expr.rs
@@ -9,9 +9,7 @@ use nom::multi::{fold_many0, many0, separated_list0, separated_list1};
 use nom::sequence::{delimited, pair, preceded, terminated, tuple};
 use nom::{error_position, IResult};
 
-use super::{
-    bool_lit, char_lit, identifier, nested_parenthesis, not_ws, num_lit, path, str_lit, ws,
-};
+use super::{bool_lit, char_lit, identifier, not_ws, num_lit, path, str_lit, ws};
 
 #[derive(Debug, PartialEq)]
 pub enum Expr<'a> {
@@ -159,6 +157,54 @@ fn expr_macro(i: &str) -> IResult<&str, Suffix<'_>> {
     )(i)
 }
 
+fn nested_parenthesis(i: &str) -> IResult<&str, ()> {
+    let mut nested = 0;
+    let mut last = 0;
+    let mut in_str = false;
+    let mut escaped = false;
+
+    for (i, b) in i.chars().enumerate() {
+        if !(b == '(' || b == ')') || !in_str {
+            match b {
+                '(' => nested += 1,
+                ')' => {
+                    if nested == 0 {
+                        last = i;
+                        break;
+                    }
+                    nested -= 1;
+                }
+                '"' => {
+                    if in_str {
+                        if !escaped {
+                            in_str = false;
+                        }
+                    } else {
+                        in_str = true;
+                    }
+                }
+                '\\' => {
+                    escaped = !escaped;
+                }
+                _ => (),
+            }
+        }
+
+        if escaped && b != '\\' {
+            escaped = false;
+        }
+    }
+
+    if nested == 0 {
+        Ok((&i[last..], ()))
+    } else {
+        Err(nom::Err::Error(error_position!(
+            i,
+            ErrorKind::SeparatedNonEmptyList
+        )))
+    }
+}
+
 fn expr_try(i: &str) -> IResult<&str, Suffix<'_>> {
     map(preceded(take_till(not_ws), char('?')), |_| Suffix::Try)(i)
 }