Error in case an operator is used as a delimiter

askama_derive/Cargo.toml

@@ -25,7 +25,7 @@ with-rocket = []
 with-warp = []
 
 [dependencies]
-parser = { package = "askama_parser", version = "0.3", path = "../askama_parser" }
+parser = { package = "askama_parser", version = "0.3.1", path = "../askama_parser" }
 mime = "0.3"
 mime_guess = "2"
 proc-macro2 = "1"

askama_derive/src/config.rs

@@ -3,6 +3,7 @@ use std::path::{Path, PathBuf};
 use std::rc::Rc;
 use std::{env, fs};
 
+use parser::expr::TWO_PLUS_CHAR_OPS;
 #[cfg(feature = "serde")]
 use serde::Deserialize;
 
@@ -161,6 +162,11 @@ impl<'a> TryInto<Syntax<'a>> for RawSyntax<'a> {
                 );
             } else if s.chars().any(|c| c.is_whitespace()) {
                 return Err(format!("delimiters may not contain white spaces: {s:?}").into());
+            } else if TWO_PLUS_CHAR_OPS.contains(&s) {
+                return Err(format!(
+                    "delimiters may not contain operators: {s:?}"
+                )
+                .into());
             }
         }
 

askama_parser/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "askama_parser"
-version = "0.3.0"
+version = "0.3.1"
 description = "Parser for Askama templates"
 documentation = "https://docs.rs/askama"
 keywords = ["markup", "template", "jinja2", "html"]

askama_parser/src/expr.rs

@@ -172,6 +172,7 @@ impl<'a> Expr<'a> {
         ))(i)
     }
 
+    // Keep in sync with `TWO_PLUS_CHAR_OPS`, below
     expr_prec_layer!(or, and, "||");
     expr_prec_layer!(and, compare, "&&");
     expr_prec_layer!(compare, bor, "==", "!=", ">=", ">", "<=", "<");
@@ -430,3 +431,6 @@ impl<'a> Suffix<'a> {
         map(preceded(take_till(not_ws), char('?')), |_| Self::Try)(i)
     }
 }
+
+pub const TWO_PLUS_CHAR_OPS: &[&str] =
+    &["||", "&&", "==", "!=", ">=", "<=", "<<", ">>", "..", "..="];