Add support for boolean literals

askama_derive/src/generator.rs

@@ -865,6 +865,7 @@ impl<'a> Generator<'a> {
 
     fn visit_expr(&mut self, buf: &mut Buffer, expr: &Expr) -> DisplayWrap {
         match *expr {
+            Expr::BoolLit(s) => self.visit_bool_lit(buf, s),
             Expr::NumLit(s) => self.visit_num_lit(buf, s),
             Expr::StrLit(s) => self.visit_str_lit(buf, s),
             Expr::Var(s) => self.visit_var(buf, s),
@@ -1127,6 +1128,11 @@ impl<'a> Generator<'a> {
         DisplayWrap::Unwrapped
     }
 
+    fn visit_bool_lit(&mut self, buf: &mut Buffer, s: &str) -> DisplayWrap {
+        buf.write(s);
+        DisplayWrap::Unwrapped
+    }
+
     fn visit_str_lit(&mut self, buf: &mut Buffer, s: &str) -> DisplayWrap {
         buf.write(&format!("\"{}\"", s));
         DisplayWrap::Unwrapped

askama_derive/src/parser.rs

@@ -8,6 +8,7 @@ use askama_shared::Syntax;
 
 #[derive(Debug)]
 pub enum Expr<'a> {
+    BoolLit(&'a str),
     NumLit(&'a str),
     StrLit(&'a str),
     Var(&'a str),
@@ -200,6 +201,11 @@ fn non_ascii(chr: u8) -> bool {
     chr >= 0x80 && chr <= 0xFD
 }
 
+named!(expr_bool_lit<Input, Expr>, map!(
+    alt!(tag!("true") | tag!("false")),
+    |s| Expr::BoolLit(str::from_utf8(&s).unwrap())
+));
+
 named!(num_lit<Input, &str>, map!(nom::digit,
     |s| str::from_utf8(s.0).unwrap()
 ));
@@ -376,6 +382,7 @@ named!(expr_group<Input, Expr>, map!(
 ));
 
 named!(expr_single<Input, Expr>, alt!(
+    expr_bool_lit |
     expr_num_lit |
     expr_str_lit |
     expr_path |

testing/templates/literals.html

@@ -1 +1,3 @@
 {{ "a" }}
+{{ true }}
+{{ false }}

testing/tests/simple.rs

@@ -114,7 +114,7 @@ struct LiteralsTemplate {}
 #[test]
 fn test_literals() {
     let s = LiteralsTemplate {};
-    assert_eq!(s.render().unwrap(), "a");
+    assert_eq!(s.render().unwrap(), "a\ntrue\nfalse");
 }
 
 struct Holder {