rebel-parse: tokenize: add support for string interpolation

1 files changed, 16 insertions, 3 deletions

diff --git a/crates/rebel-parse/src/grammar/tokenize.rs b/crates/rebel-parse/src/grammar/tokenize.rs
index 811da0d..8ca9d59 100644
--- a/crates/rebel-parse/src/grammar/tokenize.rs
+++ b/crates/rebel-parse/src/grammar/tokenize.rs
@@ -45,16 +45,17 @@ peg::parser! {
 					kind: StringKind::RawString,
 				}
 			}
-			/ "```" newline() chars:$((!"```" [_])+) "```" {
+			/ "```" newline() pieces:script_string_piece()* "```" {
 				String {
-					pieces: vec![StringPiece::Chars(chars)],
+					pieces,
 					kind: StringKind::ScriptString,
 				}
 			}
 
 		rule string_piece() -> StringPiece<'input>
-			= chars:$([^'"' | '\\']+) { StringPiece::Chars(chars) }
+			= chars:$((!"{{" [^'"' | '\\'])+) { StringPiece::Chars(chars) }
 			/ "\\" escape:string_escape() { StringPiece::Escape(escape) }
+			/ string_interp()
 
 		rule string_escape() -> char
 			= "n" { '\n' }
@@ -70,6 +71,18 @@ peg::parser! {
 				u32::from_str_radix(digits, 16).unwrap().try_into().or(Err("Invalid unicode escape"))
 			}
 
+		rule script_string_piece() -> StringPiece<'input>
+			= chars:$((!"{{" !"```" [_])+) { StringPiece::Chars(chars) }
+			/ string_interp()
+
+		rule string_interp() -> StringPiece<'input>
+			= "{{" tokens:subtoken()* "}}" {
+				StringPiece::Interp(TokenStream(tokens))
+			}
+
+		rule subtoken() -> Token<'input>
+			= !"}}" token:token() { token }
+
 		rule hex_digit()
 			= ['0'..='9' | 'a'..='f' | 'A'..='F']