parse interpolated strings

src/main.rs

@@ -58,7 +58,7 @@ use crate::base::*;
 
 pub fn main() {
     let src = "
-\"{}   {foobar}\"
+\"thing\"
     ";
     let (tokens, lex_errs) = lexer().parse(src).into_output_errors();
     if !lex_errs.is_empty() {

src/parser.rs

@@ -397,7 +397,7 @@ fn parse_string(s: &str, span: SimpleSpan) -> Result<Vec<Spanned<StringPart>>, S
     parts.push((
         if is_word {
             StringPart::Word(current_part)
-        } else if current_part == s.to_string() {
+        } else if current_part == s {
             StringPart::Inline(current_part)
         } else {
             StringPart::Data(current_part)