feat: format strings

examples/expressions.fs

@@ -1,4 +1,3 @@
 
-let f = A {
- x
- }
+let str =
+ $"int: {x + 1}"

grammar.js

@@ -1612,7 +1612,22 @@ module.exports = grammar({
  seq('\\', $._string_elem),
  ),
  char: $ => seq('\'', $._char_char, token.immediate('\'')),
- string: $ => seq('"', repeat($._string_char), '"'),
+
+ format_string_eval: $ =>
+ seq(token.immediate(prec(1000, '{')), $._expression, '}'),
+
+ format_string: $ =>
+ seq(
+ token(prec(100, '$"')),
+ repeat(choice($.format_string_eval, $._string_char)),
+ '"',
+ ),
+
+ string: $ =>
+ choice(
+ seq('"', repeat($._string_char), '"'),
+ $.format_string,
+ ),
  _verbatim_string_char: $ => choice(
  $._simple_string_char,
  $._non_escape_char,
@@ -1625,7 +1640,18 @@ module.exports = grammar({
 
  _triple_quoted_end: _ => token.immediate('"""'),
 
- triple_quoted_string: $ => seq('"""', repeat($._string_char), $._triple_quoted_end),
+ format_triple_quoted_string: $ =>
+ seq(
+ token(prec(100, '$"""')),
+ repeat(choice($.format_string_eval, $._string_char)),
+ '"""',
+ ),
+
+ triple_quoted_string: $ =>
+ choice(
+ seq('"""', repeat($._string_char), $._triple_quoted_end),
+ $.format_triple_quoted_string,
+ ),
 
  bool: _ => token(choice('true', 'false')),