1 //! See `TextTokenSource` docs.
3 use parser::TokenSource;
5 use crate::{parsing::lexer::Token, SyntaxKind::EOF, TextRange, TextSize};
7 /// Implementation of `parser::TokenSource` that takes tokens from source code text.
8 pub(crate) struct TextTokenSource<'t> {
10 /// token and its start position (non-whitespace/comment tokens)
17 /// (struct, 0) (Foo, 7) (;, 10)
19 /// `[(struct, 0), (Foo, 7), (;, 10)]`
20 token_offset_pairs: Vec<(Token, TextSize)>,
22 /// Current token and position
23 curr: (parser::Token, usize),
26 impl<'t> TokenSource for TextTokenSource<'t> {
27 fn current(&self) -> parser::Token {
31 fn lookahead_nth(&self, n: usize) -> parser::Token {
32 mk_token(self.curr.1 + n, &self.token_offset_pairs)
36 if self.curr.0.kind == EOF {
40 let pos = self.curr.1 + 1;
41 self.curr = (mk_token(pos, &self.token_offset_pairs), pos);
44 fn is_keyword(&self, kw: &str) -> bool {
45 self.token_offset_pairs
47 .map_or(false, |(token, offset)| &self.text[TextRange::at(*offset, token.len)] == kw)
51 fn mk_token(pos: usize, token_offset_pairs: &[(Token, TextSize)]) -> parser::Token {
52 let (kind, is_jointed_to_next) = match token_offset_pairs.get(pos) {
53 Some((token, offset)) => (
57 .map_or(false, |(_, next_offset)| offset + token.len == *next_offset),
61 parser::Token { kind, is_jointed_to_next }
64 impl<'t> TextTokenSource<'t> {
65 /// Generate input from tokens(expect comment and whitespace).
66 pub(crate) fn new(text: &'t str, raw_tokens: &'t [Token]) -> TextTokenSource<'t> {
67 let token_offset_pairs: Vec<_> = raw_tokens
70 let mut len = 0.into();
72 let pair = if token.kind.is_trivia() { None } else { Some((*token, len)) };
79 let first = mk_token(0, &token_offset_pairs);
80 TextTokenSource { text, token_offset_pairs, curr: (first, 0) }