//! FIXME: write short doc here use ra_parser::Token as PToken; use ra_parser::TokenSource; use crate::{parsing::lexer::Token, SyntaxKind::EOF, TextRange, TextUnit}; pub(crate) struct TextTokenSource<'t> { text: &'t str, /// start position of each token(expect whitespace and comment) /// ```non-rust /// struct Foo; /// ^------^--- /// | | ^- /// 0 7 10 /// ``` /// (token, start_offset): `[(struct, 0), (Foo, 7), (;, 10)]` start_offsets: Vec<TextUnit>, /// non-whitespace/comment tokens /// ```non-rust /// struct Foo {} /// ^^^^^^ ^^^ ^^ /// ``` /// tokens: `[struct, Foo, {, }]` tokens: Vec<Token>, /// Current token and position curr: (PToken, usize), } impl<'t> TokenSource for TextTokenSource<'t> { fn current(&self) -> PToken { self.curr.0 } fn lookahead_nth(&self, n: usize) -> PToken { mk_token(self.curr.1 + n, &self.start_offsets, &self.tokens) } fn bump(&mut self) { if self.curr.0.kind == EOF { return; } let pos = self.curr.1 + 1; self.curr = (mk_token(pos, &self.start_offsets, &self.tokens), pos); } fn is_keyword(&self, kw: &str) -> bool { let pos = self.curr.1; if pos >= self.tokens.len() { return false; } let range = TextRange::offset_len(self.start_offsets[pos], self.tokens[pos].len); self.text[range] == *kw } } fn mk_token(pos: usize, start_offsets: &[TextUnit], tokens: &[Token]) -> PToken { let kind = tokens.get(pos).map(|t| t.kind).unwrap_or(EOF); let is_jointed_to_next = if pos + 1 < start_offsets.len() { start_offsets[pos] + tokens[pos].len == start_offsets[pos + 1] } else { false }; PToken { kind, is_jointed_to_next } } impl<'t> TextTokenSource<'t> { /// Generate input from tokens(expect comment and whitespace). pub fn new(text: &'t str, raw_tokens: &'t [Token]) -> TextTokenSource<'t> { let mut tokens = Vec::new(); let mut start_offsets = Vec::new(); let mut len = 0.into(); for &token in raw_tokens.iter() { if !token.kind.is_trivia() { tokens.push(token); start_offsets.push(len); } len += token.len; } let first = mk_token(0, &start_offsets, &tokens); TextTokenSource { text, start_offsets, tokens, curr: (first, 0) } } }