rust/src/parser/mod.rs
2018-01-27 21:52:22 -05:00

94 lines
2.8 KiB
Rust

use {File, FileBuilder, Sink, SyntaxKind, Token};
use syntax_kinds::*;
mod event_parser;
use self::event_parser::Event;
/// Parse a sequence of tokens into the representative node tree
pub fn parse(text: String, tokens: &[Token]) -> File {
let events = event_parser::parse(&text, tokens);
from_events_to_file(text, tokens, events)
}
fn from_events_to_file(text: String, tokens: &[Token], events: Vec<Event>) -> File {
let mut builder = FileBuilder::new(text);
let mut idx = 0;
let mut holes = Vec::new();
let mut forward_parents = Vec::new();
for (i, event) in events.iter().enumerate() {
if holes.last() == Some(&i) {
holes.pop();
continue;
}
match event {
&Event::Start {
kind: TOMBSTONE, ..
} => (),
&Event::Start { .. } => {
forward_parents.clear();
let mut idx = i;
loop {
let (kind, fwd) = match events[idx] {
Event::Start {
kind,
forward_parent,
} => (kind, forward_parent),
_ => unreachable!(),
};
forward_parents.push((idx, kind));
if let Some(fwd) = fwd {
idx += fwd as usize;
} else {
break;
}
}
for &(idx, kind) in forward_parents.iter().into_iter().rev() {
builder.start_internal(kind);
holes.push(idx);
}
holes.pop();
}
&Event::Finish => {
while idx < tokens.len() {
let token = tokens[idx];
if is_insignificant(token.kind) {
idx += 1;
builder.leaf(token.kind, token.len);
} else {
break;
}
}
builder.finish_internal()
}
&Event::Token {
kind: _,
mut n_raw_tokens,
} => loop {
let token = tokens[idx];
if !is_insignificant(token.kind) {
n_raw_tokens -= 1;
}
idx += 1;
builder.leaf(token.kind, token.len);
if n_raw_tokens == 0 {
break;
}
},
&Event::Error { ref message } => builder.error().message(message.clone()).emit(),
}
}
builder.finish()
}
fn is_insignificant(kind: SyntaxKind) -> bool {
match kind {
WHITESPACE | COMMENT => true,
_ => false,
}
}