Struct rslint_parser::Parser

pub struct Parser<'t> {
    pub file_id: usize,
    pub state: ParserState,
    // some fields omitted
}

An extremely fast, error tolerant, completely lossless JavaScript parser

The Parser yields lower level events instead of nodes. These events are then processed into a syntax tree through a TreeSink implementation.

use rslint_parser::{
    Parser,
    syntax::expr,
    tokenize,
    TokenSource,
    ast::GroupingExpr,
    LosslessTreeSink,
    SyntaxNode,
    process,
    AstNode
};

let source = "(delete b)";

// File id is used for the labels inside parser errors to report them, the file id
// is used to look up a file's source code and path inside of a codespan `Files` implementation.
let (tokens, lexer_errors) = tokenize(source, 0);

assert!(lexer_errors.is_empty());

// The parser uses a token source which manages yielding non-whitespace tokens,
// and giving raw tokens to allow the parser to turn completed markers into syntax nodes
let token_source = TokenSource::new(source, &tokens);

let mut parser = Parser::new(token_source, 0);

// Use one of the syntax parsing functions to parse an expression.
// This adds node and token events to the parser which are then used to make a node.
// A completed marker marks the start and end indices in the events vec which signify
// the Start event, and the Finish event.
// Completed markers can be turned into an ast node with parse_marker on the parser
let completed_marker = expr::expr(&mut parser).unwrap();

parser.parse_marker::<GroupingExpr>(&completed_marker);

// Make a new text tree sink, its job is assembling events into a rowan GreenNode.
// At each point (Start, Token, Finish, Error) it also consumes whitespace.
// Other abstractions can also yield lossy syntax nodes if whitespace is not wanted.
// Swap this for a LossyTreeSink for a lossy AST result.
let mut sink = LosslessTreeSink::new(source, &tokens);

// Consume the parser and get its events, then apply them to a tree sink with `process`.
process(&mut sink, parser.finish());

let (green, errors) = sink.finish();

assert!(errors.is_empty());

// Make a new SyntaxNode from the green node
let untyped_node = SyntaxNode::new_root(green);

assert!(GroupingExpr::can_cast(untyped_node.kind()));

// Convert the untyped SyntaxNode into a typed AST node
let typed_expr = GroupingExpr::cast(untyped_node).unwrap();

assert_eq!(typed_expr.inner().unwrap().syntax().text(), "delete b");

Fields

file_id: usize

state: ParserState

Implementations

impl<'t> Parser<'t>

pub fn new(tokens: TokenSource<'t>, file_id: usize) -> Parser<'t>

Make a new parser configured to parse a script

pub fn new_module(tokens: TokenSource<'t>, file_id: usize) -> Parser<'t>

Make a new parser configured to parse a module

pub fn token_src(&self, token: &Token) -> &str

Get the source code of a token

pub fn finish(self) -> Vec<Event>

Consume the parser and return the list of events it produced

pub fn cur(&self) -> SyntaxKind

Get the current token kind of the parser

pub fn cur_tok(&self) -> Token

Get the current token of the parser

pub fn nth(&self, n: usize) -> SyntaxKind

Look ahead at a token and get its kind, The max lookahead is 4.

Panics

This method panics if the lookahead is higher than 4, or if the parser has run this method more than 10m times, as it is a sign of infinite recursion

pub fn nth_tok(&self, n: usize) -> Token

Look ahead at a token, The max lookahead is 4.

Panics

This method panics if the lookahead is higher than 4, or if the parser has run this method more than 10m times, as it is a sign of infinite recursion

pub fn at(&self, kind: SyntaxKind) -> bool

Check if the parser is currently at a specific token

pub fn nth_at(&self, n: usize, kind: SyntaxKind) -> bool

Check if a token lookahead is something, n must be smaller or equal to 4

pub fn eat(&mut self, kind: SyntaxKind) -> bool

Consume the next token if kind matches.

pub fn err_recover(&mut self, error: impl Into<ParserError>, recovery: TokenSet)

Recover from an error with a recovery set or by using a { or }.

pub fn start(&mut self) -> Marker

Starts a new node in the syntax tree. All nodes and tokens consumed between the start and the corresponding Marker::complete belong to the same node.

pub fn has_linebreak_before_n(&self, n: usize) -> bool

Check if there was a linebreak before a lookahead

pub fn bump(&mut self, kind: SyntaxKind)

Consume the next token if kind matches.

pub fn bump_remap(&mut self, kind: SyntaxKind)

Consume any token but cast it as a different kind

pub fn bump_any(&mut self)

Advances the parser by one token

pub fn err_builder(&self, message: &str) -> ErrorBuilder

Make a new error builder with error severity

pub fn error(&mut self, err: impl Into<ParserError>)

Add an error event

pub fn at_ts(&self, kinds: TokenSet) -> bool

Check if the parser's current token is contained in a token set

pub fn cur_src(&self) -> &str

Get the source code of the parser's current token.

Panics

This method panics if the token range and source code range mismatch

pub fn expect(&mut self, kind: SyntaxKind) -> bool

Try to eat a specific token kind, if the kind is not there then add an error to the events stack.

pub fn marker_range(&self, marker: &CompletedMarker) -> Range<usize>

Get the byte index range of a completed marker for error reporting.

pub fn parse_marker<T: AstNode>(&self, marker: &CompletedMarker) -> T

Parse a completed marker into an ast node.

Panics

Panics if the AST node represented by the marker does not match the generic

pub fn source(&self, range: TextRange) -> &str

Get the source code of a range

pub fn rewind(&mut self, pos: usize)

Rewind the token position back to a former position

pub fn cur_event_pos(&self) -> usize

Get the current index of the last event

pub fn drain_events(&mut self, amount: usize)

Remove amount events from the parser

pub fn token_pos(&self) -> usize

Get the current token position

pub fn warning_builder(&self, message: &str) -> ErrorBuilder

Make a new error builder with warning severity

pub fn err_and_bump(&mut self, err: impl Into<ParserError>)

Bump and add an error event

impl<'t> Parser<'t>

pub fn with_state<'a>(&'a mut self, state: ParserState) -> StateGuard<'a, 't>