Struct Parser 

pub struct Parser { /* private fields */ }

A parser that transforms a token stream into a Song AST.

The parser is created from a Vec<Token> (typically produced by Lexer::tokenize) and consumes tokens one at a time, building up the AST line by line.

Implementations

impl Parser

pub fn new(tokens: Vec<Token>) -> Self

Creates a new parser for the given token stream.

Panics

Panics if tokens is empty. The lexer always appends an Eof token, so a well-formed token stream is never empty.

pub fn parse(self) -> Result<Song, ParseError>

Parses the token stream and returns a Song AST.

Metadata directives ({title}, {artist}, etc.) automatically populate Song::metadata. Comment directives are converted to Line::Comment with the appropriate CommentStyle.

Returns a ParseError on the first structural problem encountered (e.g., unclosed directives or chords). Use parse_lenient to collect all errors and obtain a partial AST.

pub fn parse_lenient(self) -> ParseResult

Parses the token stream leniently, collecting all errors.

Unlike parse, this method does not stop at the first error. When a line cannot be parsed, the error is recorded and the parser skips to the next line to continue. The returned ParseResult contains the partial AST (all successfully parsed lines) and a list of all errors encountered.

pub fn parse_lenient_limited(self, max_errors: usize) -> ParseResult

Like parse_lenient, but stops collecting errors after max_errors have been recorded. Set to 0 to disable the limit.

pub fn populate_metadata(metadata: &mut Metadata, directive: &Directive)

Populate metadata fields from a directive’s kind and value.

This is called during parsing for unselectored directives, and again by SelectorContext::filter_song after filtering to re-derive metadata from matching selector-bearing directives.