dkanus
588790b9b4
Huge dump of refactored code. Still in the middle of the changes that are to be squashed later in a one huge monster commit, because there is no value in anything atomic here.
64 lines
2.3 KiB
Rust
64 lines
2.3 KiB
Rust
//! Parser for Fermented `UnrealScript` (`FerUS`).
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//!
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//! Consumes tokens from [`crate::lexer::TokenizedFile`] and allocates AST
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//! nodes in [`crate::arena::Arena`]. Basic expressions use a Pratt parser;
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//! the rest rely on recursive descent in [`crate::parser::grammar`].\
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//! Non-fatal errors accumulate in `Parser::diagnostics` as
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//! [`crate::diagnostics::Diagnostic`]; recovery skips to sync points defined by
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//! [`crate::parser::recovery::SyncLevel`] and synthesizes error nodes while
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//! keeping the parse going.
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//!
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//! Components:
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//! - `cursor`: token I/O, `peek`/`advance`, and lazy trivia capture;
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//! - `trivia`: trailing comments and newline counts keyed to
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//! the previous significant token and BOF;
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//! - `recovery`: panic-mode skipping and recovery adapters for results;
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//! - `pretty`: printable trees (`ExprTree`, `StmtTree`) for messages and dumps;
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//! - `errors`: [`ParseError`] and [`ParseErrorKind`].
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//!
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//! Lifetimes: `'src` ties to lexer slices; `'arena` ties to AST allocation.
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//!
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//! Guarantees:
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//!
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//! - Parser does not abort on user input. It emits diagnostics and error nodes.
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//! - Trivia is recorded as you scan and can be queried by formatters/linters.
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//! - Public surface keeps [`Parser`] small;
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//! low-level plumbing lives in submodules.
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use super::lexer;
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pub use lexer::{TokenData, Tokens};
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mod cursor;
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mod errors;
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mod grammar;
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mod recovery;
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mod trivia;
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pub use errors::ParseError;
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pub(crate) use errors::{ParseErrorKind, ParseResult};
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pub(crate) use recovery::{ResultRecoveryExt, SyncLevel};
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pub(crate) use trivia::{TriviaKind, TriviaToken};
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pub type ParseExpressionResult<'src, 'arena> =
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ParseResult<'src, 'arena, crate::ast::ExpressionRef<'src, 'arena>>;
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/// A recursive-descent parser over token from [`crate::lexer::TokenizedFile`].
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pub struct Parser<'src, 'arena> {
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arena: &'arena crate::arena::Arena,
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pub diagnostics: Vec<crate::diagnostics::Diagnostic>,
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cursor: cursor::Cursor<'src, 'src>,
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trivia: trivia::TriviaIndexBuilder<'src>,
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}
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impl<'src, 'arena> Parser<'src, 'arena> {
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pub fn new(file: &'src lexer::TokenizedFile<'src>, arena: &'arena crate::arena::Arena) -> Self {
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Self {
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arena,
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diagnostics: Vec::new(),
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cursor: cursor::Cursor::new(file),
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trivia: trivia::TriviaIndexBuilder::default(),
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}
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}
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}
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