wgsl-parse 0.4.1

Parse a wgsl source file to a syntax tree
Documentation 
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use std::str::FromStr;

use crate::{
    error::Error,
    lexer::{Lexer, Token, TokenIterator},
    syntax::*,
};

use lalrpop_util::lalrpop_mod;

lalrpop_mod!(
    #[allow(clippy::all, reason = "generated code")]
    wgsl
);
lalrpop_mod!(
    #[allow(clippy::all, reason = "generated code")]
    wgsl_recognize
);

pub use crate::parser_support::ParseEntryPoint;
use wgsl::EntryPointParser;

macro_rules! parse {
    ($source:expr, $token:ident, $entrypoint:ident) => {{
        match parse_tokens(Lexer::new($source), Token::$token) {
            Ok(ParseEntryPoint::$entrypoint(res)) => Ok(res),
            Ok(_) => unreachable!("parser parsed the wrong entrypoint"),
            Err(e) => Err(e),
        }
    }};
}

/// Parse a token stream into a syntax tree.
///
/// Low-level implementation, you probably don't want to use this. See [`parse_str`].
///
/// The `entrypoint` parameter must be one of the `EntryPointXXX` tokens, which tells the
/// parser which syntax node to expect. It returns the [`ParseEntryPoint`] union type.
pub fn parse_tokens(
    lexer: impl TokenIterator,
    entrypoint: Token,
) -> Result<ParseEntryPoint, Error> {
    let lexer = std::iter::once(Ok((0, entrypoint, 0))).chain(lexer);
    let parser = EntryPointParser::new();
    parser.parse(lexer).map_err(Into::into)
}

/// Parse a string into a syntax tree ([`TranslationUnit`]).
///
/// Identical to [`TranslationUnit::from_str`].
pub fn parse_str(source: &str) -> Result<TranslationUnit, Error> {
    parse!(source, EntryPointTranslationUnit, TranslationUnit)
}

/// Test whether a string represent a valid WGSL module ([`TranslationUnit`]).
///
/// Warning: it does not take WESL extensions into account.
pub fn recognize_str(source: &str) -> Result<(), Error> {
    let lexer = Lexer::new(source);
    let parser = wgsl_recognize::TranslationUnitParser::new();
    parser.parse(lexer).map_err(Into::into)
}

pub fn recognize_template_list(lexer: impl TokenIterator) -> Result<(), Error> {
    match parse_tokens(lexer, Token::EntryPointTryTemplateList) {
        Ok(ParseEntryPoint::TryTemplateList(_)) => Ok(()),
        Ok(_) => unreachable!("parser parsed the wrong entrypoint"),
        Err(e) => Err(e),
    }
}

impl FromStr for TranslationUnit {
    type Err = Error;

    fn from_str(source: &str) -> Result<Self, Self::Err> {
        parse!(source, EntryPointTranslationUnit, TranslationUnit)
    }
}
impl FromStr for GlobalDirective {
    type Err = Error;

    fn from_str(source: &str) -> Result<Self, Self::Err> {
        parse!(source, EntryPointGlobalDirective, GlobalDirective)
    }
}
impl FromStr for GlobalDeclaration {
    type Err = Error;

    fn from_str(source: &str) -> Result<Self, Self::Err> {
        parse!(source, EntryPointGlobalDecl, GlobalDecl)
    }
}
impl FromStr for Statement {
    type Err = Error;

    fn from_str(source: &str) -> Result<Self, Self::Err> {
        parse!(source, EntryPointStatement, Statement)
    }
}
impl FromStr for Expression {
    type Err = Error;

    fn from_str(source: &str) -> Result<Self, Self::Err> {
        parse!(source, EntryPointExpression, Expression)
    }
}
impl FromStr for LiteralExpression {
    type Err = Error;

    fn from_str(source: &str) -> Result<Self, Self::Err> {
        parse!(source, EntryPointLiteral, Literal)
    }
}
#[cfg(feature = "imports")]
impl FromStr for crate::syntax::ImportStatement {
    type Err = Error;

    fn from_str(source: &str) -> Result<Self, Self::Err> {
        parse!(source, EntryPointImportStatement, ImportStatement)
    }
}