cairo_lang_parser/

utils.rs

use std::path::PathBuf;

use cairo_lang_diagnostics::{Diagnostics, DiagnosticsBuilder};
use cairo_lang_filesystem::db::init_files_group;
use cairo_lang_filesystem::ids::{FileId, FileKind, FileLongId, SmolStrId, VirtualFile};
use cairo_lang_filesystem::span::{TextOffset, TextWidth};
use cairo_lang_primitive_token::{PrimitiveToken, ToPrimitiveTokenStream};
use cairo_lang_syntax::node::ast::SyntaxFile;
use cairo_lang_syntax::node::{SyntaxNode, TypedSyntaxNode};
use cairo_lang_utils::Intern;
use itertools::chain;

use crate::ParserDiagnostic;
use crate::db::ParserGroup;
use crate::parser::Parser;

/// A salsa database for parsing only.
#[salsa::db]
#[derive(Clone)]
pub struct SimpleParserDatabase {
    storage: salsa::Storage<SimpleParserDatabase>,
}
#[salsa::db]
impl salsa::Database for SimpleParserDatabase {}
impl Default for SimpleParserDatabase {
    fn default() -> Self {
        let mut res = Self { storage: Default::default() };
        init_files_group(&mut res);
        res
    }
}

impl SimpleParserDatabase {
    /// Parses a new file and returns its syntax root.
    ///
    /// This is similar to [Self::parse_virtual_with_diagnostics], but it is more ergonomic in cases
    /// when exact diagnostics do not matter at the usage place. If the parser has emitted error
    /// diagnostics, this function will return an error. If no error diagnostics have been
    /// emitted, the syntax root will be returned.
    pub fn parse_virtual(
        &self,
        content: impl ToString,
    ) -> Result<SyntaxNode<'_>, Diagnostics<'_, ParserDiagnostic<'_>>> {
        let (node, diagnostics) = self.parse_virtual_with_diagnostics(content);
        if diagnostics.check_error_free().is_ok() { Ok(node) } else { Err(diagnostics) }
    }

    /// Parses a new file and returns its syntax root with diagnostics.
    ///
    /// This function creates a new virtual file with the given content and parses it.
    /// Diagnostics gathered by the parser are returned alongside the result.
    pub fn parse_virtual_with_diagnostics(
        &self,
        content: impl ToString,
    ) -> (SyntaxNode<'_>, Diagnostics<'_, ParserDiagnostic<'_>>) {
        let file = FileLongId::Virtual(VirtualFile {
            parent: None,
            name: SmolStrId::from(self, "parser_input"),
            content: SmolStrId::from(self, content.to_string()),
            code_mappings: [].into(),
            kind: FileKind::Module,
            original_item_removed: false,
        })
        .intern(self);
        get_syntax_root_and_diagnostics(self, file)
    }

    /// Parses a token stream (based on whole file) and returns its syntax root.
    /// It's very similar to [Self::parse_virtual_with_diagnostics], but instead of taking a content
    /// as a string, it takes a type that implements [ToPrimitiveTokenStream] trait.
    pub fn parse_token_stream(
        &self,
        token_stream: &dyn ToPrimitiveTokenStream<Iter = impl Iterator<Item = PrimitiveToken>>,
    ) -> (SyntaxNode<'_>, Diagnostics<'_, ParserDiagnostic<'_>>) {
        let (content, offset) = primitive_token_stream_content_and_offset(token_stream);
        assert_eq!(
            offset.unwrap_or_default(),
            TextOffset::default(),
            "The content defines a file, and should not have an offset"
        );
        let file_id = FileLongId::Virtual(VirtualFile {
            parent: Default::default(),
            name: SmolStrId::from(self, "token_stream_file_parser_input"),
            content: SmolStrId::from(self, content),
            code_mappings: Default::default(),
            kind: FileKind::Module,
            original_item_removed: false,
        })
        .intern(self);
        let mut diagnostics = DiagnosticsBuilder::default();
        let syntax = Parser::parse_token_stream(self, &mut diagnostics, file_id, token_stream);
        (syntax.as_syntax_node(), diagnostics.build())
    }

    /// Parses a token stream (based on a single expression).
    /// It's very similar to the [Self::parse_token_stream].
    pub fn parse_token_stream_expr(
        &self,
        token_stream: &dyn ToPrimitiveTokenStream<Iter = impl Iterator<Item = PrimitiveToken>>,
    ) -> (SyntaxNode<'_>, Diagnostics<'_, ParserDiagnostic<'_>>) {
        let (content, offset) = primitive_token_stream_content_and_offset(token_stream);
        assert_eq!(
            offset.unwrap_or_default(),
            TextOffset::default(),
            "The content defines a file, and should not have an offset"
        );
        let vfs = VirtualFile {
            parent: Default::default(),
            name: SmolStrId::from(self, "token_stream_expr_parser_input"),
            content: SmolStrId::from(self, content),
            code_mappings: Default::default(),
            kind: FileKind::Module,
            original_item_removed: false,
        };
        let file_id = FileLongId::Virtual(vfs).intern(self);
        let mut diagnostics = DiagnosticsBuilder::default();
        let syntax = Parser::parse_token_stream_expr(self, &mut diagnostics, file_id, offset);
        (syntax.as_syntax_node(), diagnostics.build())
    }
}

/// Reads a Cairo file to the DB and returns the `syntax_root` and diagnostics of its parsing.
pub fn get_syntax_root_and_diagnostics_from_file(
    db: &SimpleParserDatabase,
    cairo_filepath: PathBuf,
) -> (SyntaxNode<'_>, Diagnostics<'_, ParserDiagnostic<'_>>) {
    let file_id = FileId::new_on_disk(db, cairo_filepath);
    get_syntax_root_and_diagnostics(db, file_id)
}

/// Returns the `syntax_root` and diagnostics of a file in the DB.
pub fn get_syntax_root_and_diagnostics<'a>(
    db: &'a SimpleParserDatabase,
    file_id: FileId<'a>,
) -> (SyntaxNode<'a>, Diagnostics<'a, ParserDiagnostic<'a>>) {
    let (syntax_file, diagnostics) = get_syntax_file_and_diagnostics(db, file_id);
    (syntax_file.as_syntax_node(), diagnostics)
}

/// Returns the `syntax_file` and diagnostics of a file in the DB.
pub fn get_syntax_file_and_diagnostics<'a>(
    db: &'a SimpleParserDatabase,
    file_id: FileId<'a>,
) -> (SyntaxFile<'a>, Diagnostics<'a, ParserDiagnostic<'a>>) {
    let diagnostics = db.file_syntax_diagnostics(file_id).clone();
    let syntax_file = db.file_module_syntax(file_id).unwrap();
    (syntax_file, diagnostics)
}

/// Collects the content string and start offset from a struct implementing
/// `ToPrimitiveTokenStream`. This concatenates all supplied tokens.
pub(crate) fn primitive_token_stream_content_and_offset(
    token_stream: &dyn ToPrimitiveTokenStream<Iter = impl Iterator<Item = PrimitiveToken>>,
) -> (String, Option<TextOffset>) {
    let mut primitive_stream = token_stream.to_primitive_token_stream();
    let Some(first) = primitive_stream.next() else {
        return ("".into(), None);
    };
    let start_offset = first
        .span
        .as_ref()
        .map(|s| TextOffset::default().add_width(TextWidth::new_for_testing(s.start as u32)));
    (chain!([first], primitive_stream).map(|t| t.content).collect(), start_offset)
}