diff --git a/crates/syntax/src/lib.rs b/crates/syntax/src/lib.rs index b8a8103cc6..58f59c384b 100644 --- a/crates/syntax/src/lib.rs +++ b/crates/syntax/src/lib.rs @@ -175,6 +175,29 @@ impl Parse { } } +impl ast::Expr { + /// Parses an `ast::Expr` from `text`. + /// + /// Note that if the parsed root node is not a valid expression, [`Parse::tree`] will panic. + /// For example: + /// ```rust,should_panic + /// # use syntax::{ast, Edition}; + /// ast::Expr::parse("let fail = true;", Edition::CURRENT).tree(); + /// ``` + pub fn parse(text: &str, edition: Edition) -> Parse { + let _p = tracing::span!(tracing::Level::INFO, "Expr::parse").entered(); + let (green, errors) = parsing::parse_text_at(text, parser::TopEntryPoint::Expr, edition); + let root = SyntaxNode::new_root(green.clone()); + + assert!( + ast::Expr::can_cast(root.kind()) || root.kind() == SyntaxKind::ERROR, + "{:?} isn't an expression", + root.kind() + ); + Parse::new(green, errors) + } +} + /// `SourceFile` represents a parse tree for a single Rust file. pub use crate::ast::SourceFile; diff --git a/crates/syntax/src/parsing.rs b/crates/syntax/src/parsing.rs index 420f4938e5..165109029f 100644 --- a/crates/syntax/src/parsing.rs +++ b/crates/syntax/src/parsing.rs @@ -18,6 +18,15 @@ pub(crate) fn parse_text(text: &str, edition: parser::Edition) -> (GreenNode, Ve (node, errors) } +pub(crate) fn parse_text_at(text: &str, entry: parser::TopEntryPoint, edition: parser::Edition) -> (GreenNode, Vec) { + let _p = tracing::span!(tracing::Level::INFO, "parse_text_at").entered(); + let lexed = parser::LexedStr::new(text); + let parser_input = lexed.to_input(); + let parser_output = entry.parse(&parser_input, edition); + let (node, errors, _eof) = build_tree(lexed, parser_output); + (node, errors) +} + pub(crate) fn build_tree( lexed: parser::LexedStr<'_>, parser_output: parser::Output,