From ae312680d6d7bb0cc00d2b8d9799249d36e0136e Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Mon, 11 Feb 2019 21:31:54 +0300 Subject: docs --- crates/ra_mbe/src/syntax_bridge.rs | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'crates/ra_mbe/src') diff --git a/crates/ra_mbe/src/syntax_bridge.rs b/crates/ra_mbe/src/syntax_bridge.rs index 798f9d8fa..848c785f8 100644 --- a/crates/ra_mbe/src/syntax_bridge.rs +++ b/crates/ra_mbe/src/syntax_bridge.rs @@ -3,12 +3,15 @@ use ra_syntax::{ ast, SyntaxKind::*, TextUnit }; +/// Maps `tt::TokenId` to the relative range of the original token. #[derive(Default)] pub struct TokenMap { /// Maps `tt::TokenId` to the *relative* source range. toknes: Vec, } +/// Convert the syntax tree (what user has written) to a `TokenTree` (what macro +/// will consume). pub fn ast_to_token_tree(ast: &ast::TokenTree) -> Option<(tt::Subtree, TokenMap)> { let mut token_map = TokenMap::default(); let node = ast.syntax(); @@ -17,6 +20,11 @@ pub fn ast_to_token_tree(ast: &ast::TokenTree) -> Option<(tt::Subtree, TokenMap) } impl TokenMap { + pub fn relative_range_of(&self, tt: tt::TokenId) -> Option { + let idx = tt.0 as usize; + self.toknes.get(idx).map(|&it| it) + } + fn alloc(&mut self, relative_range: TextRange) -> tt::TokenId { let id = self.toknes.len(); self.toknes.push(relative_range); -- cgit v1.2.3