Add classify_literal and undo expose next_token

crates/ra_syntax/src/lib.rs

@@ -40,7 +40,7 @@ pub use crate::{
     syntax_text::SyntaxText,
     syntax_node::{Direction,  SyntaxNode, WalkEvent, TreeArc, SyntaxTreeBuilder, SyntaxElement, SyntaxToken},
     ptr::{SyntaxNodePtr, AstPtr},
-    parsing::{tokenize, next_token, Token},
+    parsing::{tokenize, classify_literal, Token},
 };
 
 use ra_text_edit::AtomTextEdit;

crates/ra_syntax/src/parsing.rs

@@ -11,7 +11,7 @@ use crate::{
     syntax_node::GreenNode,
 };
 
-pub use self::lexer::{tokenize, next_token, Token};
+pub use self::lexer::{tokenize, classify_literal, Token};
 
 pub(crate) use self::reparsing::incremental_reparse;
 

crates/ra_syntax/src/parsing/lexer.rs

@@ -214,3 +214,12 @@ fn scan_literal_suffix(ptr: &mut Ptr) {
     }
     ptr.bump_while(is_ident_continue);
 }
+
+pub fn classify_literal(text: &str) -> Option<Token> {
+    let tkn = next_token(text);
+    if tkn.kind.is_literal() || tkn.len.to_usize() != text.len() {
+        return None;
+    }
+
+    Some(tkn)
+}