Do not eat token when expecting another token

Author: kraigher

vhdl_lang/src/syntax/subprogram.rs

@@ -407,14 +407,14 @@ function foo(foo : natural) return lib.foo.natural;
     pub fn parses_function_signature_many_return_error() {
         let code = Code::new("[return bar.type_mark return");
         assert_eq!(
-            code.with_stream_err(parse_signature),
-            Diagnostic::error(code.s("return", 2), "Expected ']'")
+            code.with_partial_stream(parse_signature),
+            Err(Diagnostic::error(code.s("return", 2), "Expected ']'"))
         );
 
         let code = Code::new("[foo return bar.type_mark return");
         assert_eq!(
-            code.with_stream_err(parse_signature),
-            Diagnostic::error(code.s("return", 2), "Expected ']'")
+            code.with_partial_stream(parse_signature),
+            Err(Diagnostic::error(code.s("return", 2), "Expected ']'"))
         );
     }
 

vhdl_lang/src/syntax/tokens/tokenstream.rs

@@ -50,8 +50,13 @@ impl<'a> TokenStream<'a> {
     }
 
     pub fn expect_kind(&mut self, kind: Kind) -> DiagnosticResult<Token> {
-        if let Some(token) = self.pop()? {
-            token.expect_kind(kind)
+        if let Some(token) = self.peek()? {
+            if token.kind == kind {
+                self.move_after(&token);
+                Ok(token)
+            } else {
+                Err(token.kinds_error_before(&[kind]))
+            }
         } else {
             Err(self
                 .tokenizer