Avoid intermediate String to get first char

ivoanjo · ivoanjo · commit 53949800b3a6 · 2020-09-23T12:17:50.000+01:00
diff --git a/src/main/java/org/truffleruby/parser/lexer/RubyLexer.java b/src/main/java/org/truffleruby/parser/lexer/RubyLexer.java
@@ -3497,7 +3497,7 @@ public void validateFormalIdentifier(Rope identifier) {
             compile_error("formal argument cannot be a constant");
         }
 
-        int first = identifier.getString().charAt(0);
+        int first = identifier.get(0) & 0xFF;
 
         switch (first) {
             case '@':

Original file line number	Diff line number	Diff line change
`@@ -3497,7 +3497,7 @@ public void validateFormalIdentifier(Rope identifier) {`
`3497`	`3497`	`compile_error("formal argument cannot be a constant");`
`3498`	`3498`	`}`
`3499`	`3499`
`3500`		`- int first = identifier.getString().charAt(0);`
	`3500`	`+ int first = identifier.get(0) & 0xFF;`
`3501`	`3501`
`3502`	`3502`	`switch (first) {`
`3503`	`3503`	`case '@':`