Trivial refactoring: avoid redundant method calls
diff --git a/src/antlr/GroovyLexer.g4 b/src/antlr/GroovyLexer.g4
index 4c3b76d..9f14346 100644
--- a/src/antlr/GroovyLexer.g4
+++ b/src/antlr/GroovyLexer.g4
@@ -219,6 +219,14 @@
 
         return Integer.MIN_VALUE;
     }
+
+    private static boolean isJavaIdentifierStartAndNotIdentifierIgnorable(int codePoint) {
+        return Character.isJavaIdentifierStart(codePoint) && !Character.isIdentifierIgnorable(codePoint);
+    }
+
+    private static boolean isJavaIdentifierPartAndNotIdentifierIgnorable(int codePoint) {
+        return Character.isJavaIdentifierPart(codePoint) && !Character.isIdentifierIgnorable(codePoint);
+    }
 }
 
 
@@ -891,7 +899,7 @@
     :   [a-zA-Z$_] // these are the "java letters" below 0x7F
     |   // covers all characters above 0x7F which are not a surrogate
         ~[\u0000-\u007F\uD800-\uDBFF]
-        { Character.isJavaIdentifierStart(_input.LA(-1)) && !Character.isIdentifierIgnorable(_input.LA(-1)) }?
+        { isJavaIdentifierStartAndNotIdentifierIgnorable(_input.LA(-1)) }?
     |   // covers UTF-16 surrogate pairs encodings for U+10000 to U+10FFFF
         [\uD800-\uDBFF] [\uDC00-\uDFFF]
         { Character.isJavaIdentifierStart(Character.toCodePoint((char) _input.LA(-2), (char) _input.LA(-1))) }?
@@ -907,7 +915,7 @@
     :   [a-zA-Z0-9$_] // these are the "java letters or digits" below 0x7F
     |   // covers all characters above 0x7F which are not a surrogate
         ~[\u0000-\u007F\uD800-\uDBFF]
-        { Character.isJavaIdentifierPart(_input.LA(-1)) && !Character.isIdentifierIgnorable(_input.LA(-1)) }?
+        { isJavaIdentifierPartAndNotIdentifierIgnorable(_input.LA(-1)) }?
     |   // covers UTF-16 surrogate pairs encodings for U+10000 to U+10FFFF
         [\uD800-\uDBFF] [\uDC00-\uDFFF]
         { Character.isJavaIdentifierPart(Character.toCodePoint((char) _input.LA(-2), (char) _input.LA(-1))) }?