46     function isKeywordES5(id, strict) {  argument
48         if (!strict && id === 'yield') {
51         return isKeywordES6(id, strict);
54     function isKeywordES6(id, strict) {  argument
55         if (strict && isStrictModeReservedWordES6(id)) {
85     function isReservedWordES5(id, strict) {  argument
86         return id === 'null' || id === 'true' || id === 'false' || isKeywordES5(id, strict);
89     function isReservedWordES6(id, strict) {  argument
90         return id === 'null' || id === 'true' || id === 'false' || isKeywordES6(id, strict);
145     function isIdentifierES5(id, strict) {  argument
146         return isIdentifierNameES5(id) && !isReservedWordES5(id, strict);
149     function isIdentifierES6(id, strict) {  argument
150         return isIdentifierNameES6(id) && !isReservedWordES6(id, strict);