feat: locale support for date filter, #567 (#723)

src/tokens/identifier-token.ts

@@ -1,5 +1,4 @@
 import { Token } from './token'
-import { NUMBER, TYPES, SIGN } from '../util'
 import { TokenKind } from '../parser'
 
 export class IdentifierToken extends Token {
@@ -13,13 +12,4 @@ export class IdentifierToken extends Token {
     super(TokenKind.Word, input, begin, end, file)
     this.content = this.getText()
   }
-  isNumber (allowSign = false) {
-    const begin = allowSign && TYPES[this.input.charCodeAt(this.begin)] & SIGN
-      ? this.begin + 1
-      : this.begin
-    for (let i = begin; i < this.end; i++) {
-      if (!(TYPES[this.input.charCodeAt(i)] & NUMBER)) return false
-    }
-    return true
-  }
 }