feat: upgrade antlr4 to 4.12.0 (#88)

src/lib/spark/base/SparkSqlBaseLexer.ts

@@ -0,0 +1,25 @@
+import { Lexer } from "antlr4";
+
+export default class SparkSqlBaseLexer extends Lexer {
+
+    isValidDecimal() {
+        let nextChar = this.fromCodePoint(this._input.LA(1));
+        return !(nextChar >= 'A' && nextChar <= 'Z' || nextChar >= '0' && nextChar <= '9' || nextChar == '_')
+    }
+
+    /**
+    * This method will be called when we see '/*' and try to match it as a bracketed comment.
+    * If the next character is '+', it should be parsed as hint later, and we cannot match
+    * it as a bracketed comment.
+    *
+    * Returns true if the next character is '+'.
+    */
+    isHint() {
+        let nextChar = this.fromCodePoint(this._input.LA(1));
+        return nextChar == '+'
+    }
+
+    fromCodePoint(codePoint) {
+        return String.fromCodePoint(codePoint);
+    }
+}