Convert backend code to ES modules

Bundling code now with Rollup for its flat bundling and tree shaking
support. Front end code still goes through Webpack for browser support.

lib/common/expression-cnf.js

@@ -1,6 +1,6 @@
 "use strict";
 
-const expressionParser = require("./expression-parser");
+import { map, parseLikePattern } from "./expression-parser";
 
 function or(cnf1, cnf2) {
   if (cnf1.length === 0) return cnf2;
@@ -19,10 +19,10 @@ function or(cnf1, cnf2) {
   return res;
 }
 
-function booleanCnf(exp) {
+export function booleanCnf(exp) {
   const ranges = new Map();
   const likePatterns = new Map();
-  expressionParser.map(exp, e => {
+  map(exp, e => {
     if (!Array.isArray(e)) return e;
     if (e[0] === "LIKE" || e[0] === "NOT LIKE") {
       if (
@@ -32,10 +32,7 @@ function booleanCnf(exp) {
         const key = JSON.stringify(e[1]);
         let s = likePatterns.get(key);
         if (!s) likePatterns.set(key, (s = new Map()));
-        s.set(
-          `${e[3] || ""}:${e[2]}`,
-          expressionParser.parseLikePattern(e[2], e[3])
-        );
+        s.set(`${e[3] || ""}:${e[2]}`, parseLikePattern(e[2], e[3]));
       }
     } else if ([">", ">=", "<", "<=", "=", "<>"].includes(e[0])) {
       if (!Array.isArray(e[2])) {
@@ -251,5 +248,3 @@ function likePatternIncludes(pat1, pat2, idx1 = 0, idx2 = 0) {
   if (idx1 === pat1.length && idx2 === pat2.length) return true;
   return false;
 }
-
-exports.booleanCnf = booleanCnf;