feat: ignore redundant space chars

fix: docs

Author: luo3house

README.md

@@ -2,6 +2,28 @@
 
 This is a simple engine for parsing and interpreting expressions and rules.
 
+## Install
+
+add dependency at `package.json`, then install
+
+~~~json
+"dependencies": {
+  "simple-expr-engine": "git+https://github.com/luo3house/simple-expr-engine"
+}
+~~~
+
+~~~bash
+npm install
+# or if use yarn
+yarn
+~~~
+
+### UMD
+
+Directly use UMD with global variable `simple_expr_engine`: 
+
+[https://github.com/luo3house/simple-expr-engine/tree/master/dist/umd/index.min.js](https://github.com/luo3house/simple-expr-engine/tree/master/dist/umd/index.min.js)
+
 ## Expression Grammar
 
 It is described as a JavaScript-like language. But not all features as JavaScript.
@@ -125,9 +147,10 @@ const sources = [
   "( exp < 160 ) => 10",
 ];
 try {
-  const level = Interpreter.interpretRules(
+  const result = Interpreter.interpretRules(
     Facade.buildRules(context, sources)
-  ); // 9
+  ); 
+  const level = result.valueHolder.asNumber() // 9
 } catch (e: NoRuleResultError) {
   // throw if no any rules matched
 }

__test__/interpret-rule.test.ts

@@ -11,6 +11,15 @@ test('all constant values', () => {
   expect(Interpreter.interpretRules(rules).valueHolder.asNumber()).toBe(2022);
 });
 
+test('empty expr', () => {
+  const context = {
+    variableStore: new VariableStore([]),
+  };
+  const source = ``;
+  const rules = Facade.buildRules(context, [source]);
+  expect(() => Interpreter.interpretRules(rules)).toThrow('no rule result');
+});
+
 test('as variable', () => {
   const context = {
     variableStore: new VariableStore([

__test__/tokenizer.test.ts

@@ -0,0 +1,6 @@
+import { Token } from '../src/compiler/tokenizer';
+
+test('should ignore redundant space chars', () => {
+  const tokens = Token.recognizeAll('    ( age < 18 )    '.split(' '));
+  expect(tokens.length).toBe(5);
+});

dist/cjs/index.js

@@ -570,6 +570,7 @@ var Token = /*#__PURE__*/function () {
       var tokens = [];
 
       for (var i = 0; i < characters.length; i++) {
+        if (!characters[i]) continue;
         tokens.push(Token.recognize(characters[i]));
       }
 
@@ -1209,6 +1210,7 @@ var Facade = /*#__PURE__*/function () {
     value: function buildRules(context, ruleSources) {
       var rules = [];
       ruleSources.forEach(function (ruleSource) {
+        if (!ruleSource) return;
         var characters = Token.escapeStringCharacters(ruleSource.split(''));
         rules.push(new RuleParser(context, Token.newReader(Token.recognizeAll(characters))).build());
       });

dist/esm/compiler/facade.js

@@ -16,6 +16,7 @@ export var Facade = /*#__PURE__*/function () {
     value: function buildRules(context, ruleSources) {
       var rules = [];
       ruleSources.forEach(function (ruleSource) {
+        if (!ruleSource) return;
         var characters = Token.escapeStringCharacters(ruleSource.split(''));
         rules.push(new RuleParser(context, Token.newReader(Token.recognizeAll(characters))).build());
       });

dist/esm/compiler/tokenizer.js

@@ -156,6 +156,7 @@ export var Token = /*#__PURE__*/function () {
       var tokens = [];
 
       for (var i = 0; i < characters.length; i++) {
+        if (!characters[i]) continue;
         tokens.push(Token.recognize(characters[i]));
       }
 

dist/umd/index.min.js

@@ -30,11 +30,10 @@
     "rimraf": "^3.0.2",
     "rollup": "^2.78.0",
     "rollup-plugin-bundle-size": "^1.0.3",
+    "rollup-plugin-terser": "^7.0.2",
     "ts-jest": "^28.0.5",
     "ts-node": "^10.8.2",
     "typescript": "^4.7.4"
   },
-  "dependencies": {
-    "rollup-plugin-terser": "^7.0.2"
-  }
+  "dependencies": {}
 }

package.json

@@ -6,6 +6,7 @@ export class Facade {
   static buildRules(context: Context, ruleSources: string[]): Rule[] {
     const rules: Rule[] = [];
     ruleSources.forEach((ruleSource) => {
+      if (!ruleSource) return;
       const characters = Token.escapeStringCharacters(ruleSource.split(''));
       rules.push(new RuleParser(context, Token.newReader(Token.recognizeAll(characters))).build());
     });

src/compiler/facade.ts

@@ -60,6 +60,7 @@ export class Token {
   public static recognizeAll(characters: string[]): Token[] {
     const tokens: Token[] = [];
     for (let i = 0; i < characters.length; i++) {
+      if (!characters[i]) continue;
       tokens.push(Token.recognize(characters[i]));
     }
     return tokens;