Start a lax parser

Author: kasbah

js/lib/lax_parser.js

@@ -0,0 +1,33 @@
+const {ElectroGrammarLexer} = require('./ElectroGrammarLexer');
+const {ElectroGrammarParser} = require('./ElectroGrammarParser');
+const {ElectroGrammarListener} = require('./ElectroGrammarListener');
+const antlr4 = require('antlr4');
+
+class ElectroGrammarToObjectListener extends ElectroGrammarListener {
+  constructor() {
+    super();
+    this.obj = {};
+  }
+  enterCapacitance(ctx) {
+    const cprefix_lookup = {u: 'e-6', n: 'e-9', p: 'e-12'};
+    const number = ctx.NUMBER().getText();
+    const cprefix = cprefix_lookup[ctx.CPREFIX().getText()];
+    this.obj.capacitance = Number(number + cprefix);
+    this.obj.type = 'capacitor';
+  }
+}
+
+function parse(input) {
+  const chars = new antlr4.InputStream(input);
+  const lexer = new ElectroGrammarLexer(chars);
+  const tokens = new antlr4.CommonTokenStream(lexer);
+  const parser = new ElectroGrammarParser(tokens);
+  parser.buildParseTrees = true;
+
+  const tree = parser.electro_grammar();
+  const listener = new ElectroGrammarToObjectListener();
+  const walker = antlr4.tree.ParseTreeWalker.DEFAULT.walk(listener, tree);
+  return listener.obj
+}
+
+module.exports = {parse};

js/test/test_equals.js

@@ -2,7 +2,7 @@
 const assert = require('better-assert')
 
 const equals = require('../lib/equals')
-const parse = require('../lib/parse')
+const parse = require('../lib/lax_parser')
 
 describe('equality check', () => {
     it('does not equal components of different types', () => {

js/test/test_parse.js renamed to js/test/test_lax_parser.js

@@ -1,6 +1,6 @@
-/*const assert = require('better-assert');
+const assert = require('better-assert');
 
-const {parse} = require('../lib/index');
+const {parse} = require('../lib/lax_parser')
 
 describe('parsing', () => {
     it("doesn't parse nonsense", () => {
@@ -267,6 +267,7 @@ describe('SMD Capacitors', () => {
     })
 })
 
+/*
 describe('SMD Resistors', () => {
     it('parses a resistor', () => {
         const c = parse('1k 0603').component