Refactor: Replace Nearley with Chevrotain parser workflow

transpiler.js

@@ -1,5 +1,4 @@
-import nearley from 'nearley';
-import grammar from './grammar.js';
+import { HiLexer, parser, astBuilder } from './parser.js';
 
 /**
  * Generates JavaScript code from a Hi AST.
@@ -7,7 +6,7 @@ import grammar from './grammar.js';
  * @returns {string} The equivalent JavaScript code.
  */
 function generate(ast) {
-    if (!ast) return ''; // Handle potential nulls from grammar
+    if (!ast) return '';
     
     const generator = {
         Program: (node) => node.body.map(generate).join('\n'),
@@ -51,32 +50,26 @@ function generate(ast) {
  * @returns {string} The equivalent JavaScript code.
  */
 export function hi2js(sourceCode) {
-    // 1. Create a nearley parser instance from our compiled grammar
-    const parser = new nearley.Parser(nearley.Grammar.fromCompiled(grammar));
-
-    try {
-        // 2. Feed the source code to the parser
-        parser.feed(sourceCode);
-
-        // 3. Check for ambiguity and get the AST
-        if (parser.results.length > 1) {
-            console.warn("Master, the grammar is ambiguous. Using the first parse tree.");
-        }
-        if (parser.results.length === 0) {
-            // Throw an error only if the input was not empty.
-            if (sourceCode.trim().length > 0) {
-              throw new Error("Unexpected end of input. The code is incomplete.");
-            }
-            return ""; // Return empty string for empty input.
-        }
-        const ast = parser.results[0];
-
-        // 4. Generate JavaScript from the AST
-        return generate(ast);
-
-    } catch (err) {
-        // Provide a more helpful error message
-        const message = err.message.replace(/ Instead, I found a "[^"]+" token here:/, ".");
-        throw new Error(`Parsing error: ${message}`);
+    if (!sourceCode.trim()) {
+        return "";
     }
+    // 1. Lexing
+    const lexResult = HiLexer.tokenize(sourceCode);
+    if (lexResult.errors.length > 0) {
+        throw new Error(`Lexing error: ${lexResult.errors[0].message}`);
+    }
+
+    // 2. Parsing
+    parser.input = lexResult.tokens;
+    const cst = parser.program();
+    if (parser.errors.length > 0) {
+        const err = parser.errors[0];
+        throw new Error(`Parsing error: ${err.message}`);
+    }
+
+    // 3. Building AST from CST
+    const ast = astBuilder.visit(cst);
+
+    // 4. Generating JavaScript from AST
+    return generate(ast);
 }