1 files changed, 52 insertions, 0 deletions
diff --git a/js/baba-yaga/runner.js b/js/baba-yaga/runner.js
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+++ b/js/baba-yaga/runner.js
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+// runner.js
+// Provides a host-agnostic evaluate(source, host) entrypoint that lexes, parses, and interprets.
+
+import { createLexer } from './src/core/lexer.js';
+import { createParser } from './src/core/parser.js';
+import { createInterpreter } from './src/core/interpreter.js';
+
+/**
+ * Evaluate source code in the toy language and return a result object.
+ * @param {string} source - The program source code.
+ * @param {object} host - Optional host bindings, e.g. { io: { out, in } }.
+ * @returns {object} Result object with { ok: boolean, value?: any, error?: string }
+ */
+export function evaluate(source, host = {}) {
+  try {
+    const lexer = createLexer(source);
+    const tokens = lexer.allTokens();
+    const parser = createParser(tokens, false, source);
+    const ast = parser.parse();
+    const interpreter = createInterpreter(ast, host);
+    const result = interpreter.interpret();
+    return { ok: true, value: result };
+  } catch (error) {
+    return { ok: false, error: error.message };
+  }
+}
+
+/**
+ * Create a code frame showing the error location in source code
+ * @param {string} source - The source code
+ * @param {object} location - Location object with line/column
+ * @param {string} message - Error message
+ * @returns {string} Formatted code frame
+ */
+export function makeCodeFrame(source, location, message) {
+  if (!location || !location.line) {
+    return message;
+  }
+
+  const lines = source.split('\n');
+  const lineIndex = location.line - 1;
+  const line = lines[lineIndex];
+  
+  if (!line) {
+    return message;
+  }
+
+  const column = location.column || 1;
+  const pointer = ' '.repeat(Math.max(0, column - 1)) + '^';
+  
+  return `${message}\n  ${location.line} | ${line}\n     | ${pointer}`;
+}