Add unannotated file

README.md

@@ -10,6 +10,8 @@ work from end to end.
 
 ### [Want to jump into the code? Click here](super-tiny-compiler.js)
 
+[(Or if you would prefer to read it without annotations, click here.)](super-tiny-compiler-unannotated.js)
+
 ---
 
 ### Why should I care?

super-tiny-compiler-unannotated.js

@@ -0,0 +1,252 @@
+function tokenizer(input) {
+  var current = 0;
+  var tokens = [];
+
+  while (current < input.length) {
+    var char = input[current];
+
+    if (char === '(') {
+      tokens.push({
+        type: 'paren',
+        value: '('
+      });
+      current++;
+      continue;
+    }
+
+    if (char === ')') {
+      tokens.push({
+        type: 'paren',
+        value: ')'
+      });
+      current++;
+      continue;
+    }
+
+    var WHITESPACE = /\s/;
+    if (WHITESPACE.test(char)) {
+      current++;
+      continue;
+    }
+
+    var NUMBERS = /[0-9]/;
+    if (NUMBERS.test(char)) {
+      var value = '';
+
+      while (NUMBERS.test(char)) {
+        value += char;
+        char = input[++current];
+      }
+
+      tokens.push({
+        type: 'number',
+        value: value
+      });
+
+      continue;
+    }
+
+    var LETTERS = /[a-zA-Z]/;
+    if (LETTERS.test(char)) {
+      var value = '';
+
+      while (LETTERS.test(char)) {
+        value += char;
+        char = input[++current];
+      }
+
+      tokens.push({
+        type: 'name',
+        value: value
+      });
+
+      continue;
+    }
+
+    throw new TypeError('I dont know what this character is: ' + char);
+  }
+
+  return tokens;
+}
+
+function parser(tokens) {
+  var current = 0;
+
+  function walk() {
+    var token = tokens[current];
+
+    if (token.type === 'number') {
+      current++;
+
+      return {
+        type: 'NumberLiteral',
+        value: token.value
+      };
+    }
+
+    if (
+      token.type === 'paren' &&
+      token.value === '('
+    ) {
+      token = tokens[++current];
+
+      var node = {
+        type: 'CallExpression',
+        name: token.value,
+        params: []
+      };
+
+      token = tokens[++current];
+
+      while (
+        token.type !== 'paren' ||
+        token.value !== ')'
+      ) {
+        node.params.push(walk());
+        token = tokens[current];
+      }
+
+      current++;
+
+      return node;
+    }
+
+    throw new TypeError(token.type);
+  }
+
+  var ast = {
+    type: 'Program',
+    body: []
+  };
+
+  while (current < tokens.length) {
+    ast.body.push(walk());
+  }
+
+  return ast;
+}
+
+function traverser(ast, visitor) {
+  function traverseArray(array, parent) {
+    array.forEach(function(child) {
+      traverseNode(child, parent);
+    });
+  }
+
+  function traverseNode(node, parent) {
+    var method = visitor[node.type];
+
+    if (method) {
+      method(node, parent);
+    }
+
+    switch (node.type) {
+      case 'Program':
+        traverseArray(node.body, node);
+        break;
+
+      case 'CallExpression':
+        traverseArray(node.params, node);
+        break;
+
+      case 'NumberLiteral':
+        break;
+
+      default:
+        throw new TypeError(node.type);
+    }
+  }
+
+  traverseNode(ast, null);
+}
+
+function transformer(ast) {
+  var newAst = {
+    type: 'Program',
+    body: []
+  };
+
+  ast._context = newAst.body;
+
+  traverser(ast, {
+    NumberLiteral: function(node, parent) {
+      parent._context.push({
+        type: 'NumberLiteral',
+        value: node.value
+      });
+    },
+
+    CallExpression: function(node, parent) {
+      var expression = {
+        type: 'CallExpression',
+        callee: {
+          type: 'Identifier',
+          name: node.name
+        },
+        arguments: []
+      };
+
+      node._context = expression.arguments;
+
+      if (parent.type !== 'CallExpression') {
+        expression = {
+          type: 'ExpressionStatement',
+          expression: expression
+        };
+      }
+
+      parent._context.push(expression);
+    }
+  });
+
+  return newAst;
+}
+
+function codeGenerator(node) {
+  switch (node.type) {
+    case 'Program':
+      return node.body.map(codeGenerator)
+        .join('\n');
+
+    case 'ExpressionStatement':
+      return (
+        codeGenerator(node.expression) +
+        ';'
+      );
+
+    case 'CallExpression':
+      return (
+        codeGenerator(node.callee) +
+        '(' +
+        node.arguments.map(codeGenerator)
+          .join(', ') +
+        ')'
+      );
+
+    case 'Identifier':
+      return node.name;
+
+    case 'NumberLiteral':
+      return node.value;
+
+    default:
+      throw new TypeError(node.type);
+  }
+}
+
+function compiler(input) {
+  var tokens = tokenizer(input);
+  var ast    = parser(tokens);
+  var newAst = transformer(ast);
+  var output = codeGenerator(newAst);
+
+  return output;
+}
+
+module.exports = {
+  tokenizer: tokenizer,
+  parser: parser,
+  transformer: transformer,
+  codeGenerator: codeGenerator,
+  compiler: compiler
+};