Merge remote-tracking branch 'thejameskyle/master'

README.md

@@ -10,8 +10,6 @@ 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

@@ -1,252 +0,0 @@
-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.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
-};

super-tiny-compiler.js

@@ -74,14 +74,14 @@
  */
 
 /**
- * Today we're going write a compiler together. But not just any compiler... A
+ * Today we're going to write a compiler together. But not just any compiler... A
  * super duper teeny tiny compiler! A compiler that is so small that if you
  * remove all the comments this file would only be ~200 lines of actual code.
  *
  * We're going to compile some lisp-like function calls into some C-like
  * function calls.
  *
- * If you are familiar with one or the other. I'll just give you a quick intro.
+ * If you are not familiar with one or the other. I'll just give you a quick intro.
  *
  * If we had two functions `add` and `subtract` they would be written like this:
  *
@@ -446,7 +446,7 @@ function tokenizer(input) {
     //    ^^^
     //    Name token
     //
-    var LETTERS = /[a-zA-Z]/;
+    var LETTERS = /[a-z]/i;
     if (LETTERS.test(char)) {
       var value = '';