ast.js

function Node(type) {
    return function _Node(nodes, attrs) {
      if(!(Array.isArray(nodes) && nodes.length)) {
        var msg = 'Node "'+type+'" needs an array of at least one subnode.';
        throw new Error(msg);
      }
      return {
        type: type,
        nodes: nodes,
        attrs: attrs,
      };
    }
  }
  
  function capitalize(str) {
    return str.charAt(0).toUpperCase() + str.slice(1);
  }
  
  var types = [
    'assignment',
    'exponentiation',
    'multiplication',
    'division',
    'addition',
    'subtraction',
    'negation',
    'modulo',
    'function',
    'functiondec',
    'variable',
    'number',
  ];
  
  var ast = types.reduce(function(obj, type) {
    obj[capitalize(type)] = Node(type);
    return obj;
  }, {});
  
  module.exports = ast;