| function noop(value) { |
| return value; |
| } |
| |
| function generateMultiplier(multiplier) { |
| if (multiplier.min === 0 && multiplier.max === 0) { |
| return '*'; |
| } |
| |
| if (multiplier.min === 0 && multiplier.max === 1) { |
| return '?'; |
| } |
| |
| if (multiplier.min === 1 && multiplier.max === 0) { |
| return multiplier.comma ? '#' : '+'; |
| } |
| |
| if (multiplier.min === 1 && multiplier.max === 1) { |
| return ''; |
| } |
| |
| return ( |
| (multiplier.comma ? '#' : '') + |
| (multiplier.min === multiplier.max |
| ? '{' + multiplier.min + '}' |
| : '{' + multiplier.min + ',' + (multiplier.max !== 0 ? multiplier.max : '') + '}' |
| ) |
| ); |
| } |
| |
| function generateSequence(node, forceBraces, decorate) { |
| var result = node.terms.map(function(term) { |
| return generate(term, forceBraces, decorate); |
| }).join(node.combinator === ' ' ? ' ' : ' ' + node.combinator + ' '); |
| |
| if (node.explicit || forceBraces) { |
| result = (result[0] !== ',' ? '[ ' : '[') + result + ' ]'; |
| } |
| |
| return result; |
| } |
| |
| function generate(node, forceBraces, decorate) { |
| var result; |
| |
| switch (node.type) { |
| case 'Group': |
| result = |
| generateSequence(node, forceBraces, decorate) + |
| (node.disallowEmpty ? '!' : ''); |
| break; |
| |
| case 'Multiplier': |
| // return since node is a composition |
| return ( |
| generate(node.term, forceBraces, decorate) + |
| decorate(generateMultiplier(node), node) |
| ); |
| |
| case 'Type': |
| result = '<' + node.name + '>'; |
| break; |
| |
| case 'Property': |
| result = '<\'' + node.name + '\'>'; |
| break; |
| |
| case 'Keyword': |
| result = node.name; |
| break; |
| |
| case 'AtKeyword': |
| result = '@' + node.name; |
| break; |
| |
| case 'Function': |
| result = node.name + '('; |
| break; |
| |
| case 'String': |
| case 'Token': |
| result = node.value; |
| break; |
| |
| case 'Comma': |
| result = ','; |
| break; |
| |
| default: |
| throw new Error('Unknown node type `' + node.type + '`'); |
| } |
| |
| return decorate(result, node); |
| } |
| |
| module.exports = function(node, options) { |
| var decorate = noop; |
| var forceBraces = false; |
| |
| if (typeof options === 'function') { |
| decorate = options; |
| } else if (options) { |
| forceBraces = Boolean(options.forceBraces); |
| if (typeof options.decorate === 'function') { |
| decorate = options.decorate; |
| } |
| } |
| |
| return generate(node, forceBraces, decorate); |
| }; |