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 generateTypeOpts(node) {
|
switch (node.type) {
|
case 'Range':
|
return (
|
' [' +
|
(node.min === null ? '-∞' : node.min) +
|
',' +
|
(node.max === null ? '∞' : node.max) +
|
']'
|
);
|
|
default:
|
throw new Error('Unknown node type `' + node.type + '`');
|
}
|
}
|
|
function generateSequence(node, decorate, forceBraces, compact) {
|
var combinator = node.combinator === ' ' || compact ? node.combinator : ' ' + node.combinator + ' ';
|
var result = node.terms.map(function(term) {
|
return generate(term, decorate, forceBraces, compact);
|
}).join(combinator);
|
|
if (node.explicit || forceBraces) {
|
result = (compact || result[0] === ',' ? '[' : '[ ') + result + (compact ? ']' : ' ]');
|
}
|
|
return result;
|
}
|
|
function generate(node, decorate, forceBraces, compact) {
|
var result;
|
|
switch (node.type) {
|
case 'Group':
|
result =
|
generateSequence(node, decorate, forceBraces, compact) +
|
(node.disallowEmpty ? '!' : '');
|
break;
|
|
case 'Multiplier':
|
// return since node is a composition
|
return (
|
generate(node.term, decorate, forceBraces, compact) +
|
decorate(generateMultiplier(node), node)
|
);
|
|
case 'Type':
|
result = '<' + node.name + (node.opts ? decorate(generateTypeOpts(node.opts), node.opts) : '') + '>';
|
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;
|
var compact = false;
|
|
if (typeof options === 'function') {
|
decorate = options;
|
} else if (options) {
|
forceBraces = Boolean(options.forceBraces);
|
compact = Boolean(options.compact);
|
if (typeof options.decorate === 'function') {
|
decorate = options.decorate;
|
}
|
}
|
|
return generate(node, decorate, forceBraces, compact);
|
};
|
