Catharsis
A JavaScript parser for Google Closure Compiler
type expressions.
Catharsis is designed to be:
- Accurate. Catharsis is based on a PEG.js grammar that's designed to
handle any valid type expression. It uses a Mocha test suite
to verify the parser's accuracy.
- Fast. Parse results are cached, so the parser is invoked only when necessary.
- Flexible. Catharsis can also convert parse results back into type expressions.
Example
var catharsis = require('catharsis');
var type = '!Object';
var parsedType;
var expr;
try {
parsedType = catharsis.parse('!Object');
console.log('%j', parsedType); // {"type":"NameExpression,"name":"Object","nullable":false}
}
catch(e) {
console.error('unable to parse %s: %s', type, e);
}
expr = catharsis.stringify(parsedType);
console.log(expr); // !Object
See the test/specs/
directory for more examples of Catharsis' parse results.
Methods
parse(type, opts)
Parse the Closure Compiler type type
, and return the parse results. Throws an error if the type
cannot be parsed.
Parameters
type
: A string containing a Closure Compiler type expression.opts
: Options for parsing the type expression.
opts.useCache
: Specifies whether to use the cache of parsed types. Defaults to true
.
Returns
An object containing the parse results.
stringify(parsedType, opts)
Stringify the parsed Closure Compiler type expression parsedType
, and return the type expression.
If validation is enabled, throws an error if the stringified type expression cannot be parsed.
Parameters
parsedType
: An object containing a parsed Closure Compiler type expression.opts
: Options for stringifying the parse results.
opts.useCache
: Specifies whether to use the cache of stringified parse results. Defaults to
true
.opts.validate
: Specifies whether to validate the stringified parse results by attempting to
parse them as a type expression. Defaults to false
.
Returns
A string containing the type expression.
Installation
With npm:
npm install catharsis
Or without:
git clone git://github.com/hegemonic/catharsis.git
Roadmap and known issues
Take a look at the issue tracker to see what's in
store for Catharsis.
Bug reports, feature requests, and pull requests are always welcome! If you're working on a large
pull request, please contact me in advance so I can help things go smoothly.
Note: The parse tree's format should not be considered final until Catharsis reaches version
1.0. I'll do my best to provide release notes for any changes.
Changelog
- 0.3.0 (March 2013):
- The
parse()
and stringify()
methods are now synchronous, and the parseSync()
and
stringifySync()
methods have been removed. Note: This change is not backwards-compatible
with previous versions. - The parse results now use a significantly different format from previous versions. The new
format is more expressive and is similar, but not identical, to the format used by the
doctrine parser. Note: This change is not
backwards-compatible with previous versions.
- Name expressions that contain a reserved word now include a
reservedWord: true
property. - Union types that are optional or nullable, or that can be passed a variable number of times,
are now parsed and stringified correctly.
- Optional function types and record types are now parsed and stringified correctly.
- Function types now longer include
new
or this
properties unless the properties are defined
in the type expression. In addition, the new
and this
properties can now use any type
expression. - In record types, the key for a field type can now use any type expression.
- Standalone single-character literals, such as ALL (
*
), are now parsed and stringified
correctly. null
and undefined
literals with additional properties, such as repeatable
, are now
stringified correctly.
- 0.2.0 (November 2012):
- Added
stringify()
and stringifySync()
methods, which convert a parsed type to a type
expression. - Simplified the parse results for function signatures. Note: This change is not
backwards-compatible with previous versions.
- Corrected minor errors in README.md.
- 0.1.1 (November 2012): Added
opts
argument to parse()
and parseSync()
methods. Note: The
change to parse()
is not backwards-compatible with previous versions. - 0.1.0 (November 2012): Initial release.
License
MIT license.