Create an Options Parser.

[sbstp]

Features:
 - Argument collection
 - Long options: --long
 - Short options: -s
 - Option description
 - Default values
 - Type checking and error reporting
 - Available types: string, boolean, int, +int, float, +float
 - Type inference using the default value (when provided)
 - Automatic convertion of types (from strings)
 - Mandatory options and error reporting
 - Automatic help and version display (when turned on)

Parsing:
    Values are assigned using an equal sign.
        --opt=val, -o=val
    Short options can be grouped together. The last
    option of a short option group can have a value:
        -abc=def c gets the value 'def'

     -a             => {a: true}
     -a=value       => {a: 'value'}
     -ab            => {a: true, b: true}
     -ab=value      => {a: true, b: 'value'}
     --long=value   => {long: 'value'}

     Anything that is not preceded by an option is considered
     a plain argument.

[maximecb]

Thank you for this contribution :)

[maximecb]

Hi @SBSTP

I decided to make use of your options parser in the turing-turtle example program just to dogfood it a little bit.

I've run into some minor issues and have some suggestions for improvements.

1. it seems that when the options fail to parse as expected, the option parser crashes, no help or usage is displayed:

./higgs ../examples/turing-turtle.js -- -w 200 -h 200

TypeError: call to non-function "charCodeAt" RegExpContext(1B9F0) ("stdlib/regexp.js"@980:28) RegExp_prototype_test(1C281) ("stdlib/regexp.js"@2675:19) testIntPositive(7759D) ("lib/options.js"@326:16) Options_prototype_parse(776E6) ("lib/options.js"@454:22) ___examples_turing_turtle_js(22AEF) ("../examples/turing-turtle.js"@275:12)

1. I would suggest adding tests for invalid strings. To at least make sure no exception is thrown.
2. The lib is imported as such:

var Options = require('lib/options').Options;

It seems to me that there isn't really much of a use case for having multiple options parsers though? Maybe require('lib/options') should produce a "singleton" option parser, avoiding the need to instantiate one. Let me know what you think.

1. The .add(.., .., ..., ...) syntax with all the null and optional arguments is confusing. I'd prefer something like:

options.add({name: 'width', type: '+int', shortname:'w', desc:'canvas width'});

I'm aware that you already have a syntax to add many options at once this way. I think that .add() should probably work this way as well.

1. It might be useful to have some optional min and max values for numerical arguments.

[sbstp]

Ok I found why it doesn't work. The format is

./higgs ../examples/turing-turtle.js -- -w=200 -h=200
                                          ^      ^

Using spaces makes the parser much more complex and creates ambiguities as to what is an option value and what's a plain argument, hence why I used =. Still though, the parser shouldn't crash because of that.

[maximecb]

Yes, no complaints on the use of equals, I prefer it this way also. It's only the crashing that seemed an issue.

[sbstp]

Yes, I fixed it now, it yields a type error. I'm working on the API changes.

[maximecb]

Btw, JS also has a SyntaxError: https://github.com/higgsjs/Higgs/blob/master/source/stdlib/error.js#L135