PythonStyleListSlice

Python like list slicing in javascript. Transpiles JavaScript to allow for arr[1:2], arr[::2], arr[-1], arr[-1] = 5, etc...

Installation

npm -g install python-style-slicing

Node API

#### PSS::transpile(code, filename='dummy.js', sourceMap=false)
- code: the code to transpile
- filename: original file code came from. Used in creation of sourcemaps. Defaults to 'dummy.js'
- sourceMap: boolean indicating whether or not to generate source maps. Defaults to false

##### Example usage

``
import PSS from 'python-style-slicing';

const code = ['var x = [1, 2, 3, 4, 5];', 'console.log(x[::2]);'].join('\n');

const output = PSS.transpile(code, 'test.js', true);
`

CLI


pss [file] [--s] [-o output_location]

If no file given, pss will read from stdin. If no output location given, pss will output to stdout. The --s flag option indicates whether or not to generate source maps along with output.

How It Works


Uses a modified version of the acorn parser to generate an AST with the following new nodes:
`
ComputedMemberRangeExpression: {
startExpression: Expression,
endExpression: Expression,
skipExpression: Expression
},
ComputedMemberAssignmentExpression:
`

A modified version of the escodegen code generator then generates code.
`
ComputedMemberRangeExpression ->
__$$__computedMemberRangeGet__$$__(array, startExpression, endExpression, skipExpression)
ComputedMemberAssignmentExpression ->
__$$__computedMemberSet__$$__(array, property, value, operator)
ComputedMember ->
__$$__ComputedMemberGet__$$__(array, property)
``

License

MIT