UNIcodeX/nim-argparse

Argument parsing for Nim

argparse

Command line argument parsing library. It generates the parser at compile time so that parsed options have a well-defined type.

Example

After defining your expected arguments with newParser(...), use:

1. run(...) to parse and execute any run: blocks you've defined. This will automatically display help text when -h/--help is used.
2. parse(...) to parse without executing.

Both procs will parse the process' command line if no arguments are given.

See the docs for more info

run()

import argparse

var p = newParser("My Program"):
  flag("-a", "--apple")
  flag("-b", help="Show a banana")
  option("-o", "--output", help="Output to this file")
  command("somecommand"):
    arg("name")
    arg("others", nargs = -1)
    run:
      echo opts.name
      echo opts.others
      echo opts.parentOpts.apple
      echo opts.parentOpts.b
      echo opts.parentOpts.output

p.run(@["--apple", "-o=foo", "somecommand", "myname", "thing1", "thing2"])

parse()

import argparse

var p = newParser("My Program"):
  flag("-a", "--apple")
  flag("-b", help="Show a banana")
  option("-o", "--output", help="Output to this file")
  arg("name")
  arg("others", nargs = -1)

var opts = p.parse(@["--apple", "-o=foo", "hi"])
assert opts.apple == true
assert opts.b == false
assert opts.output == "foo"
assert opts.name == "hi"
assert opts.others == @[]

TODO

• --long-flags
• --arguments=withvalues
• help argument
• arguments
• variable args
• sub commands (git-style)
• sub commands access parent opts
• render docs
• --help special case
• --version
• default values
• raise exception on invalid args
• Handle --arg val --nother-arg val2 (spaces instead of = or : between key and value)
• Access to object type names (so you can do handleOpts(opts: TheGeneratedType) = ...)
• Make it so you don't have to use a wrapping macro
• parse strings into sequences (shlex-like)
• fail on unknown arguments
• let options have a list of acceptable values (choices)

Development

Running tests

Run tests with:

nimble test

Run a single test with:

nim c -r tests/test1.nim -g "somepatternmatchingthetestname"

Building the docs

When you publish a new version, publish the docs by running ./builddocs.sh then pushing master.