clap — Command line argument parser for Pharo
Named after and inspired by clap-rs, but this is an independent implementation.
Currently still in the initial implementation phase, meaning the main pieces are there but many features are still missing and may force changes in the design.
starting from a Pharo image
Metacello new baseline: 'Clap'; repository: 'github://cdlm/clap-st/src'; load.
starting from the shell
git clone https://github.com/cdlm/clap-st.git cd clap-st curl get.pharo.org/alpha | bash
…and then, in the image just downloaded, open a workspace and evaluate:
Metacello new baseline: 'Clap'; repository: 'gitlocal://./src'; load.
# setup $PHARO fari build fari run
running the tests
In-image tests run the usual way; some of them rely on Mocketry. Additionally, a few more tests exercise the included commands through the whole system, including VM startup and shutdown; running those requires Bats:
# $CLAP should contain whatever command launches your VM and image: # export CLAP="$PHARO_VM $PHARO_IMAGE" # or, with fari: export CLAP="fari run --" bats tests
You can also check the
.travis.yml file for reference.
Defining and invoking commands
Commands and subcommands are instances of
ClapCommand. To make a command
accessible from the command line, return it from a class-side factory method
<commandline> pragma. For instance, here's how we declare the
traditional hello, world! example, with the actual behavior delegated the
ClapCommandLineExamples >> sayHello:
hello "The usual Hello-World example, demonstrating a Clap command with a couple options." <commandline> ^ (ClapCommand withName: 'hello') description: 'Provides greetings'; add: ClapFlag forHelp; add: ((ClapFlag withName: 'shout') description: 'Greet loudly'); add: ((ClapPositional withName: 'who') description: 'Recipient of the greetings'; defaultMeaning: [ 'world' ]); meaning: [ :args | args atName: 'help' ifFound: [ :help | help value. help context exitSuccess ]. (self with: args) sayHello ]
For now, Clap installs itself as a named command line handler; e.g., to run the
hello example command:
$PHARO_VM $PHARO_IMAGE clap hello $PHARO_VM $PHARO_IMAGE clap hello --shout you
Commands can also be tested from within the image; running them from an interactive session will not quit the image, but any output from the command will still go to the standard output:
ClapCommandLineExamples hello runWith: #('hello' '--help').
Many thanks to everyone who has contributed to clap in one way or another:
Clément Mastin, Damien Pollet, Rajula Vineet Reddy