Default parameter for :make if $* is empty?

Question

Is it possible to provide a default if $* is empty in a :make?

I'd like to specify :makeprg so that:

1. :make runs swift build
2. :make foo bar runs swift foo bar.

Answer 1

This isn't really a vim answer, but consider having an actual makefile (or a shell script, but makefiles are beautiful for this kind of thing—see the language agnostic makefile and is it worth using make).

Then, you don't need weird workarounds for vim's $* (I had to look it up to be sure of what you were talking about).

For example (pay attention to the tabs, which are showing as spaces, unfortunately):

all: build_output

build_output:
    swift build

foo_output:
    swift foo

bar_output:
    swift bar

Then you can simply make, make foo_output, or make bar_output, where *_output is a file or directory tree generated by swift *.

Let make do its job. Don't beat it to death.

The equivalent shell script would have to be something like

#! /usr/bin/env bash

set -euo pipefail

usage() {
  cat <<DOG
usage: $0 [args...]
DOG
}

die() {
  local ex="${1:-1}"
  exit "$ex"
}

usage_and_die() { usage && die; }

build() {
  swift build
}

foo() {
  swift foo
}

bar() {
  swift bar
}

main() {
  if (($# < 1)) ; then
    build
  else
    for param;
      case "$param" in
        -h|--help) usage_and_die ;;
        *) "$param" ;;
      esac
    done
  fi
}

main "$@"

And the complexity of this beast will only grow. Just use make.

Vim?

I suppose you could do something like

command -nargs=* Make if len(<q-args>) > 0 | make <q-args> | else | make build | endif
setlocal makeprg=swift

But then you have to use this new command, and maintain it, and all that garbage. Plus, if you have a workflow, why not encode that in your makefile, and let others benefit from seeing it?