A Bash script to switch between Elm 0.18 and 0.19

elmswitch

#!/usr/bin/env bash
#
# Switch between using different Elm family revisions; right now can switch between Elm 0.18.0 and Elm 0.19.0 revision
# "ecosystems".  From the command line, invokde either
#   elmswitch 18
# or
#   elmswitch 19
#
# It is planned to add other revisions and patch revisions as desired.
#
# Assumptions:
#
# 1.  Elm 0.18.0 version is found at /usr/local/bin/elm
# 2.  Elm 0.19.0 version is found at ~/node-modules/elm
#
# elm-format and elm-live are also switched.
#
# Finally, when elm18 is selected, then in addition to elm-format and elm-live, the following elm aliases are available:
#
# elm-make
# elm-package
# elm-reactor
# elm-repl

remove_all () {
  rm -f elm
  rm -f elm-app
  rm -f elm-format
  rm -f elm-live
  rm -f elm-make
  rm -f elm-package
  rm -f elm-reactor
  rm -f elm-repl
}

case $1 in
  "18" ) cd /usr/local/bin
	 remove_all
	 SUPERPATH="/usr/local//lib/node_modules"
	 ln -s $SUPERPATH/elm/binwrappers/elm elm
	 ln -s $SUPERPATH/create-elm-app/bin/elm-app-cli.js elm-app
	 ln -s $SUPERPATH/elm-live/bin/elm-live.js elm-live
	 ln -s $SUPERPATH/elm/binwrappers/elm-make elm-make
	 ln -s $SUPERPATH/elm/binwrappers/elm-package elm-package
         ln -s $SUPERPATH/elm/binwrappers/elm-reactor elm-reactor
	 ln -s $SUPERPATH/elm/binwrappers/elm-repl elm-repl;;
  "19" ) cd /usr/local/bin
	 remove_all
	 SUPERPATH="$HOME/node_modules"
	 ln -s $SUPERPATH/elm/bin/elm elm
	 ln -s $SUPERPATH/elm-format/bin/elm-format elm-format
	 ln -s $SUPERPATH/elm-live/bin/elm-live elm-live;;
  *) echo "Value '$1' invalid; must be '18' or 19'"; exit 1;;
esac
echo "Switched to Elm 0.$1.0"
cd -
exit 0