Bourne Shell script to print out Merlin's inferred signature of an OCaml file (module)

sig

#!/usr/bin/env sh

# Works with merlin version 2.5.4. Using protocol described at
# https://github.com/ocaml/merlin/blob/master/doc/dev/OLD-PROTOCOL.md#type-checking

usage ()
{
  echo Usage: either of the following will work:
  echo
  echo '  sig module.ml'
  echo '  sig module.mli'

  exit 1
}

[ -z "$1" ] && usage

it=~/tmp/it

echo '["tell","start","end","module It = struct' >$it
sed 's/"/\\"/g' ${1%i} >>$it
echo ' end let () = ()"]' >>$it
echo '["type","expression","It","at","end"]' >>$it

ocamlmerlin <$it | sed -e '/^\["return",true\]$/d' -e 's/^\["return","sig *//' -e 's/ *end"\]$//' -e 's/\\"/"/g' -e 's/\\n/\
/g' | sed -e '/^ *$/d' -e 's/^  //'

# Reason syntax tweaks (untested, but should work):
#
# L20: echo '["tell","start","end","module It = {' >$it
# L22: echo '}; let () = ();"]' >>$it
# L25: ocamlmerlin <$it | sed -e '/^\["return",true\]$/d' -e 's/^\["return","{//' -e 's/};"\]$//' -e 's/\\"/"/g' -e 's/\\n/\
# /g' | sed -e '/^ *$/d' -e 's/^  //'