jq replacement (‽)

jq

#!/usr/bin/env bash

if [[ -z "$1" ]]; then
  echo "No filter given, abort"
  exit 1
fi

tmp=$(mktemp -d)
jq="$tmp/jq"

cat > "$jq" <<EOF
#!/usr/bin/env nix-shell
#!nix-shell -i runhaskell -p 'haskellPackages.ghcWithPackages (h: [ h.lens-aeson h.lens h.safe h.protolude ])'
{-# LANGUAGE OverloadedStrings, NoImplicitPrelude #-}

import Protolude
import Data.String (String)
import Data.Aeson
import Data.Aeson.Lens
import Control.Lens
import System.FilePath.Lens

import System.Environment (getArgs)
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL


main = do
  data_ <- BL.getContents
  let out = case (eitherDecode' data_ :: Either String Value) of
              Left err  -> panic $ "decoding failed: " <> toS err
              Right val -> userProgram val
  BL.putStr $ encode (out :: Value)

userProgram =
EOF

echo "$1" | sed 's/^/  /' >> "$jq"
chmod +x "$jq"
"$jq"

Usage:

$ chmod +x jq
$ echo '{"a": 4}' | ~/tmp/jq '(key "a" . _Integral) +~ 5'
{"a":9}