click-format

#!/usr/bin/env bash
# ==============================================================================
# click-format
#
#   Formatting helper script for click.
#
#   Takes a Hoon command and an optional list of Clay file dependencies (as
#   paths or beams) and formats them as a text representation of a Hoon noun.
#   When jammed, this noun can be passed to conn.c to execute the command on a
#   running ship.
#
#   If a dependency file is passed as a beam, it will be interpreted as-is. If a
#   dependency file is passed as a path, the default beak (i.e. [our base now])
#   will be prepended to it.
#
#   The structure of a conn.c thread call looks like this:
#
#       [42 %fyrd [%base %hi %tape [%ship ~zod]]]
#        1  2      3     4   5      6     7
#
#       1 = Unique ID for mapping results to requests
#       2 = Command to conn.c routing the request
#       3 = Desk in which thread lives
#       4 = Name of thread
#       5 = Mark for output type
#       6 = Mark for input type
#       7 = Input to thread as a noun
#
#   (1) - (6) are held constant by this client. (7) is provided by the user.
#
# ==============================================================================

# ==========================================================
# CONSTANTS
# ==========================================================

# Request ID
# A client that ran many simultaneous queries would want to somehow assign these
RID=0

# Command
# See conn.c for information about other commands and how they work
COMMAND="%fyrd"

# Desk
# Desk in which the thread lives. All threads used by click live in '%base'.
DESK="%base"

# Threads
# Name of thread to call. Only 'eval' and 'khan-eval' are used by click.
EVAL_TED="%eval"
KHAN_TED="%khan-eval"
THREAD=$EVAL_TED

# Output mark
# Output format of thread results (always noun for click)
MARK_OUT="%noun"

# Input mark
# Format of input to thread (always constant for click)
MARK_IN="%ted-eval"

# ==========================================================
# VARIABLES
# ==========================================================

STATUS=0
TED_IN=""

# ==========================================================
# FUNCTIONS
# ==========================================================

show_help() {
    cat <<EOF
Usage:
    $(basename "$0") [options] <hoon> [<dependency> ...]

    Format a text representation of a Hoon noun for use as input to eval threads via conn.c

    options:
        -h  Show usage info
        -k  Format for the 'khan-eval' thread instead
EOF
}

# ==========================================================
# MAIN
# ==========================================================

# reset getopts
OPTIND=1

# parse options
while getopts ":hk" OPT; do
    case "$OPT" in
        k)
            THREAD=$KHAN_TED
            ;;
        \?)
            echo "Invalid option: -$OPTARG" >&2
            STATUS=1
            ;&
        h)
            show_help
            exit "$STATUS"
            ;;
  esac
done

# skip over opts after parsing
shift $((OPTIND-1))

# check for mandatory input
if [[ $# -lt 1 ]]; then
    echo "ERROR: no command" >&2
    show_help
    exit 1
fi

# setup input page
if [[ $# -eq 1 ]]; then
    TED_IN="[$MARK_IN '$1']"
else
    TED_IN="'$1'"
    shift
    TED_IN="[$MARK_IN [$TED_IN [$* ~]]]"
fi

# format command
echo "[$RID $COMMAND [$DESK $THREAD $MARK_OUT $TED_IN]]"