#!/bin/sh

alias :=_newword
alias '(=:'
alias ')=;'

_stack="" # top is 
_builtin_dictionary="swap dup rot over drop add sub div mod mul put" # + - / * .
_dictionary=

_newword() {
	name="$1"
	shift
	export "\$${name}_definition=\"$*\""
}

_execword() {
	eval "def='$1_definition'"
	for word in $def; do
		case "$_builtin_dictionary" in
			*"$word"*)  "_$word" "$_stack" ;;
			*) _execword "$word" ;;
		esac
	done
}

_swap() {
	one="$1"
	two="$2"
	shift
	_stack="$2 $1 $*"
}

_dup() {
	_stack="$1 $*"
}

_rot() {
	one="$1"
	two="$2"
	thr="$3"
	shift 3
	_stack="$3 $1 $2 $*"
}

_over() {
	_stack="$2 $*"
}

_drop() {
	shift
	_stack="$*"
}

_add() {
	one="$1"
	two="$2"
	shift 2
	_stack="$(( one + two )) $*"
}

_sub() {
	one="$1"
	two="$2"
	shift 2
	_stack="$(( two - one )) $*"
}

_div() {
	one="$1"
	two="$2"
	shift 2
	_stack="$(( two / one )) $*"
}

_mod() {
	one="$1"
	two="$2"
	shift 2
	_stack="$(( two % one )) $*"
}

_mul() {
	one="$1"
	two="$2"
	shift 2
	_stack="$(( one * two )) $*"
}

_put() {
	one="$1"
	shift
	printf '%s \n' "$one"
	_stack="$*"
}