added first prototype

f.sh

@@ -0,0 +1,95 @@
+#!/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="$*"
+}