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Add dup, rot, and over to Forbble example

This commit is contained in:
Sage Vaillancourt 2020-11-08 13:05:26 -05:00
parent fe86f7c836
commit 35f0a94f40
1 changed files with 38 additions and 1 deletions
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39
src/examples/forbble.pbl
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@ -48,6 +48,16 @@
(def ^ "^") (def ^ "^")
(def $ "$") (def $ "$")
(def swap "swap") (def swap "swap")
(def dup "dup")
(def rot "rot")
(def over "over")
; Duplicate the top element of the stack
(def _dup (fn (_) (
(def _top (at 0 stack))
(if (iserr _top) (prnl "dup: STACK EMPTY")
(stkadd _top))
)))
; Swap the top two elements of the stack, if possible ; Swap the top two elements of the stack, if possible
(def _swap (fn (_) ( (def _swap (fn (_) (
@ -58,6 +68,24 @@
(prnl "swap: STACK TOO SMALL") (prnl "swap: STACK TOO SMALL")
)))) ))))
; Rotate the third element to be above the first and second elements
(def _rot (fn (_) (
(if (> (len stack) 2) (
(def (_c _b _a) ((bop 0) (bop 0) (bop 0)))
(stkadd _b)
(stkadd _c)
(stkadd _a))
(prnl "rot: STACK TOO SMALL")
))))
; Rotate the third element to be above the first and second elements
(def _over (fn (_) (
(if (> (len stack) 1) (
(def _a (at 1 stack))
(stkadd _a))
(prnl "over: STACK TOO SMALL")
))))
; Defines a given symbol using a given list of Forth inputs ; Defines a given symbol using a given list of Forth inputs
(def compile (fn (func sym) ( (def compile (fn (func sym) (
(def _x (at 0 func)) (def _x (at 0 func))
@ -78,6 +106,9 @@
(if (= * _x) (twop *) (if (= * _x) (twop *)
(if (= / _x) (twop /) (if (= / _x) (twop /)
(if (= "swap" _x) (_swap 0) (if (= "swap" _x) (_swap 0)
(if (= "dup" _x) (_dup 0)
(if (= "rot" _x) (_rot 0)
(if (= "over" _x) (_over 0)
(if (= "^" _x) (pch (bop 0)) (if (= "^" _x) (pch (bop 0))
(if (= ":" _x) ( ; Compile a phrase into the next symbol (if (= ":" _x) ( ; Compile a phrase into the next symbol
(def var (at 1 list)) (def var (at 1 list))
@ -88,7 +119,7 @@
(def _e (eval _x)) (def _e (eval _x))
(if (iserr (len _e)) () (feval _e)) (if (iserr (len _e)) () (feval _e))
) )
))))))))) ))))))))))))
; A switch/case operator might be good, to avoid huge closing-paren chains ; A switch/case operator might be good, to avoid huge closing-paren chains
; If any list is left, recurse into it ; If any list is left, recurse into it
@ -113,10 +144,16 @@
(feval (: "in" $)) (feval (: "in" $))
(feval (: "i>f" 1 ft / $)) (feval (: "i>f" 1 ft / $))
(feval (: "i>y" 1 yd / $)) (feval (: "i>y" 1 yd / $))
; Convert between Farenheit and Celcius ; Convert between Farenheit and Celcius
(feval (: "f>c" 32 - 5 * 9 /$)) (feval (: "f>c" 32 - 5 * 9 /$))
(feval (: "c>f" 9 * 5 / 32 + $)) (feval (: "c>f" 9 * 5 / 32 + $))
; Math
(feval (: "sq" dup * $))
; Gets next Fibonacci number from two on stack
(feval (: "fib" swap over + dup . $))
; A simple REPL. Exits on 'q' ; A simple REPL. Exits on 'q'
(def repl (fn (_) ( (def repl (fn (_) (
(prn "forbble::> ") (prn "forbble::> ")