Passes (updated) tests.

https://git.sr.ht/~sforman/joytest

implementations/Python/simplejoy.py

@@ -86,7 +86,7 @@ def isnt_stack(el):
     Raise NotAListError if el isn't a stack/quote/list.
     '''
     if not isinstance(el, tuple):
-        raise NotAListError(f'Not a list {_s(el)}')
+        raise NotAListError(f'Not a list: {_s(el)}')
 
 
 '''
@@ -828,8 +828,11 @@ def pop(stack):
         -----------
 
     '''
-    _, s23 = get_n_items(1, stack)
-    return s23
+    try:
+        _, stack = stack
+    except ValueError:
+        raise StackUnderflowError('Cannot pop empty stack.') from None
+    return stack
 
 
 @inscribe
@@ -845,7 +848,10 @@ def rest(stack):
     '''
     s0, stack = get_n_items(1, stack)
     isnt_stack(s0)
-    _, s1 = get_n_items(1, s0)
+    try:
+        _, s1 = s0
+    except ValueError:
+        raise StackUnderflowError('Cannot take rest of empty list.') from None
     return s1, stack
 
 
@@ -1074,6 +1080,16 @@ Start with increment and decrement:
 < ≡ lt
 >= ≡ ge
 <= ≡ le
+!= ≡ ne
+<> ≡ ne
+
+% ≡ mod
++ ≡ add
+- ≡ sub
+* ≡ mul
+/ ≡ floordiv
+div ≡ floordiv
+
 
 
 ? ≡ dup bool
@@ -1086,114 +1102,113 @@ abs ≡ dup 0 < [] [neg] branch
 anamorphism ≡ [pop []] swap [dip swons] genrec
 app1 ≡ grba infrst
 app2 ≡ [grba swap grba swap] dip [infrst] cons ii
-app3 3 appN
-appN [grabN] codi map disenstacken
-at drop first
-average [sum] [size] cleave /
-b [i] dip i
-binary unary popd
-ccccons ccons ccons
-ccons cons cons
-clear [] swaack pop
+app3 ≡ 3 appN
+appN ≡ [grabN] codi map disenstacken
+at ≡ drop first
+average ≡ [sum] [size] cleave /
+b ≡ [i] dip i
+binary ≡ unary popd
+ccccons ≡ ccons ccons
+ccons ≡ cons cons
+clear ≡ [] swaack pop
 cleave ≡ fork popdd
-clop cleave popdd
-cmp [[>] swap] dipd [ifte] ccons [=] swons ifte
+clop ≡ cleave popdd
+cmp ≡ [[>] swap] dipd [ifte] ccons [=] swons ifte
 codi ≡ cons dip
-codireco codi reco
-dinfrirst dip infrst
+codireco ≡ codi reco
+dinfrirst ≡ dip infrst
 dipd ≡ [dip] codi
-disenstacken ? [uncons ?] loop pop
-down_to_zero [0 >] [dup --] while
-drop [rest] times
+disenstacken ≡ ? [uncons ?] loop pop
+down_to_zero ≡ [0 >] [dup --] while
+drop ≡ [rest] times
 dupd ≡ [dup] dip
-dupdd [dup] dipd
+dupdd ≡ [dup] dipd
 dupdip ≡ dupd dip
 dupdipd ≡ dup dipd
-enstacken stack [clear] dip
-first uncons pop
-flatten <{} [concat] step
+enstacken ≡ stack [clear] dip
+first ≡ uncons pop
+flatten ≡ <{} [concat] step
 fork ≡ [i] app2
-fourth rest third
-gcd true [tuck mod dup 0 >] loop pop
-genrec [[genrec] ccccons] nullary swons concat ifte
-grabN <{} [cons] times
+fourth ≡ rest third
+gcd ≡ true [tuck mod dup 0 >] loop pop
+genrec ≡ [[genrec] ccccons] nullary swons concat ifte
+grabN ≡ <{} [cons] times
 grba ≡ [stack popd] dip
 hypot [sqr] ii + sqrt
-ifte [nullary] dipd swap branch
+ifte ≡ [nullary] dipd swap branch
 ii ≡ [dip] dupdip i
 infra ≡ swons swaack [i] dip swaack
 infrst ≡ infra first
-make_generator [codireco] ccons
+make_generator ≡ [codireco] ccons
 manual ≡ [] words [help] step pop
-mod %
-neg 0 swap -
-not [true] [false] branch
-nulco [nullary] cons
-nullary [stack] dinfrirst
-of swap at
-pam [i] map
-pm [+] [-] clop
+neg ≡ 0 swap -
+not ≡ [true] [false] branch
+nulco ≡ [nullary] cons
+nullary ≡ [stack] dinfrirst
+of ≡ swap at
+pam ≡ [i] map
+pm ≡ [+] [-] clop
 popd ≡ [pop] dip
 popdd ≡ [pop] dipd
 popop ≡ pop pop
 popopop ≡ pop popop
-popopd [popop] dip
-popopdd [popop] dipd
-product 1 swap [*] step
-quoted [unit] dip
-range [0 <=] [1 - dup] anamorphism
-range_to_zero unit [down_to_zero] infra
-reco rest cons
-rest uncons popd
-reverse <{} shunt
+popopd ≡ [popop] dip
+popopdd ≡ [popop] dipd
+product ≡ 1 swap [*] step
+quoted ≡ [unit] dip
+range ≡ [0 <=] [1 - dup] anamorphism
+range_to_zero ≡ unit [down_to_zero] infra
+reco ≡ rest cons
+rest ≡ uncons popd
+reverse ≡ <{} shunt
 roll> ≡ swap swapd
 roll< ≡ swapd swap
-rollup roll>
+rollup ≡ roll>
 rolldown roll<
-rrest rest rest
-run <{} infra
-second rest first
-shift uncons [swons] dip
-shunt [swons] step
-size [pop ++] step_zero
-spiral_next [[[abs] ii <=] [[<>] [pop !-] ||] &&] [[!-] [[++]] [[--]] ifte dip] [[pop !-] [--] [++] ifte] ifte
-split_at [drop] [take] clop
-split_list [take reverse] [drop] clop
-sqr dup *
-stackd [stack] dip
-step_zero 0 roll> step
-stuncons stack uncons
-sum [+] step_zero
+rrest ≡ rest rest
+run ≡ <{} infra
+second ≡ rest first
+shift ≡ uncons [swons] dip
+shunt ≡ [swons] step
+size ≡ [pop ++] step_zero
+spiral_next ≡ [[[abs] ii <=] [[<>] [pop !-] ||] &&] [[!-] [[++]] [[--]] ifte dip] [[pop !-] [--] [++] ifte] ifte
+split_at ≡ [drop] [take] clop
+split_list ≡ [take reverse] [drop] clop
+sqr ≡ dup *
+stackd ≡ [stack] dip
+step_zero ≡ 0 roll> step
+stuncons ≡ stack uncons
+sum ≡ [+] step_zero
 swapd ≡ [swap] dip
 swons ≡ swap cons
-swoncat swap concat
-sqr dup mul
-tailrec [i] genrec
-take <<{} [shift] times pop
-ternary binary popd
-third rest second
-tuck dup swapd
-unary nullary popd
+swoncat ≡ swap concat
+sqr ≡ dup mul
+tailrec ≡ [i] genrec
+take ≡ <<{} [shift] times pop
+ternary ≡ binary popd
+third ≡ rest second
+tuck ≡ dup swapd
+unary ≡ nullary popd
 uncons ≡ [first] [rest] cleave
 unit ≡ [] cons
-unquoted [i] dip
-unswons uncons swap
-while swap nulco dupdipd concat loop
+unquoted ≡ [i] dip
+unswons ≡ uncons swap
+while ≡ swap nulco dupdipd concat loop
 x ≡ dup i
 step ≡ [_step0] x
 _step0 ≡ _step1 [popopop] [_stept] branch
 _step1 ≡ [?] dipd roll<
 _stept ≡ [uncons] dipd [dupdipd] dip x
-times [_times0] x
-_times0 _times1 [popopop] [_timest] branch
-_times1 [dup 0 >] dipd roll<
-_timest [[--] dip dupdipd] dip x
-map [_map0] cons [[] [_map?] [_mape]] dip tailrec
-_map? pop bool not
-_mape popd reverse
-_map0 [_map1] dipd _map2
-_map1 stackd shift
-_map2 [infrst] cons dipd roll< swons
+times ≡ [_times0] x
+_times0 ≡ _times1 [popopop] [_timest] branch
+_times1 ≡ [dup 0 >] dipd roll<
+_timest ≡ [[--] dip dupdipd] dip x
+map ≡ [_map0] cons [[] [_map?] [_mape]] dip tailrec
+_map? ≡ pop bool not
+_mape ≡ popd reverse
+_map0 ≡ [_map1] dipd _map2
+_map1 ≡ stackd shift
+_map2 ≡ [infrst] cons dipd roll< swons
 '''