1 # -*- coding: utf-8 -*-
3 # Copyright © 2014, 2015, 2017, 2018 Simon Forman
5 # This file is part of Thun
7 # Thun is free software: you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation, either version 3 of the License, or
10 # (at your option) any later version.
12 # Thun is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with Thun. If not see <http://www.gnu.org/licenses/>.
21 This module contains the Joy function infrastructure and a library of
22 functions. Its main export is a Python function initialize() that
23 returns a dictionary of Joy functions suitable for use with the joy()
26 from inspect import getdoc
27 from functools import wraps
30 from .parser import text_to_expression, Symbol
31 from .utils.stack import list_to_stack, iter_stack, pick, pushback
32 from .utils.brutal_hackery import rename_code_object
38 def inscribe(function):
39 '''A decorator to inscribe functions into the default dictionary.'''
40 _dictionary[function.name] = function
45 '''Return a dictionary of Joy functions for use with joy().'''
46 return _dictionary.copy()
55 ('mod', ['%', 'rem', 'remainder', 'modulus']),
58 ('getitem', ['pick', 'at']),
69 ('rolldown', ['roll<']),
70 ('rollup', ['roll>']),
75 def add_aliases(D, A):
77 Given a dict and a iterable of (name, [alias, ...]) pairs, create
78 additional entries in the dict mapping each alias to the named function
79 if it's in the dict. Aliases for functions not in the dict are ignored.
81 for name, aliases in A:
92 third == rest rest first
94 product == 1 swap [*] step
96 swoncat == swap concat
97 flatten == [] swap [concat] step
101 enstacken == stack [clear] dip
102 disenstacken == ? [uncons ?] loop pop
104 dinfrirst == dip infra first
105 nullary == [stack] dinfrirst
106 unary == [stack [pop] dip] dinfrirst
107 binary == [stack [popop] dip] dinfrirst
108 ternary == [stack [popop pop] dip] dinfrirst
112 size == 0 swap [pop ++] step
113 cleave == [i] app2 [popd] dip
114 average == [sum 1.0 *] [size] cleave /
115 gcd == 1 [tuck modulus dup 0 >] loop pop
116 least_fraction == dup [gcd] infra [div] concat map
117 *fraction == [uncons] dip uncons [swap] dip concat [*] infra [*] dip cons
118 *fraction0 == concat [[swap] dip * [*] dip] infra
119 down_to_zero == [0 >] [dup --] while
120 range_to_zero == unit [down_to_zero] infra
121 anamorphism == [pop []] swap [dip swons] genrec
122 range == [0 <=] [1 - dup] anamorphism
123 while == swap [nullary] cons dup dipd concat loop
125 primrec == [i] genrec
126 step_zero == 0 roll> step
130 ##z-down == [] swap uncons swap
131 ##z-up == swons swap shunt
132 ##z-right == [swons] cons dip uncons swap
133 ##z-left == swons [uncons swap] dip swap
136 ##divisor == popop 2 *
138 ##radical == swap dup * rollup * 4 * - sqrt
141 ##q0 == [[divisor] [minusb] [radical]] pam
142 ##q1 == [[root1] [root2]] pam
143 ##quadratic == [q0] ternary i [q1] ternary
147 ##PE1.1 == + dup [+] dip
148 ##PE1.2 == dup [3 & PE1.1] dip 2 >>
149 ##PE1.3 == 14811 swap [PE1.2] times pop
150 ##PE1 == 0 0 66 [7 PE1.3] times 4 PE1.3 pop
152 #PE1.2 == [PE1.1] step
153 #PE1 == 0 0 66 [[3 2 1 3 1 2 3] PE1.2] times [3 2 1 3] PE1.2 pop
157 def FunctionWrapper(f):
158 '''Set name attribute.'''
160 raise ValueError('Function %s must have doc string.' % f.__name__)
161 f.name = f.__name__.rstrip('_') # Don't shadow builtins.
165 def SimpleFunctionWrapper(f):
167 Wrap functions that take and return just a stack.
171 @rename_code_object(f.__name__)
172 def inner(stack, expression, dictionary):
173 return f(stack), expression, dictionary
177 def BinaryBuiltinWrapper(f):
179 Wrap functions that take two arguments and return a single result.
183 @rename_code_object(f.__name__)
184 def inner(stack, expression, dictionary):
185 (a, (b, stack)) = stack
187 return (result, stack), expression, dictionary
191 def UnaryBuiltinWrapper(f):
193 Wrap functions that take one argument and return a single result.
197 @rename_code_object(f.__name__)
198 def inner(stack, expression, dictionary):
201 return (result, stack), expression, dictionary
205 class DefinitionWrapper(object):
207 Provide implementation of defined functions, and some helper methods.
210 def __init__(self, name, body_text, doc=None):
211 self.name = self.__name__ = name
212 self.body = text_to_expression(body_text)
213 self._body = tuple(iter_stack(self.body))
214 self.__doc__ = doc or body_text
216 def __call__(self, stack, expression, dictionary):
217 expression = list_to_stack(self._body, expression)
218 return stack, expression, dictionary
221 def parse_definition(class_, defi):
223 Given some text describing a Joy function definition parse it and
224 return a DefinitionWrapper.
226 name, proper, body_text = (n.strip() for n in defi.partition('=='))
228 raise ValueError('Definition %r failed' % (defi,))
229 return class_(name, body_text)
232 def add_definitions(class_, defs, dictionary):
234 Scan multi-line string defs for definitions and add them to the
237 for definition in _text_to_defs(defs):
238 class_.add_def(definition, dictionary)
241 def add_def(class_, definition, dictionary):
243 Add the definition to the dictionary.
245 F = class_.parse_definition(definition)
246 dictionary[F.name] = F
249 def _text_to_defs(text):
250 return (line.strip() for line in text.splitlines() if '==' in line)
259 @SimpleFunctionWrapper
261 '''Parse the string on the stack to a Joy expression.'''
263 expression = text_to_expression(text)
264 return expression, stack
268 @SimpleFunctionWrapper
276 ((head, tail), stack) = stack
281 @SimpleFunctionWrapper
289 ((head, tail), stack) = stack
294 @SimpleFunctionWrapper
299 getitem == drop first
301 Expects an integer and a quote on the stack and returns the item at the
302 nth position in the quote counting from 0.
306 -------------------------
310 n, (Q, stack) = stack
311 return pick(Q, n), stack
315 @SimpleFunctionWrapper
322 Expects an integer and a quote on the stack and returns the quote with
323 n items removed off the top.
327 ----------------------
331 n, (Q, stack) = stack
342 @SimpleFunctionWrapper
345 Expects an integer and a quote on the stack and returns the quote with
346 just the top n items in reverse order (because that's easier and you can
347 use reverse if needed.)
351 ----------------------
355 n, (Q, stack) = stack
368 @SimpleFunctionWrapper
371 Use a Boolean value to select one of two items.
375 ----------------------
380 ---------------------
383 Currently Python semantics are used to evaluate the "truthiness" of the
384 Boolean value (so empty string, zero, etc. are counted as false, etc.)
386 (if_, (then, (else_, stack))) = stack
387 return then if if_ else else_, stack
391 @SimpleFunctionWrapper
394 Use a Boolean value to select one of two items from a sequence.
398 ------------------------
403 -----------------------
406 The sequence can contain more than two items but not fewer.
407 Currently Python semantics are used to evaluate the "truthiness" of the
408 Boolean value (so empty string, zero, etc. are counted as false, etc.)
410 (flag, (choices, stack)) = stack
411 (else_, (then, _)) = choices
412 return then if flag else else_, stack
416 @SimpleFunctionWrapper
418 '''Given a list find the maximum.'''
420 return max(iter_stack(tos)), stack
424 @SimpleFunctionWrapper
426 '''Given a list find the minimum.'''
428 return min(iter_stack(tos)), stack
432 @SimpleFunctionWrapper
434 '''Given a quoted sequence of numbers return the sum.
436 sum == 0 swap [+] step
439 return sum(iter_stack(tos)), stack
443 @SimpleFunctionWrapper
446 Expects an item on the stack and a quote under it and removes that item
447 from the the quote. The item is only removed once.
451 ------------------------
455 (tos, (second, stack)) = S
456 l = list(iter_stack(second))
458 return list_to_stack(l), stack
462 @SimpleFunctionWrapper
464 '''Given a list remove duplicate items.'''
466 I = list(iter_stack(tos))
467 list_to_stack(sorted(set(I), key=I.index))
468 return list_to_stack(sorted(set(I), key=I.index)), stack
472 @SimpleFunctionWrapper
474 '''Given a list return it sorted.'''
476 return list_to_stack(sorted(iter_stack(tos))), stack
480 @SimpleFunctionWrapper
483 The cons operator expects a list on top of the stack and the potential
484 member below. The effect is to add the potential member into the
487 (tos, (second, stack)) = S
488 return (second, tos), stack
492 @SimpleFunctionWrapper
495 Inverse of cons, removes an item from the top of the list on the stack
496 and places it under the remaining list.
500 return tos, (item, stack)
504 @SimpleFunctionWrapper
506 '''Clear everything from the stack.
517 @SimpleFunctionWrapper
519 '''Duplicate the top item on the stack.'''
521 return tos, (tos, stack)
525 @SimpleFunctionWrapper
528 Copy the second item down on the stack to the top of the stack.
541 @SimpleFunctionWrapper
544 Copy the item at TOS under the second item of the stack.
552 (tos, (second, stack)) = S
553 return tos, (second, (tos, stack))
557 @SimpleFunctionWrapper
559 '''Swap the top two items on stack.'''
560 (tos, (second, stack)) = S
561 return second, (tos, stack)
565 @SimpleFunctionWrapper
568 old_stack, stack = stack
569 return stack, old_stack
573 @SimpleFunctionWrapper
576 The stack operator pushes onto the stack a list containing all the
577 elements of the stack.
583 @SimpleFunctionWrapper
586 The unstack operator expects a list on top of the stack and makes that
587 the stack discarding the rest of the stack.
593 @SimpleFunctionWrapper
595 '''Pop and discard the top item from the stack.'''
600 @SimpleFunctionWrapper
602 '''Pop and discard the second item from the stack.'''
603 (tos, (_, stack)) = stack
608 @SimpleFunctionWrapper
610 '''Pop and discard the third item from the stack.'''
611 (tos, (second, (_, stack))) = stack
612 return tos, (second, stack)
616 @SimpleFunctionWrapper
618 '''Pop and discard the first and second items from the stack.'''
623 @SimpleFunctionWrapper
625 '''Duplicate the second item on the stack.'''
626 (tos, (second, stack)) = S
627 return tos, (second, (second, stack))
631 @SimpleFunctionWrapper
633 '''Reverse the list on the top of the stack.
636 reverse == [] swap shunt
640 for term in iter_stack(tos):
646 @SimpleFunctionWrapper
648 '''Concatinate the two lists on the top of the stack.
651 [a b c] [d e f] concat
652 ----------------------------
656 (tos, (second, stack)) = S
657 for term in reversed(list(iter_stack(second))):
663 @SimpleFunctionWrapper
665 '''Like concat but reverses the top list into the second.
668 shunt == [swons] step == reverse swap concat
670 [a b c] [d e f] shunt
671 ---------------------------
675 (tos, (second, stack)) = stack
678 second = term, second
683 @SimpleFunctionWrapper
686 Replace the two lists on the top of the stack with a list of the pairs
687 from each list. The smallest list sets the length of the result list.
689 (tos, (second, stack)) = S
692 for a, b in zip(iter_stack(tos), iter_stack(second))
694 return list_to_stack(accumulator), stack
698 @SimpleFunctionWrapper
702 return tos + 1, stack
706 @SimpleFunctionWrapper
710 return tos - 1, stack
714 @SimpleFunctionWrapper
725 a, (b, stack) = stack
731 return int(math.floor(n))
733 floor.__doc__ = math.floor.__doc__
737 @SimpleFunctionWrapper
740 divmod(x, y) -> (quotient, remainder)
742 Return the tuple (x//y, x%y). Invariant: div*y + mod == x.
751 Return the square root of the number a.
752 Negative numbers return complex roots.
757 assert a < 0, repr(a)
758 r = math.sqrt(-a) * 1j
763 @SimpleFunctionWrapper
773 (a, (b, (c, stack))) = S
774 return b, (c, (a, stack))
778 @SimpleFunctionWrapper
788 (a, (b, (c, stack))) = S
789 return c, (a, (b, stack))
794 # if isinstance(text, str):
795 # return run(text, stack)
800 @SimpleFunctionWrapper
802 '''The identity function.'''
807 @SimpleFunctionWrapper
809 '''True if the form on TOS is void otherwise False.'''
811 return _void(form), stack
815 return any(not _void(i) for i in iter_stack(form))
826 def words(stack, expression, dictionary):
827 '''Print all the words in alphabetical order.'''
828 print(' '.join(sorted(dictionary)))
829 return stack, expression, dictionary
834 def sharing(stack, expression, dictionary):
835 '''Print redistribution information.'''
836 print("You may convey verbatim copies of the Program's source code as"
837 ' you receive it, in any medium, provided that you conspicuously'
838 ' and appropriately publish on each copy an appropriate copyright'
839 ' notice; keep intact all notices stating that this License and'
840 ' any non-permissive terms added in accord with section 7 apply'
841 ' to the code; keep intact all notices of the absence of any'
842 ' warranty; and give all recipients a copy of this License along'
844 ' You should have received a copy of the GNU General Public License'
845 ' along with Thun. If not see <http://www.gnu.org/licenses/>.')
846 return stack, expression, dictionary
851 def warranty(stack, expression, dictionary):
852 '''Print warranty information.'''
853 print('THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY'
854 ' APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE'
855 ' COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM'
856 ' "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR'
857 ' IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES'
858 ' OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE'
859 ' ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS'
860 ' WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE'
861 ' COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.')
862 return stack, expression, dictionary
865 # def simple_manual(stack):
867 # Print words and help for each word.
869 # for name, f in sorted(FUNCTIONS.items()):
871 # boxline = '+%s+' % ('-' * (len(name) + 2))
874 # '| %s |' % (name,),
876 # d if d else ' ...',
886 def help_(S, expression, dictionary):
887 '''Accepts a quoted symbol on the top of the stack and prints its docs.'''
888 ((symbol, _), stack) = S
889 word = dictionary[symbol]
891 return stack, expression, dictionary
899 # Several combinators depend on other words in their definitions,
900 # we use symbols to prevent hard-coding these, so in theory, you
901 # could change the word in the dictionary to use different semantics.
902 S_choice = Symbol('choice')
903 S_first = Symbol('first')
904 S_getitem = Symbol('getitem')
905 S_genrec = Symbol('genrec')
906 S_loop = Symbol('loop')
908 S_ifte = Symbol('ifte')
909 S_infra = Symbol('infra')
910 S_step = Symbol('step')
911 S_times = Symbol('times')
912 S_swaack = Symbol('swaack')
913 S_truthy = Symbol('truthy')
918 def i(stack, expression, dictionary):
920 The i combinator expects a quoted program on the stack and unpacks it
921 onto the pending expression for evaluation.
930 return stack, pushback(quote, expression), dictionary
935 def x(stack, expression, dictionary):
941 ... [Q] x = ... [Q] dup i
942 ... [Q] x = ... [Q] [Q] i
943 ... [Q] x = ... [Q] Q
947 return stack, pushback(quote, expression), dictionary
952 def b(stack, expression, dictionary):
958 ... [P] [Q] b == ... [P] i [Q] i
959 ... [P] [Q] b == ... P Q
962 q, (p, (stack)) = stack
963 return stack, pushback(p, pushback(q, expression)), dictionary
968 def dupdip(stack, expression, dictionary):
972 [F] dupdip == dup [F] dip
982 return stack, pushback(F, (a, expression)), dictionary
987 def infra(stack, expression, dictionary):
989 Accept a quoted program and a list on the stack and run the program
990 with the list as its stack.
993 ... [a b c] [Q] . infra
994 -----------------------------
995 c b a . Q [...] swaack
998 (quote, (aggregate, stack)) = stack
999 return aggregate, pushback(quote, (stack, (S_swaack, expression))), dictionary
1004 def genrec(stack, expression, dictionary):
1006 General Recursion Combinator.
1009 [if] [then] [rec1] [rec2] genrec
1010 ---------------------------------------------------------------------
1011 [if] [then] [rec1 [[if] [then] [rec1] [rec2] genrec] rec2] ifte
1013 From "Recursion Theory and Joy" (j05cmp.html) by Manfred von Thun:
1014 "The genrec combinator takes four program parameters in addition to
1015 whatever data parameters it needs. Fourth from the top is an if-part,
1016 followed by a then-part. If the if-part yields true, then the then-part
1017 is executed and the combinator terminates. The other two parameters are
1018 the rec1-part and the rec2-part. If the if-part yields false, the
1019 rec1-part is executed. Following that the four program parameters and
1020 the combinator are again pushed onto the stack bundled up in a quoted
1021 form. Then the rec2-part is executed, where it will find the bundled
1022 form. Typically it will then execute the bundled form, either with i or
1023 with app2, or some other combinator."
1025 The way to design one of these is to fix your base case [then] and the
1026 test [if], and then treat rec1 and rec2 as an else-part "sandwiching"
1027 a quotation of the whole function.
1029 For example, given a (general recursive) function 'F':
1032 F == [I] [T] [R1] [R2] genrec
1034 If the [I] if-part fails you must derive R1 and R2 from:
1039 Just set the stack arguments in front, and figure out what R1 and R2
1040 have to do to apply the quoted [F] in the proper way. In effect, the
1041 genrec combinator turns into an ifte combinator with a quoted copy of
1042 the original definition in the else-part:
1045 F == [I] [T] [R1] [R2] genrec
1046 == [I] [T] [R1 [F] R2] ifte
1048 Primitive recursive functions are those where R2 == i.
1051 P == [I] [T] [R] primrec
1052 == [I] [T] [R [P] i] ifte
1053 == [I] [T] [R P] ifte
1056 (rec2, (rec1, stack)) = stack
1057 (then, (if_, _)) = stack
1058 F = (if_, (then, (rec1, (rec2, (S_genrec, ())))))
1059 else_ = pushback(rec1, (F, rec2))
1060 return (else_, stack), (S_ifte, expression), dictionary
1065 def map_(S, expression, dictionary):
1067 Run the quoted program on TOS on the items in the list under it, push a
1068 new list with the results (in place of the program and original list.
1070 # (quote, (aggregate, stack)) = S
1071 # results = list_to_stack([
1072 # joy((term, stack), quote, dictionary)[0][0]
1073 # for term in iter_stack(aggregate)
1075 # return (results, stack), expression, dictionary
1076 (quote, (aggregate, stack)) = S
1078 return (aggregate, stack), expression, dictionary
1080 for term in iter_stack(aggregate):
1082 batch = (s, (quote, (S_infra, (S_first, batch))))
1083 stack = (batch, ((), stack))
1084 return stack, (S_infra, expression), dictionary
1087 #def cleave(S, expression, dictionary):
1089 # The cleave combinator expects two quotations, and below that an item X.
1090 # It first executes [P], with X on top, and saves the top result element.
1091 # Then it executes [Q], again with X, and saves the top result.
1092 # Finally it restores the stack to what it was below X and pushes the two
1093 # results P(X) and Q(X).
1095 # (Q, (P, (x, stack))) = S
1096 # p = joy((x, stack), P, dictionary)[0][0]
1097 # q = joy((x, stack), Q, dictionary)[0][0]
1098 # return (q, (p, stack)), expression, dictionary
1103 def branch(stack, expression, dictionary):
1105 Use a Boolean value to select one of two quoted programs to run.
1109 branch == roll< choice i
1113 False [F] [T] branch
1114 --------------------------
1118 -------------------------
1122 (then, (else_, (flag, stack))) = stack
1123 return stack, pushback(then if flag else else_, expression), dictionary
1128 def ifte(stack, expression, dictionary):
1130 If-Then-Else Combinator
1133 ... [if] [then] [else] ifte
1134 ---------------------------------------------------
1135 ... [[else] [then]] [...] [if] infra select i
1140 ... [if] [then] [else] ifte
1141 -------------------------------------------------------
1142 ... [else] [then] [...] [if] infra first choice i
1145 Has the effect of grabbing a copy of the stack on which to run the
1146 if-part using infra.
1148 (else_, (then, (if_, stack))) = stack
1149 expression = (S_infra, (S_first, (S_choice, (S_i, expression))))
1150 stack = (if_, (stack, (then, (else_, stack))))
1151 return stack, expression, dictionary
1156 def cond(stack, expression, dictionary):
1158 This combinator works like a case statement. It expects a single quote
1159 on the stack that must contain zero or more condition quotes and a
1160 default quote. Each condition clause should contain a quoted predicate
1161 followed by the function expression to run if that predicate returns
1162 true. If no predicates return true the default function runs.
1164 It works by rewriting into a chain of nested `ifte` expressions, e.g.::
1166 [[[B0] T0] [[B1] T1] [D]] cond
1167 -----------------------------------------
1168 [B0] [T0] [[B1] [T1] [D] ifte] ifte
1171 conditions, stack = stack
1173 expression = _cond(conditions, expression)
1175 # Attempt to preload the args to first ifte.
1176 (P, (T, (E, expression))) = expression
1178 # If, for any reason, the argument to cond should happen to contain
1179 # only the default clause then this optimization will fail.
1182 stack = (E, (T, (P, stack)))
1183 return stack, expression, dictionary
1186 def _cond(conditions, expression):
1187 (clause, rest) = conditions
1188 if not rest: # clause is [D]
1191 return (P, (T, (_cond(rest, ()), (S_ifte, expression))))
1196 def dip(stack, expression, dictionary):
1198 The dip combinator expects a quoted program on the stack and below it
1199 some item, it hoists the item into the expression and runs the program
1200 on the rest of the stack.
1208 (quote, (x, stack)) = stack
1209 expression = (x, expression)
1210 return stack, pushback(quote, expression), dictionary
1215 def dipd(S, expression, dictionary):
1217 Like dip but expects two items.
1221 ---------------------
1225 (quote, (x, (y, stack))) = S
1226 expression = (y, (x, expression))
1227 return stack, pushback(quote, expression), dictionary
1232 def dipdd(S, expression, dictionary):
1234 Like dip but expects three items.
1238 -----------------------
1242 (quote, (x, (y, (z, stack)))) = S
1243 expression = (z, (y, (x, expression)))
1244 return stack, pushback(quote, expression), dictionary
1249 def app1(S, expression, dictionary):
1251 Given a quoted program on TOS and anything as the second stack item run
1252 the program and replace the two args with the first result of the
1257 -----------------------------------
1258 ... [x ...] [Q] . infra first
1260 (quote, (x, stack)) = S
1261 stack = (quote, ((x, stack), stack))
1262 expression = (S_infra, (S_first, expression))
1263 return stack, expression, dictionary
1268 def app2(S, expression, dictionary):
1269 '''Like app1 with two items.
1273 -----------------------------------
1274 ... [y ...] [Q] . infra first
1275 [x ...] [Q] infra first
1278 (quote, (x, (y, stack))) = S
1279 expression = (S_infra, (S_first,
1280 ((x, stack), (quote, (S_infra, (S_first,
1282 stack = (quote, ((y, stack), stack))
1283 return stack, expression, dictionary
1288 def app3(S, expression, dictionary):
1289 '''Like app1 with three items.
1292 ... z y x [Q] . app3
1293 -----------------------------------
1294 ... [z ...] [Q] . infra first
1295 [y ...] [Q] infra first
1296 [x ...] [Q] infra first
1299 (quote, (x, (y, (z, stack)))) = S
1300 expression = (S_infra, (S_first,
1301 ((y, stack), (quote, (S_infra, (S_first,
1302 ((x, stack), (quote, (S_infra, (S_first,
1303 expression))))))))))
1304 stack = (quote, ((z, stack), stack))
1305 return stack, expression, dictionary
1310 def step(S, expression, dictionary):
1312 Run a quoted program on each item in a sequence.
1316 -----------------------
1321 ------------------------
1325 ... [a b c] [Q] . step
1326 ----------------------------------------
1327 ... a . Q [b c] [Q] step
1329 The step combinator executes the quotation on each member of the list
1330 on top of the stack.
1332 (quote, (aggregate, stack)) = S
1334 return stack, expression, dictionary
1335 head, tail = aggregate
1336 stack = quote, (head, stack)
1338 expression = tail, (quote, (S_step, expression))
1339 expression = S_i, expression
1340 return stack, expression, dictionary
1345 def times(stack, expression, dictionary):
1347 times == [-- dip] cons [swap] infra [0 >] swap while pop
1351 --------------------- w/ n <= 0
1356 ---------------------------------
1361 --------------------------------- w/ n > 1
1362 ... . Q (n - 1) [Q] times
1365 # times == [-- dip] cons [swap] infra [0 >] swap while pop
1366 (quote, (n, stack)) = stack
1368 return stack, expression, dictionary
1371 expression = n, (quote, (S_times, expression))
1372 expression = pushback(quote, expression)
1373 return stack, expression, dictionary
1376 # The current definition above works like this:
1379 # --------------------------------------
1380 # [P] nullary [Q [P] nullary] loop
1382 # while == [pop i not] [popop] [dudipd] primrec
1384 #def while_(S, expression, dictionary):
1385 # '''[if] [body] while'''
1386 # (body, (if_, stack)) = S
1387 # while joy(stack, if_, dictionary)[0][0]:
1388 # stack = joy(stack, body, dictionary)[0]
1389 # return stack, expression, dictionary
1394 def loop(stack, expression, dictionary):
1396 Basic loop combinator.
1400 -----------------------
1404 ------------------------
1408 quote, (flag, stack) = stack
1410 expression = pushback(quote, (quote, (S_loop, expression)))
1411 return stack, expression, dictionary
1416 def cmp_(stack, expression, dictionary):
1418 cmp takes two values and three quoted programs on the stack and runs
1419 one of the three depending on the results of comparing the two values:
1423 ------------------------- a > b
1427 ------------------------- a = b
1431 ------------------------- a < b
1434 L, (E, (G, (b, (a, stack)))) = stack
1435 expression = pushback(G if a > b else L if a < b else E, expression)
1436 return stack, expression, dictionary
1439 #def nullary(S, expression, dictionary):
1441 # Run the program on TOS and return its first result without consuming
1442 # any of the stack (except the program on TOS.)
1444 # (quote, stack) = S
1445 # result = joy(stack, quote, dictionary)
1446 # return (result[0][0], stack), expression, dictionary
1449 #def unary(S, expression, dictionary):
1450 # (quote, stack) = S
1451 # _, return_stack = stack
1452 # result = joy(stack, quote, dictionary)[0]
1453 # return (result[0], return_stack), expression, dictionary
1456 #def binary(S, expression, dictionary):
1457 # (quote, stack) = S
1458 # _, (_, return_stack) = stack
1459 # result = joy(stack, quote, dictionary)[0]
1460 # return (result[0], return_stack), expression, dictionary
1463 #def ternary(S, expression, dictionary):
1464 # (quote, stack) = S
1465 # _, (_, (_, return_stack)) = stack
1466 # result = joy(stack, quote, dictionary)[0]
1467 # return (result[0], return_stack), expression, dictionary
1470 # FunctionWrapper(binary),
1471 # FunctionWrapper(cleave),
1472 # FunctionWrapper(nullary),
1473 # FunctionWrapper(ternary),
1474 # FunctionWrapper(unary),
1475 # FunctionWrapper(while_),
1479 BinaryBuiltinWrapper(operator.add),
1480 BinaryBuiltinWrapper(operator.and_),
1481 BinaryBuiltinWrapper(operator.div),
1482 BinaryBuiltinWrapper(operator.eq),
1483 BinaryBuiltinWrapper(operator.floordiv),
1484 BinaryBuiltinWrapper(operator.ge),
1485 BinaryBuiltinWrapper(operator.gt),
1486 BinaryBuiltinWrapper(operator.le),
1487 BinaryBuiltinWrapper(operator.lshift),
1488 BinaryBuiltinWrapper(operator.lt),
1489 BinaryBuiltinWrapper(operator.mod),
1490 BinaryBuiltinWrapper(operator.mul),
1491 BinaryBuiltinWrapper(operator.ne),
1492 BinaryBuiltinWrapper(operator.or_),
1493 BinaryBuiltinWrapper(operator.pow),
1494 BinaryBuiltinWrapper(operator.rshift),
1495 BinaryBuiltinWrapper(operator.sub),
1496 BinaryBuiltinWrapper(operator.truediv),
1497 BinaryBuiltinWrapper(operator.xor),
1499 UnaryBuiltinWrapper(abs),
1500 UnaryBuiltinWrapper(bool),
1501 UnaryBuiltinWrapper(floor),
1502 UnaryBuiltinWrapper(operator.neg),
1503 UnaryBuiltinWrapper(operator.not_),
1504 UnaryBuiltinWrapper(sqrt),
1507 del F # Otherwise Sphinx autodoc will pick it up.
1510 add_aliases(_dictionary, ALIASES)
1513 DefinitionWrapper.add_definitions(definitions, _dictionary)