Core library

This page lists the public words currently defined in the top-level core library module.

core.ff

Source: ff/lib/core/core.ff
Import: .import <core/core>

Word	Stack effect	Description
true	-- 1	Pushes the canonical true value.
false	-- 0	Pushes the canonical false value.
--	n -- n-1	Decrements an integer by one.
++	n -- n+1	Increments an integer by one.
pred	n -- n n-1	Duplicates a value and pushes its predecessor.
succ	n -- n n+1	Duplicates a value and pushes its successor.
slip	[A] b -- a* b	Runs a quotation under the top value and restores that value afterward.
swapd	a b c -- b a c	Swaps the lower two items of the top three.
dupd	a b -- a a b	Duplicates the second item while leaving the top item in place.
drop2	a b --	Drops the top two values.
dip	a [B] -- b* a	Runs a quotation while temporarily stashing the top item.
dipd	a b [B] -- b* a b	Runs a quotation under the top two items.
dig	a b c -- b c a	Rotates the third item to the top.
bury	a b c -- c a b	Rotates the top item below the next two items.
rot	a b c -- c b a	Reorders the top three values by reversing their outer positions.
over	a b -- a b a	Copies the second item to the top.
dup2	a b -- a b a b	Duplicates the top pair.
run	[A] -- a* [A]	Evaluates a quotation while leaving the quotation on the stack.
nip	a b -- b	Removes the second item from the top pair.
tuck	a b -- b a b	Copies the top item beneath the next item.
sip	a [B] -- a b* a	Runs a quotation with a copy of the preserved top item.
sipd	a [B] c -- a b* a c	Runs sip one level deeper under the top item.
bi	a [B] [C] -- b c	Applies two quotations to the same input value.
bi2	a b [C] [D] -- c d	Applies two quotations to the same input pair.
zero?	n -- flag	Tests whether a value is zero.
not	flag -- flag'	Logical negation for truthy/falsey integer flags.
nz?	n -- flag	Tests whether a value is non-zero.
truthy?	n -- flag	Normalizes a value to a truthiness flag.
falsey?	n -- flag	Tests whether a value is falsey.
!=	a b -- flag	Tests whether two values differ.
<=	a b -- flag	Tests whether a is less than or equal to b.
>=	a b -- flag	Tests whether a is greater than or equal to b.
sort2	a b -- min max	Orders a pair from smaller to larger.
between?	lo hi n -- flag	Tests whether a value lies between two bounds.
bxor	a b -- n	Computes bitwise exclusive-or.
and	a b -- flag	Returns a truthy flag when both inputs are truthy.
or	a b -- flag	Returns a truthy flag when either input is truthy.
nand	a b -- flag	Returns the negation of and.
nor	a b -- flag	Returns the negation of or.
or_else	a [B] [C] -- flag	Short-circuits to true or evaluates a fallback quotation.
and_also	a [B] [C] -- flag	Short-circuits to false or evaluates a continuation quotation.
choose	a b flag -- a or b	Selects one of two values based on a flag.
branch	a flag [B] [C] -- b* or c*	Evaluates one of two quotations based on a flag.
empty?	… -- … flag	Tests whether the data stack is empty.
pushtop	… a -- a …	Moves the top item to the bottom of the current stack.
loop	a [B] n -- a b* [B]	Repeats a quotation n times, leaving the quotation.
times	a [B] n -- a b*	Repeats a quotation n times and discards the quotation.
seq	a n [B] -- a b*	Builds a sequence of repeated quotation applications from a seed value.
range	a b -- a..b	Expands an inclusive integer range.
count	n -- 1..n	Pushes the integers from 1 through n.