59 lines
670 B
ReStructuredText
59 lines
670 B
ReStructuredText
--------------
|
|
|
|
select
|
|
^^^^^^^^
|
|
|
|
Basis Function Combinator
|
|
|
|
|
|
Use a Boolean value to select one of two items from a sequence.
|
|
::
|
|
|
|
[A B] false select
|
|
------------------------
|
|
A
|
|
|
|
|
|
[A B] true select
|
|
-----------------------
|
|
B
|
|
|
|
The sequence can contain more than two items but not fewer.
|
|
Currently Python semantics are used to evaluate the "truthiness" of the
|
|
Boolean value (so empty string, zero, etc. are counted as false, etc.)
|
|
|
|
|
|
Gentzen diagram.
|
|
|
|
|
|
Definition
|
|
~~~~~~~~~~
|
|
|
|
if not basis.
|
|
|
|
|
|
Derivation
|
|
~~~~~~~~~~
|
|
|
|
if not basis.
|
|
|
|
|
|
Source
|
|
~~~~~~~~~~
|
|
|
|
if basis
|
|
|
|
|
|
Discussion
|
|
~~~~~~~~~~
|
|
|
|
Lorem ipsum.
|
|
|
|
|
|
Crosslinks
|
|
~~~~~~~~~~
|
|
|
|
Lorem ipsum.
|
|
|
|
|