Help: Clarify if(<variable>) documentation (#15335)

When the variable is not defined the signature is actually accepting
a string.  Also clarify fall-through from if(<constant>) case.
This commit is contained in:
Brad King 2015-01-08 13:36:11 -05:00
parent c118816d44
commit 7a2c3f0c0e

View File

@ -42,11 +42,12 @@ Possible expressions are:
or a non-zero number. False if the constant is ``0``, ``OFF``,
``NO``, ``FALSE``, ``N``, ``IGNORE``, ``NOTFOUND``, the empty string,
or ends in the suffix ``-NOTFOUND``. Named boolean constants are
case-insensitive. If the argument is not one of these constants, it
is treated as a variable.
case-insensitive. If the argument is not one of these specific
constants, it is treated as a variable or string and the following
signature is used.
``if(<variable>)``
True if the variable is defined to a value that is not a false
``if(<variable|string>)``
True if given a variable that is defined to a value that is not a false
constant. False otherwise. (Note macro arguments are not variables.)
``if(NOT <expression>)``