(guile.info.gz) List Predicates
Info Catalog
(guile.info.gz) List Syntax
(guile.info.gz) Lists
(guile.info.gz) List Constructors
22.2.2 List Predicates
----------------------
Often it is useful to test whether a given Scheme object is a list or
not. List-processing procedures could use this information to test
whether their input is valid, or they could do different things
depending on the datatype of their arguments.
-- Scheme Procedure: list? x
-- C Function: scm_list_p (x)
Return `#t' iff X is a proper list, else `#f'.
The predicate `null?' is often used in list-processing code to tell
whether a given list has run out of elements. That is, a loop somehow
deals with the elements of a list until the list satisfies `null?'.
Then, the algorithm terminates.
-- Scheme Procedure: null? x
-- C Function: scm_null_p (x)
Return `#t' iff X is the empty list, else `#f'.
Info Catalog
(guile.info.gz) List Syntax
(guile.info.gz) Lists
(guile.info.gz) List Constructors
automatically generated byinfo2html