std-dotted-pair-p


Synopsis

(std-dotted-pair-p <expr>)

Description

Predicate if the expression is a dotted pair, as (x . y) created with (CONS <atom> <atom>)

Examples

(std-dotted-pair-p '(0 . 1))   => T
(std-dotted-pair-p '((0 . 1))) => nil
(std-dotted-pair-p '(0 1 . 2)) => nil

Note

There exists bad lists like (0 1 . 2) which are no valid lists and no dotted pairs. You cannot pass them to list functions like LENGTH or LAST.

Arguments

expr: any valid lisp expression

Return Value

T or nil.

Side Effects

None.

Module

(std-require 'STDLIST)

Defined in STDLIST