define-color-alias

define-color-alias Function

Summary

Lets you define an alias for a color specification or alias.

Package

color

Signature

define-color-alias name color &optional if-exists => name

Arguments

`name`⇩	The name of the new alias.
`color`⇩	A color specification for the new alias.
`if-exists`⇩	One of `:replace`, `:error` or `:ignore`.

Values

name

The name of the new alias.

Description

The function define-color-alias defines name to be a color alias for color, which may be another color alias or a color spec.

When color is a color spec rather than another color name, the entry is better described as a "color translation" rather than a "color alias". In particular, calling get-color-alias-translation on name will just return name. get-color-spec with name will return color.

if-exists controls what happens in name is already a known alias:

`:replace`	Replace any existing alias.
`:error`	Raise an error if alias is already defined.
`:ignore`	Ignore redefinition of an alias.

if-exists defaulrs to :replace.

Examples: 1

CL-USER 16 > (color:define-color-alias :mygray :darkslategray)
:mygray
 
CL-USER 17 > (color:define-color-alias :mygray :darkslategray
                                       :error)
 
Error: :MYGRAY names an existing alias for #(:RGB 0.1843133S0 0.309803S0 0.309803S0)
  1 (continue) Replace :MYGRAY with the alias :DARKSLATEGRAY
  2 Continue, without redefining alias :MYGRAY
  3 Try a new name for the alias, instead of :MYGRAY
  4 (abort) Return to level 0.
  5 Return to top loop level 0.
  6 Destroy process.
 
Type :c followed by a number to proceed or type :? for other options
 
CL-USER 18 : 1 >

Examples: 2

CL-USER 19 > (color:define-color-alias :lispworks-blue 
                (color:make-rgb 0.70s0 0.90s0 0.99s0))
:lispworks-blue
 
CL-USER 20 >