factor/library/styles.factor

! :folding=indent:collapseFolds=1:

! $Id$
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! Copyright (C) 2004 Slava Pestov.
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IN: styles
USE: combinators
USE: kernel
USE: lists
USE: namespaces
USE: stack

! A style is an alist whose key/value pairs hold
! significance to the 'fwrite-attr' word when applied to a
! stream that supports attributed string output.

: default-style ( -- style )
    #! Push the default style object.
    "styles" get [ "default" get ] bind ;

: paragraph ( -- style )
    #! Push the paragraph break meta-style.
    "styles" get [ "paragraph" get ] bind ;

: <style> ( alist -- )
    #! Create a new style object, cloned from the default
    #! style.
    default-style clone tuck alist> ;

: get-style ( obj-path -- style )
    #! Push a style named by an object path, for example
    #! [ "prompt" ] or [ "vocabularies" "math" ].
    dup [
        "styles" get [ object-path ] bind
        [ default-style ] unless*
    ] [
        drop default-style
    ] ifte ;

: set-style ( style name -- )
    ! XXX: use object path...
    "styles" get [ set ] bind ;

: init-styles ( -- )
    <namespace> "styles" set

    [
        [ "font" | "Monospaced" ]
    ] "default" set-style

    [
        [ "bold" | t ]
    ] default-style append "prompt" set-style
    
    [
        [ "ansi-fg" | "0" ]
        [ "ansi-bg" | "2" ]
        [ "fg" | [ 255 0 0 ] ]
    ] default-style append "comments" set-style ;