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: namespaces
USE: stack

!!! A style is a namespace whose variable names and values hold
!!! significance to the 'fwrite-attr' word when applied to a
!!! stream that supports attributed string output.
!!!
!!! The default style enumerates the canonical names and values
!!! to determine a style.

: 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
    "styles" get [
        <namespace> [
            f "ansi-fg"         set
            f "ansi-bg"         set
            f "fg"              set
            f "bg"              set
            f "bold"            set
            f "italics"         set
            f "underline"       set
            f "link"            set
            "Monospaced" "font" set
        ] extend "default"      set
    
        ! A paragraph break
        <namespace> [
            t "paragraph"       set
        ] extend "paragraph"    set
    ] bind

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

init-styles