chickadee » scss

scss

Description

An implementation of the s-expression based CSS notation SCSS. It slightly modifies and extends the original implementation of the WebIt! (site seems defunct) framework.

Author

Moritz Heidkamp

Documentation

Only the emitter side is implemented at the moment.

Syntax

stylesheet ::= (css <import-clause>* <rule>+)

import-clause ::= (import <string>)

rule ::= (<complex-selector> <declaration>+)

complex-selector ::= <single-selector> |
                     <grouping-selector>

simple-selector ::= <symbol> |
                    (= class <symbol>) |
                    (= class <simple-selector> <symbol>) |
                    (= pclass <symbol>) |
                    (= pclass <simple-selector> <symbol>) |
                    (= id <symbol>) |
                    (= id <simple-selector> <symbol>)

path-selector ::= (<combinator> <single-selector>+)

combinator ::= // | + | >

single-selector ::= <simple-selector> |
                    <path-selector>

grouping-selector ::= (<single-selector>+)

declaration ::= (<symbol> <scheme-expression>) |
                (! (<symbol> <scheme-expression>))

Alternatively the following extended syntax dubbed SCSS Plus is available:

stylesheet ::= (css+ <import-clause>* <rule>+)

import-clause ::= (import <string>)

rule ::= (<complex-selector> [<declaration> | <nested-rule>]+)

nested-rule ::= (<path-selector> [<declaration> | <nested-rule>]+)

complex-selector ::= <single-selector> |
                     <grouping-selector>

simple-selector ::= <symbol> |
                    (= class <symbol>) |
                    (= class <simple-selector> <symbol>) |
                    (= pclass <symbol>) |
                    (= pclass <simple-selector> <symbol>) |
                    (= id <symbol>) |
                    (= id <simple-selector> <symbol>)

path-selector ::= (<combinator> <single-selector>+)

combinator ::= // | + | > | &

single-selector ::= <simple-selector> |
                    <path-selector>

grouping-selector ::= (<single-selector>+)

declaration ::= (<symbol> <scheme-expression>) |
                (! (<symbol> <scheme-expression>))

The two differences are that you can nest rules which results in much more compact stylesheets as well as use the & combinator which will concatenate nested selectors.

Emitter

write-css scss #!optional portprocedure

Write the CSS translation of scss (which is a list following the syntax described under Syntax) to port.

css->scss scssprocedure

Like write-css but returns the CSS translation as a string instead of writing it to a port.

scss2css

scss2css is a program that is installed with this egg. It takes a file name argument which should contain an SCSS document. If no file name is given it will read from standard input instead. The document will be read and evaled. The result of that is passed to scss->css which in turn writes the resulting CSS to standard output. When the -n option is passed the document won't be evaled.

Examples

Basic

(write-css '(css (p (text-align center))))

=>

p { text-align: center } 

More Complex

(write-css '(css (((= class p note) (+ p p))
                  (font-style italic)
                  (background-color "#ccc"))
                 (|#content| 
                  (width 100em))))

=>

p.note, p + p { font-style: italic; background-color: #ccc }
#content { width: 100em }

SCSS Plus

(write-css '(css+ ((= id main)
                   (display block)
                   ((// p)
                    (font-size 1em)
                    ((& .error)
                     (! (color red)))))))

=>

#main { display: block }
#main p { font-size: 1em }
#main p.error { color: red !important }

History

0.5.0
Re-implemented from scratch, fixing various corner cases. The undocumented scss-plus module that was installed by previous versions does not exist anymore. scss->css returns a string instead of writing to a port. Instead, write-css can be used to write to a port now.

License

 Copyright (c) 2010-2014, Moritz Heidkamp
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are
 met:
 
 Redistributions of source code must retain the above copyright
 notice, this list of conditions and the following disclaimer.
 
 Redistributions in binary form must reproduce the above copyright
 notice, this list of conditions and the following disclaimer in the
 documentation and/or other materials provided with the distribution.
 
 Neither the name of the author nor the names of its contributors may
 be used to endorse or promote products derived from this software
 without specific prior written permission.
 
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 OF THE POSSIBILITY OF SUCH DAMAGE.

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