chickadee » eggdoc


An egg documentation tool.


Note to egg authors: Please don't document your eggs using eggdoc anymore! The canonical documentation source is the Chicken wiki, and wiki pages are the recommended way to document eggs.

eggdoc is an SXML documentation tool which produces HTML pages for Chicken eggs. It uses the sxml-transforms extension to transform your SXML via a comprehensive XML stylesheet, simplifying the creation of egg documentation. It's also quite customizable.

Other eggs, such as eggdoc-svnwiki and eggdoc-texinfo, can be loaded to transform your source document into other formats.


Generic API

eggdoc:transform DOC #!optional STYLESHEETprocedure
eggdoc->html DOC #!optional STYLESHEETprocedure

Transform the SXML document DOC using the optional SXSLT stylesheet STYLESHEET. If not specified, the built-in stylesheet will be used, which is also accessible with (eggdoc:make-stylesheet). Transformation output is displayed to current-output-port. Also returns the parse result as an alist (see eggdoc:result).

This is a generic transformer which by default outputs HTML, but can be overridden by other eggs (such as eggdoc-svnwiki) to output other formats. By default, eggdoc:transformer will invoke eggdoc->html/really.

eggdoc->html is a deprecated alias to eggdoc:transform and historically was the entry point to eggdoc. The name is a misnomer, as it can be overridden to generate other formats.

eggdoc:make-stylesheet DOCprocedure

Returns the default SXSLT stylesheet. This is a procedure because the stylesheet is built dynamically using the contents of the SXML document DOC. For example, the value of the (name) tag is retrieved at build time and inserted in the header and the usage information.

You can append to or modify this stylesheet and then pass it to eggdoc->html. This is done in doctype's eggdoc to provide a new tag, (strings), which makes the SXML much cleaner.

This procedure invokes eggdoc:make-html-stylesheet by default. However, it may be overridden by other eggs to return other stylesheet formats; for example, eggdoc-svnwiki may return an SXML->svnwiki stylesheet.

HTML output API

This is the underlying HTML output API used by the default eggdoc:transform transformer. Typically, it is not necessary to call these directly, although you might want to alter the HTML doctype or CSS.

eggdoc:make-html-stylesheet DOCprocedure

Returns the default SXML to HTML stylesheet.

eggdoc->html/really DOCprocedure

Transform eggdoc to HTML using eggdoc:make-html-stylesheet. This procedure ensures you will get HTML output regardless of any transformer overrides.


The DOCTYPE for this document, typically as defined in the doctype extension. This defaults to doctype:xhtml-1.0-strict.


CSS text inserted verbatim between the document's <style> tags. This must be <!-- wrapped in HTML comments -->. The default is quite reasonable.

If you wish to source a CSS file instead of inserting the text directly, you can override the eggdoc-style tag in the default stylesheet to do so.

Miscellaneous API

eggdoc:warnings BOOLparameter

If #t, warn on transformation errors. If #f, transformation error output is suppressed. Defaults to #t.

eggdoc:make-defsig TAG SIG BODYprocedure

Use this procedure inside a stylesheet to generate a new signature tag, just like procedure or macro. It expands to a (definition (signatures (signature ...))) expression. For example,

(eggdoc->html doc `( ,@(eggdoc:make-stylesheet doc)
                     (constant *macro* . ,eggdoc:make-defsig)
                     (method   *macro* . ,eggdoc:make-defsig) ))

will create new constant and method tags.

Internal API

This API is used by eggs such as eggdoc-svnwiki to override the default output format.


The default stylesheet creator, invoked by eggdoc:make-stylesheet. Defaults to eggdoc:make-html-stylesheet.


The default output transformer, invoked by eggdoc:transform (and eggdoc->html). Defaults to eggdoc->html/really.


An alist containing the parse result for the last parse. The same value is returned from the eggdoc transformer, but some eggdoc scripts discard it.

The only key currently defined is name, which contains the egg name as derived by eggdoc:derive-egg-name.

eggdoc:derive-egg-name DOCprocedure

Get egg name from DOC from the name element. Implicitly adds a (name NAME) association to eggdoc:results.

Document structure


Document section tags must be nested in the order section -> subsection -> subsubsection -> subsubsubsection. You may not nest section tags of the same level, as in (section "name" (section ...)), and you may not skip a level. eggdoc won't complain if you violate these rules---the HTML driver is pretty lax---but the appearance will be off and eggdoc-texinfo will fail on such a document. eggdoc-texinfo is more sensitive to malformed documents, so it is recommended to generate .info and .pdf output as well to ensure your document is correct.

documentation, examples, and license are section tags in disguise. In particular, (documentation (section ...)) is invalid; use (documentation (subsection ...)).


Complete examples for the Chicken extensions args, doctype, eggdoc, hostinfo, sxml-tools, sxml-transforms, and vector-lib are provided in the egg under src/.

About this egg


Jim Ursetto

Version history

transformer override mechanism
eggdoc:make-defsig; subsub[sub]section tags; with-default-param tag
setup scripts adds documentation and version info [Thanks to Jim Miller]
Initial release




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