- 1 mgl-pax ASDF System Details
- 2 Links
- 3 Background
- 4 Tutorial
- 5 Emacs Integration
- 6 Basics
- 7 Markdown Support
- 8 Documentation Printer Variables
- 9 Locative Types
- 10 Extension API
- 11 Transcripts
- 12 Utilities
- Version: 0.0.2
- Description: Exploratory programming tool and documentation generator.
- Licence: MIT, see COPYING.
- Author: Gábor Melis
- Mailto: [email protected]
- Homepage: http:https://quotenil.com
Here is the official repository and the HTML documentation for the latest version.
As a user, I frequently run into documentation that's incomplete
and out of date, so I tend to stay in the editor and explore the
code by jumping around with SLIME's M-.
. As a library
author, I spend a great deal of time polishing code, but precious
little writing documentation.
In fact, I rarely write anything more comprehensive than docstrings for exported stuff. Writing docstrings feels easier than writing a separate user manual and they are always close at hand during development. The drawback of this style is that users of the library have to piece the big picture together themselves.
That's easy to solve, I thought, let's just put all the narrative that holds docstrings together in the code and be a bit like a Literate Programming weenie turned inside out. The original prototype which did almost everything I wanted was this:
(defmacro defsection (name docstring)
`(defun ,name () ,docstring))
Armed with DEFSECTION
, I soon found myself organizing code following
the flow of user level documentation and relegated comments to
implementational details entirely. However, some portions of
DEFSECTION
docstrings were just listings of all the functions,
macros and variables related to the narrative, and this list was
effectively repeated in the DEFPACKAGE
form complete with little
comments that were like section names. A clear violation of
OAOO, one of them had to go, so DEFSECTION
got a list of
symbols to export.
That was great, but soon I found that the listing of symbols is
ambiguous if, for example, a function, a compiler macro and a class
are named by the same symbol. This did not concern exporting, of
course, but it didn't help readability. Distractingly, on such
symbols, M-.
was popping up selection dialogs. There were two
birds to kill, and the symbol got accompanied by a type which was
later generalized into the concept of locatives:
(defsection @mgl-pax-introduction ()
"A single line for one man ..."
(foo class)
(bar function))
After a bit of elisp hacking, M-.
was smart enough to disambiguate
based on the locative found in the vicinity of the symbol and
everything was good for a while.
Then I realized that sections could refer to other sections if there
were a SECTION
locative. Going down that path, I soon began to feel
the urge to generate pretty documentation as all the necessary
information was manifest in the DEFSECTION
forms. The design
constraint imposed on documentation generation was that following
the typical style of upcasing symbols in docstrings there should be
no need to explicitly mark up links: if M-.
works, then the
documentation generator shall also be able find out what's being
referred to.
I settled on Markdown as a reasonably non-intrusive format, and a few thousand lines later PAX was born.
PAX provides an extremely poor man's Explorable Programming environment. Narrative primarily lives in so called sections that mix markdown docstrings with references to functions, variables, etc, all of which should probably have their own docstrings.
The primary focus is on making code easily explorable by using
SLIME's M-.
(slime-edit-definition
). See how to enable some
fanciness in Emacs Integration. Generating documentation
from sections and all the referenced items in Markdown or HTML
format is also implemented.
With the simplistic tools provided, one may accomplish similar effects as with Literate Programming, but documentation is generated from code, not vice versa and there is no support for chunking yet. Code is first, code must look pretty, documentation is code.
In typical use, PAX packages have no :EXPORT
's defined. Instead the
DEFINE-PACKAGE
form gets a docstring which may mention section
names (defined with DEFSECTION
). When the code is loaded into the
lisp, pressing M-.
in SLIME on the name of the section will take
you there. Sections can also refer to other sections, packages,
functions, etc and you can keep exploring.
Here is an example of how it all works together:
(mgl-pax:define-package :foo-random
(:documentation "This package provides various utilities for
random. See FOO-RANDOM:@FOO-RANDOM-MANUAL.")
(:use #:common-lisp #:mgl-pax))
(in-package :foo-random)
(defsection @foo-random-manual (:title "Foo Random manual")
"Here you describe what's common to all the referenced (and
exported) functions that follow. They work with *FOO-STATE*,
and have a :RANDOM-STATE keyword arg. Also explain when to
choose which."
(foo-random-state class)
(state (reader foo-random-state))
"Hey we can also print states!"
(print-object (method () (foo-random-state t)))
(*foo-state* variable)
(gaussian-random function)
(uniform-random function)
;; this is a subsection
(@foo-random-examples section))
(defclass foo-random-state ()
((state :reader state)))
(defmethod print-object ((object foo-random-state) stream)
(print-unreadable-object (object stream :type t)))
(defvar *foo-state* (make-instance 'foo-random-state)
"Much like *RANDOM-STATE* but uses the FOO algorithm.")
(defun uniform-random (limit &key (random-state *foo-state*))
"Return a random number from the between 0 and LIMIT (exclusive)
uniform distribution."
nil)
(defun gaussian-random (stddev &key (random-state *foo-state*))
"Return a random number from a zero mean normal distribution with
STDDEV."
nil)
(defsection @foo-random-examples (:title "Examples")
"Let's see the transcript of a real session of someone working
with FOO:
```cl-transcript
(values (princ :hello) (list 1 2))
.. HELLO
=> :HELLO
=> (1 2)
(make-instance 'foo-random-state)
==> #<FOO-RANDOM-STATE >
```")
Generating documentation in a very stripped down markdown format is easy:
(describe @foo-random-manual)
For this example, the generated markdown would look like this:
# Foo Random manual
###### \[in package FOO-RANDOM\]
Here you describe what's common to all the referenced (and
exported) functions that follow. They work with *FOO-STATE*,
and have a :RANDOM-STATE keyword arg. Also explain when to
choose which.
- [class] FOO-RANDOM-STATE
- [reader] STATE FOO-RANDOM-STATE
Hey we can also print states!
- [method] PRINT-OBJECT (OBJECT FOO-RANDOM-STATE) STREAM
- [variable] *FOO-STATE* #<FOO-RANDOM-STATE >
Much like *RANDOM-STATE* but uses the FOO algorithm.
- [function] GAUSSIAN-RANDOM STDDEV &KEY (RANDOM-STATE *FOO-STATE*)
Return a random number from a zero mean normal distribution with
STDDEV.
- [function] UNIFORM-RANDOM LIMIT &KEY (RANDOM-STATE *FOO-STATE*)
Return a random number from the between 0 and LIMIT (exclusive)
uniform distribution.
## Examples
Let's see the transcript of a real session of someone working
with FOO:
```cl-transcript
(values (princ :hello) (list 1 2))
.. HELLO
=> :HELLO
=> (1 2)
(make-instance 'foo-random-state)
==> #<FOO-RANDOM-STATE >
```
More fancy markdown or HTML output with automatic markup and linking
of uppercase symbol names found in docstrings, section numbering,
table of contents, etc is possible by calling the DOCUMENT
function.
One can even generate documentation for different, but related
libraries at the same time with the output going to different files,
but with cross-page links being automatically added for symbols
mentioned in docstrings. For a complete example of how to generate
HTML with multiple pages, see src/doc.lisp
.
Note how (VARIABLE *FOO-STATE*)
in the DEFSECTION
form both
exports *FOO-STATE*
and includes its documentation in
@FOO-RANDOM-MANUAL
. The symbols VARIABLE
and FUNCTION
are just two
instances of 'locatives' which are used in DEFSECTION
to refer to
definitions tied to symbols. See Locative Types.
The transcript in the code block tagged with cl-transcript
is
automatically checked for up-to-dateness. See
Transcripts.
Integration into SLIME's M-.
(slime-edit-definition
) allows one
to visit the source location of the thing that's identified by a
symbol and the locative before or after the symbol in a buffer. With
this extension, if a locative is the previous or the next expression
around the symbol of interest, then M-.
will go straight to the
definition which corresponds to the locative. If that fails, M-.
will try to find the definitions in the normal way which may involve
popping up an xref buffer and letting the user interactively select
one of possible definitions.
Note that the this feature is implemented in terms of
SWANK-BACKEND:FIND-SOURCE-LOCATION
and
SWANK-BACKEND:FIND-DEFINITIONS
whose support varies across the Lisp
implementations.
In the following examples, pressing M-.
when the cursor is on one
of the characters of FOO
or just after FOO
, will visit the
definition of function FOO
:
function foo
foo function
(function foo)
(foo function)
In particular, references in a DEFSECTION
form are in (SYMBOL
LOCATIVE
) format so M-.
will work just fine there.
Just like vanilla M-.
, this works in comments and docstrings. In
this example pressing M-.
on FOO
will visit FOO
's default
method:
;;;; See FOO `(method () (t t t))` for how this all works.
;;;; But if the locative has semicolons inside: FOO `(method
;;;; () (t t t))`, then it won't, so be wary of line breaks
;;;; in comments.
With a prefix argument (C-u M-.
), one can enter a symbol plus a
locative separated by whitespace to preselect one of the
possibilities.
The M-.
extensions can be enabled by adding this to your Emacs
initialization file (or loading src/pax.el
):
;;; MGL-PAX M-. integration
(defun slime-edit-locative-definition (name &optional where)
(or (slime-locate-definition name (slime-locative-before))
(slime-locate-definition name (slime-locative-after))
(slime-locate-definition name (slime-locative-after-in-brackets))
;; support "foo function" and "function foo" syntax in
;; interactive use
(let ((pos (cl-position ?\s name)))
(when pos
(or (slime-locate-definition (cl-subseq name 0 pos)
(cl-subseq name (1+ pos)))
(slime-locate-definition (cl-subseq name (1+ pos))
(cl-subseq name 0 pos)))))))
(defun slime-locative-before ()
(ignore-errors (save-excursion
(slime-beginning-of-symbol)
(slime-last-expression))))
(defun slime-locative-after ()
(ignore-errors (save-excursion
(slime-end-of-symbol)
(slime-forward-sexp)
(slime-last-expression))))
(defun slime-locative-after-in-brackets ()
(ignore-errors (save-excursion
(slime-end-of-symbol)
(skip-chars-forward "`" (+ (point) 1))
(when (and (= 1 (skip-chars-forward "\\]" (+ (point) 1)))
(= 1 (skip-chars-forward "\\[" (+ (point) 1))))
(buffer-substring-no-properties
(point)
(progn (search-forward "]" nil (+ (point) 1000))
(1- (point))))))))
(defun slime-locate-definition (name locative)
(when locative
(let ((location
(slime-eval
;; Silently fail if mgl-pax is not loaded.
`(cl:when (cl:find-package :mgl-pax)
(cl:funcall
(cl:find-symbol
(cl:symbol-name :locate-definition-for-emacs) :mgl-pax)
,name ,locative)))))
(when (and (consp location)
(not (eq (car location) :error)))
(slime-edit-definition-cont
(list (make-slime-xref :dspec `(,name)
:location location))
"dummy name"
where)))))
(add-hook 'slime-edit-definition-hooks 'slime-edit-locative-definition)
Now let's examine the most important pieces in detail.
-
[macro] DEFSECTION NAME (&KEY (PACKAGE '*PACKAGE*) (READTABLE '*READTABLE*) (EXPORT T) TITLE (DISCARD-DOCUMENTATION-P *DISCARD-DOCUMENTATION-P*)) &BODY ENTRIES
Define a documentation section and maybe export referenced symbols. A bit behind the scenes, a global variable with
NAME
is defined and is bound to aSECTION
object. By convention, section names start with the character@
. See Tutorial for an example.ENTRIES
consists of docstrings and references. Docstrings are arbitrary strings in markdown format, references are defined in the form:(symbol locative)
For example,
(FOO FUNCTION)
refers to the functionFOO
,(@BAR SECTION)
says that@BAR
is a subsection of this one.(BAZ (METHOD () (T T T)))
refers to the default method of the three argument generic functionBAZ
.(FOO FUNCTION)
is equivalent to(FOO (FUNCTION))
.A locative in a reference can either be a symbol or it can be a list whose
CAR
is a symbol. In either case, the symbol is the called the type of the locative while the rest of the elements are the locative arguments. See Locative Types for the list of locative types available out of the box.The same symbol can occur multiple times in a reference, typically with different locatives, but this is not required.
The references are not looked up (see
RESOLVE
in the Extension API) until documentation is generated, so it is allowed to refer to things yet to be defined.If
EXPORT
is true (the default), the referenced symbols andNAME
are candidates for exporting. A candidate symbol is exported if-
it is accessible in
PACKAGE
(it's notOTHER-PACKAGE:SOMETHING
) and -
there is a reference to it in the section being defined with a locative whose type is approved by
EXPORTABLE-LOCATIVE-TYPE-P
.
See
DEFINE-PACKAGE
if you use the export feature. The idea with confounding documentation and exporting is to force documentation of all exported symbols.When
DISCARD-DOCUMENTATION-P
(defaults to*DISCARD-DOCUMENTATION-P*
) is true,ENTRIES
will not be recorded to save memory. -
-
[variable] *DISCARD-DOCUMENTATION-P* NIL
The default value of
DEFSECTION
'sDISCARD-DOCUMENTATION-P
argument. One may want to set*DISCARD-DOCUMENTATION-P*
to true before building a binary application.
-
[macro] DEFINE-PACKAGE PACKAGE &REST OPTIONS
This is like
CL:DEFPACKAGE
but silences warnings and errors signaled when the redefined package is at variance with the current state of the package. Typically this situation occurs when symbols are exported by callingEXPORT
(as is the case withDEFSECTION
) as opposed to adding:EXPORT
forms to theDEFPACKAGE
form and the package definition is reevaluated. See the section on package variance in the SBCL manual.The bottom line is that if you rely on
DEFSECTION
to do the exporting, then you'd better useDEFINE-PACKAGE
.
-
[function] DOCUMENT OBJECT &KEY STREAM PAGES (FORMAT :MARKDOWN)
Write
OBJECT
inFORMAT
toSTREAM
diverting some output toPAGES
.FORMAT
can be anything 3BMD supports which is currently:MARKDOWN
,:HTML
and:PLAIN
.STREAM
may be a stream object,T
orNIL
as withCL:FORMAT
.Most often, this function is called on section objects like
(DOCUMENT @MGL-PAX-MANUAL)
, but it supports all kinds of objects for whichDOCUMENT-OBJECT
is defined. To look up the documentation of functionDOCUMENT
:(document #'document)
To generate the documentation for separate libraries with automatic cross-links:
(document (list @cube-manual @mat-manual))
Note that not only first class objects can have documentation. For instance, variables and deftypes are not represented by objects. That's why
CL:DOCUMENTATION
has aDOC-TYPE
argument.DOCUMENT
does not have anything like that, instead it relies onREFERENCE
objects to carry the extra information. We are going to see later how references and locatives work. Until then, here is an example on how to look up the documentation of typeFOO
:(document (locate 'foo 'type))
One can call
DESCRIBE
onSECTION
objects to get documentation in markdown format with less markup than the default. SeeDESCRIBE-OBJECT
(METHOD () (SECTION T))
.There are quite a few special variables that affect how output is generated, see Documentation Printer Variables.
The rest of this description deals with how to generate multiple pages.
The
PAGES
argument is to create multi-page documents by routing some of the generated output to files, strings or streams.PAGES
is a list of page specification elements. A page spec is a plist with keys:OBJECTS
,:OUTPUT
,:URI-FRAGMENT
,:SOURCE-URI-FN
,:HEADER-FN
and:FOOTER-FN
.OBJECTS
is a list of objects (references are allowed but not required) whose documentation is to be sent toOUTPUT
.OUTPUT
can be a number things:-
If it's a list whose first element is a string or a pathname, then output will be sent to the file denoted by that and the rest of the elements of the list are passed on as arguments to
CL:OPEN
. One extra keyword argument is:ENSURE-DIRECTORIES-EXIST
. If it's true,ENSURE-DIRECTORIES-EXIST
will be called on the pathname before it's opened. -
If it's
NIL
, then output will be collected in a string. -
If it's
T
, then output will be sent to*STANDARD-OUTPUT*
. -
If it's a stream, then output will be sent to that stream.
If some pages are specified,
DOCUMENT
returns a list of designators for generated output. If a page whoseOUTPUT
refers to a file that was created (which doesn't happen if nothing would be written to it), then the corresponding pathname is included in the list. For strings the string itself, while for streams the stream object is included in the list. This way it's possible to write some pages to files and some to strings and have the return value indicate what was created. The output designators in the returned list are ordered by creation time.If no
PAGES
are specified,DOCUMENT
returns a single pathname, string or stream object according to the value of theSTREAM
argument.Note that even if
PAGES
is specified,STREAM
acts as a catch all taking the generated documentation for references not claimed by any pages. Also, the filename, string or stream corresponding toSTREAM
is always the first element in list of generated things that is the return value.HEADER-FN
, if notNIL
, is a function of a single stream argument which is called just before the first write to the page. Since:FORMAT
:HTML
only generates HTML fragments, this makes it possible to print arbitrary headers, typically setting the title, css stylesheet, or charset.FOOTER-FN
is similar toHEADER-FN
, but it's called after the last write to the page. For HTML, it typically just closes the body.URI-FRAGMENT
is a string such as"doc/manual.html"
that specifies where the page will be deployed on a webserver. It defines how links between pages will look. If it's not specified andOUTPUT
refers to a file, then it defaults to the name of the file. IfURI-FRAGMENT
isNIL
, then no links will be made to or from that page.Finally,
SOURCE-URI-FN
is a function of a single,REFERENCE
argument. If it returns a value other thanNIL
, then it must be a string representing an URI. IfFORMAT
is:HTML
and*DOCUMENT-MARK-UP-SIGNATURES*
is true, then the locative as displayed in the signature will be a link to this uri. SeeMAKE-GITHUB-SOURCE-URI-FN
.PAGES
may look something like this:`((;; The section about SECTIONs and everything below it ... :objects (,@mgl-pax-sections) ;; ... is so boring that it's not worth the disk space, so ;; send it to a string. :output (nil) ;; Explicitly tell other pages not to link to these guys. :uri-fragment nil) ;; Send the @MGL-PAX-EXTENSIONS section and everything reachable ;; from it ... (:objects (,@mgl-pax-extension-api) ;; ... to build/tmp/pax-extension-api.html. :output ("build/tmp/pax-extension-api.html") ;; However, on the web server html files will be at this ;; location relative to some common root, so override the ;; default: :uri-fragment "doc/dev/pax-extension-api.html" ;; Set html page title, stylesheet, charset. :header-fn 'write-html-header ;; Just close the body. :footer-fn 'write-html-footer) (:objects (,@mgl-pax-manual) :output ("build/tmp/manual.html") ;; Links from the extension api page to the manual page will ;; be to ../user/pax-manual#<anchor>, while links going to ;; the opposite direction will be to ;; ../dev/pax-extension-api.html#<anchor>. :uri-fragment "doc/user/pax-manual.html" :header-fn 'write-html-header :footer-fn 'write-html-footer))
-
The Markdown in docstrings is processed with the 3BMD library.
Docstrings can be indented in any of the usual styles. PAX normalizes indentation by converting:
(defun foo ()
"This is
indented
differently")
to
(defun foo ()
"This is
indented
differently")
See DOCUMENT-OBJECT
for the details.
For syntax highlighting, github's fenced code blocks markdown extension to mark up code blocks with triple backticks is enabled so all you need to do is write:
```elisp
(defun foo ())
```
to get syntactically marked up HTML output. Copy doc/style.css
from PAX and you are set. The language tag, elisp
in this example,
is optional and defaults to common-lisp
.
See the documentation of 3BMD and colorize for the details.
Displaying pretty mathematics in TeX format is supported via
MathJax. It can be done inline with $
like this:
$\int_0^\infty e^{-x^2} dx=\frac{\sqrt{\pi}}{2}$
which is diplayed as $$
like this:
$$\int_0^\infty e^{-x^2} dx=\frac{\sqrt{\pi}}{2}$$
to get:
MathJax will leave code blocks (including those inline with
backticks) alone. Outside code blocks, escape $
by prefixing it
with a backslash to scare MathJax off.
Escaping all those backslashes in TeX fragments embedded in Lisp strings can be pain. Pythonic String Reader can help with that.
Docstrings are assumed to be in markdown format and they are pretty much copied verbatim to the documentation subject to a few knobs described below.
-
[variable] *DOCUMENT-UPPERCASE-IS-CODE* T
When true, words with at least three characters and no lowercase characters naming an interned symbol are assumed to be code as if they were marked up with backticks which is especially useful when combined with
*DOCUMENT-LINK-CODE*
. For example, this docstring:"`FOO` and FOO."
is equivalent to this:
"`FOO` and `FOO`."
iff
FOO
is an interned symbol. To suppress this behavior, add a backslash to the beginning of the symbol or right after the leading * if it would otherwise be parsed as markdown emphasis:"\\MGL-PAX *\\DOCUMENT-NORMALIZE-PACKAGES*"
The number of backslashes is doubled above because that's how the example looks in a docstring. Note that the backslash is discarded even if
*DOCUMENT-UPPERCASE-IS-CODE*
is false.
-
[variable] *DOCUMENT-LINK-CODE* T
When true, during the process of generating documentation for a
SECTION
, HTML anchors are added before the documentation of every reference that's not to a section. Also, markdown style reference links are added when a piece of inline code found in a docstring refers to a symbol that's referenced by one of the sections being documented. AssumingBAR
is defined, the documentation for:(defsection @foo (foo function) (bar function)) (defun foo (x) "Calls `BAR` on `X`." (bar x))
would look like this:
- [function] FOO X Calls [`BAR`][1] on `X`.
Instead of
BAR
, one can write[bar][]
or[`bar`][]
as well. Since symbol names are parsed according toREADTABLE-CASE
, character case rarely matters.Now, if
BAR
has references with different locatives:(defsection @foo (foo function) (bar function) (bar type)) (defun foo (x) "Calls `BAR` on `X`." (bar x))
then documentation would link to all interpretations:
- [function] FOO X Calls `BAR`([`1`][link-id-1] [`2`][link-id-2]) on `X`.
This situation occurs in PAX with
SECTION
(0
1
) which is both a class (seeSECTION
) and a locative type denoted by a symbol (seeSECTION
). Back in the example above, clearly, there is no reason to link to typeBAR
, so one may wish to select the function locative. There are two ways to do that. One is to specify the locative explicitly as the id of a reference link:"Calls [BAR][function] on X."
However, if in the text there is a locative immediately before or after the symbol, then that locative is used to narrow down the range of possibilities. This is similar to what the
M-.
extension does. In a nutshell, ifM-.
works without questions then the documentation will contain a single link. So this also works without any markup:"Calls function `BAR` on X."
This last option needs backticks around the locative if it's not a single symbol.
Note that
*DOCUMENT-LINK-CODE*
can be combined with*DOCUMENT-UPPERCASE-IS-CODE*
to have links generated for uppercase names with no quoting required.
-
[variable] *DOCUMENT-LINK-SECTIONS* T
When true, HTML anchors are generated before the heading of sections which allows the table of contents to contain links and also code-like references to sections (like
@FOO-MANUAL
) to be translated to links with the section title being the name of the link.
-
[variable] *DOCUMENT-MIN-LINK-HASH-LENGTH* 4
Recall that markdown reference style links (like
[label][id]
) are used for linking to sections and code. It is desirable to have ids that are short to maintain legibility of the generated markdown, but also stable to reduce the spurious diffs in the generated documentation which can be a pain in a version control system.Clearly, there is a tradeoff here. This variable controls how many characters of the md5 sum of the full link id (the reference as a string) are retained. If collisions are found due to the low number of characters, then the length of the hash of the colliding reference is increased.
This variable has no effect on the HTML generated from markdown, but it can make markdown output more readable.
-
[variable] *DOCUMENT-MARK-UP-SIGNATURES* T
When true, some things such as function names and arglists are rendered as bold and italic. In
:HTML
output, locative types become links to sources (if:SOURCE-URI-FN
is provided, seeDOCUMENT
), and the symbol becomes a self-link for your permalinking pleasure.For example, a reference is rendered in markdown roughly as:
- [function] foo x y
With this option on, the above becomes:
- [function] **foo** *x y*
Also, in HTML
**foo**
will be a link to that very entry and[function]
may turn into a link to sources.
-
[variable] *DOCUMENT-MAX-NUMBERING-LEVEL* 3
A non-negative integer. In their hierarchy, sections on levels less than this value get numbered in the format of
3.1.2
. Setting it to 0 turns numbering off.
-
[variable] *DOCUMENT-MAX-TABLE-OF-CONTENTS-LEVEL* 3
A non-negative integer. Top-level sections are given a table of contents which includes a nested tree of section titles whose depth is limited by this value. Setting it to 0 turns generation of the table of contents off. If
*DOCUMENT-LINK-SECTIONS*
is true, then the table of contents will link to the sections.
-
[variable] *DOCUMENT-TEXT-NAVIGATION* NIL
If true, then before each heading a line is printed with links to the previous, parent and next section. Needs
*DOCUMENT-LINK-SECTIONS*
to be on to work.
-
[variable] *DOCUMENT-FANCY-HTML-NAVIGATION* T
If true and the output format is HTML, then headings get a navigation component that consists of links to the previous, parent, next section and a permalink. This component is normally hidden, it is visible only when the mouse is over the heading. Needs
*DOCUMENT-LINK-SECTIONS*
to be on to work.
-
[variable] *DOCUMENT-NORMALIZE-PACKAGES* T
If true, symbols are printed relative to
SECTION-PACKAGE
of the innermost containing section or with full package names if there is no containing section. To eliminate ambiguity[in package ...]
messages are printed right after the section heading if necessary. If false, symbols are always printed relative to the current package.
These are the locatives type supported out of the box. As all locative types, they are symbols and their names should make it obvious what kind of things they refer to. Unless otherwise noted, locatives take no arguments.
-
[locative] ASDF/SYSTEM:SYSTEM
Refers to an asdf system. The generated documentation will include meta information extracted from the system definition. This also serves as an example of a symbol that's not accessible in the current package and consequently is not exported.
-
[locative] SECTION
Refers to a section defined by
DEFSECTION
.
-
[locative] VARIABLE &OPTIONAL INITFORM
Refers to a global special variable.
INITFORM
, or if not specified, the global value of the variable is included in the documentation.
-
[locative] CONSTANT &OPTIONAL INITFORM
Refers to a
DEFCONSTANT
.INITFORM
, or if not specified, the value of the constant is included in the documentation.
- [locative] MACRO
- [locative] COMPILER-MACRO
-
[locative] FUNCTION
Note that the arglist in the generated documentation depends on the quality of
SWANK-BACKEND:ARGLIST
. It may be that default values of optional and keyword arguments are missing.
- [locative] GENERIC-FUNCTION
-
[locative] METHOD METHOD-QUALIFIERS METHOD-SPECIALIZERS
See
CL:FIND-METHOD
for the description of the arguments. To refer to the default method of the three argument generic functionFOO
:(foo (method () (t t t)))
-
[locative] ACCESSOR CLASS-NAME
To refer to an accessor named
FOO-SLOT
of classFOO
:(foo-slot (accessor foo))
-
[locative] READER CLASS-NAME
To refer to a reader named
FOO-SLOT
of classFOO
:(foo-slot (reader foo))
-
[locative] WRITER CLASS-NAME
To refer to a writer named
FOO-SLOT
of classFOO
:(foo-slot (writer foo))
-
[locative] STRUCTURE-ACCESSOR
This is a synonym of
FUNCTION
with the difference that the often ugly and certainly uninformative lambda list will not be printed.
- [locative] CLASS
- [locative] CONDITION
-
[locative] TYPE
TYPE
can refer to classes as well, but it's better style to use the more specificCLASS
locative type for that. Another difference toCLASS
is that an attempt is made at printing the arguments of type specifiers.
- [locative] PACKAGE
-
[locative] DISLOCATED
Refers to a symbol in a non-specific context. Useful for preventing autolinking. For example, if there is a function called
FOO
then`FOO`
will be linked to (if
*DOCUMENT-LINK-CODE*
) its definition. However,[`FOO`][dislocated]
will not be. On a dislocated locative
LOCATE
always fails with aLOCATE-ERROR
condition.
-
[locative] LOCATIVE LAMBDA-LIST
This is the locative for locatives. When
M-.
is pressed onVARIABLE
in(VARIABLE LOCATIVE)
, this is what makes it possible to land at the(DEFINE-LOCATIVE-TYPE VARIABLE ...)
form. Similarly,(LOCATIVE LOCATIVE)
leads to this very definition.
-
[locative] INCLUDE SOURCE &KEY LINE-PREFIX HEADER FOOTER HEADER-NL FOOTER-NL
Refers to a region of a file.
SOURCE
can be a string or a pathname in which case the whole file is being pointed to or it can explicitly supplySTART
,END
locatives.INCLUDE
is typically used to include non-lisp files in the documentation (say markdown or elisp as in the next example) or regions of lisp source files. This can reduce clutter and duplication.(defsection example-section () (pax.el (include #.(asdf:system-relative-pathname :mgl-pax "src/pax.el") :header-nl "```elisp" :footer-nl "```")) (foo-example (include (:start (foo function) :end (end-of-foo-example variable)) :header-nl "```commonlisp" :footer-nl "```")) (defun foo (x) (1+ x)) ;;; Since file regions are copied verbatim, comments survive. (defmacro bar ()) ;;; This comment is the last thing in FOO-EXAMPLE's ;;; documentation since we use the dummy END-OF-FOO-EXAMPLE ;;; variable to mark the end location. (defvar end-of-foo-example) ;;; More irrelevant code follows.
In the above example, pressing
M-.
onPAX.EL
will open thesrc/pax.el
file and put the cursor on its first character.M-.
onFOO-EXAMPLE
will go to the source location of the(asdf:system locative)
locative.When documentation is generated, the entire
pax.el
file is included in the markdown surrounded by the strings given asHEADER-NL
andFOOTER-NL
(if any). The trailing newline character is assumed implicitly. If that's undesirable, then useHEADER
andFOOTER
instead. The documentation ofFOO-EXAMPLE
will be the region of the file from the source location of theSTART
locative (inclusive) to the source location of theEND
locative (exclusive).START
andEND
default to the beginning and end of the file, respectively.Note that the file of the source location of
:START
and:END
must be the same. IfSOURCE
is pathname designator, then it must be absolute so that the locative is context independent.Finally, if specified
LINE-PREFIX
is a string that's prepended to each line included in the documentation. For example, a string of four spaces makes markdown think it's a code block.
While Common Lisp has rather good introspective abilities, not
everything is first class. For example, there is no object
representing the variable defined with (DEFVAR FOO)
. (MAKE-REFERENCE 'FOO 'VARIABLE)
constructs a REFERENCE
that
captures the path to take from an object (the symbol FOO
) to an
entity of interest (for example, the documentation of the variable).
The path is called the locative. A locative can be applied to an
object like this:
(locate 'foo 'variable)
which will return the same reference as (MAKE-REFERENCE 'FOO 'VARIABLE)
. Operations need to know how to deal with references
which we will see in LOCATE-AND-COLLECT-REACHABLE-OBJECTS
,
LOCATE-AND-DOCUMENT
and LOCATE-AND-FIND-SOURCE
.
Naturally, (LOCATE 'FOO 'FUNCTION)
will simply return #'FOO
, no
need to muck with references when there is a perfectly good object.
-
[function] LOCATE OBJECT LOCATIVE &KEY (ERRORP T)
Follow
LOCATIVE
fromOBJECT
and return the object it leads to or aREFERENCE
if there is no first class object corresponding to the location. IfERRORP
, then aLOCATE-ERROR
condition is signaled when lookup fails.
-
[condition] LOCATE-ERROR ERROR
Signaled by
LOCATE
when lookup fails andERRORP
is true.
- [reader] LOCATE-ERROR-MESSAGE LOCATE-ERROR (:MESSAGE)
- [reader] LOCATE-ERROR-OBJECT LOCATE-ERROR (:OBJECT)
- [reader] LOCATE-ERROR-LOCATIVE LOCATE-ERROR (:LOCATIVE)
-
[function] RESOLVE REFERENCE &KEY (ERRORP T)
A convenience function to
LOCATE
REFERENCE
's object with its locative.
-
[class] REFERENCE
A
REFERENCE
represents a path (REFERENCE-LOCATIVE
) to take from an object (REFERENCE-OBJECT
).
- [reader] REFERENCE-OBJECT REFERENCE (:OBJECT)
- [reader] REFERENCE-LOCATIVE REFERENCE (:LOCATIVE)
- [function] MAKE-REFERENCE OBJECT LOCATIVE
-
[function] LOCATIVE-TYPE LOCATIVE
The first element of
LOCATIVE
if it's a list. If it's a symbol then it's that symbol itself. Typically, methods of generic functions working with locatives take locative type and locative args as separate arguments to allow methods have eql specializers on the type symbol.
-
[function] LOCATIVE-ARGS LOCATIVE
The
REST
ofLOCATIVE
if it's a list. If it's a symbol then it's ().
One may wish to make the DOCUMENT
function and M-.
navigation
work with new object types. Extending DOCUMENT
can be done by
defining a DOCUMENT-OBJECT
method. To allow these objects to be
referenced from DEFSECTION
a LOCATE-OBJECT
method is to be defined.
Finally, for M-.
FIND-SOURCE
can be specialized. Finally,
EXPORTABLE-LOCATIVE-TYPE-P
may be overridden if exporting does not
makes sense. Here is a stripped down example of how all this is done
for ASDF:SYSTEM:
(define-locative-type asdf:system ()
"Refers to an asdf system. The generated documentation will include
meta information extracted from the system definition. This also
serves as an example of a symbol that's not accessible in the
current package and consequently is not exported.")
(defmethod locate-object (symbol (locative-type (eql 'asdf:system))
locative-args)
(assert (endp locative-args))
;; FIXME: This is slow as hell.
(or (asdf:find-system symbol nil)
(locate-error)))
(defmethod canonical-reference ((system asdf:system))
(make-reference (asdf/find-system:primary-system-name system) 'asdf:system))
(defmethod document-object ((system asdf:system) stream)
(with-heading (stream system
(format nil "~A ASDF System Details"
(asdf/find-system:primary-system-name system)))
(flet ((foo (name fn &key type)
(let ((value (funcall fn system)))
(when value
(case type
((:link)
(format stream "- ~A: [~A](~A)~%" name value value))
((:mailto)
(format stream "- ~A: [~A](mailto:~A)~%"
name value value))
((nil)
(format stream "- ~A: ~A~%" name value)))))))
(foo "Version" 'asdf/component:component-version)
(foo "Description" 'asdf/system:system-description)
(foo "Licence" 'asdf/system:system-licence)
(foo "Author" 'asdf/system:system-author)
(foo "Maintainer" 'asdf/system:system-maintainer)
(foo "Mailto" 'asdf/system:system-mailto :type :mailto)
(foo "Homepage" 'asdf/system:system-homepage :type :link)
(foo "Bug tracker" 'asdf/system:system-bug-tracker)
(foo "Long description" 'asdf/system:system-long-description))))
(defmethod find-source ((system asdf:system))
`(:location
(:file ,(namestring (asdf/system:system-source-file system)))
(:position 1)
(:snippet "")))
-
[macro] DEFINE-LOCATIVE-TYPE LOCATIVE-TYPE LAMBDA-LIST &BODY DOCSTRING
Declare
LOCATIVE-TYPE
as aLOCATIVE
. One gets two things in return: first, a place to document the format and semantics ofLOCATIVE-TYPE
(inLAMBDA-LIST
andDOCSTRING
); second, being able to reference(LOCATIVE-TYPE LOCATIVE)
. For example, if you have:(define-locative-type variable (&optional initform) "Dummy docstring.")
then
(VARIABLE LOCATIVE)
refers to this form.
-
[generic-function] EXPORTABLE-LOCATIVE-TYPE-P LOCATIVE-TYPE
Return true iff symbols in references with
LOCATIVE-TYPE
are to be exported by default when they occur in aDEFSECTION
. The default method returnsT
, while the methods forPACKAGE
,ASDF:SYSTEM
andMETHOD
returnNIL
.DEFSECTION
calls this function to decide what symbols to export when itsEXPORT
argument is true.
-
[generic-function] LOCATE-OBJECT OBJECT LOCATIVE-TYPE LOCATIVE-ARGS
Return the object
OBJECT
+ locative refers to. For example, ifLOCATIVE-TYPE
is the symbolPACKAGE
, this returns(FIND-PACKAGE SYMBOL)
. Signal aLOCATE-ERROR
condition by calling theLOCATE-ERROR
function if lookup fails. Signal other errors if the types of the argument are bad, for instanceLOCATIVE-ARGS
is not the empty list in the package example. If aREFERENCE
is returned then it must be canonical in the sense that callingCANONICAL-REFERENCE
on it will return the same reference. For extension only, don't call this directly.
-
[function] LOCATE-ERROR &REST FORMAT-AND-ARGS
Call this function to signal a
LOCATE-ERROR
condition from aLOCATE-OBJECT
method.FORMAT-AND-ARGS
contains a format string and args suitable forFORMAT
from which theLOCATE-ERROR-MESSAGE
is constructed. IfFORMAT-AND-ARGS
isNIL
, then the message will beNIL
too.The object and the locative are not specified, they are added by
LOCATE
when it resignals the condition.
-
[generic-function] CANONICAL-REFERENCE OBJECT
Return a
REFERENCE
that resolves toOBJECT
.
-
[generic-function] COLLECT-REACHABLE-OBJECTS OBJECT
Return a list of objects representing all things that would be documented in a (
DOCUMENT
OBJECT
) call. For sections this is simply the union of references reachable from references inSECTION-ENTRIES
. The returned objects can be anything provided thatCANONICAL-REFERENCE
works on them. The list need not includeOBJECT
itself.One only has to specialize this for new container-like objects.
-
[method] COLLECT-REACHABLE-OBJECTS OBJECT
This default implementation returns the empty list. This means that nothing is reachable from
OBJECT
.
-
[generic-function] DOCUMENT-OBJECT OBJECT STREAM
Write
OBJECT
(and its references recursively) inFORMAT
toSTREAM
.The
DOCUMENT
function calls this generic function withLEVEL
0, passingFORMAT
on. Add methods specializing onOBJECT
to customize how objects of that type are presented in the documentation.
-
[method] DOCUMENT-OBJECT (STRING STRING) STREAM
Print
STRING
verbatim toSTREAM
after cleaning up indentation.Docstrings in sources are indented in various ways which can easily mess up markdown. To handle the most common cases leave the first line alone, but from the rest of the lines strip the longest run of leading spaces that is common to all non-blank lines.
-
[generic-function] FIND-SOURCE OBJECT
Like
SWANK:FIND-DEFINITION-FOR-THING
, but this one is a generic function to be extensible. In fact, the default implementation simply defers toSWANK:FIND-DEFINITION-FOR-THING
. This function is called byLOCATE-DEFINITION-FOR-EMACS
which lies behind theM-.
extension (see Emacs Integration).If successful, the return value looks like this:
(:location (:file "/home/mega/own/mgl/pax/test/test.lisp") (:position 24) nil)
The
NIL
is the source snippet which is optional. Note that position 1 is the first character. If unsuccessful, the return values is like:(:error "Unknown source location for SOMETHING")
Let's see how to extend DOCUMENT
and M-.
navigation if there is
no first class object to represent the thing of interest. Recall
that LOCATE
returns a REFERENCE
object in this case. DOCUMENT-OBJECT
and FIND-SOURCE
defer to LOCATE-AND-DOCUMENT
and
LOCATE-AND-FIND-SOURCE
which have LOCATIVE-TYPE
in their argument
list for EQL
specializing pleasure. Here is a stripped down example
of how the VARIABLE
locative is defined:
(define-locative-type variable (&optional initform)
"Refers to a global special variable. INITFORM, or if not specified,
the global value of the variable is included in the documentation.")
(defmethod locate-object (symbol (locative-type (eql 'variable)) locative-args)
(assert (<= (length locative-args) 1))
(make-reference symbol (cons locative-type locative-args)))
(defmethod locate-and-document (symbol (locative-type (eql 'variable))
locative-args stream)
(destructuring-bind (&optional (initform nil initformp)) locative-args
(locate-and-print-bullet locative-type locative-args symbol stream)
(write-char #\Space stream)
(multiple-value-bind (value unboundp) (symbol-global-value symbol)
(print-arglist (prin1-to-string (cond (initformp initform)
(unboundp "-unbound-")
(t value)))
stream))
(terpri stream)
(with-dislocated-symbols ((list symbol))
(maybe-print-docstring symbol locative-type stream))))
(defmethod locate-and-find-source (symbol (locative-type (eql 'variable))
locative-args)
(declare (ignore locative-args))
(find-one-location (swank-backend:find-definitions symbol)
'("variable" "defvar" "defparameter"
"special-declaration")))
-
[method] COLLECT-REACHABLE-OBJECTS (REFERENCE REFERENCE)
If
REFERENCE
can be resolved to a non-reference, callCOLLECT-REACHABLE-OBJECTS
with it, else callLOCATE-AND-COLLECT-REACHABLE-OBJECTS
on the object, locative-type, locative-args ofREFERENCE
-
[generic-function] LOCATE-AND-COLLECT-REACHABLE-OBJECTS OBJECT LOCATIVE-TYPE LOCATIVE-ARGS
Called by
COLLECT-REACHABLE-OBJECTS
onREFERENCE
objects, this function has essentially the same purpose as its caller but it has different arguments to allow specializing onLOCATIVE-TYPE
.
-
[method] LOCATE-AND-COLLECT-REACHABLE-OBJECTS OBJECT LOCATIVE-TYPE LOCATIVE-ARGS
This default implementation returns the empty list. This means that nothing is reachable from the reference.
-
[method] DOCUMENT-OBJECT (REFERENCE REFERENCE) STREAM
If
REFERENCE
can be resolved to a non-reference, callDOCUMENT-OBJECT
with it, else call LOCATE-AND-DOCUMENT-OBJECT on the object, locative-type, locative-args ofREFERENCE
-
[generic-function] LOCATE-AND-DOCUMENT OBJECT LOCATIVE-TYPE LOCATIVE-ARGS STREAM
Called by
DOCUMENT-OBJECT
onREFERENCE
objects, this function has essentially the same purpose asDOCUMENT-OBJECT
but it has different arguments to allow specializing onLOCATIVE-TYPE
.
-
[method] FIND-SOURCE (REFERENCE REFERENCE)
If
REFERENCE
can be resolved to a non-reference, callFIND-SOURCE
with it, else callLOCATE-AND-FIND-SOURCE
on the object, locative-type, locative-args ofREFERENCE
-
[generic-function] LOCATE-AND-FIND-SOURCE OBJECT LOCATIVE-TYPE LOCATIVE-ARGS
Called by
FIND-SOURCE
onREFERENCE
objects, this function has essentially the same purpose asFIND-SOURCE
but it has different arguments to allow specializing onLOCATIVE-TYPE
.
-
[method] LOCATE-AND-FIND-SOURCE OBJECT LOCATIVE-TYPE LOCATIVE-ARGS
This default implementation simply calls
FIND-SOURCE
withOBJECT
which should cover the common case of a macro expanding to, for instance, a defun but having its own locative type.
We have covered the basic building blocks of reference based
extensions. Now let's see how the obscure
DEFINE-SYMBOL-LOCATIVE-TYPE
and
DEFINE-DEFINER-FOR-SYMBOL-LOCATIVE-TYPE
macros work together to
simplify the common task of associating definition and documentation
with symbols in a certain context.
-
[macro] DEFINE-SYMBOL-LOCATIVE-TYPE LOCATIVE-TYPE LAMBDA-LIST &BODY DOCSTRING
Similar to
DEFINE-LOCATIVE-TYPE
but it assumes that all things locatable withLOCATIVE-TYPE
are going to be just symbols defined with a definer defined withDEFINE-DEFINER-FOR-SYMBOL-LOCATIVE-TYPE
. It is useful to attach documentation and source location to symbols in a particular context. An example will make everything clear:(define-symbol-locative-type direction () "A direction is a symbol. (After this `M-.` on `DIRECTION LOCATIVE` works and it can also be included in DEFSECTION forms.)") (define-definer-for-symbol-locative-type define-direction direction () "With DEFINE-DIRECTION one can document how what a symbol means when interpreted as a direction.") (define-direction up () "UP is equivalent to a coordinate delta of (0, -1).")
After all this,
(UP DIRECTION)
refers to theDEFINE-DIRECTION
form above.
-
[macro] DEFINE-DEFINER-FOR-SYMBOL-LOCATIVE-TYPE NAME LOCATIVE-TYPE &BODY DOCSTRING
Define a macro with
NAME
which can be used to attach documentation, a lambda-list and source location to a symbol in the context ofLOCATIVE-TYPE
. The defined macro's arglist is (SYMBOL
LAMBDA-LIST
&OPTIONAL
DOCSTRING
).LOCATIVE-TYPE
is assumed to have been defined withDEFINE-SYMBOL-LOCATIVE-TYPE
.
Section
objects rarely need to be dissected since
DEFSECTION
and DOCUMENT
cover most needs. However, it is plausible
that one wants to subclass them and maybe redefine how they are
presented.
-
[class] SECTION
DEFSECTION
stores itsNAME
,TITLE
andENTRIES
inSECTION
objects.
-
[reader] SECTION-NAME SECTION (:NAME)
The name of the global variable whose value is this section object.
-
[reader] SECTION-PACKAGE SECTION (:PACKAGE)
*PACKAGE*
will be bound to this package when generating documentation for this section.
-
[reader] SECTION-READTABLE SECTION (:READTABLE)
*READTABLE*
will be bound to this when generating documentation for this section.
-
[reader] SECTION-TITLE SECTION (:TITLE)
Used in generated documentation.
-
[reader] SECTION-ENTRIES SECTION (:ENTRIES)
A list of strings and
REFERENCE
objects in the order they occurred inDEFSECTION
.
-
[method] DESCRIBE-OBJECT (SECTION SECTION) STREAM
SECTION
objects are printed by callingDOCUMENT
on them with all Documentation Printer Variables, except for*DOCUMENT-NORMALIZE-PACKAGES*
, turned off to reduce clutter.
What are transcripts for? When writing a tutorial, one often wants to include a REPL session with maybe a few defuns and a couple of forms whose output or return values are shown. Also, in a function's docstring an example call with concrete arguments and return values speaks volumes. A transcript is a text that looks like a repl session, but which has a light markup for printed output and return values, while no markup (i.e. prompt) for lisp forms. The PAX transcripts may include output and return values of all forms, or only selected ones. In either case the transcript itself can be easily generated from the source code.
The main worry associated with including examples in the
documentation is that they tend to get out-of-sync with the code.
This is solved by being able to parse back and update transcripts.
In fact, this is exactly what happens during documentation
generation with PAX. Code sections tagged cl-transcript
are
retranscribed and checked for inconsistency (that is, any difference
in output or return values). If the consistency check fails, an
error is signalled that includes a reference to the object being
documented.
Going beyond documentation, transcript consistency checks can be used for writing simple tests in a very readable form. For example:
(+ 1 2)
=> 3
(values (princ :hello) (list 1 2))
.. HELLO
=> :HELLO
=> (1 2)
All in all, transcripts are a handy tool especially when combined
with the Emacs support to regenerate them and with
PYTHONIC-STRING-READER
and its triple-quoted strings that allow one
to work with nested strings with less noise. The triple-quote syntax
can be enabled with:
(in-readtable pythonic-string-syntax)
Typical transcript usage from within Emacs is simple: add a lisp
form to a docstring or comment at any indentation level. Move the
cursor right after the end of the form as if you were to evaluate it
with C-x C-e
. The cursor is marked by #\^
:
This is part of a docstring.
```cl-transcript
(values (princ :hello) (list 1 2))^
```
Note that the use of fenced code blocks with the language tag
cl-transcript
is only to tell PAX to perform consistency checks at
documentation generation time.
Now invoke the elisp function mgl-pax-transcribe
where the cursor
is and the fenced code block from the docstring becomes:
(values (princ :hello) (list 1 2))
.. HELLO
=> :HELLO
=> (1 2)
^
Then you change the printed message and add a comment to the second return value:
(values (princ :hello-world) (list 1 2))
.. HELLO
=> :HELLO
=> (1
;; This value is arbitrary.
2)
When generating the documentation you get a
TRANSCRIPTION-CONSISTENCY-ERROR
because the printed output and the
first return value changed so you regenerate the documentation by
marking the region of bounded by #\|
and the cursor at #\^
in
the example:
|(values (princ :hello-world) (list 1 2))
.. HELLO
=> :HELLO
=> (1
;; This value is arbitrary.
2)
^
then invoke the elisp function mgl-pax-retranscribe-region
to get:
(values (princ :hello-world) (list 1 2))
.. HELLO-WORLD
=> :HELLO-WORLD
=> (1
;; This value is arbitrary.
2)
^
Note how the indentation and the comment of (1 2)
was left alone
but the output and the first return value got updated.
Alternatively, C-u 1 mgl-pax-transcribe
will emit commented markup:
(values (princ :hello) (list 1 2))
;.. HELLO
;=> :HELLO
;=> (1 2)
C-u 0 mgl-pax-retranscribe-region
will turn commented into
non-commented markup. In general, the numeric prefix argument is the
index of the syntax to be used in MGL-PAX
:*SYNTAXES*
. Without a
prefix argument mgl-pax-retranscribe-region
will not change the
markup style.
Finally, not only do both functions work at any indentation level, but in comments too:
;;;; (values (princ :hello) (list 1 2))
;;;; .. HELLO
;;;; => :HELLO
;;;; => (1 2)
Transcription support in emacs can be enabled by adding this to your
Emacs initialization file (or loading src/transcribe.el
):
;;; MGL-PAX transcription
(defun mgl-pax-transcribe-last-expression ()
"A bit like C-u C-x C-e (slime-eval-last-expression) that
inserts the output and values of the sexp before the point, this
does the same but with MGL-PAX:TRANSCRIBE. Use a numeric prefix
argument as in index to select one of the Common Lisp
MGL-PAX:*SYNTAXES* as the SYNTAX argument to MGL-PAX:TRANSCRIBE.
Without a prefix argument, the first syntax is used."
(interactive)
(insert
(save-excursion
(let* ((end (point))
(start (progn (backward-sexp)
(move-beginning-of-line nil)
(point))))
(mgl-pax-transcribe start end (mgl-pax-transcribe-syntax-arg)
nil nil nil)))))
(defun mgl-pax-retranscribe-region (start end)
"Updates the transcription in the current region (as in calling
MGL-PAX:TRANSCRIBE with :UPDATE-ONLY T). Use a numeric prefix
argument as in index to select one of the Common Lisp
MGL-PAX:*SYNTAXES* as the SYNTAX argument to MGL-PAX:TRANSCRIBE.
Without a prefix argument, the syntax of the input will not be
changed."
(interactive "r")
(let* ((point-at-start-p (= (point) start))
(point-at-end-p (= (point) end))
(transcript (mgl-pax-transcribe start end
(mgl-pax-transcribe-syntax-arg)
t t nil)))
(if point-at-start-p
(save-excursion
(goto-char start)
(delete-region start end)
(insert transcript))
(save-excursion
(goto-char start)
(delete-region start end))
(insert transcript))))
(defun mgl-pax-transcribe-syntax-arg ()
(if current-prefix-arg
(prefix-numeric-value current-prefix-arg)
nil))
(defun mgl-pax-transcribe (start end syntax update-only echo
first-line-special-p)
(let ((transcription
(slime-eval
`(cl:if (cl:find-package :mgl-pax)
(cl:funcall
(cl:find-symbol
(cl:symbol-name :transcribe-for-emacs) :mgl-pax)
,(buffer-substring-no-properties start end)
',syntax ',update-only ',echo ',first-line-special-p)
t))))
(if (eq transcription t)
(error "MGL-PAX is not loaded.")
transcription)))
-
[function] TRANSCRIBE INPUT OUTPUT &KEY UPDATE-ONLY (INCLUDE-NO-OUTPUT UPDATE-ONLY) (INCLUDE-NO-VALUE UPDATE-ONLY) (ECHO T) CHECK-CONSISTENCY DEFAULT-SYNTAX (INPUT-SYNTAXES *SYNTAXES*) (OUTPUT-SYNTAXES *SYNTAXES*)
Read forms from
INPUT
and write them (iffECHO
) toOUTPUT
followed by any output and return values produced by callingEVAL
on the form.INPUT
can be a stream or a string, whileOUTPUT
can be a stream orNIL
in which case transcription goes into a string. The return value is theOUTPUT
stream or the string that was constructed.A simple example is this:
(transcribe "(princ 42) " nil) => "(princ 42) .. 42 => 42 "
However, the above may be a bit confusing since this documentation uses
TRANSCRIBE
markup syntax in this very example, so let's do it differently. If we have a file with these contents:(values (princ 42) (list 1 2))
it is transcribed to:
(values (princ 42) (list 1 2)) .. 42 => 42 => (1 2)
Output to all standard streams is captured and printed with the
:OUTPUT
prefix (".."
). The return values above are printed with the:READABLE
prefix ("=>"
). Note how these prefixes are always printed on a new line to facilitate parsing.Updating
TRANSCRIBE
is able to parse its own output. If we transcribe the previous output above, we get it back exactly. However, if we remove all output markers, leave only a placeholder value marker and pass:UPDATE-ONLY
T
with source:(values (princ 42) (list 1 2)) =>
we get this:
(values (princ 42) (list 1 2)) => 42 => (1 2)
With
UPDATE-ONLY
, printed output of a form is only transcribed if there were output markers in the source. Similarly, withUPDATE-ONLY
, return values are only transcribed if there were value markers in the source.No Output/Values
If the form produces no output or returns no values, then whether or not output and values are transcribed is controlled by
INCLUDE-NO-OUTPUT
andINCLUDE-NO-VALUE
, respectively. By default, neither is on so:(values) .. =>
is transcribed to
(values)
With
UPDATE-ONLY
true, we probably wouldn't like to lose those markers since they were put there for a reason. Hence, withUPDATE-ONLY
,INCLUDE-NO-OUTPUT
andINCLUDE-NO-VALUE
default to true. So withUPDATE-ONLY
the above example is transcribed to:(values) .. => ; No value
where the last line is the
:NO-VALUE
prefix.Consistency Checks
If
CHECK-CONSISTENCY
is true, thenTRANSCRIBE
signals a continuableTRANSCRIPTION-OUTPUT-CONSISTENCY-ERROR
whenever a form's output as a string is different from what was inINPUT
, provided thatINPUT
contained the output. Similary, for values, a continuableTRANSCRIPTION-VALUES-CONSISTENCY-ERROR
is signalled if a value read from the source does not print as the as the value returned byEVAL
. This allows readable values to be hand-indented without failing consistency checks:(list 1 2) => (1 2)
Unreadable Values
The above scheme involves
READ
, so consistency of unreadable values cannot be treated the same. In fact, unreadable values must even be printed differently for transcribe to be able to read them back:(defclass some-class () ()) (defmethod print-object ((obj some-class) stream) (print-unreadable-object (obj stream :type t) (format stream \"~%~%end\"))) (make-instance 'some-class) ==> #<SOME-CLASS --> --> end>
where
"==>"
is the:UNREADABLE
prefix and"-->"
is the:UNREADABLE-CONTINUATION
prefix. As with outputs, a consistency check between an unreadable value from the source and the value fromEVAL
is performed withSTRING=
. That is, the value fromEVAL
is printed to a string and compared to the source value. Hence, any change to unreadable values will break consistency checks. This is most troublesome with instances of classes with the defaultPRINT-OBJECT
method printing the memory address. There is currently no remedy for that, except for customizingPRINT-OBJECT
or not transcribing that kind of stuff.Syntaxes
Finally, a transcript may employ different syntaxes for the output and values of different forms. When
INPUT
is read, the syntax for each form is determined by trying to match all prefixes from all syntaxes inINPUT-SYNTAXES
against a line. If there are no output or values for a form inINPUT
, then the syntax remains undetermined.When
OUTPUT
is written, the prefixes to be used are looked up inDEFAULT-SYNTAX
ofOUTPUT-SYNTAXES
, ifDEFAULT-SYNTAX
is notNIL
. IfDEFAULT-SYNTAX
isNIL
, then the syntax used by the same form in theINPUT
is used or (if that could not be determined) the syntax of the previous form. If there was no previous form, then the first syntax ifOUTPUT-SYNTAXES
is used.To produce a transcript that's executable Lisp code, use
:DEFAULT-SYNTAX
:COMMENTED-1:
(make-instance 'some-class) ;==> #<SOME-CLASS ;--> ;--> end> (list 1 2) ;=> (1 ;-> 2)
To translate the above to uncommented syntax, use
:DEFAULT-SYNTAX
:DEFAULT
. IfDEFAULT-SYNTAX
isNIL
(the default), the same syntax will be used in the output as in the input as much as possible.
-
[variable] *SYNTAXES* ((:DEFAULT (:OUTPUT "..") (:NO-VALUE "=> ; No value") (:READABLE "=>") (:UNREADABLE "==>") (:UNREADABLE-CONTINUATION "-->")) (:COMMENTED-1 (:OUTPUT ";..") (:NO-VALUE ";=> ; No value") (:READABLE ";=>") (:READABLE-CONTINUATION ";->") (:UNREADABLE ";==>") (:UNREADABLE-CONTINUATION ";-->")) (:COMMENTED-2 (:OUTPUT ";;..") (:NO-VALUE ";;=> ; No value") (:READABLE ";;=>") (:READABLE-CONTINUATION ";;->") (:UNREADABLE ";;==>") (:UNREADABLE-CONTINUATION ";;-->")))
The default syntaxes used by
TRANSCRIBE
for reading and writing lines containing output and values of an evaluated form.A syntax is a list of of the form
(SYNTAX-ID &REST PREFIXES)
wherePREFIXES
is a list of(PREFIX-ID PREFIX-STRING)
elements. For example the syntax:COMMENTED-1
looks like this:(:commented-1 (:output ";..") (:no-value ";=> No value") (:readable ";=>") (:readable-continuation ";->") (:unreadable ";==>") (:unreadable-continuation ";-->"))
All of the above prefixes must be defined for every syntax except for
:READABLE-CONTINUATION
. If that's missing (as in the:DEFAULT
syntax), then the following value is read withREAD
and printed withPRIN1
(hence no need to mark up the following lines).When writing, an extra space is added automatically if the line to be prefixed is not empty. Similarly, the first space following the prefix discarded when reading.
See
TRANSCRIBE
for how the actual syntax to be used is selected.
-
[condition] TRANSCRIPTION-ERROR ERROR
Represents syntactic errors in the
SOURCE
argument ofTRANSCRIBE
and also serves as the superclass ofTRANSCRIPTION-CONSISTENCY-ERROR
.
-
[condition] TRANSCRIPTION-CONSISTENCY-ERROR TRANSCRIPTION-ERROR
A common superclass for
TRANSCRIPTION-OUTPUT-CONSISTENCY-ERROR
andTRANSCRIPTION-VALUES-CONSISTENCY-ERROR
.
-
[condition] TRANSCRIPTION-OUTPUT-CONSISTENCY-ERROR TRANSCRIPTION-CONSISTENCY-ERROR
Signaled (with
CERROR
) byTRANSCRIBE
when invoked with:CHECK-CONSISTENCY
and the output of a form is not the same as what was parsed.
-
[condition] TRANSCRIPTION-VALUES-CONSISTENCY-ERROR TRANSCRIPTION-CONSISTENCY-ERROR
Signaled (with
CERROR
) byTRANSCRIBE
when invoked with:CHECK-CONSISTENCY
and the values of a form are inconsistent with their parsed representation.
-
[function] MAKE-GITHUB-SOURCE-URI-FN ASDF-SYSTEM GITHUB-URI &KEY GIT-VERSION
Return a function suitable as
:SOURCE-URI-FN
of a page spec (see thePAGES
argument ofDOCUMENT
). The function looks the source location of the reference passed to it, and if the location is found, the path is made relative to the root directory ofASDF-SYSTEM
and finally an URI pointing to github is returned. The URI looks like this:https://github.com/melisgl/mgl-pax/blob/master/src/pax-early.lisp#L12
"master" in the above link comes from
GIT-VERSION
.If
GIT-VERSION
isNIL
, then an attempt is made to determine to current commit id from the.git
in the directory holdingASDF-SYSTEM
. If no.git
directory is found, then no links to github will be generated.A separate warning is signalled whenever source location lookup fails or if the source location points to a directory not below the directory of
ASDF-SYSTEM
.