pm39 interface analysis
Contents
Introduction
This analysis of the ConTeXt interface is an effort to understand how different kinds of commands are expressed, to help support the effort of generated a DITA document set.
I used the interface file context-en.xml
:
- file name
- context-en.xml
- date collected
- 2020-06-27
- size
- 1685184
- md5
- 48edfd4fb6e71aee7a49023f0527a461
I used xmlstarlet:
http://xmlstar.sourceforge.net
...to gather and process most of data from context-en.xml
; for the queries that required XPath 2.0+ features, I used Xmplify.app.
Vocabulary and Other Assumptions
The interface file is made up of a number of cd:interface
elements that describe a hierarchy based on source files.
Inside this hierarchy of interface elements are a set of cd:command
elements. I'm going to refer to these elements as **stanzas**.
Some commands are instances of a more general idea of functionality. I'm going to refer to the parent elements of instances as **classes**.
Each stanza can refer to one of a number of different kinds of entities:
- a command
- a paired command, which describes the start and stop commands for a section
- a class, with enumerated instances of that class that are available by default as part of the distribution
Commands may or may not also be indicated as **environments**, which describe a set of generated commands.
There are 4028 stanzas in the interface file, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command)' context-en.xml
Attributes Used in The Root Element of a Stanza
Root elements of a stanza can have one of several available attributes. The patterns of some of these attributes give hints to the function or purpose of the stanza.
From the following XPath expression:
distinct-values(//cd:interface/cd:interface/cd:command/@*/name())
...we have a list of 11 attributes found attached to root elements of stanzas in the interface:
- file
- level
- name
- category
- type
- variant
- generated
- begin
- end
- scope
- coreprimitive
(Note that we also appear to have two misspellings of "category"; see #misspelled_category)
The file Attribute
The file
attribute specifies the source file that defines the command.
4027 stanzas have the file
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@file])' context-en.xml
One command does not have the file
attribuite, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v '//cd:interface/cd:interface/cd:command[not(@file)]/@name' context-en.xml
... is: doifelseframed
.
The level Attribute
The value of the level
attribute loosely specifies how the command is part of the typesetting system.
The level
attribute has three possible values in the interface:
- style
- document
- system
Commands with a level of style
or document
are expected to be used by people using ConTeXt to prepare documents; commands with the level of system
are internal commands with an expected audience of programmers and implementors who need to know about ConTeXt internals.
4025 stanzas have the level
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@level])' context-en.xml
The three commands that do not have the level
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v '//cd:interface/cd:interface/cd:command[not(@level)]/@name' context-en.xml
...are setupoutput
, postponingnotes
, and script
.
The name Attribute
The name
attribute specifies the name associated with the stanza, and may refer to a command, a stem for a command pair or environment, or a class.
4028 stanzas have this attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@name])' context-en.xml
There is no stanza in the interface without this attribute in its root element.
The category Attribute
The category
attribute specifies the category (or categories?) assigned to a given stanza.
As reported by the Xpath expression:
distinct-values(//cd:interface/cd:interface/cd:command/@category)
...there are 79 discrete values for categories used in the interface:
- mathematics
- alignment
- attribute
- background
- background colors
- background conditional
- rules
- rules colors
- graphics
- structure
- conditional
- buffer conditional
- buffer
- buffer lua
- buffer verbatim
- fonts
- catcode
- characters
- characters fonts
- language
- colors
- colors conditional
- tables
- float tables
- counter
- counter language
- counter conditional
- system
- language alignment
- fonts colors
- xml
- pdf conditional
- pdf background rules
- pdf background
- structure conditional
- structure lua
- structure conditional xml
- rules metapost
- background layout
- background layout metapost
- structure fonts counter
- structure background
- structure counter
- fonts conditional
- background rules
- background rules mathematics
- graphics conditional
- graphics buffer
- graphics structure
- layout
- whitespace
- whitespace layout
- symbols
- fonts whitespace
- language conditional
- background metapost
- layout conditional
- tables buffer
- lua
- structure layout
- mathematics alignment
- mathematics tables
- graphics metapost
- graphics metapost fonts
- graphics metapost conditional
- structure notes
- structure notes conditional
- background fonts colors
- bibliography
- bibliography conditional
- references
- references conditional
- symbols conditional
- symbols graphics
- xml conditional
- xml language
- verbatim
- verbatim conditional
....although if these are space-separated, there is overlap.
Note: this analysis does not include stanzas with misspelled category attributes.
Note for the DITA rendering of the interface: if these are space separated, they can be parsed out into separate category
elements.
The type Attribute
At the root level of a stanza, the type
attribute can indicate the type of the stanza.
369 stanzas have the type
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@type])' context-en.xml
It does not appear that this is a required attribute.
As reported by the Xpath expression:
distinct-values(//cd:interface/cd:interface/cd:command/@type)
At the root level of the stanza, the type
element has one possible value:
- environment
This attribute is significant for indicating this stanza describes an environment.
The variant Attribute
The variant
attribute specifies more information about the type of the stanza, and may be used to disambiguate stanzas.
3299 stanzas have the variant
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@variant])' context-en.xml
It does not appear that this is a required attribute.
As reported by the Xpath expression:
distinct-values(//cd:interface/cd:interface/cd:command/@variant)
...31 discrete values are used in the interface for the variant
attribute:
- argument
- instance
- example
- page
- list
- direct
- interactionmenu
- button
- name
- 1
- 2
- 3
- matrix
- example:title
- string
- preset
- command
- assignment
- item
- symbol
- none
- combination
- instance:assignment
- collector
- layer
- userdata
- alternative
- instance:ownnumber
- instance:argument
- angles
- example:angles
A value of instance
is important for interpreting the kind of stanza.
The generated Attribute
The generated
attribute indicates if the stanza is describing a set of commands.
138 stanzas have the generated
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@generated])' context-en.xml
It does not appear that this is a required attribute.
As reported by the Xpath expression:
distinct-values(//cd:interface/cd:interface/cd:command/@generated)
...the generated
element has one possible value:
- yes
This attribute is significant for indicating this stanza describes a generated command.
The begin and end Attributes
The begin
and end
attributes indicate the strings that must be prepended to the command stem to create the command pair.
41 stanzas have both begin
and end
attributes, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@begin and @end])' context-en.xml
(This is also the number of stanzas that have either of these attributes.)
It does not appear that these are required attributes.
The scope Attribute
I am not sure what the scope
attribute indicates.
10 stanzas have the scope
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@scope])' context-en.xml
As reported by the Xpath expression:
distinct-values(//cd:interface/cd:interface/cd:command/@scope)
...the scope
element has two possible values:
- formula
- itemgroup
It does not appear that this is a required attribute.
The coreprimitive Attribute
I an not sure what the coreprimitive
attribute indicates.
3 stanzas have the coreprimitive
attribute, as reported by:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@coreprimitive])' context-en.xml
As reported by the Xpath expression:
distinct-values(//cd:interface/cd:interface/cd:command/@coreprimitive)
...the coreprimitive
element has one possible value:
- yes
It does not appear that this is a required attribute.
Elements Used in a Stanza
Elements Used
(Forthcoming)
Structures
(Forthcoming)
Attributes
(Forthcoming)
Kinds of Stanzas
(Forthcoming)
Things to Ponder
It is not clear how the begin
and end
attributes interact with the environment
attribute. However, according to:
xml sel -N cd=http://www.pragma-ade.com/commands -t -v 'count(//cd:interface/cd:interface/cd:command[@begin and @end and @environment])' context-en.xml
...no stanzas have this attribute signature.
Apendicies
Attributes that are Likely Misspellings of "Category?"
- catehory
- Line 861 - <cd:command catehory="pdf" file="back-ini.mkiv" level="style" name="setupbackend">
- Line 3361 - <cd:command catehory="pdf" file="scrn-but.mkvi" level="style" name="definebutton">
- Line 3374 - <cd:command catehory="pdf" file="scrn-but.mkvi" level="style" name="setupbutton">
- Line 3409 - <cd:command catehory="pdf" file="scrn-but.mkvi" generated="yes" level="document" name="button" variant="example">
- Line 3428 - <cd:command catehory="pdf" file="scrn-but.mkvi" level="document" name="button">
- Line 3441 - <cd:command catehory="pdf" file="scrn-but.mkvi" level="style" name="overlaybutton">
- Line 3448 - <cd:command catehory="pdf" file="scrn-but.mkvi" level="style" name="overlaybutton" variant="direct">
- Line 3455 - <cd:command catehory="pdf" file="scrn-but.mkvi" level="style" name="MPmenubuttons">
- Line 3462 - <cd:command catehory="pdf" file="scrn-fld.mkvi" level="style" name="overlayrollbutton">
- Line 3472 - <cd:command catehory="pdf" file="scrn-fld.mkvi" level="style" name="definepushbutton">
- Line 3482 - <cd:command catehory="pdf" file="scrn-fld.mkvi" level="style" name="pushbutton">
- Line 3492 - <cd:command catehory="pdf" file="scrn-fld.mkvi" level="style" name="definepushsymbol">
- Line 3504 - <cd:command catehory="pdf" file="scrn-fld.mkvi" level="style" name="rollbutton" variant="interactionmenu">
- Line 3520 - <cd:command catehory="pdf" file="scrn-fld.mkvi" level="style" name="rollbutton" variant="button">
- catgeory
- Line 19207 - <cd:command catgeory="fonts whitespace" file="typo-pnc.mkic" level="style" name="defineperiodkerning">
- Line 19220 - <cd:command catgeory="fonts whitespace" file="typo-pnc.mkic" level="style" name="setupperiodkerning">
- Line 19232 - <cd:command catgeory="fonts whitespace" file="typo-pnc.mkic" level="style" name="setperiodkerning">
- Line 19240 - <cd:command catgeory="fonts whitespace" file="typo-pnc.mkic" level="style" name="resetperiodkerning"/>