docstrip_util(n) Literate programming tool docstrip_util(n)______________________________________________________________________________NAMEdocstrip_util - Docstrip-related utilities
SYNOPSIS
package require Tcl 8.4
package require docstrip ?1.2?
package require docstrip::util ?1.3?
pkgProvide name version terminals
pkgIndex ?terminal ...?
fileoptions ?option value ...?
docstrip::util::index_from_catalogue dir pattern ?option value ...?
docstrip::util::modules_from_catalogue target source ?option value ...?
docstrip::util::classical_preamble metaprefix message target ?source
terminals ...?
docstrip::util::classical_postamble metaprefix message target ?source
terminals ...?
docstrip::util::packages_provided text ?setup-script?
docstrip::util::ddt2man text
docstrip::util::guards subcmd text
docstrip::util::patch source-var terminals fromtext diff ?option value
...?
docstrip::util::thefile filename ?option value ...?
docstrip::util::import_unidiff diff-text ?warning-var?
_________________________________________________________________DESCRIPTION
The docstrip::util package is meant for collecting various utility pro‐
cedures that are mainly useful at installation or development time. It
is separate from the base package to avoid overhead when the latter is
used to source code.
PACKAGE INDEXING COMMANDS
Like raw ".tcl" files, code lines in docstrip source files can be
searched for package declarations and corresponding indices con‐
structed. A complication is however that one cannot tell from the code
blocks themselves which will fit together to make a working package;
normally that information would be found in an accompanying ".ins"
file, but parsing one of those is not an easy task. Therefore doc‐
strip::util introduces an alternative encoding of such information, in
the form of a declarative Tcl script: the catalogue (of the contents in
a source file).
The special commands which are available inside a catalogue are:
pkgProvide name version terminals
Declares that the code for a package with name name and version
version is made up from those modules in the source file which
are selected by the terminals list of guard expression termi‐
nals. This code should preferably not contain a package provide
command for the package, as one will be provided by the package
loading mechanisms.
pkgIndex ?terminal ...?
Declares that the code for a package is made up from those mod‐
ules in the source file which are selected by the listed guard
expression terminals. The name and version of this package is
determined from package provide command(s) found in that code
(hence there must be such a command in there).
fileoptions ?option value ...?
Declares the fconfigure options that should be in force when
reading the source; this can usually be ignored for pure ASCII
files, but if the file needs to be interpreted according to some
other -encoding then this is how to specify it. The command
should normally appear first in the catalogue, as it takes
effect only for commands following it.
Other Tcl commands are supported too ? a catalogue is parsed by being
evaluated in a safe interpreter ? but they are rarely needed. To allow
for future extensions, unknown commands in the catalogue are silently
ignored.
To simplify distribution of catalogues together with their source
files, the catalogue is stored in the source file itself as a module
selected by the terminal 'docstrip.tcl::catalogue'. This supports both
the style of collecting all catalogue lines in one place and the style
of putting each catalogue line in close proximity of the code that it
declares.
Putting catalogue entries next to the code they declare may look as
follows
% First there's the catalogue entry
% \begin{tcl}
%<docstrip.tcl::catalogue>pkgProvide foo::bar 1.0 {foobar load}
% \end{tcl}
% second a metacomment used to include a copyright message
% \begin{macrocode}
%<*foobar>
%% This file is placed in the public domain.
% \end{macrocode}
% third the package implementation
% \begin{tcl}
namespace eval foo::bar {
# ... some clever piece of Tcl code elided ...
% \end{tcl}
% which at some point may have variant code to make use of a
% |load|able extension
% \begin{tcl}
%<*load>
load [file rootname [info script]][info sharedlibextension]
%</load>
%<*!load>
# ... even more clever scripted counterpart of the extension
# also elided ...
%</!load>
}
%</foobar>
% \end{tcl}
% and that's it!
The corresponding set-up with pkgIndex would be
% First there's the catalogue entry
% \begin{tcl}
%<docstrip.tcl::catalogue>pkgIndex foobar load
% \end{tcl}
% second a metacomment used to include a copyright message
% \begin{tcl}
%<*foobar>
%% This file is placed in the public domain.
% \end{tcl}
% third the package implementation
% \begin{tcl}
package provide foo::bar 1.0
namespace eval foo::bar {
# ... some clever piece of Tcl code elided ...
% \end{tcl}
% which at some point may have variant code to make use of a
% |load|able extension
% \begin{tcl}
%<*load>
load [file rootname [info script]][info sharedlibextension]
%</load>
%<*!load>
# ... even more clever scripted counterpart of the extension
# also elided ...
%</!load>
}
%</foobar>
% \end{tcl}
% and that's it!
docstrip::util::index_from_catalogue dir pattern ?option value ...?
This command is a sibling of the standard pkg_mkIndex command,
in that it adds package entries to "pkgIndex.tcl" files. The
difference is that it indexes docstrip-style source files rather
than raw ".tcl" or loadable library files. Only packages listed
in the catalogue of a file are considered.
The dir argument is the directory in which to look for files
(and whose "pkgIndex.tcl" file should be amended). The pattern
argument is a glob pattern of files to look into; a typical
value would be *.dtx or *.{dtx,ddt}. Remaining arguments are
option-value pairs, where the supported options are:
-recursein dirpattern
If this option is given, then the index_from_catalogue
operation will be repeated in each subdirectory whose
name matches the dirpattern. -recursein * will cause the
entire subtree rooted at dir to be indexed.
-sourceconf dictionary
Specify fileoptions to use when reading the catalogues of
files (and also for reading the packages if the catalogue
does not contain a fileoptions command). Defaults to
being empty. Primarily useful if your system encoding is
very different from that of the source file (e.g., one is
a two-byte encoding and the other is a one-byte encod‐
ing). ascii and utf-8 are not very different in that
sense.
-options terminals
The terminals is a list of terminals in addition to doc‐
strip.tcl::catalogue that should be held as true when
extracting the catalogue. Defaults to being empty. This
makes it possible to make use of "variant sections" in
the catalogue itself, e.g. gaurd some entries with an
extra "experimental" and thus prevent them from appearing
in the index unless that is generated with "experimental"
among the -options.
-report boolean
If the boolean is true then the return value will be a
textual, probably multiline, report on what was done.
Defaults to false, in which case there is no particular
return value.
-reportcmd commandPrefix
Every item in the report is handed as an extra argument
to the command prefix. Since index_from_catalogue would
typically be used at a rather high level in installation
scripts and the like, the commandPrefix defaults to "puts
stdout". Use list to effectively disable this feature.
The return values from the prefix are ignored.
The package ifneeded scripts that are generated contain one
package require docstrip command and one docstrip::sourcefrom
command. If the catalogue entry was of the pkgProvide kind then
the package ifneeded script also contains the package provide
command.
Note that index_from_catalogue never removes anything from an
existing "pkgIndex.tcl" file. Hence you may need to delete it
(or have pkg_mkIndex recreate it from scratch) before running
index_from_catalogue to update some piece of information, such
as a package version number.
docstrip::util::modules_from_catalogue target source ?option value ...?
This command is an alternative to index_from_catalogue which
creates Tcl Module (".tm") files rather than "pkgIndex.tcl"
entries. Since this action is more similar to what docstrip
classically does, it has features for putting pre- and postam‐
bles on the generated files.
The source argument is the name of the source file to generate
".tm" files from. The target argument is the directory which
should count as a module path, i.e., this is what the relative
paths derived from package names are joined to. The supported
options are:
-preamble message
A message to put in the preamble (initial block of com‐
ments) of generated files. Defaults to a space. May be
several lines, which are then separated by newlines. Tra‐
ditionally used for copyright notices or the like, but
metacomment lines provide an alternative to that.
-postamble message
Like -preamble, but the message is put at the end of the
file instead of the beginning. Defaults to being empty.
-sourceconf dictionary
Specify fileoptions to use when reading the catalogue of
the source (and also for reading the packages if the cat‐
alogue does not contain a fileoptions command). Defaults
to being empty. Primarily useful if your system encoding
is very different from that of the source file (e.g., one
is a two-byte encoding and the other is a one-byte encod‐
ing). ascii and utf-8 are not very different in that
sense.
-options terminals
The terminals is a list of terminals in addition to doc‐
strip.tcl::catalogue that should be held as true when
extracting the catalogue. Defaults to being empty. This
makes it possible to make use of "variant sections" in
the catalogue itself, e.g. gaurd some entries with an
extra "experimental" guard and thus prevent them from
contributing packages unless those are generated with
"experimental" among the -options.
-formatpreamble commandPrefix
Command prefix used to actually format the preamble.
Takes four additional arguments message, targetFilename,
sourceFilename, and terminalList and returns a fully for‐
matted preamble. Defaults to using classical_preamble
with a metaprefix of '##'.
-formatpostamble commandPrefix
Command prefix used to actually format the postamble.
Takes four additional arguments message, targetFilename,
sourceFilename, and terminalList and returns a fully for‐
matted postamble. Defaults to using classical_postamble
with a metaprefix of '##'.
-report boolean
If the boolean is true (which is the default) then the
return value will be a textual, probably multiline,
report on what was done. If it is false then there is no
particular return value.
-reportcmd commandPrefix
Every item in the report is handed as an extra argument
to this command prefix. Defaults to list, which effec‐
tively disables this feature. The return values from the
prefix are ignored. Use for example "puts stdout" to get
report items written immediately to the terminal.
An existing file of the same name as one to be created will be
overwritten.
docstrip::util::classical_preamble metaprefix message target ?source
terminals ...?
This command returns a preamble in the classical docstrip style
##
## This is `TARGET',
## generated by the docstrip::util package.
##
## The original source files were:
##
## SOURCE (with options: `foo,bar')
##
## Some message line 1
## line2
## line3
if called as
docstrip::util::classical_preamble {##}\
"\nSome message line 1\nline2\nline3" TARGET SOURCE {foo bar}
The command supports preambles for files generated from multiple
sources, even though modules_from_catalogue at present does not
need that.
docstrip::util::classical_postamble metaprefix message target ?source
terminals ...?
This command returns a postamble in the classical docstrip style
## Some message line 1
## line2
## line3
##
## End of file `TARGET'.
if called as
docstrip::util::classical_postamble {##}\
"Some message line 1\nline2\nline3" TARGET SOURCE {foo bar}
In other words, the source and terminals arguments are ignored,
but supported for symmetry with classical_preamble.
docstrip::util::packages_provided text ?setup-script?
This command returns a list where every even index element is
the name of a package provided by text when that is evaluated as
a Tcl script, and the following odd index element is the corre‐
sponding version. It is used to do package indexing of extracted
pieces of code, in the manner of pkg_mkIndex.
One difference to pkg_mkIndex is that the text gets evaluated in
a safe interpreter. package require commands are silently
ignored, as are unknown commands (which includes source and
load). Other errors cause processing of the text to stop, in
which case only those package declarations that had been encoun‐
tered before the error will be included in the return value.
The setup-script argument can be used to customise the evalua‐
tion environment, if the code in text has some very special
needs. The setup-script is evaluated in the local context of the
packages_provided procedure just before the text is processed.
At that time, the name of the slave command for the safe inter‐
preter that will do this processing is kept in the local vari‐
able c. To for example copy the contents of the ::env array to
the safe interpreter, one might use a setup-script of
$c eval [list array set env [array get ::env]]
SOURCE PROCESSING COMMANDS
Unlike the previous group of commands, which would use doc‐
strip::extract to extract some code lines and then process those fur‐
ther, the following commands operate on text consisting of all types of
lines.
docstrip::util::ddt2man text
The ddt2man command reformats text from the general docstrip
format to doctools ".man" format (Tcl Markup Language for Man‐
pages). The different line types are treated as follows:
comment and metacomment lines
The '%' and '%%' prefixes are removed, the rest of the
text is kept as it is.
empty lines
These are kept as they are. (Effectively this means that
they will count as comment lines after a comment line and
as code lines after a code line.)
code lines
example_begin and example_end commands are placed at the
beginning and end of every block of consecutive code
lines. Brackets in a code line are converted to lb and rb
commands.
verbatim guards
These are processed as usual, so they do not show up in
the result but every line in a verbatim block is treated
as a code line.
other guards
These are treated as code lines, except that the actual
guard is emphasised.
At the time of writing, no project has employed doctools markup
in master source files, so experience of what works well is not
available. A source file could however look as follows
% [manpage_begin gcd n 1.0]
% [moddesc {Greatest Common Divisor}]
% [require gcd [opt 1.0]]
% [description]
%
% [list_begin definitions]
% [call [cmd gcd] [arg a] [arg b]]
% The [cmd gcd] procedure takes two arguments [arg a] and [arg b] which
% must be integers and returns their greatest common divisor.
proc gcd {a b} {
% The first step is to take the absolute values of the arguments.
% This relieves us of having to worry about how signs will be treated
% by the remainder operation.
set a [expr {abs($a)}]
set b [expr {abs($b)}]
% The next line does all of Euclid's algorithm! We can make do
% without a temporary variable, since $a is substituted before the
% [lb]set a $b[rb] and thus continues to hold a reference to the
% "old" value of [var a].
while {$b>0} { set b [expr { $a % [set a $b] }] }
% In Tcl 8.3 we might want to use [cmd set] instead of [cmd return]
% to get the slight advantage of byte-compilation.
%<tcl83> set a
%<!tcl83> return $a
}
% [list_end]
%
% [manpage_end]
If the above text is fed through docstrip::util::ddt2man then
the result will be a syntactically correct doctools manpage,
even though its purpose is a bit different.
It is suggested that master source code files with doctools
markup are given the suffix ".ddt", hence the "ddt" in ddt2man.
docstrip::util::guards subcmd text
The guards command returns information (mostly of a statistical
nature) about the ordinary docstrip guards that occur in the
text. The subcmd selects what is returned.
counts List the guard expression terminals with counts. The for‐
mat of the return value is a dictionary which maps the
terminal name to the number of occurencies of it in the
file.
exprcount
List the guard expressions with counts. The format of the
return value is a dictionary which maps the expression to
the number of occurencies of it in the file.
exprerr
List the syntactically incorrect guard expressions (e.g.
parentheses do not match, or a terminal is missing). The
return value is a list, with the elements in no particu‐
lar order.
expressions
List the guard expressions. The return value is a list,
with the elements in no particular order.
exprmods
List the guard expressions with modifiers. The format of
the return value is a dictionary where each index is a
guard expression and each entry is a string with one
character for every guard line that has this expression.
The characters in the entry specify what modifier was
used in that line: +, -, *, /, or (for guard without mod‐
ifier:) space. This is the most primitive form of the
information gathered by guards.
names List the guard expression terminals. The return value is
a list, with the elements in no particular order.
rotten List the malformed guard lines (this does not include
lines where only the expression is malformed, though).
The format of the return value is a dictionary which maps
line numbers to their contents.
docstrip::util::patch source-var terminals fromtext diff ?option value
...?
This command tries to apply a diff file (for example a contrib‐
uted patch) that was computed for a generated file to the doc‐
strip source. This can be useful if someone has edited a gener‐
ated file, thus mistaking it for being the source. This command
makes no presumptions which are specific for the case that the
generated file is a Tcl script.
patch requires that the source file to patch is kept as a list
of lines in a variable, and the name of that variable in the
calling context is what goes into the source-var argument. The
terminals is the list of terminals used to extract the file that
has been patched. The diff is the actual diff to apply (in a
format as explained below) and the fromtext is the contents of
the file which served as "from" when the diff was computed.
Options can be used to further control the process.
The process works by "lifting" the hunks in the diff from gener‐
ated to source file, and then applying them to the elements of
the source-var. In order to do this lifting, it is necessary to
determine how lines in the fromtext correspond to elements of
the source-var, and that is where the terminals come in; the
source is first extracted under the given terminals, and the
result of that is then matched against the fromtext. This pro‐
duces a map which translates line numbers stated in the diff to
element numbers in source-var, which is what is needed to lift
the hunks.
The reason that both the terminals and the fromtext must be
given is twofold. First, it is very difficult to keep track of
how many lines of preamble are supplied some other way than by
copying lines from source files. Second, a generated file might
contain material from several source files. Both make it impos‐
sible to predict what line number an extracted file would have
in the generated file, so instead the algorithm for computing
the line number map looks for a block of lines in the fromtext
which matches what can be extracted from the source. This match‐
ing is affected by the following options:
-matching mode
How equal must two lines be in order to match? The sup‐
ported modes are:
exact Lines must be equal as strings. This is the
default.
anyspace
All sequences of whitespace characters are con‐
verted to single spaces before comparing.
nonspace
Only non-whitespace characters are considered when
comparing.
none Any two lines are considered to be equal.
-metaprefix string
The -metaprefix value to use when extracting. Defaults to
"%%", but for Tcl code it is more likely that "#" or "##"
had been used for the generated file.
-trimlines boolean
The -trimlines value to use when extracting. Defaults to
true.
The return value is in the form of a unified diff, containing
only those hunks which were not applied or were only partially
applied; a comment in the header of each hunk specifies which
case is at hand. It is normally necessary to manually review
both the return value from patch and the patched text itself, as
this command cannot adjust comment lines to match new content.
An example use would look like
set sourceL [split [docstrip::util::thefile from.dtx] \n]
set terminals {foo bar baz}
set fromtext [docstrip::util::thefile from.tcl]
set difftext [exec diff --unified from.tcl to.tcl]
set leftover [docstrip::util::patch sourceL $terminals $fromtext\
[docstrip::util::import_unidiff $difftext] -metaprefix {#}]
set F [open to.dtx w]; puts $F [join $sourceL \n]; close $F
return $leftover
Here, "from.dtx" was used as source for "from.tcl", which some‐
one modified into "to.tcl". We're trying to construct a "to.dtx"
which can be used as source for "to.tcl".
docstrip::util::thefile filename ?option value ...?
The thefile command opens the file filename, reads it to end,
closes it, and returns the contents (dropping a final newline if
there is one). The option-value pairs are passed on to fconfig‐
ure to configure the open file channel before anything is read
from it.
docstrip::util::import_unidiff diff-text ?warning-var?
This command parses a unified (diff flags -U and --unified) for‐
mat diff into the list-of-hunks format expected by doc‐
strip::util::patch. The diff-text argument is the text to parse
and the warning-var is, if specified, the name in the calling
context of a variable to which any warnings about parsing prob‐
lems will be appended.
The return value is a list of hunks. Each hunk is a list of five
elements "start1 end1 start2 end2 lines". start1 and end1 are
line numbers in the "from" file of the first and last respec‐
tively lines of the hunk. start2 and end2 are the corresponding
line numbers in the "to" file. Line numbers start at 1. The
lines is a list with two elements for each line in the hunk; the
first specifies the type of a line and the second is the actual
line contents. The type is - for lines only in the "from" file,
+ for lines that are only in the "to" file, and 0 for lines that
are in both.
SEE ALSO
docstrip, doctools, doctools_fmt
KEYWORDS
\.ddt, Tcl module, catalogue, diff, docstrip, doctools, documentation,
literate programming, module, package indexing, patch, source
CATEGORY
Documentation tools
COPYRIGHT
Copyright (c) 2003?2010 Lars Hellstr�m <Lars dot Hellstrom at residenset dot net>
docstrip 1.3 docstrip_util(n)
