Provided by: tcllib_1.19-dfsg-2_all 
NAME
docstrip_util - Docstrip-related utilities
SYNOPSIS
package require Tcl 8.4
package require docstrip ?1.2?
package require docstrip::util ?1.3.1?
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 procedures 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 constructed. 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 docstrip::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 terminals.
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 modules 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 encoding). ascii and utf-8
are not very different in that sense.
-options terminals
The terminals is a list of terminals in addition to docstrip.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 postambles 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 comments) of generated files. Defaults
to a space. May be several lines, which are then separated by newlines. Traditionally 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 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 encoding). ascii and
utf-8 are not very different in that sense.
-options terminals
The terminals is a list of terminals in addition to docstrip.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 formatted
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 formatted
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 effectively 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
corresponding 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 encountered before the error will be included in the return value.
The setup-script argument can be used to customise the evaluation 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 interpreter that will do this processing is kept in the local variable c. To
for example copy the contents of the ::env array to the safe interpreter, one might use a setup-
script of
$c eval [list array set env [array get ::env]]
SOURCE PROCESSING COMMANDS
Unlike the previous group of commands, which would use docstrip::extract to extract some code lines and
then process those further, the following commands operate on text consisting of all types of lines.
docstrip::util::ddt2man text
The ddt2man command reformats text from the general docstrip format to doctools ".man" format (Tcl
Markup Language for Manpages). The different line types are treated as follows:
comment and metacomment lines
The '%' and '%%' prefixes are removed, the rest of the text is kept as it is.
empty lines
These are kept as they are. (Effectively this means that they will count as comment lines
after a comment line and as code lines after a code line.)
code lines
example_begin and example_end commands are placed at the beginning and end of every block
of consecutive code lines. Brackets in a code line are converted to lb and rb commands.
verbatim guards
These are processed as usual, so they do not show up in the result but every line in a
verbatim block is treated as a code line.
other guards
These are treated as code lines, except that the actual guard is emphasised.
At the time of writing, no project has employed doctools markup in master source files, so
experience of what works well is not available. A source file could however look as follows
% [manpage_begin gcd n 1.0]
% [keywords divisor]
% [keywords math]
% [moddesc {Greatest Common Divisor}]
% [require gcd [opt 1.0]]
% [description]
%
% [list_begin definitions]
% [call [cmd gcd] [arg a] [arg b]]
% The [cmd gcd] procedure takes two arguments [arg a] and [arg b] which
% must be integers and returns their greatest common divisor.
proc gcd {a b} {
% The first step is to take the absolute values of the arguments.
% This relieves us of having to worry about how signs will be treated
% by the remainder operation.
set a [expr {abs($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 format 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 particular 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 modifier:) 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 contributed patch) that was computed for a
generated file to the docstrip source. This can be useful if someone has edited a generated 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 generated 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 produces 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 impossible 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 matching is
affected by the following options:
-matching mode
How equal must two lines be in order to match? The supported modes are:
exact Lines must be equal as strings. This is the default.
anyspace
All sequences of whitespace characters are converted 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 someone 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 fconfigure 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) format diff into the list-of-hunks
format expected by docstrip::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 problems 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 respectively
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, .dtx, LaTeX, Tcl module, catalogue, diff, docstrip, doctools, documentation, literate programming,
module, package indexing, patch, source
CATEGORY
Documentation tools
COPYRIGHT
Copyright (c) 2003–2010 Lars Hellström <Lars dot Hellstrom at residenset dot net>