NAME
Tk::TextHighlight - a Tk::TextUndo/Tk::Text::SuperText widget with syntax highlighting capabilities, can also use Kate languages.
SYNOPSIS
use Tk;
my $haveKateInstalled = 0;
eval "use Syntax::Highlight::Engine::Kate; \$haveKateInstalled = 1; 1";
use Tk::TextHighlight; #-OR- use Tk::ROTextHighlight;
my $m = new MainWindow;
my $e = $m->Scrolled('TextHighlight', #NOTE: always "TextHighlight"!
-syntax => 'Perl',
-commentchar => '#',
-scrollbars => 'se',
)->pack(-expand => 1, -fill => 'both');
if ($haveKateInstalled) {
my ($sections, $kateExtensions) = $e->fetchKateInfo;
$e->addKate2ViewMenu($sections);
}
$m->configure(-menu => $e->menu);
$m->MainLoop;
DESCRIPTION
Tk::TextHighlight inherits Tk::Text::SuperText, if available, or Tk::TextUndo and all its options and methods. It provides an enhanced Tk Text widget that specializes in code-editing by additionally providing smart brace-matching / jumping between braces (but skipping ones in comments), language-specific text color-highlighting, and a "readonly" option for simply viewing text one doesn't want changed. Besides syntax highlighting, methods and bindings are provided for commenting and uncommenting as well as reindenting and unindenting a selected area, and automatic intelligent indenting of new lines.
Setting the -readonly flag or creating a symlink to the TextHighlight.pm source file and naming it ROTextHighlight.pm, then "using" it ("use Tk::ROTextHighlight") in the program provides all the same functionality in a "readonly" widget for text viewers, etc. Tk::TextHighlight also supports highlighting of all the many lauguages and file formats supported by Syntax::Highlight::Engine::Kate, if that optional module is installed. For Perl programmers in particular, TextHighlight can use either the module Syntax::Highlight::Perl, or the optional and better one: Syntax::Highlight::Perl::Improved. There is also a "PerlCool" version that leans toward "cooler" colors (greens, blues, violets), preferred by the author. One can also choose Kate's Perl highlighter: Syntax::Highlight::Engine::Kate::Perl, if the Kate modules are installed.
Syntax highlighting is done through a plugin approach. Adding languages is a matter of writing plugin modules. Theoretically this is not limited to programming languages. The plugin approach could also provide the possibility for grammar or spell checking in spoken languages.
Currently there is built-in support for Bash, HTML, Perl, Pod, and Xresources. Optionally many others if Syntax::Highlight::Engine::Kate is installed.
STANDARD OPTIONS
-background -borderwidth -cursor -exportselection -font -foreground -highlightbackground -highlightcolor -highlightthickness -insertbackground -insertborderwidth -insertofftime -insertontime -insertwidth -padx -pady -relief -selectbackground -selectborderwidth -selectforeground -setgrid -spacing1 -spacing2 -spacing3 -state -tabs -takefocus -xscrollcommand -yscrollcommand
WIDGET-SPECIFIC OPTIONS
- Name: autoindent
- Class: Autoindent
- Switch: -autoindent
-
Boolean, when you press the enter button, should the next line begin at the same position as the current line or not. This indentation works with either spaces or tabs are used (See also: -indentchar).
Default: false (start each new line at column 0).
- Name: commentchar
- Class: Commentchar
- Switch: -commentchar
-
This is slightly misleading - it represents a string of one or more characters. Normally when using the selectionComment() method, each selected line is prepended with the commentchar string. A Special exception is made if the string is "/*", "(*", or "<!--", as these normally represent comment braces, which must have a beginning and ending string, and the selectionComment() method automatically recognizes these special cases and instead automatically wraps the entire block of selected text with the specified commentchar string and it's proper terminating string. When specifying the -syntax parameter when creating the TextHighlight widget, and editing files containing C code, HTML, Pascal, etc. they should consider also specifying the corresponding -commentchar string appropriate for files containing that language. See also -syntaxcomments
Default: "#".
-
Boolean, if true, disables the popup menu under the right mouse button (ButtonPress-3). Unlike -noPopupMenu This can be configured programatically at run-time. See also -noPopupMenu.
Default: false (Menu will popup when right mouse button is pressed over the widget).
- Name: highlightInBackground
- Class: HighlightInBackground
- Switch: -highlightInBackground
-
Perform rehighlighting (after text changes) in a background thread (if true), which, in most cases this should be desirable.
Default: false Recommended value now: true (modern multi-threaded computer processors should handle this fine now)!
- Name: indentchar
- Class: Indentchar
- Switch: -indentchar
-
String to be inserted when the [Tab] key is pressed or when indenting. Can also be set to one or more spaces.
Default: "\t" (tab character).
- Name: match
- Class: Match
- Switch: -match
-
string of pairs for brace/bracket/curly etc matching. If this description doesn't make anything clear, don't worry, the default setting will:
Default: "[]{}()"
if you don't want matching to be available, simply set it to "".
- Name: matchoptions
- Class: Matchoptions
- Switch: -matchoptions
-
Options list for the tag 'Match' (the temporary color of the matched brace character, if found, while the cursor is on the other matching brace.
Default: [-background = 'red', -foreground => 'yellow']>
You can also specify this option as a space separated string. Might come in handy for your Xresource files, ie. "-background red -foreground yellow".
- Name: Not available
- Class: Not available
- Switch: -noPlugInit
-
Disables TextHighlight feature of initializing default rules when no .rules file present.
Default: false (Enable initialing with default rules).
- Name: noPopupMenu
- Class: NoPopupMenu
- Switch: -noPopupMenu
-
Disables the right mouse button (Button-3) popup menu common on Tk::Text* widgets.
NOTE: Unlike -disablemenu, this must be set in initial configuration and can not be changed by configure() later. (See also -disablemenu).
Default: false (Menu will be created and will popup when right mouse button is pressed over the widget - unless -disablemenu is later configured to true).
- Name: Not available
- Class: Not available
- Switch: -noRulesEditMenu
-
Don't show the Rules Editor option in the View submenu of the right-click menu.
Default: false (Include this option item in the View submenu).
- Name: Not available
- Class: Not available
- Switch: -noRulesMenu
-
Don't show any of the TextHighlight menu items (combines -noSyntaxMenu, -noRulesEditMenu, and -noSaveRulesMenu options.
Default: false (Include all three, except any blocked by the more specific options described above).
- Name: Not available
- Class: Not available
- Switch: -noSaveRulesMenu
-
Don't show the Save Rules submenu option in the View submenu of the right-click menu.
Default: false (Include this option item in the View submenu).
- Name: Not available
- Class: Not available
- Switch: -noSyntaxMenu
-
Don't show the Syntax submenu option in the View submenu of the right-click menu.
Default: false (Include this submenu in the View submenu).
- Name: readOnly
- Class: ReadOnly
- Switch: -readonly
-
If set to a true value, causes the TextHighlight widget to be "readonly" (content not changeable by the user). If false, the widget content is editable. The default is 0 (false), unless a copy of or symlink to the TextHighlight.pm module file named "ROTextHighlight.pm", and the module is "used" as "Tk::ROTextHighlight", in which case the value is fixed as 1 (true), regardless of this setting, and can not be changed to false.
Default: false (if "use TextHighlight"), true (if "use ROTextHighlight").
- Name: not available
- Class: not available
- Switch -rules
-
Specify the color and font options for highlighting. You specify a list looking a bit like this.
[ ['Tagname1', @options1], ['Tagname2', @options2], ]
The names of the tags are depending on the syntax that is highlighted. See the language modules for more information about this data structure.
Default: The rules set by whatever language plugin is in use.
- Name: rulesdir
- Class: Rulesdir
- Switch -rulesdir
-
Specify the directory where this widget stores its coloring definitions. Files in this directory are stored as "HTML.rules", "Perl.rules" etc. By default it is set to '', which means that when you switch syntax the highlighting rules are not loaded or stored. The hard coded defaults in the language modules will be used.
- Name: not available
- Class: not available
- Switch -smartindent
-
Boolean, when pressing the enter button and -autoindent is also true, the indentation is also affected by the last character on the previous line, ie. if "{", "(", "[", etc. is an opening bracket character, and on the indentation and first character of the following line, ie. "}", ")", etc., to be (hopefully) more convenient for programmers.
Default: true (but practically false, since -autoindent currently defaults to false).
- Name: syntax
- Class: Syntax
- Switch: -syntax
-
Specifies the language for highlighting. At this moment the possible values are None, HTML, Perl, Pod Kate::Language, and Xresources.
Default: None
If Syntax::Highlight::Engine::Kate is installed, you may specify any language that the Kate syntax highlight engine supports.
Alternatively it is possible to specify a reference to your independent plugin.
- Name: syntax
- Class: Syntax
- Switch: -syntaxcomments
-
Boolean, when set to true, the -commentchar will be set (overridden) to the comment string for the specific language (-syntax) for certain supported languages (C, C++, CSS, HTML, Modula-II, Pascal, Perl, and XML).
Default: false (use the preset string in -commentchar.
- Name: Not available
- Class: Not available
- Switch: -updatecall
-
Here you can specify a callback that will be executed whenever the insert cursor has moved or text has been modified, so your application can keep track of position etc. Don't make this callback to heavy, the widget will get sluggish quickly!
Default: none (sub {})
METHODS
- addKate2ViewMenu($sections)
-
Inserts the list of Kate-supported languages to the widget's Syntax. View right-mousebutton popup menu along with the basic TextHight-supported choices. These choices can then be selected to change the current language-highlighting used in the text in the widget. $sections is a hash-ref normally returned as the 1st item in the list returned by fetchKateInfo. NOTE: No menu items will be added if Kate is not installed or if -noRulesMenu or -noSyntaxMenu are set!
- beginUndoBlock
-
Used in application programs when wishing to group together a series of edits that, in the event of a call to Undo() should be undone together as a group. This method should be called before the first insertion or deletion. See also endUndoBlock.
- clipboardCopy
-
Copies any selected text to the system's CLIPBOARD paste-buffer.
Default bindings: Control-c.
- clipboardCut
-
Default bindings: Control-x.
Deletes the selected text from the widget and puts it in the system's CLIPBOARD paste-buffer.
- clipboardPaste
-
Pastes the content of the system's CLIPBOARD paste-buffer at the current cursor position and selects it.
Default bindings: Control-v.
- delete(index1, ?index2?)
-
Delete a range of characters from the text. If both index1 and index2 are specified, then delete all the characters starting with the one given by index1 and stopping just before index2 (i.e. the character at index2 is not deleted). If index2 doesn't specify a position later in the text than index1 then no characters are deleted. If index2 isn't specified then the single character at index1 is deleted. It is not allowable to delete characters in a way that would leave the text without a newline as the last character. The command returns an empty string. If more indices are given, multiple ranges of text will be deleted. All indices are first checked for validity before any deletions are made. They are sorted and the text is removed from the last range to the first range to deleted text does not cause a undesired index shifting side-effects. If multiple ranges with the same start index are given, then the longest range is used. If overlapping ranges are given, then they will be merged into spans that do not cause deletion of text outside the given ranges due to text shifted during deletion.
- doAutoIndent(boolean)
-
Checks the indention of the previous line and indents the line where the cursor is equally deep. If a <true> value is passed in, and -autoindent is set to true. Otherwise, false will cause no indentation to be added when pressing the Return key. Note if both -autoindent and -smartindent are set to true values, indentation will also be affected by the indentation of the next line, and whether the current line ends with an opening brace character or the next line begins with an opening brace character, causing indentation to be more typical to that used in computer source code. -smartindent is ignored if -autoindent is false.
Default bindings: Return key: doAutoIndent(true), Shift-Return: doAutoIndent(false)
- EmptyDocument
-
Resets the widget to an empty state (ie. $w->delete('0.0', 'end'), except is actionable even if the widget is readonly!
- extendSelect
-
Selects text between the insert cursor to the current mouse position when pressed, then adjusted again if the mouse is released in a different place than when pressed. The insert cursor should remain in it's current location (like a pivot point).
Default bindings: Shift-ButtonPress-3, and ButtonPress-3 if the -noPopupMenu option is set to true.
- endUndoBlock
-
Used in application programs when wishing to group together a series of edits that, in the event of a call to Undo() should be undone together as a group. This method should be called after the last insertion or deletion. See also beginUndoBlock.
- fetchKateInfo
-
Returns 3 hashrefs containing information about the installed Kate highlight engine (if installed). The three hashrefs contain in order: The first can be passed to the addkate2viewmenu() method to add the Kate languages to the Syntax.View menu. the keys are "Kate::language" and the values are what's needed to instantiate Kate for that language. the 2nd is a list of file- extension pattern suitable for matching against file-names and the values are the reccomended Kate language for that file-extension. It will return (undef, undef, undef) if Kate is not installed.
- get(index1, ?index2?)
-
Return a range of characters from the text. The return value will be all the characters in the text starting with the one whose index is index1 and ending just before the one whose index is index2 (the character at index2 will not be returned). If index2 is omitted then the single character at index1 is returned. If there are no characters in the specified range (e.g. index1 is past the end of the file or index2 is less than or equal to index1) then an empty string is returned. If the specified range contains embedded windows, no information about them is included in the returned string. If multiple index pairs are given, multiple ranges of text will be returned in a list. Invalid ranges will not be represented with empty strings in the list. The ranges are returned in the order passed to get.
- getViewMenu
-
Returns the "View" submenu of the Popup menu, which the application can clone and include in their application's menu, particularly if they do not wish to use the normal mouse button-3 popup menu. Note, this may not work (untested) if -noPopupMenu is set to true, but will if -disablemenu is (See -disablemenu and -noPopupMenu).
- highlight($begin, $end)
-
Does syntax highlighting on the section of text indicated by $begin and $end. $begin and $end are linenumbers not indexes!
- highlightCheck($begin, $end)
-
An insert or delete has taken place affecting the section of text between $begin and $end. highlightCheck is being called after and insert or delete operation. $begin and $end (again, linenumbers, not indexes) indicate the section of text affected. highlightCheck checks what needs to be highlighted again and does the highlighting.
- highlightLine($line)
-
Does syntax highlighting on linenumber $line.
- highlightPlug
-
Checks whether the appropriate highlight plugin has been loaded. If none or the wrong one is loaded, it loads the correct plugin. It returns a reference to the plugin loaded. It also checks wether the rules have changed. If so, it restarts highlighting from the beginning of the text.
- highlightPlugInit
-
Loads and initalizes a highlighting plugin. First it checks the value of the -syntax option to see which plugin should be loaded. Then it checks wether a set of rules is defined to this plugin in the -rules option. If not, it tries to obtain a set of rules from disk using rulesFetch. If this fails as well it will use the hardcoded rules from the syntax plugin.
- highlightPurge($line)
-
Tells the widget that the text from linenumber $line to the end of the text is not to be considered highlighted any more.
- highlightVisual
-
Calls visualEnd to see what part of the text is visible on the display, and adjusts highlighting accordingly.
- insert(index, chars, ?tagList, chars, tagList, ...?)
-
Inserts all of the chars arguments just before the character at index. If index refers to the end of the text (the character after the last newline) then the new text is inserted just before the last newline instead. If there is a single chars argument and no tagList, then the new text will receive any tags that are present on both the character before and the character after the insertion point; if a tag is present on only one of these characters then it will not be applied to the new text. If tagList is specified then it consists of a list of tag names; the new characters will receive all of the tags in this list and no others, regardless of the tags present around the insertion point. If multiple chars-tagList argument pairs are present, they produce the same effect as if a separate insert widget command had been issued for each pair, in order. The last tagList argument may be omitted.
- Insert(string)
-
Do NOT confuse this with the lower-case insert method. Insert string at the point of the insertion cursor. If there is a selection in the text, and it covers the point of the insertion cursor, then it deletes the selection before inserting.
- InsertKeypress(character)
-
Inserts character at the insert mark. If in overstrike mode, it firsts deletes the character at the insert mark.
- insertTab
-
Inserts the -indentchar string (Default is tab character. See -indentchar
Default bindings: Tab key
- insertTabChar
-
Inserts a tab character (always). See -indentchar
Default bindings: Alt-Tab
- linenumber($index)
-
Returns the linenumber part of an index. You may also specify indexes like 'end' or 'insert' etc.
- jumpToMatchingChar(boolean)
-
If the cursor is sitting on a bracing character (see -match option), the cursor will jump to the matching character. If passed a true value, then the two brace characters and the text between them will be selected. There is no point in calling this method directly, but rather it can be bound to a key-sequence (Default is currently Control-p (jump only), and Control-P (jump and select eveything inbetween).
- Load($filename)
-
Replaces the content of the widget with the content of file $filename. Returns 1 (true) if successful, 0 (false) otherwise. One can check the Perl variable $! for error message on failure.
- matchCheck
-
Checks wether the character that is just before the 'insert'-mark should be matched, and if so, should it match forwards or backwards. It then calls matchFind.
- matchFind($direction, $char, $match, $start, $stop)
-
Matches $char to $match, skipping nested $char/$match pairs, and displays the match found (if any).
- pastePrimaryAtMouse
-
Paste the primary selection at the current mouse position.
Default bindings: ButtonRelease-2
- PostPopupMenu
-
Pops up the menu associated with Tk::Text* widgets, including submenu items associated with TextHighlight, ie. the language plugins, rules editor, etc. Note: both -noPopupMenu and -disablemenu must NOT be set to true.
Default bindings: ButtonPress-3 (mouse button 3), Control-Key-m
- readonly [ (boolean) ]
-
Get or set readonly status for the widget. If a true or false value are passed in, the widget's state will be configured to either readonly or normal (editable) respectively. This should normally be done by the configure(-readonly, boolean) function. NOTE: If using via "use ROTextHighlight" (copy or symlink), then the readonly state is fixed and any changes here will be ignored.
- Redo
-
Reapply the last change (or block of changes) undone by the last call to Undo.
- ResetUndo
-
Reset (clear) the Undo history stack.
- rulesEdit
-
Pops up a window that enables the user to set the color and font options for the current syntax.
- rulesFetch
-
Checks whether the file:
$text->cget('-rulesdir') . '/' . $text->cget('-syntax') . '.rules'
exists, and if so attempts to load this as a set of rules.
- rulesSave
-
Saves the currently loaded rules as
$text->cget('-rulesdir') . '/' . $text->cget('-syntax') . '.rules'
- selectionComment
-
Comment currently selected text.
- selectionIndent
-
Indent currently selected text.
- selectionModify
-
Used by the other selection... methods to do the actual work.
- selectionUnComment
-
Uncomment currently selected text.
- selectionUnIndent
-
Unindent currently selected text.
- setRule(rulename, colorattribute, color)
-
Allows altering of individual rules by the programmer.
- Undo
-
Undo the last change (or block of changes) to the text (the top of the Undo stack).
SYNTAX HIGHLIGHTING, The Gory Details
This section is a brief description of how the syntax highlighting process works. Note: Most users should not need to worry about this stuff when simply incorporating a Tk::TextHighlight widget into their Perl/Tk application, except for perhaps writing a few lines of code in their application to determine the value of the -syntax flag (see the SYNOPSIS section for an example) from the content or extension of a file they plan to edit in the widget, ie.:
$e->configure(-syntax => 'Perl') if (filename =~ /\.p[lm]$/);
Users will hardly ever need to change the default rules for any of the language plugins, as Tk::TextHighlight will automatically change any highlight rule colors that match (clash with) the user's specified background color, preventing invisible text, when the plugin is initiated!
Initiating plugin:
The highlighting plugin is only then initiated when it is needed. When some highlighting needs to be done, the widget calls highlightPlug to retrieve a reference to the plugin.
highlightPlug checks wether a plugin is present. Next it will check whether the -rules option has been specified or wether the -rules option has changed. If no rules are specified in -rules, it will look for a pathname in the -rulesdir option. If that is found it will try to load a file called '*.rules', where * is the value of -syntax.
If no plugin is present, or the -syntax option has changed value, highlightPlug loads the plugin. and constructs optionally giving it a reference to the found rules as parameter. if no rules are specified, the plugin will use its internal hardcoded defaults.
Changing the rules
A set of rules is a list, containing lists of tagnames, followed by options. If you want to see what they look like, you can have a look at the constructors of each plugin module. Every plugin has a fixed set of tagnames it can handle.
There are two ways to change the rules.
You can invoke the rulesEdit method, which is also available through the View menu. The result is a popup in which you can specify color and font options for each tagname. After pressing 'Ok', the edited rules will be applied. If -rulesdir is specified, the rules will be saved on disk as rulesdir/syntax.rules.
You can also use configure to specify a new set of rules. In this you have ofcause more freedom to use all available tag options. For more details about those there is a nice section about tag options in the Tk::Text documentation. After the call to configure it is wise to call highlightPlug.
Highlighting text
Syntax highlighting is done in a lazy manor. Only that piece of text is highlighted that is needed to present the user a pretty picture. This is done to minimize use of system resources. Highlighting is running on the foreground. Jumping directly to the end of a long fresh loaded textfile may very well take a couple of seconds.
Highlighting is done on a line by line basis. At the end of each line the highlighting status is saved in the list in -colorinf, so when highlighting the next line, the highlight method of TextHighlight will know how to begin.
More information about those methods is available in the documentation of Tk::TextHighlight::None and Tk::TextHighlight::Template.
Inheriting Tk::TextHighlight::Template
For many highlighting problems Tk::TextHighlight::Template provides a nice basis to start from. Your code could look like this:
package Tk::TextHighlight::MySyntax;
use strict;
use base('Tk::TextHighlight::Template');
sub new {
my ($proto, $wdg, $rules) = @_;
my $class = ref($proto) || $proto;
Next, specify the set of hardcoded rules.
if (not defined($rules)) {
$rules = [
['Tagname1', -foreground => 'red'],
['Tagname1', -foreground => 'red'],
];
};
Call the constructor of Tk::TextHighlight::Template and bless your object.
my $self = $class->SUPER::new($rules);
So now we have the SUPER class avalable and we can start defining a couple of things.
You could add a couple of lists, usefull for keywords etc.
$self->lists({
'Keywords' => ['foo', 'bar'],
'Operators' => ['and', 'or'],
});
For every tag you have to define a corresponding callback like this.
$self->callbacks({
'Tagname1' => \&Callback1,
'Tagname2' => \&Callback2,
});
You have to define a default tagname like this:
$self->stackPush('Tagname1');
Perhaps do a couple of other things but in the end, wrap up the new method.
bless ($self, $class);
return $self;
}
Then you need define the callbacks that are mentioned in the callbacks hash. When you just start writing your plugin i suggest you make them look like this:
sub callback1 {
my ($self $txt) = @_;
return $self->parserError($txt); #for debugging your later additions
}
Later you add matching statements inside these callback methods. For instance, if you want callback1 to parse spaces it is going to look like this:
sub callback1 {
my ($self $txt) = @_;
if ($text =~ s/^(\s+)//) { #spaces
$self->snippetParse($1, 'Tagname1'); #the tagname here is optional
return $text;
}
return $self->parserError($txt); #for debugging your later additions
}
If callback1 is the callback that is called by default, you have to add the mechanism for checking lists to it. Hnce, the code will look like this:
sub callback1 {
my ($self $txt) = @_;
if ($text =~ s/^(\s+)//) { #spaces
$self->snippetParse($1, 'Tagname1'); #the tagname here is optional
return $text;
}
if ($text =~ s/^([^$separators]+)//) { #fetching a bare part
if ($self->tokenTest($1, 'Reserved')) {
$self->snippetParse($1, 'Reserved');
} elsif ($self->tokenTest($1, 'Keyword')) {
$self->snippetParse($1, 'Keyword');
} else { #unrecognized text
$self->snippetParse($1);
}
return $text
}
return $self->parserError($txt); #for debugging your later additions
}
Have a look at the code of Tk::TextHighlight::Bash. Things should clear up. Then, last but not least, you need a syntax method.
Using another module as basis
An example of this approach is the Perl syntax module.
Also with this approach you will have to meet the minimum criteria as set out in the From scratch section.
CONTRIBUTIONS
If you have written a plugin, i will be happy to include it in the next release of Tk::TextHighlight. If you send it to me, please have it accompanied with the sample of code that you used for testing.
AUTHOR
Jim Turner, <https://metacpan.org/author/TURNERJW>
COPYRIGHT
This module is Copyright (C) 2007-2024 by
Jim Turner, <turnerjw784 at yahoo.com>
All rights reserved.
You may distribute this module under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file.
This is a derived work from Tk::CodeText, by Hans Jeuken (haje at toneel.demon.nl)
Thanks go to Mr. Hans Jeuken for his great work in making this and the Kate modules possible. He did the hard work!
LICENSE
Copyright 2007-2024 Jim Turner. <turnerjw784 at yahoo.com>
This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:
http://www.perlfoundation.org/artistic_license_2_0
Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.
If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.
This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.
This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.
Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
BUGS
Please report any bugs or feature requests to bug-tk-TextHighlight at rt.cpan.org, or through the web interface at https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Tk-TextHighlight. I will be notified, and then you'llautomatically be notified of progress on your bug as I make changes.
TODO
Consider adding some of the Tk::TextUndo methods not currently provided by either this module Tk::Text, or Tk::Text::SuperText.
Add additional language modules. I am going to need help on this one. We currently support all the original Tk::CodeText languages (included) plus all those supported by Syntax::Highlight::Engine::Kate, if it's installed.
The sample files in the test suite should be set up so that conformity with the language specification can actually be verified.