Difference between revisions of "Verbatim text"

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</texcode>
 
</texcode>
  
The commands embed example.sc in the pdf, so that it is accessible by double-clicking on a generated icon.
+
 
If you use Acrobat Reader (Preview.app in MacOSX does not provide support for the behaviour) example.sc will be open in the related application (i.e. SuperCollider.app).
+
So that you can have this structure for each code snippet:
 +
 
 +
<texcode>
 +
\input example
 +
 
 +
\useattachment[ex][example.sc]
 +
\attachment[ex]
 +
</texcode>
 +
 
 +
 
 +
The commands embed example.sc in the pdf, so that it is accessible by double-clicking on a generated icon. In this case the icon is placed after the colorized code frame.
 +
If you use Acrobat Reader (Preview.app in MacOSX does not provide support for the behaviour) example.sc will be open in the related application (e.g. SuperCollider.app in the discussed case).
  
  

Revision as of 11:59, 17 May 2007

< Visuals | Verbatim with line breaks >

Displayed text

\starttyping, \typebuffer

Unlike LaTeX's verbatim environment, ConTeXt's typing environments have quite a range of built-in options for formatting the verbatim text, see below.

In-line text

\startTEX ... \stopTEX only works when typesetting the whole paragraph. If you need to type only a command or two as in-line text, you can use the following Taco's macro (hopefully this will land in the core once in the future):

\def\typeTEX
  {\bgroup
   \def\processinlineverbatim##1%
     {\processingverbatimtrue
      \localcatcodestrue
      \def\endofverbatimcommand{\TEXendofcommand##1}%
      \bgroup
      \aftergroup\endofverbatimcommand
      \futurelet\next\doprocessinlineverbatim}%
   \initializetyping{TEX}%
   \startverbatimcolor
   \processinlineverbatim\egroup }

Now you can say:

\typeTEX+\typeTEX{\typeTEX is a wonderful macro}+, isn't it?

Source: [1]

Embedded formatting commands

The option=commands setting allows the usage of ConTeXt commands inside verbatim text, as in this example:

\definetyping[C][option=commands]
\startC
#include <stdio.h>
int main(){
	return 0;
	/BTEX{\em unreachedCode;}/ETEX
}
\stopC

Included Formatters

There are already some formatters for several programming languages in the ConTeXt distribution:

Code Language
C C
EIF Eiffel
JS JavaScript
JV Java
MP MetaPost & MetaFont
PAS Pascal & Modula
PL Perl 5
SQL SQL
TEX TeX
XML XML

Your own formatter

(from a ML answer by Taco, 2006-12-25, "Making a verbatim file for another language")

You should start from the definition that is closest to the language you want to define (especially wrt comment and string syntax) and can probably have a go at making a version of this. Some questions occur:

Where should i put my file?

  1. Possibly the best place is: In the context distribution, but that depends a bit on what language it is, precisely (you can email me the completed file, in that case).
  2. Second best place: http://modules.contextgarden.net, so it can be included in cont-ext.zip (third-party addons that are distributed by Pragma-Ade alongside the normal distribution).
  3. Third best: The directory <$HOME/texmf/tex/context/base> (the place where your TeX installation finds local files).
  4. Final option: Same directory as the file to be processed

Do I have to do anything else to get ConTeXt to recognise and use it?

Your file has to have a name like verb-xxxx.tex, with xxxx a lowercase short identifier (example: verb-php.tex), and then you have to use one or two commands to make ConTeXt use the file.

First:

\installprettytype [PHP]        [PHP]

This maps the command \starttyping[option=PHP] to verb-php.tex.

The first argument is the option as passed to \starttyping, the second argument is an uppercase version of xxxx (thus allowing ConTeXt to find the file),

And you probably also want:

\definetyping[PHP]   [option=PHP]

Because that allows \startPHP ... \stopPHP as a shortcut to \setuptyping[option=PHP]

Wait for LuaTeX

Unless you need that highlighting urgently, I would wait for LuaTeX and write it in lua then (which is certainly less painful than writing it in plain TeX). But it's up to you. I found those TeX definitions too complicated to even try to understand, I would never dare to try writing one by myself. -- Mojca

Tabbing

The tab character normally corresponds to one character, as can be seen above. That value can be adjusted, using the following code (available in the 2005.06.01 version and later):

\definetyping[C][tab=3]
% for older ConTeXt versions: \chardef\spacespertab=3
\startC
int func(int a){
	if(a > 4)
		return 0;
	else
		return 10;
}
\stopC

Syntax highlighting in color

\setupcolors[state=start]
\setuptyping[option=color]

\starttext
\startXML
... your XML code ...
\stopXML
\stoptext

Defining your own set of colors

Sometimes you may be not quite satisfied with the default colors used in the built-in syntax highlighting. Taco posted this solution in the discussion on the mailing list:

\setupcolors[state=start]
\setuptyping[option=color]

% define the colors to fit your document style
\definecolor[MYcolorone]  [r=.8,g=.5,b=.5]
\definecolor[MYcolortwo]  [r=.8,g=.5,b=.2]
\definecolor[MYcolorthree][r=.8,g=.5,b=.8]
\definecolor[MYcolorfour] [r=.8,g=.2,b=.5]

% define a palete using these four colors
\definepalet[MYcolors]
  [prettyone=MYcolorone,
   prettytwo=MYcolortwo,
   prettythree=MYcolorthree,
   prettyfour=MYcolorfour]

% XML code will be typeset with the palette you just defined
\definepalet[XMLcolorpretty] [MYcolors] % the name is magic !

\starttext
\startXML
... your XML code ...
\stopXML
\stoptext

This results in:

Line numbering

In technical documents it can be required to display some code listings with the line numbers. You can do this with ConTeXt, and even more. All the features shown here are also available when displaying external files with \typefile.

Preliminary setting

Let's define our own typing style, named "code". The typing is put in a framedtext, to demonstrate the wrapping feature in a next section.

\defineframedtext
  [framedcode]
  [strut=yes,
   offset=2mm,
   width=7cm,
   align=right]

\definetyping[code][numbering=line,
                    bodyfont=small,
                    before={\startframedcode},
                    after={\stopframedcode}]

Default line numbering

With the defined typing, every line is numbered, and the number goes in the margin. The option to have the line numbers displayed is numbering=line.

\startcode
This is the first line
This is a rather long line that is wrapped, so look how the line numbering is done
Another line

Last line after an empty line
\stopcode

It is rendered as:

Line numbers in the text

To have the line numbers in the text, change the linenumbering setup like this:

\setuplinenumbering[location=intext]
\startcode
This is the first line
This is a rather long line that is wrapped, so look how the line numbering is done
Another line

Last line after an empty line
\stopcode

Continuing the numbering

Another handy feature is the ability to continue the numbering from one portion of code to another. Use the option continue for this.

\startcode
This is the first line
This is a rather long line that is wrapped, so look how the line numbering is done
Another line

Last line after an empty line
\stopcode

Some normal text to explain the first piece of code,
and introduce the following lines.

\startcode[continue]
This is the first continuing line
This is a rather long line that is wrapped, so look how the line numbering is done
Another line
Last line
\stopcode

Arbitrary starting line number

You can also decide what the starting line number is. Use the option start=number for this.

\startcode[start=200]
This is the first line
This is a rather long line that is wrapped, so look how the line numbering is done
Another line
Last line
\stopcode

Line number steps

You want to print a number every two lines? Ok, just use the option step=number for this.

\startcode[start=200,step=2]
This is the first line
This is a rather long line that is wrapped, so look how the line numbering is done
Another line
Last line
\stopcode


A different approach to formatting and code colorization

Supposing that:

a) you are much more fluent in another programming language than TeX

b) you have a large project involving many code snippet to be inserted and colorized

you can go for another, less elegant, way to format your verbatim text, which can include all the discussed ConTeXt benefits.

Writing a parser/formatter

It fairly simple to write a little parser which takes as its input your source file and gives in output a .tex file containing the code plus the opportune commands for colorization. You can then include the resulting .tex file in the global ConTeXt document file. As an example, this is a Python script for the SuperCollider language, which has a striclty Smalltalk-like syntax.

Fed with this source code contained in example.sc file:



the script outputs this tex code, which is written into a file contained in the same folder of the source file (named example.tex):

\startSC
/BTEX{\color[SCred] //// an example starting with a comment}/ETEX
/BTEX{\color[SCgrey] "this is a string"}/ETEX .postln ;

/BTEX{\color[SCgreen] \letterbackslash aSymbol}/ETEX  ;

/BTEX{\color[SCblue] ThisClassDoesNotExists}/ETEX  ;
\stopSC

Basically, the idea is to envelope each item to be colorized inside a /BTEX /ETEX block. Note that inside the block the text is no more verbatim, so you have to define some string replacement for special characters (e.g. _, %, $, \, etc). As an example, the problem of the backslash (\) is solved here by replacing it with \letterbackslash. The example uses some definitions (explained before) which have to be put in the global ConTeXt file

\defineframedtext
  [framedSC]
  [framecolor=cirmaBlue,
   strut=yes,
   offset=2mm,
   width=local,
   align=right]

\definetyping[SC][option=commands, 
					tab=2,numbering=line,
                    before={\startframedSC},
                    after={\stopframedSC}]

also, example.tex requires color definitions, which are created following SuperCollider colorization interpreter scheme and have to be inserted in the global ConTeXt file:

%% SC colors %%
\definecolor [SCwhite] [r=1.0, g=1.0, b=1.0] 
\definecolor [SCblack] [r=0.0, g=0.0, b=0.0] 
\definecolor [SCblue] [r=0.0, g=0.0, b=0.75] 
\definecolor [SCred] [r=0.75, g=0.0, b=0.0] 
\definecolor [SCgrey] [r=0.376, g=0.376, b=0.376] 
\definecolor [SCgreen] [r=0.0, g=0.45, b=0.0]

\definecolor[cirmaBlue] [r=.0,g=.2,b=.6]  % for frame

You can then insert example.tex in the global ConTeXt file with

\input example

After compiling, this is the result.

Embedding the source code

If your document is inteded to provide code examples to be tested by the readers, the presence of format signs (e.g. line numbers) can create some troubles while copying and pasting the code text from your document to the language environment. More generally, the copy and paste approach, being slow and possbily related to encodings, is not satisfying at all. You can include source files in the pdf with a couple of ConTeXt commands:

\useattachment[ex][example.sc]
\attachment[ex]


So that you can have this structure for each code snippet:

\input example

\useattachment[ex][example.sc]
\attachment[ex]


The commands embed example.sc in the pdf, so that it is accessible by double-clicking on a generated icon. In this case the icon is placed after the colorized code frame. If you use Acrobat Reader (Preview.app in MacOSX does not provide support for the behaviour) example.sc will be open in the related application (e.g. SuperCollider.app in the discussed case).


The discussed approach has been implemented here.

(-a- --> User:Andrea)