@Section
   @Title { Changing the appearance of all programs simultaneously }
   @Tag { cpsetup }
@Begin
@PP
We have just seen that the {@Code "@CP"}, {@Code "@Eiffel"} etc. symbols
have many options for changing the appearance of the program text.  However,
most people would not want to have a different style for every program text
in their document; they want to define the style once at the start, and have
all their program texts come out in that style without laboriously setting
options on every symbol.  You do this by copying the setup file and
changing it.
@PP
For general information about how to make your own setup file, consult
Section {@NumberOf setup}.  The options that determine the default
values are in the @Code "@Use" clause which occupies most of the setup
programs. @RawIndex { programs }
programs.setup @SubIndex { setup files for }
setup.files. @RawIndex { setup files }
setup.files.for.programs @SubIndex { for programs }
file.  Here is part of the @Code "@Use" clause from {@Code cprint}:
@ID @Code @Tbl
   mv { 0.5vx }
   aformat { @Cell A | @Cell B | @Cell C }
   bformat { @Cell { "    #" A } | @Cell { "{" B } | @Cell "}" }
{
@Rowa A { "@Use {  @CPSetup" }
@Rowb A { "pipe" } B {          }
@Rowb A { "numbered" } B { No         }
@Rowb A { "style" } B { fixed         }

@Rowa 
@Rowb A { "fixedfont" }			B { Courier  }
@Rowb A { "fixedsize" }			B { -1.0p         }
@Rowb A { "fixedline" }			B { 1.0vx         }
@Rowb A { "fixedspace" }		B { lout         }
@Rowb A { "fixedtabin" }		B { 8		  }
@Rowb A { "fixedtabout" }		B { 8s		  }

@Rowa 
@Rowb A { "fixedidentifiers" }		B { Base  }
@Rowb A { "fixedkeywords" }		B { Base  }
@Rowb A { "fixedoperators" }		B { Base  }
@Rowb A { "fixednumbers" }		B { Base  }
@Rowb A { "fixedstrings" }		B { Base  }
@Rowb A { "fixedcomments" }		B { Base  }
@Rowb A { "fixedlinenumbers" }		B { Base  }

@Rowa 
@Rowb A { "fixedidentifiersformat" }	B { "@Body"  }
@Rowb A { "fixedkeywordsformat" }	B { "@Body"  }
@Rowb A { "fixedoperatorsformat" }	B { "@Body"  }
@Rowb A { "fixednumbersformat" }	B { "@Body"  }
@Rowb A { "fixedstringsformat" }	B { "@Body"  }
@Rowb A { "fixedcommentsformat" }	B { "@Body"  }
@Rowb A { "fixedlinenumbersformat" }	B { "@Body"  }

@Rowa 
@Rowa A { "..." }

@Rowa 
@Rowa A { "}" }
}
The @Code pipe option will be explained in Section {@NumberOf pipes}.  The
options whose name begins with @Code "fixed" apply only when
@Code style is {@Code fixed}; there are corresponding options, not
shown, which apply when @Code style is {@Code varying} and {@Code symbol}.
@PP
We can see in this extract that the default value of @Code style is
{@Code fixed}, and of @Code "numbers" is {@Code No}.  We can also see the
default font family, font face, font size, line spacing, spacing mode,
and tab settings when the style is {@Code "fixed"}.  The font family
name for @Code "fixed" style is {@Code "Courier"}, but for the other
styles (not shown) it is empty.  This causes the @Code "fixed" style
to always switch to Courier, and the other styles to use the same font
family as in the surrounding document.
@PP
The options from @Code "fixedidentifiers" to @Code "fixedlinenumbers" allow
you to set the font face to use for each of these parts of your
program.  People who want fixed-width fonts do not usually want very
exciting font faces either, so the default values above are all
{@Code "Base"}, but for the {@Code varying} and {@Code symbol} styles,
the default identifier face is {@Code Slope}, the default keyword
face is {@Code Bold}, and so on.  You can actually give a family name
before the face name in these options, allowing you to switch font
families for different parts of the program if you wish.
@PP
The @Code fixedidentifiersformat option allows you to make a more
radical change to the format of identifiers than just the font.  Within
this option, @Code "@Body" stands for the identifier being formatted, and
by applying Lout symbols to it, you apply them to every identifier.  For
example,
@ID @Code "fixedidentifiersformat { red @Colour @Body }"
will cause identifiers to be printed red.
@FootNote {
@Code "@Colour" is not a Lout primitive like, say, {@Code "@Font"}; it is
defined when you write @Code "@SysInclude { doc }" or the equivalent for
the other document types.  This is true of quite a few generally useful
symbols, including {@Code "@Box"} and {@Code "@I"}.  If you want to use
these symbols here, you must include your setup file @I after
@Code "@SysInclude { doc }" or whatever, the reverse of the usual
arrangement, so that they are defined before Lout reads your setup
file.  This is always done when formatting programs independently of
any document, so you can use these symbols in a setup file given by
a @Code { -S } command line flag.
}  If you do use exotic formats, remember that in some programming languages,
comments and even strings may occupy more than one line:  {@Code "@Box"},
for example, will give a logical but probably unwanted result when
formatting a multi-line string.
@PP
As always with setup files, to change a default value, delete the preceding
@Code "#" and change the part between braces.  For example, suppose you are
happy with @Code "fixed" except that you want bold keywords.  Then one line
needs to be changed, to
@ID @Code "fixedkeywords { Bold }"
Or suppose you like @Code "varying" as it stands, but would like it to be
the default style rather than {@Code "fixed"}.  Again, only one line needs
to be changed, to {@Code "style { varying }"}.
@PP
It is probably not a good idea to change the default value of
@Code { numbered } to {@Code Yes}, because small fragments of
code within paragraphs will then get line numbers as well as large
displayed programs.  If you do have many large numbered programs as
well as small fragments, a better approach would be to place
@ID @OneRow @Code @Verbatim {
import @CPSetup
macro @NCP { @CP numbered { Yes } }
}
(or the equivalent for your language) in your @Code mydefs file, so that
you can type @Code "@NCP" instead of {@Code "@CP numbered { Yes }"}.
@PP
The setup files for the other languages are identical to this one, except
that the symbol after @Code "@Use" is different, and some of the
default values may be different.  Changing an option affects only the
language of that setup file; if you have multiple languages you can
have multiple setup files and change their options quite independently
of each other.
@End @Section