@Section
@Title { Embedded mode }
@Tag { embedded }
@Begin
@PP
When the C program texts are to be embedded in a larger Lout document,
the procedure is somewhat different. You need to include the
@Code "cprint" setup file, like this:
@ID @OneRow @Code {
"@SysInclude { cprint }"
"@SysInclude { doc }"
"@Doc @Text @Begin"
"..."
"@End @Text"
}
This file includes everything needed to set up for C program formatting.
@PP
The C parts of the document are enclosed in @Code "@CP { ... }" like this:
@ID @OneRow @Code {
"@IndentedDisplay @CP {"
"#include <stdio.h>"
""
"treeprint(p) /* print tree p recursively */"
"struct tnode *p;"
"{"
" if (p != NULL) {"
" treeprint(p->left);"
" printf(\"%4d %s\\n\", p->count, p->word);"
" treeprint(p->right);"
" }"
"}"
"}"
}
Although C programs violate the rules of legal Lout input in many ways,
these rules are suspended by the @Code "@CP" symbol, allowing the C
text to be incorporated with absolutely no modifications. The result is
@ID @OneRow @CP {
#include <stdio.h>
treeprint(p) /* print tree p recursively */
struct tnode *p;
{
if (p != NULL) {
treeprint(p->left);
printf("%4d %s\n", p->count, p->word);
treeprint(p->right);
}
}
}
We have chosen to use the @Code "@IndentedDisplay" symbol from Section
{@NumberOf displays} to obtain an indented display, but in fact
@Code "@CP" may appear anywhere at all. When including a C text within
a paragraph, use @Code "@OneCol @CP { ... }" to prevent it being broken
across two lines, if desired.
@PP
In cases where the C text has unbalanced braces, it is necessary to
use the alternative form @Code "@CP @Begin ... @End @CP" so that
Lout does not confuse C braces with Lout braces.
@PP
The @Code "@CP" symbol has a @Code "style" option for changing the
printing style. The default value of @Code "style" is {@Code "fixed"},
which produces the style shown above. To obtain a varying-width font
style, use @Code "style { varying }" like this:
@ID @OneRow @Code {
"@CP"
" style { varying }"
"{"
"#include <stdio.h>"
""
"treeprint(p) /* print tree p recursively */"
"struct tnode *p;"
"{"
" if (p != NULL) {"
" treeprint(p->left);"
" printf(\"%4d %s\\n\", p->count, p->word);"
" treeprint(p->right);"
" }"
"}"
"}"
}
The result in this case will be
@ID @OneRow @CP style { varying }
{
#include <stdio.h>
treeprint(p) /* print tree p recursively */
struct tnode *p;
{
if (p != NULL) {
treeprint(p->left);
printf("%4d %s\n", p->count, p->word);
treeprint(p->right);
}
}
}
There is also a third style called @Code "style { symbol }" which is
similar to @Code "varying" except that it uses characters from the
Adobe Symbol font to produce a more mathematical-looking result:
@ID @OneRow @CP style { symbol }
{
#include <stdio.h>
treeprint(p) /* print tree p recursively */
struct tnode *p;
{
if (p != NULL) {
treeprint(p->left);
printf("%4d %s\n", p->count, p->word);
treeprint(p->right);
}
}
}
The @Code "@CP" symbol has additional options which allow a finer
control over the style. Here they all are, with their default values:
@ID @OneRow @Code {
"@CP"
" style { fixed }"
" font { Courier }"
" strings { Base }"
" identifiers { Base }"
" comments { Base }"
" keywords { Base }"
" numbers { Base }"
" operators { Base }"
" size { -1.0p }"
" line { 1.0vx }"
" tabin { 8 }"
" tabout { 8s }"
"{"
" ..."
"}"
}
We are already familiar with {@Code "style"}. After that comes
{@Code "font"}, which determines the font family to use, followed
by six options giving the particular faces within that family in which to
print C strings, identifiers, comments, keywords, numbers, and
operators. {@Code "Base"} means the basic face; other commonly available
choices are {@Code "Slope"} and {@Code "Bold"}. These options may all be
set to different faces if desired. The default values shown are correct
for @Code "style { fixed }" only; the other styles have other defaults
(Section {@NumberOf cpsetup}).
@PP
The @Code "size" option is the font size to use, and @Code "line" is the
inter-line spacing. The default values specify that @Code "size" is
to be one point smaller than in the surrounding document; this was done
to compensate for Courier's relatively large appearance compared
to other fonts of the same nominal size. Again, these defaults are
different for different values of {@Code "style"}.
@PP
The @Code "tabin" and @Code "tabout" options are the subject of
Section {@NumberOf tabs}.
@End @Section
