1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
@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
|
