1 /* this file is #include'd (x times) by convert.c */
2
3 /* You need to define the following macros before including this
4 template. They are undefined at the end of this file to give a
5 clean slate for the next inclusion.
6
7 - CTYPE
8
9 The type of an element of the C array, for example 'char'.
10
11 - FROM_CTYPE
12
13 The function that converts a CTYPE to a SCM, for example
14 scm_from_char.
15
16 - UVEC_TAG
17
18 The tag of a suitable uniform vector that can hold the CTYPE, for
19 example 's8'.
20
21 - UVEC_CTYPE
22
23 The C type of an element of the uniform vector, for example
24 scm_t_int8.
25
26 - SCM2CTYPES
27
28 The name of the 'SCM-to-C' function, for example scm_c_scm2chars.
29
30 - CTYPES2SCM
31
32 The name of the 'C-to-SCM' function, for example, scm_c_chars2scm.
33
34 - CTYPES2UVECT
35
36 The name of the 'C-to-uniform-vector' function, for example
37 scm_c_chars2byvect. It will create a uniform vector of kind
38 UVEC_TAG.
39
40 - CTYPES2UVECT_2
41
42 The name of a second 'C-to-uniform-vector' function. Leave
43 undefined if you want only one such function.
44
45 - CTYPE_2
46 - UVEC_TAG_2
47 - UVEC_CTYPE_2
48
49 The tag and C type of the second kind of uniform vector, for use
50 with the function described above.
51
52 */
53
54 /* The first level does not expand macros in the arguments. */
55 #define paste(a1,a2,a3) a1##a2##a3
56 #define stringify(a) #a
57
58 /* But the second level does. */
59 #define F(pre,T,suf) paste(pre,T,suf)
60 #define S(T) stringify(T)
61
62 /* Convert a vector, list or uniform vector into a C array. If the
63 result array in argument 2 is NULL, malloc() a new one.
64 */
65
66 CTYPE *
SCM2CTYPES(SCM obj,CTYPE * data)67 SCM2CTYPES (SCM obj, CTYPE *data)
68 {
69 scm_t_array_handle handle;
70 size_t i, len;
71 ssize_t inc;
72 const UVEC_CTYPE *uvec_elements;
73
74 obj = F(scm_any_to_,UVEC_TAG,vector) (obj);
75 uvec_elements = F(scm_,UVEC_TAG,vector_elements) (obj, &handle, &len, &inc);
76
77 if (data == NULL)
78 data = scm_malloc (len * sizeof (CTYPE));
79 for (i = 0; i < len; i++, uvec_elements += inc)
80 data[i] = uvec_elements[i];
81
82 scm_array_handle_release (&handle);
83
84 return data;
85 }
86
87 /* Converts a C array into a vector. */
88
89 SCM
CTYPES2SCM(const CTYPE * data,long n)90 CTYPES2SCM (const CTYPE *data, long n)
91 {
92 long i;
93 SCM v;
94
95 v = scm_c_make_vector (n, SCM_UNSPECIFIED);
96
97 for (i = 0; i < n; i++)
98 SCM_SIMPLE_VECTOR_SET (v, i, FROM_CTYPE (data[i]));
99
100 return v;
101 }
102
103 /* Converts a C array into a uniform vector. */
104
105 SCM
CTYPES2UVECT(const CTYPE * data,long n)106 CTYPES2UVECT (const CTYPE *data, long n)
107 {
108 scm_t_array_handle handle;
109 long i;
110 SCM uvec;
111 UVEC_CTYPE *uvec_elements;
112
113 uvec = F(scm_make_,UVEC_TAG,vector) (scm_from_long (n), SCM_UNDEFINED);
114 uvec_elements = F(scm_,UVEC_TAG,vector_writable_elements) (uvec, &handle,
115 NULL, NULL);
116 for (i = 0; i < n; i++)
117 uvec_elements[i] = data[i];
118
119 scm_array_handle_release (&handle);
120
121 return uvec;
122 }
123
124 #ifdef CTYPE2UVECT_2
125
126 SCM
CTYPES2UVECT_2(const CTYPE_2 * data,long n)127 CTYPES2UVECT_2 (const CTYPE_2 *data, long n)
128 {
129 scm_t_array_handle handle;
130 long i;
131 SCM uvec;
132 UVEC_CTYPE_2 *uvec_elements;
133
134 uvec = F(scm_make_,UVEC_TAG_2,vector) (scm_from_long (n), SCM_UNDEFINED);
135 uvec_elements = F(scm_,UVEC_TAG_2,vector_writable_elements) (uvec, &handle,
136 NULL, NULL);
137
138 for (i = 0; i < n; i++)
139 uvec_elements[i] = data[i];
140
141 scm_array_handle_release (&handle);
142
143 return uvec;
144 }
145
146 #endif
147
148 #undef paste
149 #undef stringify
150 #undef F
151 #undef S
152
153 #undef CTYPE
154 #undef FROM_CTYPE
155 #undef UVEC_TAG
156 #undef UVEC_CTYPE
157 #undef SCM2CTYPES
158 #undef CTYPES2SCM
159 #undef CTYPES2UVECT
160 #ifdef CTYPES2UVECT_2
161 #undef CTYPES2UVECT_2
162 #undef CTYPE_2
163 #undef UVEC_TAG_2
164 #undef UVEC_CTYPE_2
165 #endif
166
167 /*
168 Local Variables:
169 c-file-style: "gnu"
170 End:
171 */
172