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Upgrade to Encode 1.00, from Dan Kogai.
[perl5.git] / ext / Encode / Encode / encode.h
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1#ifndef ENCODE_H
2#define ENCODE_H
3
4#ifndef U8
5/* A tad devious this:
6 perl normally has a #define for U8 - if that isn't present
7 then we typedef it - leaving it #ifndef so we can do data parts without
8 getting extern references to the code parts
9 */
10typedef unsigned char U8;
11#endif
12
13typedef struct encpage_s encpage_t;
14
15
16struct encpage_s
17{
18 /* fields ordered to pack nicely on 32-bit machines */
19 const U8 *seq; /* Packed output sequences we generate if we match */
20 encpage_t *next; /* Page to go to if we match */
21 U8 min; /* Min value of octet to match this entry */
22 U8 max; /* Max value of octet to match this entry */
23 U8 dlen; /* destination length - size of entries in seq */
24 U8 slen; /* source length - number of source octets needed */
25};
26
27/*
28 At any point in a translation there is a page pointer which points at an array
29 of the above structures.
30
31 Basic operation :
32 get octet from source stream.
33 if (octet >= min && octet < max) {
34 if slen is 0 then we cannot represent this character.
35 if we have less than slen octets (including this one) then we have a partial character.
36 otherwise
37 copy dlen octets from seq + dlen*(octet-min) to output
38 (dlen may be zero if we don't know yet.)
39 load page pointer with next to continue.
40 (is slen is one this is end of a character)
41 get next octet.
42 }
43 else {
44 increment the page pointer to look at next slot in the array
45 }
46
47 arrays SHALL be constructed so there is an entry which matches ..0xFF at the end,
48 and either maps it or indicates no representation.
49
50 if MSB of slen is set then mapping is an approximate "FALLBACK" entry.
51
52*/
53
54
55typedef struct encode_s encode_t;
56struct encode_s
57{
58 encpage_t *t_utf8; /* Starting table for translation from the encoding to UTF-8 form */
59 encpage_t *f_utf8; /* Starting table for translation from UTF-8 to the encoding */
60 const U8 *rep; /* Replacement character in this encoding e.g. "?" */
61 int replen; /* Number of octets to represent replacement character */
62 U8 min_el; /* Minimum octets to represent a character */
63 U8 max_el; /* Maximum octets to represent a character */
64 const char *name[2]; /* name(s) of this encoding */
65};
66
67#ifdef U8
68/* See comment at top of file for deviousness */
69
70extern int do_encode(encpage_t *enc, const U8 *src, STRLEN *slen,
71 U8 *dst, STRLEN dlen, STRLEN *dout, int approx);
72
73extern void Encode_DefineEncoding(encode_t *enc);
74
75#endif
76
77#define ENCODE_NOSPACE 1
78#define ENCODE_PARTIAL 2
79#define ENCODE_NOREP 3
80#define ENCODE_FALLBACK 4
81#endif