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Diffstat (limited to 'erts/emulator/pcre/ucpinternal.h')
-rw-r--r-- | erts/emulator/pcre/ucpinternal.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/erts/emulator/pcre/ucpinternal.h b/erts/emulator/pcre/ucpinternal.h new file mode 100644 index 0000000000..9893d39672 --- /dev/null +++ b/erts/emulator/pcre/ucpinternal.h @@ -0,0 +1,94 @@ +/************************************************* +* Unicode Property Table handler * +*************************************************/ + +/* %ExternalCopyright% */ + +#ifndef _UCPINTERNAL_H +#define _UCPINTERNAL_H + +/* Internal header file defining the layout of the bits in each pair of 32-bit +words that form a data item in the table. */ + +typedef struct cnode { + pcre_uint32 f0; + pcre_uint32 f1; +} cnode; + +/* Things for the f0 field */ + +#define f0_scriptmask 0xff000000 /* Mask for script field */ +#define f0_scriptshift 24 /* Shift for script value */ +#define f0_rangeflag 0x00f00000 /* Flag for a range item */ +#define f0_charmask 0x001fffff /* Mask for code point value */ + +/* Things for the f1 field */ + +#define f1_typemask 0xfc000000 /* Mask for char type field */ +#define f1_typeshift 26 /* Shift for the type field */ +#define f1_rangemask 0x0000ffff /* Mask for a range offset */ +#define f1_casemask 0x0000ffff /* Mask for a case offset */ +#define f1_caseneg 0xffff8000 /* Bits for negation */ + +/* The data consists of a vector of structures of type cnode. The two unsigned +32-bit integers are used as follows: + +(f0) (1) The most significant byte holds the script number. The numbers are + defined by the enum in ucp.h. + + (2) The 0x00800000 bit is set if this entry defines a range of characters. + It is not set if this entry defines a single character + + (3) The 0x00600000 bits are spare. + + (4) The 0x001fffff bits contain the code point. No Unicode code point will + ever be greater than 0x0010ffff, so this should be OK for ever. + +(f1) (1) The 0xfc000000 bits contain the character type number. The numbers are + defined by an enum in ucp.h. + + (2) The 0x03ff0000 bits are spare. + + (3) The 0x0000ffff bits contain EITHER the unsigned offset to the top of + range if this entry defines a range, OR the *signed* offset to the + character's "other case" partner if this entry defines a single + character. There is no partner if the value is zero. + +------------------------------------------------------------------------------- +| script (8) |.|.|.| codepoint (21) || type (6) |.|.| spare (8) | offset (16) | +------------------------------------------------------------------------------- + | | | | | + | | |-> spare | |-> spare + | | | + | |-> spare |-> spare + | + |-> range flag + +The upper/lower casing information is set only for characters that come in +pairs. The non-one-to-one mappings in the Unicode data are ignored. + +When searching the data, proceed as follows: + +(1) Set up for a binary chop search. + +(2) If the top is not greater than the bottom, the character is not in the + table. Its type must therefore be "Cn" ("Undefined"). + +(3) Find the middle vector element. + +(4) Extract the code point and compare. If equal, we are done. + +(5) If the test character is smaller, set the top to the current point, and + goto (2). + +(6) If the current entry defines a range, compute the last character by adding + the offset, and see if the test character is within the range. If it is, + we are done. + +(7) Otherwise, set the bottom to one element past the current point and goto + (2). +*/ + +#endif /* _UCPINTERNAL_H */ + +/* End of ucpinternal.h */ |