encoding.h File Reference

The encoding interface and implementations used by the parser. More...

#include "prism/defines.h"
#include "prism/util/pm_strncasecmp.h"
#include <assert.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

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Data Structures
struct	pm_encoding_t
	This struct defines the functions necessary to implement the encoding interface so we can determine how many bytes the subsequent character takes. More...

Macros
#define	PRISM_ENCODING_ALPHABETIC_BIT   1 << 0
	All of the lookup tables use the first bit of each embedded byte to indicate whether the codepoint is alphabetical.
#define	PRISM_ENCODING_ALPHANUMERIC_BIT   1 << 1
	All of the lookup tables use the second bit of each embedded byte to indicate whether the codepoint is alphanumeric.
#define	PRISM_ENCODING_UPPERCASE_BIT   1 << 2
	All of the lookup tables use the third bit of each embedded byte to indicate whether the codepoint is uppercase.
#define	PM_ENCODING_UTF_8_ENTRY   (&pm_encodings[PM_ENCODING_UTF_8])
	This is the default UTF-8 encoding.
#define	PM_ENCODING_US_ASCII_ENTRY   (&pm_encodings[PM_ENCODING_US_ASCII])
	This is the US-ASCII encoding.
#define	PM_ENCODING_ASCII_8BIT_ENTRY   (&pm_encodings[PM_ENCODING_ASCII_8BIT])
	This is the ASCII-8BIT encoding.
#define	PM_ENCODING_EUC_JP_ENTRY   (&pm_encodings[PM_ENCODING_EUC_JP])
	This is the EUC-JP encoding.
#define	PM_ENCODING_WINDOWS_31J_ENTRY   (&pm_encodings[PM_ENCODING_WINDOWS_31J])
	This is the Windows-31J encoding.

Enumerations
enum	pm_encoding_type_t {   PM_ENCODING_UTF_8 = 0 , PM_ENCODING_US_ASCII , PM_ENCODING_ASCII_8BIT , PM_ENCODING_EUC_JP ,   PM_ENCODING_WINDOWS_31J , PM_ENCODING_BIG5 , PM_ENCODING_BIG5_HKSCS , PM_ENCODING_BIG5_UAO ,   PM_ENCODING_CESU_8 , PM_ENCODING_CP51932 , PM_ENCODING_CP850 , PM_ENCODING_CP852 ,   PM_ENCODING_CP855 , PM_ENCODING_CP949 , PM_ENCODING_CP950 , PM_ENCODING_CP951 ,   PM_ENCODING_EMACS_MULE , PM_ENCODING_EUC_JP_MS , PM_ENCODING_EUC_JIS_2004 , PM_ENCODING_EUC_KR ,   PM_ENCODING_EUC_TW , PM_ENCODING_GB12345 , PM_ENCODING_GB18030 , PM_ENCODING_GB1988 ,   PM_ENCODING_GB2312 , PM_ENCODING_GBK , PM_ENCODING_IBM437 , PM_ENCODING_IBM720 ,   PM_ENCODING_IBM737 , PM_ENCODING_IBM775 , PM_ENCODING_IBM852 , PM_ENCODING_IBM855 ,   PM_ENCODING_IBM857 , PM_ENCODING_IBM860 , PM_ENCODING_IBM861 , PM_ENCODING_IBM862 ,   PM_ENCODING_IBM863 , PM_ENCODING_IBM864 , PM_ENCODING_IBM865 , PM_ENCODING_IBM866 ,   PM_ENCODING_IBM869 , PM_ENCODING_ISO_8859_1 , PM_ENCODING_ISO_8859_2 , PM_ENCODING_ISO_8859_3 ,   PM_ENCODING_ISO_8859_4 , PM_ENCODING_ISO_8859_5 , PM_ENCODING_ISO_8859_6 , PM_ENCODING_ISO_8859_7 ,   PM_ENCODING_ISO_8859_8 , PM_ENCODING_ISO_8859_9 , PM_ENCODING_ISO_8859_10 , PM_ENCODING_ISO_8859_11 ,   PM_ENCODING_ISO_8859_13 , PM_ENCODING_ISO_8859_14 , PM_ENCODING_ISO_8859_15 , PM_ENCODING_ISO_8859_16 ,   PM_ENCODING_KOI8_R , PM_ENCODING_KOI8_U , PM_ENCODING_MAC_CENT_EURO , PM_ENCODING_MAC_CROATIAN ,   PM_ENCODING_MAC_CYRILLIC , PM_ENCODING_MAC_GREEK , PM_ENCODING_MAC_ICELAND , PM_ENCODING_MAC_JAPANESE ,   PM_ENCODING_MAC_ROMAN , PM_ENCODING_MAC_ROMANIA , PM_ENCODING_MAC_THAI , PM_ENCODING_MAC_TURKISH ,   PM_ENCODING_MAC_UKRAINE , PM_ENCODING_SHIFT_JIS , PM_ENCODING_SJIS_DOCOMO , PM_ENCODING_SJIS_KDDI ,   PM_ENCODING_SJIS_SOFTBANK , PM_ENCODING_STATELESS_ISO_2022_JP , PM_ENCODING_STATELESS_ISO_2022_JP_KDDI , PM_ENCODING_TIS_620 ,   PM_ENCODING_UTF8_MAC , PM_ENCODING_UTF8_DOCOMO , PM_ENCODING_UTF8_KDDI , PM_ENCODING_UTF8_SOFTBANK ,   PM_ENCODING_WINDOWS_1250 , PM_ENCODING_WINDOWS_1251 , PM_ENCODING_WINDOWS_1252 , PM_ENCODING_WINDOWS_1253 ,   PM_ENCODING_WINDOWS_1254 , PM_ENCODING_WINDOWS_1255 , PM_ENCODING_WINDOWS_1256 , PM_ENCODING_WINDOWS_1257 ,   PM_ENCODING_WINDOWS_1258 , PM_ENCODING_WINDOWS_874 , PM_ENCODING_MAXIMUM }
	These are all of the encodings that prism supports.

Functions
size_t	pm_encoding_utf_8_char_width (const uint8_t *b, ptrdiff_t n)
	Return the size of the next character in the UTF-8 encoding.
size_t	pm_encoding_utf_8_alpha_char (const uint8_t *b, ptrdiff_t n)
	Return the size of the next character in the UTF-8 encoding if it is an alphabetical character.
size_t	pm_encoding_utf_8_alnum_char (const uint8_t *b, ptrdiff_t n)
	Return the size of the next character in the UTF-8 encoding if it is an alphanumeric character.
bool	pm_encoding_utf_8_isupper_char (const uint8_t *b, ptrdiff_t n)
	Return true if the next character in the UTF-8 encoding if it is an uppercase character.
const pm_encoding_t *	pm_encoding_find (const uint8_t *start, const uint8_t *end)
	Parse the given name of an encoding and return a pointer to the corresponding encoding struct if one can be found, otherwise return NULL.

Variables
const uint8_t	pm_encoding_unicode_table [256]
	This lookup table is referenced in both the UTF-8 encoding file and the parser directly in order to speed up the default encoding processing.
const pm_encoding_t	pm_encodings [PM_ENCODING_MAXIMUM]
	This is the table of all of the encodings that prism supports.

Detailed Description

The encoding interface and implementations used by the parser.

Macro Definition Documentation

PM_ENCODING_UTF_8_ENTRY

#define PM_ENCODING_UTF_8_ENTRY   (&pm_encodings[PM_ENCODING_UTF_8])

This is the default UTF-8 encoding.

We need a reference to it to quickly create parsers.

PM_ENCODING_US_ASCII_ENTRY

#define PM_ENCODING_US_ASCII_ENTRY   (&pm_encodings[PM_ENCODING_US_ASCII])

This is the US-ASCII encoding.

We need a reference to it to be able to compare against it when a string is being created because it could possibly need to fall back to ASCII-8BIT.

PM_ENCODING_ASCII_8BIT_ENTRY

#define PM_ENCODING_ASCII_8BIT_ENTRY   (&pm_encodings[PM_ENCODING_ASCII_8BIT])

This is the ASCII-8BIT encoding.

We need a reference to it so that pm_strpbrk can compare against it because invalid multibyte characters are not a thing in this encoding. It is also needed for handling Regexp encoding flags.

PM_ENCODING_EUC_JP_ENTRY

#define PM_ENCODING_EUC_JP_ENTRY   (&pm_encodings[PM_ENCODING_EUC_JP])

This is the EUC-JP encoding.

We need a reference to it to quickly process regular expression modifiers.

PM_ENCODING_WINDOWS_31J_ENTRY

#define PM_ENCODING_WINDOWS_31J_ENTRY   (&pm_encodings[PM_ENCODING_WINDOWS_31J])

This is the Windows-31J encoding.

We need a reference to it to quickly process regular expression modifiers.

Function Documentation

pm_encoding_utf_8_char_width()

size_t pm_encoding_utf_8_char_width	(	const uint8_t *	b,
		ptrdiff_t	n
	)

Return the size of the next character in the UTF-8 encoding.

Parameters

b	The bytes to read.
n	The number of bytes that can be read.

Returns

The number of bytes that the next character takes if it is valid in the encoding, or 0 if it is not.

pm_encoding_utf_8_alpha_char()

size_t pm_encoding_utf_8_alpha_char	(	const uint8_t *	b,
		ptrdiff_t	n
	)

Return the size of the next character in the UTF-8 encoding if it is an alphabetical character.

Parameters

b	The bytes to read.
n	The number of bytes that can be read.

Returns

The number of bytes that the next character takes if it is valid in the encoding, or 0 if it is not.

pm_encoding_utf_8_alnum_char()

size_t pm_encoding_utf_8_alnum_char	(	const uint8_t *	b,
		ptrdiff_t	n
	)

Return the size of the next character in the UTF-8 encoding if it is an alphanumeric character.

Parameters

b	The bytes to read.
n	The number of bytes that can be read.

Returns

The number of bytes that the next character takes if it is valid in the encoding, or 0 if it is not.

pm_encoding_utf_8_isupper_char()

bool pm_encoding_utf_8_isupper_char	(	const uint8_t *	b,
		ptrdiff_t	n
	)

Return true if the next character in the UTF-8 encoding if it is an uppercase character.

Parameters

b	The bytes to read.
n	The number of bytes that can be read.

Returns

True if the next character is valid in the encoding and is an uppercase character, or false if it is not.

pm_encoding_find()

const pm_encoding_t * pm_encoding_find	(	const uint8_t *	start,
		const uint8_t *	end
	)

Parse the given name of an encoding and return a pointer to the corresponding encoding struct if one can be found, otherwise return NULL.

Parameters

start	A pointer to the first byte of the name.
end	A pointer to the last byte of the name.

Returns

A pointer to the encoding struct if one is found, otherwise NULL.

Variable Documentation

pm_encoding_unicode_table

const uint8_t pm_encoding_unicode_table[256]

extern

This lookup table is referenced in both the UTF-8 encoding file and the parser directly in order to speed up the default encoding processing.

It is used to indicate whether a character is alphabetical, alphanumeric, or uppercase in unicode mappings.

This lookup table is referenced in both the UTF-8 encoding file and the parser directly in order to speed up the default encoding processing.

Note that this table is different from other encodings where we used a lookup table because the indices of those tables are the byte representations, not the codepoints themselves.