A C string is a reference to an array of C characters terminated by NUL.
Modulebase-4.20.2.0Haskell2010
Foreign.C.String
Utilities for primitive marshalling of C strings.
The marshalling converts each Haskell character, representing a Unicode code point, to one or more bytes in a manner that, by default, is determined by the current locale. As a consequence, no guarantees can be made about the relative length of a Haskell string and its corresponding C string, and therefore all the marshalling routines include memory allocation. The translation between Unicode and the encoding of the current locale may be lossy.
- 4 types
- 25 values
- Packagebase-4.20.2.0
- Exports29
- LanguageHaskell2010
- LicenceBSD-3-Clause
- SourceString.hs
C strings
2 declarationsA string with explicit length information in bytes instead of a terminating NUL (allowing NUL characters in the middle of the string).
Using a locale-dependent encoding
These functions are different from their CAString counterparts
in that they will use an encoding determined by the current locale,
rather than always assuming ASCII.
Marshal a NUL terminated C string into a Haskell string.
Marshal a C string with explicit length into a Haskell string.
Marshal a Haskell string into a NUL terminated C string.
the Haskell string may not contain any NUL characters
new storage is allocated for the C string and must be explicitly freed using free or finalizerFree.
Marshal a Haskell string into a C string (ie, character array) with explicit length information.
new storage is allocated for the C string and must be explicitly freed using free or finalizerFree.
Marshal a Haskell string into a NUL terminated C string using temporary storage.
the Haskell string may not contain any NUL characters
the memory is freed when the subcomputation terminates (either normally or via an exception), so the pointer to the temporary storage must not be used after this.
Marshal a Haskell string into a C string (ie, character array) in temporary storage, with explicit length information.
the memory is freed when the subcomputation terminates (either normally or via an exception), so the pointer to the temporary storage must not be used after this.
Using 8-bit characters
These variants of the above functions are for use with C libraries that are ignorant of Unicode. These functions should be used with care, as a loss of information can occur.
Convert a Haskell character to a C character. This function is only safe on the first 256 characters.
Convert a C byte, representing a Latin-1 character, to the corresponding Haskell character.
Convert a Haskell character to a C unsigned char.
This function is only safe on the first 256 characters.
Convert a C unsigned char, representing a Latin-1 character, to
the corresponding Haskell character.
Convert a Haskell character to a C signed char.
This function is only safe on the first 256 characters.
Convert a C signed char, representing a Latin-1 character, to the
corresponding Haskell character.
Marshal a NUL terminated C string into a Haskell string.
Marshal a C string with explicit length into a Haskell string.
Marshal a Haskell string into a NUL terminated C string.
the Haskell string may not contain any NUL characters
new storage is allocated for the C string and must be explicitly freed using free or finalizerFree.
Marshal a Haskell string into a C string (ie, character array) with explicit length information.
new storage is allocated for the C string and must be explicitly freed using free or finalizerFree.
Marshal a Haskell string into a NUL terminated C string using temporary storage.
the Haskell string may not contain any NUL characters
the memory is freed when the subcomputation terminates (either normally or via an exception), so the pointer to the temporary storage must not be used after this.
Marshal a Haskell string into a C string (ie, character array) in temporary storage, with explicit length information.
the memory is freed when the subcomputation terminates (either normally or via an exception), so the pointer to the temporary storage must not be used after this.
C wide strings
8 declarationsThese variants of the above functions are for use with C libraries
that encode Unicode using the C wchar_t type in a system-dependent
way. The only encodings supported are
UTF-32 (the C compiler defines
STDC_ISO_10646), orUTF-16 (as used on Windows systems).
A C wide string is a reference to an array of C wide characters terminated by NUL.
A wide character string with explicit length information in CWchars instead of a terminating NUL (allowing NUL characters in the middle of the string).
Marshal a NUL terminated C wide string into a Haskell string.
Marshal a C wide string with explicit length into a Haskell string.
Marshal a Haskell string into a NUL terminated C wide string.
the Haskell string may not contain any NUL characters
new storage is allocated for the C wide string and must be explicitly freed using free or finalizerFree.
Marshal a Haskell string into a C wide string (ie, wide character array) with explicit length information.
new storage is allocated for the C wide string and must be explicitly freed using free or finalizerFree.
Marshal a Haskell string into a NUL terminated C wide string using temporary storage.
the Haskell string may not contain any NUL characters
the memory is freed when the subcomputation terminates (either normally or via an exception), so the pointer to the temporary storage must not be used after this.
Marshal a Haskell string into a C wide string (i.e. wide character array) in temporary storage, with explicit length information.
the memory is freed when the subcomputation terminates (either normally or via an exception), so the pointer to the temporary storage must not be used after this.