NAME

src/spf_vtable.c - Parrot sprintf

DESCRIPTION

Implements the two families of functions Parrot_sprintf may use to retrieve arguments.

Var args Functions

PARROT_CANNOT_RETURN_NULL PARROT_WARN_UNUSED_RESULT static STRING *getchr_va(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Gets a char out of the va_list in obj and returns it as a Parrot STRING.

size is unused.

PARROT_WARN_UNUSED_RESULT static HUGEINTVAL getint_va(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Gets an integer out of the va_list in obj and returns it as a Parrot STRING.

size is an enum spf_type_t value which indicates the storage type of the integer.

PARROT_WARN_UNUSED_RESULT static UHUGEINTVAL getuint_va(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Gets an unsigned integer out of the va_list in obj and returns it as a Parrot STRING.

size is an enum spf_type_t value which indicates the storage type of the integer.

PARROT_WARN_UNUSED_RESULT static HUGEFLOATVAL getfloat_va(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Gets an floating-point number out of the va_list in obj and returns it as a Parrot STRING.

size is an enum spf_type_t value which indicates the storage type of the number.

PARROT_WARN_UNUSED_RESULT PARROT_CANNOT_RETURN_NULL static STRING *getstring_va(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Gets an string out of the va_list in obj and returns it as a Parrot STRING.

size is an enum spf_type_t value which indicates the storage type of the string.

PARROT_WARN_UNUSED_RESULT PARROT_CAN_RETURN_NULL static void *getptr_va(PARROT_INTERP, SHIM(INTVAL size), NOTNULL(SPRINTF_OBJ *obj))

Gets a void * out of the va_list in obj and returns it.

size is unused.

PMC Functions

PARROT_CANNOT_RETURN_NULL PARROT_WARN_UNUSED_RESULT static STRING *getchr_pmc(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Same as getchr_va() except that a vtable is used to get the value from obj.

PARROT_WARN_UNUSED_RESULT static HUGEINTVAL getint_pmc(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Same as getint_va() except that a vtable is used to get the value from obj.

PARROT_WARN_UNUSED_RESULT static UHUGEINTVAL getuint_pmc(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Same as getuint_va() except that a vtable is used to get the value from obj.

PARROT_WARN_UNUSED_RESULT static HUGEFLOATVAL getfloat_pmc(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Same as getfloat_va() except that a vtable is used to get the value from obj.

PARROT_WARN_UNUSED_RESULT PARROT_CANNOT_RETURN_NULL static STRING *getstring_pmc(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Same as getstring_va() except that a vtable is used to get the value from obj.

PARROT_WARN_UNUSED_RESULT PARROT_CANNOT_RETURN_NULL static void *getptr_pmc(PARROT_INTERP, INTVAL size, NOTNULL(SPRINTF_OBJ *obj))

Same as getptr_va() except that a vtable is used to get the value from obj.

SEE ALSO

src/misc.h, src/misc.c, src/spf_render.c.

HISTORY

When I was first working on this implementation of sprintf, I ran into a problem. I wanted to re-use the implementation for a Parrot bytecode-level sprintf, but that couldn't be done, since it used va_* directly. For a while I thought about generating two versions of the source with a Perl script, but that seemed like overkill. Eventually I came across this idea -- pass in a specialized vtable with methods for extracting things from the arglist, whatever it happened to be. This is the result.

TODO

In the future, it may be deemed desirable to similarly vtable-ize appending things to the string, allowing for faster PIO_printf() &c, as well as a version that writes directly to a C string. However, at this point neither of those is needed.