UDatatype Struct Reference

The UDatatype struct holds methods for a specific class of data. More...

Data Fields
const char *	name
	ASCII name of type, ending with '!'.
int(*	make )(UThread *, const UCell *from, UCell *res)
	Make a new instance of the type.
int(*	convert )(UThread *, const UCell *from, UCell *res)
	Convert data to a new instance of the type.
void(*	copy )(UThread *, const UCell *from, UCell *res)
	Make a clone of an existing value.
int(*	compare )(UThread *, const UCell *a, const UCell *b, int test)
	Perform a comparison between cells.
int(*	operate )(UThread *, const UCell *, const UCell *, UCell *res, int)
	Perform an operation on two cells.
const UCell *(*	select )(UThread *, const UCell *, const UCell *sel, UCell *tmp)
	Get the value which a path node references.
void(*	toString )(UThread *, const UCell *cell, UBuffer *str, int depth)
	Convert cell to its string data representation.
void(*	toText )(UThread *, const UCell *cell, UBuffer *str, int depth)
	Convert cell to its string textual representation.
void(*	recycle )(UThread *, int phase)
	Performs thread global garbage collection duties for the datatype.
void(*	mark )(UThread *, UCell *cell)
	Responsible for marking any buffers referenced by the cell as used.
void(*	destroy )(UBuffer *buf)
	Free any memory or other resources the buffer uses.
void(*	markBuf )(UThread *, UBuffer *buf)
	Responsible for marking other buffers referenced by this buffer as used.
void(*	toShared )(UCell *cell)
	Change any buffer ids in the cell so that they reference the shared environment (negate the id).
void(*	bind )(UThread *, UCell *cell, const UBindTarget *bt)
	Bind cell to target.

Detailed Description

The UDatatype struct holds methods for a specific class of data.

When implementing custom types, the unset.h methods can be used.

See also

USeriesType

Field Documentation

compare

int(* UDatatype::compare) (UThread *, const UCell *a, const UCell *b, int test)

Perform a comparison between cells.

If the test is UR_COMPARE_SAME, then the type of cells a & b are guaranteed to be the same by the caller. Otherwise, one of the cells might not be of the datatype for this compare method.

When the test is UR_COMPARE_ORDER or UR_COMPARE_ORDER_CASE, then the method should return 1, 0, or -1, if cell a is greater than, equal to, or lesser than cell b.

The method should only check for datatypes with a lesser or equal ur_type(), as the caller will use the compare method for the higher ordered type.

Parameters

a	First cell.
b	Second cell.
test	Type of comparison to do.

Returns

Non-zero if the camparison is true.

convert

int(* UDatatype::convert) (UThread *, const UCell *from, UCell *res)

Convert data to a new instance of the type.

From and res are guaranteed to point to different cells.

Convert should perform a shallow copy on any complex types which can be nested.

Parameters

from	Value to convert.
res	Cell for new instance.

Returns

UR_OK/UR_THROW

copy

void(* UDatatype::copy) (UThread *, const UCell *from, UCell *res)

Make a clone of an existing value.

From and res are guaranteed to point to different cells.

Parameters

from	Value to copy.
res	Cell for new instance.

make

int(* UDatatype::make) (UThread *, const UCell *from, UCell *res)

Make a new instance of the type.

From and res are guaranteed to point to different cells.

Make should perform a shallow copy on any complex types which can be nested.

Parameters

from	Value which describes the new instance.
res	Cell for new instance.

Returns

UR_OK/UR_THROW

mark

void(* UDatatype::mark) (UThread *, UCell *cell)

Responsible for marking any buffers referenced by the cell as used.

Use ur_markBuffer().

operate

int(* UDatatype::operate) (UThread *, const UCell *, const UCell *, UCell *res, int)

Perform an operation on two cells.

The method should only check for datatypes with a lesser or equal ur_type(), as the caller will use the operate method for the higher ordered type.

Parameters

a	First cell.
b	Second cell.
res	Result cell.
op	Type of operation to do.

Returns

UR_OK/UR_THROW

recycle

void(* UDatatype::recycle) (UThread *, int phase)

Performs thread global garbage collection duties for the datatype.

This is called twice from ur_recycle(), first with UR_RECYCLE_MARK, then with UR_RECYCLE_SWEEP.

select

const UCell *(* UDatatype::select) (UThread *, const UCell *, const UCell *sel, UCell *tmp)

Get the value which a path node references.

If the selector is invalid, call ur_error() and return 0.

Parameters

cell	Cell of this datatype.
sel	Selector value.
tmp	Storage for result (if needed). If used, then return tmp.

Returns

Pointer to result cell or 0 if an error is thrown.

toString

void(* UDatatype::toString) (UThread *, const UCell *cell, UBuffer *str, int depth)

Convert cell to its string data representation.

Parameters

cell	Cell of this datatype.
str	String buffer to append to.
depth	Indentation depth.

toText

void(* UDatatype::toText) (UThread *, const UCell *cell, UBuffer *str, int depth)

Convert cell to its string textual representation.

Parameters

cell	Cell of this datatype.
str	String buffer to append to.
depth	Indentation depth.

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The documentation for this struct was generated from the following files:

• urlan.h
• datatypes.c