Tcl Library Procedures Tcl_CreateMathFunc(3TCL)
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NAME
Tcl_CreateMathFunc, Tcl_GetMathFuncInfo, Tcl_ListMathFuncs -
Define, query and enumerate math functions for expressionsSYNOPSIS
#include
voidTcl_CreateMathFunc(interp, name, numArgs, argTypes, proc, clientData)
int |Tcl_GetMathFuncInfo(interp, name, numArgsPtr, argTypesPtr, procPtr, clientDataPtr)|
Tcl_Obj * |
Tcl_ListMathFuncs(interp, pattern) |
ARGUMENTSTcl_Interp *interp (in) Interpreter in
which new func-
tion will be defined. | CONST char *name (in) || Name for new function.int numArgs (in) Number of argu-
ments to new function; also gives size of argTypes array.Tcl_ValueType *argTypes (in) Points to an
array giving the permissible types for each argument to function.Tcl_MathProc *proc (in) Procedure that
implements the function.ClientData clientData (in) Arbitrary one-
word value to pass to proc when it is invoked.int *numArgsPtr (out) Points to a vari-
able that will be set to contain Tcl Last change: 8.4 1Tcl Library Procedures Tcl_CreateMathFunc(3TCL)
the number of arguments to the function.Tcl_ValueType **argTypesPtr (out) Points to a vari-
able that will be set to contain a pointer to an array giving the permissible types for each argument to the function which will need to be freed upusing Tcl_Free.
Tcl_MathProc **procPtr (out) Points to a vari-
able that will be set to contain a pointer to the implementation code for the function (or NULL if the function is implemented directly in bytecode.)ClientData *clientDataPtr (out) Points to a vari-
able that will be set to contain the clientData argument passed toTcl_CreateMathFunc
when the function was created if the function is not implemented directly in bytecode. CONST char *pattern (in) Pattern to match against function names so as to filter them (by passing toTcl_StringMatch),
or NULL to not apply any filter._________________________________________________________________
Tcl Last change: 8.4 2Tcl Library Procedures Tcl_CreateMathFunc(3TCL)
DESCRIPTION
Tcl allows a number of mathematical functions to be used in expressions, such as sin, cos, and hypot.Tcl_CreateMathFunc allows applications to add additional
functions to those already provided by Tcl or to replace existing functions. Name is the name of the function as it will appear in expressions. If name doesn't already exist as a function then a new function is created. If it does exist, then the existing function is replaced. NumArgs and argTypes describe the arguments to the function. Each entryin the argTypes array must be one of TCL_INT, TCL_DOUBLE, |
TCL_WIDE_INT, or TCL_EITHER to indicate whether the |
corresponding argument must be an integer, a double- |
precision floating value, a wide (64-bit) integer, or any, |
respectively. Whenever the function is invoked in an expression Tcl will invoke proc. Proc should have arguments and result thatmatch the type Tcl_MathProc:
typedef int Tcl_MathProc(
ClientData clientData,Tcl_Interp *interp,
Tcl_Value *args,
Tcl_Value *resultPtr);
When proc is invoked the clientData and interp argumentswill be the same as those passed to Tcl_CreateMathFunc.
Args will point to an array of numArgs Tcl_Value structures,
which describe the actual arguments to the function: |typedef struct Tcl_Value { |
Tcl_ValueType type; |
long intValue; | double doubleValue; |Tcl_WideInt wideValue; |
} Tcl_Value; |
The type field indicates the type of the argument and is one |of TCL_INT, TCL_DOUBLE or TCL_WIDE_INT. It will match the
argTypes value specified for the function unless theargTypes value was TCL_EITHER. Tcl converts the argument
supplied in the expression to the type requested in argTypes, if that is necessary. Depending on the value of the type field, the intValue, doubleValue or wideValue field | will contain the actual value of the argument. Proc should compute its result and store it either as aninteger in resultPtr->intValue or as a floating value in
resultPtr->doubleValue. It should set also resultPtr->type
to one of TCL_INT, TCL_DOUBLE or TCL_WIDE_INT to indicate |
which value was set. Under normal circumstances proc shouldreturn TCL_OK. If an error occurs while executing the func-
tion, proc should return TCL_ERROR and leave an error
Tcl Last change: 8.4 3Tcl Library Procedures Tcl_CreateMathFunc(3TCL)
message in the interpreter's result.Tcl_GetMathFuncInfo retrieves the values associated with |
function name that were passed to a preceding |Tcl_CreateMathFunc call. Normally, the return code is |
TCL_OK but if the named function does not exist, TCL_ERROR |
is returned and an error message is placed in the | interpreter's result. | If an error did not occur, the array reference placed in the | variable pointed to by argTypesPtr is newly allocated, and |should be released by passing it to Tcl_Free. Some func- |
tions (the standard set implemented in the core) are imple- |
mented directly at the bytecode level; attempting to | retrieve values for them causes a NULL to be stored in the | variable pointed to by procPtr and the variable pointed to | by clientDataPtr will not be modified. |Tcl_ListMathFuncs returns a Tcl object containing a list of |
all the math functions defined in the interpreter whose name | matches pattern. In the case of an error, NULL is returned | and an error message is left in the interpreter result, and | otherwise the returned object will have a reference count of | zero. KEYWORDS expression, mathematical functionSEE ALSO
expr(1T), info(1T), Tcl_Free(3TCL), Tcl_NewListObj(3TCL)
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:_______________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE|
|____________________|__________________|_
| Availability | runtime/tcl-8 |
|____________________|__________________|_
| Interface Stability| Uncommitted ||____________________|_________________|
NOTES Source for Tcl is available on http://opensolaris.org. Tcl Last change: 8.4 4