Index of Section 3 Manual Pages
| Interix / SUA | Tcl_GetMathFuncInfo.3 | Interix / SUA |
Tcl_CreateMathFunc(3) Tcl Library ProceduresTcl_CreateMathFunc(3)
_________________________________________________________________
NAME
Tcl_CreateMathFunc, Tcl_GetMathFuncInfo, Tcl_ListMathFuncs
- Define, query and enumerate math functions for expres-
sions
SYNOPSIS
#include
void
Tcl_CreateMathFunc(interp, name, numArgs, argTypes, proc, clientData)
int |
Tcl_GetMathFuncInfo(interp, name, numArgsPtr, argTypesPtr, procPtr, clientDataPtr)|
Tcl_Obj * |
Tcl_ListMathFuncs(interp, pattern) |
ARGUMENTS
Tcl_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
variable that
will be set to
contain the
number of argu-
ments to the
function.
Tcl_ValueType **argTypesPtr (out) Points to a
variable 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 up using
Tcl_Free.
Tcl_MathProc **procPtr (out) Points to a
variable 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
variable that
will be set to
contain the
clientData
argument passed
to Tcl_Cre-
ateMathFunc
when the func-
tion was cre-
ated 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 pass-
ing to
Tcl_String-
Match), or NULL
to not apply
any filter.
_________________________________________________________________
DESCRIPTION
Tcl allows a number of mathematical functions to be used
in expressions, such as sin, cos, and hypot. Tcl_Cre-
ateMathFunc allows applications to add additional func-
tions 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 entry in the argTypes array must be one of |
TCL_INT, TCL_DOUBLE, TCL_WIDE_INT, or TCL_EITHER to indi- |
cate whether the corresponding argument must be an inte- |
ger, 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 that
match 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 arguments
will be the same as those passed to Tcl_CreateMathFunc.
Args will point to an array of numArgs Tcl_Value struc-
tures, which describe the actual arguments to the func-
tion: |
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 the
argTypes 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 an
integer 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 nor-
mal circumstances proc should return TCL_OK. If an error
occurs while executing the function, proc should return
TCL_ERROR and leave an error message in the interpreter's
result.
Tcl_GetMathFuncInfo retrieves the values associated with |
function name that were passed to a preceding Tcl_Cre- |
ateMathFunc 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 inter- |
preter'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 |
functions (the standard set implemented in the core) are |
implemented 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 ref- |
erence count of zero.
KEYWORDS
expression, mathematical function
SEE ALSO
expr(n), info(n), Tcl_Free(3), Tcl_NewListObj(3)
Tcl 8.4 Tcl_CreateMathFunc(3)