- NAME
- Tcl_CreateMathFunc, Tcl_GetMathFuncInfo, Tcl_ListMathFuncs — Define, query and enumerate math functions for expressions
- NOTICE OF EVENTUAL DEPRECATION
- SYNOPSIS
- #include <tcl.h>
- 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
- DESCRIPTION
- REFERENCE COUNT MANAGEMENT
- SEE ALSO
- KEYWORDS
Tcl_CreateMathFunc, Tcl_GetMathFuncInfo, Tcl_ListMathFuncs — Define, query and enumerate math functions for expressions
The Tcl_CreateMathFunc and Tcl_GetMathFuncInfo functions
are rendered somewhat obsolete by the ability to create functions for
expressions by placing commands in the tcl::mathfunc namespace,
as described in the mathfunc manual page; the API described on
this page is not expected to be maintained indefinitely.
#include <tcl.h>
void
Tcl_CreateMathFunc(interp, name, numArgs, argTypes, proc, clientData)
int
Tcl_GetMathFuncInfo(interp, name, numArgsPtr, argTypesPtr, procPtr,
clientDataPtr)
Tcl_Obj *
Tcl_ListMathFuncs(interp, pattern)
- Tcl_Interp *interp (in)
-
Interpreter in which new function will be defined.
- const char *name (in)
-
Name for new function.
- int numArgs (in)
-
Number of arguments 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
arguments 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_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 to Tcl_StringMatch), or NULL to not apply any filter.
Tcl allows a number of mathematical functions to be used in
expressions, such as sin, cos, and hypot.
These functions are represented by commands in the namespace,
tcl::mathfunc. The Tcl_CreateMathFunc function is
an obsolete way for applications to add additional functions
to those already provided by Tcl or to replace existing functions.
It should not be used by new applications, which should create
math functions using Tcl_CreateObjCommand to create a command
in the tcl::mathfunc namespace.
In the Tcl_CreateMathFunc interface,
Name is the name of the function as it will appear in expressions.
If name does not already exist in the ::tcl::mathfunc
namespace, then a new command is created in that namespace.
If name 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 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 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 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
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 normal 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_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 functions (the
standard set implemented in the core, and those defined by placing
commands in the tcl::mathfunc namespace) do not have
argument type information; 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. The variable pointed to by numArgsPointer
will contain -1, and no argument types will be stored in the variable
pointed to by argTypesPointer.
Tcl_ListMathFuncs returns a Tcl value containing a list of all
the math functions defined in the interpreter whose name matches
pattern. The returned value has a reference count of zero.
Tcl_ListMathFuncs always returns a zero-reference object, much
like Tcl_NewObj.
expr, info, Tcl_CreateObjCommand, Tcl_Free, Tcl_NewListObj
expression, mathematical function
Copyright © 1989-1993 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc.