Import Tcl 8.5.15 (as of svn r89086)
This commit is contained in:
Zachary Ware
156
doc/CrtMathFnc.3
Normal file
156
doc/CrtMathFnc.3
Normal file
@@ -0,0 +1,156 @@
|
||||
'\"
|
||||
'\" Copyright (c) 1989-1993 The Regents of the University of California.
|
||||
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
|
||||
'\"
|
||||
'\" See the file "license.terms" for information on usage and redistribution
|
||||
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
||||
'\"
|
||||
.so man.macros
|
||||
.TH Tcl_CreateMathFunc 3 8.4 Tcl "Tcl Library Procedures"
|
||||
.BS
|
||||
.SH NAME
|
||||
Tcl_CreateMathFunc, Tcl_GetMathFuncInfo, Tcl_ListMathFuncs \- Define, query and enumerate math functions for expressions
|
||||
.SH SYNOPSIS
|
||||
.nf
|
||||
\fB#include <tcl.h>\fR
|
||||
.sp
|
||||
void
|
||||
\fBTcl_CreateMathFunc\fR(\fIinterp, name, numArgs, argTypes, proc, clientData\fR)
|
||||
.sp
|
||||
int
|
||||
\fBTcl_GetMathFuncInfo\fR(\fIinterp, name, numArgsPtr, argTypesPtr, procPtr,
|
||||
clientDataPtr\fR)
|
||||
.sp
|
||||
Tcl_Obj *
|
||||
\fBTcl_ListMathFuncs\fR(\fIinterp, pattern\fR)
|
||||
.SH ARGUMENTS
|
||||
.AS Tcl_ValueType *clientDataPtr out
|
||||
.AP Tcl_Interp *interp in
|
||||
Interpreter in which new function will be defined.
|
||||
.AP "const char" *name in
|
||||
Name for new function.
|
||||
.AP int numArgs in
|
||||
Number of arguments to new function; also gives size of \fIargTypes\fR array.
|
||||
.AP Tcl_ValueType *argTypes in
|
||||
Points to an array giving the permissible types for each argument to
|
||||
function.
|
||||
.AP Tcl_MathProc *proc in
|
||||
Procedure that implements the function.
|
||||
.AP ClientData clientData in
|
||||
Arbitrary one-word value to pass to \fIproc\fR when it is invoked.
|
||||
.AP int *numArgsPtr out
|
||||
Points to a variable that will be set to contain the number of
|
||||
arguments to the function.
|
||||
.AP 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 \fITcl_Free\fR.
|
||||
.AP 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).
|
||||
.AP ClientData *clientDataPtr out
|
||||
Points to a variable that will be set to contain the clientData
|
||||
argument passed to \fITcl_CreateMathFunc\fR when the function was
|
||||
created if the function is not implemented directly in bytecode.
|
||||
.AP "const char" *pattern in
|
||||
Pattern to match against function names so as to filter them (by
|
||||
passing to \fITcl_StringMatch\fR), or NULL to not apply any filter.
|
||||
.BE
|
||||
|
||||
.SH DESCRIPTION
|
||||
.PP
|
||||
Tcl allows a number of mathematical functions to be used in
|
||||
expressions, such as \fBsin\fR, \fBcos\fR, and \fBhypot\fR.
|
||||
These functions are represented by commands in the namespace,
|
||||
\fBtcl::mathfunc\fR. The \fBTcl_CreateMathFunc\fR 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 \fBTcl_CreateObjCommand\fR to create a command
|
||||
in the \fBtcl::mathfunc\fR namespace.
|
||||
.PP
|
||||
In the \fBTcl_CreateMathFunc\fR interface,
|
||||
\fIName\fR is the name of the function as it will appear in expressions.
|
||||
If \fIname\fR does not already exist in the \fB::tcl::mathfunc\fR
|
||||
namespace, then a new command is created in that namespace.
|
||||
If \fIname\fR does exist, then the existing function is replaced.
|
||||
\fINumArgs\fR and \fIargTypes\fR describe the arguments to the function.
|
||||
Each entry in the \fIargTypes\fR array must be
|
||||
one of \fBTCL_INT\fR, \fBTCL_DOUBLE\fR, \fBTCL_WIDE_INT\fR,
|
||||
or \fBTCL_EITHER\fR to indicate whether the corresponding argument must be an
|
||||
integer, a double-precision floating value, a wide (64-bit) integer,
|
||||
or any, respectively.
|
||||
.PP
|
||||
Whenever the function is invoked in an expression Tcl will invoke
|
||||
\fIproc\fR. \fIProc\fR should have arguments and result that match
|
||||
the type \fBTcl_MathProc\fR:
|
||||
.CS
|
||||
typedef int Tcl_MathProc(
|
||||
ClientData \fIclientData\fR,
|
||||
Tcl_Interp *\fIinterp\fR,
|
||||
Tcl_Value *\fIargs\fR,
|
||||
Tcl_Value *\fIresultPtr\fR);
|
||||
.CE
|
||||
.PP
|
||||
When \fIproc\fR is invoked the \fIclientData\fR and \fIinterp\fR
|
||||
arguments will be the same as those passed to \fBTcl_CreateMathFunc\fR.
|
||||
\fIArgs\fR will point to an array of \fInumArgs\fR Tcl_Value structures,
|
||||
which describe the actual arguments to the function:
|
||||
.CS
|
||||
typedef struct Tcl_Value {
|
||||
Tcl_ValueType \fItype\fR;
|
||||
long \fIintValue\fR;
|
||||
double \fIdoubleValue\fR;
|
||||
Tcl_WideInt \fIwideValue\fR;
|
||||
} Tcl_Value;
|
||||
.CE
|
||||
.PP
|
||||
The \fItype\fR field indicates the type of the argument and is
|
||||
one of \fBTCL_INT\fR, \fBTCL_DOUBLE\fR or \fBTCL_WIDE_INT\fR.
|
||||
It will match the \fIargTypes\fR value specified for the function unless
|
||||
the \fIargTypes\fR value was \fBTCL_EITHER\fR. Tcl converts
|
||||
the argument supplied in the expression to the type requested in
|
||||
\fIargTypes\fR, if that is necessary.
|
||||
Depending on the value of the \fItype\fR field, the \fIintValue\fR,
|
||||
\fIdoubleValue\fR or \fIwideValue\fR
|
||||
field will contain the actual value of the argument.
|
||||
.PP
|
||||
\fIProc\fR should compute its result and store it either as an integer
|
||||
in \fIresultPtr->intValue\fR or as a floating value in
|
||||
\fIresultPtr->doubleValue\fR.
|
||||
It should set also \fIresultPtr->type\fR to one of
|
||||
\fBTCL_INT\fR, \fBTCL_DOUBLE\fR or \fBTCL_WIDE_INT\fR
|
||||
to indicate which value was set.
|
||||
Under normal circumstances \fIproc\fR should return \fBTCL_OK\fR.
|
||||
If an error occurs while executing the function, \fIproc\fR should
|
||||
return \fBTCL_ERROR\fR and leave an error message in the interpreter's result.
|
||||
.PP
|
||||
\fBTcl_GetMathFuncInfo\fR retrieves the values associated with
|
||||
function \fIname\fR that were passed to a preceding
|
||||
\fBTcl_CreateMathFunc\fR call. Normally, the return code is
|
||||
\fBTCL_OK\fR but if the named function does not exist, \fBTCL_ERROR\fR
|
||||
is returned and an error message is placed in the interpreter's
|
||||
result.
|
||||
.PP
|
||||
If an error did not occur, the array reference placed in the variable
|
||||
pointed to by \fIargTypesPtr\fR is newly allocated, and should be
|
||||
released by passing it to \fBTcl_Free\fR. Some functions (the
|
||||
standard set implemented in the core, and those defined by placing
|
||||
commands in the \fBtcl::mathfunc\fR 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
|
||||
\fIprocPtr\fR and the variable pointed to by \fIclientDataPtr\fR
|
||||
will not be modified. The variable pointed to by \fInumArgsPointer\fR
|
||||
will contain -1, and no argument types will be stored in the variable
|
||||
pointed to by \fIargTypesPointer\fR.
|
||||
.PP
|
||||
\fBTcl_ListMathFuncs\fR returns a Tcl object containing a list of all
|
||||
the math functions defined in the interpreter whose name matches
|
||||
\fIpattern\fR. The returned object has a reference count of zero.
|
||||
|
||||
.SH "SEE ALSO"
|
||||
expr(n), info(n), Tcl_CreateObjCommand(3), Tcl_Free(3), Tcl_NewListObj(3)
|
||||
|
||||
.SH KEYWORDS
|
||||
expression, mathematical function
|
||||
Reference in New Issue
Block a user