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Diffstat (limited to 'doc/SetResult.3')
| -rw-r--r-- | doc/SetResult.3 | 101 |
1 files changed, 66 insertions, 35 deletions
diff --git a/doc/SetResult.3 b/doc/SetResult.3 index 2245794..bbeedf1 100644 --- a/doc/SetResult.3 +++ b/doc/SetResult.3 @@ -9,7 +9,7 @@ .TH Tcl_SetResult 3 8.0 Tcl "Tcl Library Procedures" .BS .SH NAME -Tcl_SetObjResult, Tcl_GetObjResult, Tcl_SetResult, Tcl_GetStringResult, Tcl_AppendResult, Tcl_AppendResultVA, Tcl_AppendElement, Tcl_ResetResult, Tcl_FreeResult \- manipulate Tcl result +Tcl_SetObjResult, Tcl_GetObjResult, Tcl_SetResult, Tcl_GetStringResult, Tcl_AppendResult, Tcl_AppendResultVA, Tcl_AppendElement, Tcl_ResetResult, Tcl_TransferResult, Tcl_FreeResult \- manipulate Tcl result .SH SYNOPSIS .nf \fB#include <tcl.h>\fR @@ -28,21 +28,25 @@ const char * .sp \fBTcl_AppendResultVA\fR(\fIinterp, argList\fR) .sp -\fBTcl_AppendElement\fR(\fIinterp, element\fR) -.sp \fBTcl_ResetResult\fR(\fIinterp\fR) .sp +.VS 8.6 +\fBTcl_TransferResult\fR(\fIsourceInterp, result, targetInterp\fR) +.VE 8.6 +.sp +\fBTcl_AppendElement\fR(\fIinterp, element\fR) +.sp \fBTcl_FreeResult\fR(\fIinterp\fR) .SH ARGUMENTS -.AS Tcl_FreeProc freeProc out +.AS Tcl_FreeProc sourceInterp out .AP Tcl_Interp *interp out Interpreter whose result is to be modified or read. .AP Tcl_Obj *objPtr in -Object value to become result for \fIinterp\fR. +Tcl value to become result for \fIinterp\fR. .AP char *result in String value to become result for \fIinterp\fR or to be appended to the existing result. -.AP char *element in +.AP "const char" *element in String value to append as a list element to the existing result of \fIinterp\fR. .AP Tcl_FreeProc *freeProc in @@ -52,37 +56,50 @@ Address of procedure to call to release storage at .AP va_list argList in An argument list which must have been initialized using \fBva_start\fR, and cleared using \fBva_end\fR. +.AP Tcl_Interp *sourceInterp in +.VS 8.6 +Interpreter that the result and error information should be copied from. +.VE 8.6 +.AP Tcl_Interp *targetInterp in +.VS 8.6 +Interpreter that the result and error information should be copied to. +.VE 8.6 +.AP int result in +.VS 8.6 +If \fBTCL_OK\fR, only copy the result. If \fBTCL_ERROR\fR, copy the error +information as well. +.VE 8.6 .BE .SH DESCRIPTION .PP The procedures described here are utilities for manipulating the result value in a Tcl interpreter. -The interpreter result may be either a Tcl object or a string. +The interpreter result may be either a Tcl value or a string. For example, \fBTcl_SetObjResult\fR and \fBTcl_SetResult\fR -set the interpreter result to, respectively, an object and a string. +set the interpreter result to, respectively, a value and a string. Similarly, \fBTcl_GetObjResult\fR and \fBTcl_GetStringResult\fR -return the interpreter result as an object and as a string. -The procedures always keep the string and object forms +return the interpreter result as a value and as a string. +The procedures always keep the string and value forms of the interpreter result consistent. For example, if \fBTcl_SetObjResult\fR is called to set -the result to an object, +the result to a value, then \fBTcl_GetStringResult\fR is called, -it will return the object's string value. +it will return the value's string representation. .PP \fBTcl_SetObjResult\fR arranges for \fIobjPtr\fR to be the result for \fIinterp\fR, replacing any existing result. -The result is left pointing to the object +The result is left pointing to the value referenced by \fIobjPtr\fR. \fIobjPtr\fR's reference count is incremented since there is now a new reference to it from \fIinterp\fR. -The reference count for any old result object -is decremented and the old result object is freed if no +The reference count for any old result value +is decremented and the old result value is freed if no references to it remain. .PP -\fBTcl_GetObjResult\fR returns the result for \fIinterp\fR as an object. -The object's reference count is not incremented; -if the caller needs to retain a long-term pointer to the object +\fBTcl_GetObjResult\fR returns the result for \fIinterp\fR as a value. +The value's reference count is not incremented; +if the caller needs to retain a long-term pointer to the value they should use \fBTcl_IncrRefCount\fR to increment its reference count in order to keep it from being freed too early or accidentally changed. .PP @@ -98,19 +115,19 @@ and \fBTcl_SetResult\fR re-initializes \fIinterp\fR's result to point to an empty string. .PP \fBTcl_GetStringResult\fR returns the result for \fIinterp\fR as a string. -If the result was set to an object by a \fBTcl_SetObjResult\fR call, -the object form will be converted to a string and returned. -If the object's string representation contains null bytes, +If the result was set to a value by a \fBTcl_SetObjResult\fR call, +the value form will be converted to a string and returned. +If the value's string representation contains null bytes, this conversion will lose information. For this reason, programmers are encouraged to -write their code to use the new object API procedures +write their code to use the new value API procedures and to call \fBTcl_GetObjResult\fR instead. .PP \fBTcl_ResetResult\fR clears the result for \fIinterp\fR and leaves the result in its normal empty initialized state. -If the result is an object, +If the result is a value, its reference count is decremented and the result is left -pointing to an unshared object representing an empty string. +pointing to an unshared value representing an empty string. If the result is a dynamically allocated string, its memory is free*d and the result is left as a empty string. \fBTcl_ResetResult\fR also clears the error state managed by @@ -137,12 +154,20 @@ call; the last argument in the list must be a NULL pointer. .PP \fBTcl_AppendResultVA\fR is the same as \fBTcl_AppendResult\fR except that instead of taking a variable number of arguments it takes an argument list. -.SH "OLD STRING PROCEDURES" +.PP +.VS 8.6 +\fBTcl_TransferResult\fR moves a result from one interpreter to another, +optionally (dependent on the \fIresult\fR parameter) including the error +information dictionary as well. The interpreters must be in the same thread. +The source interpreter will have its result reset by this operation. +.VE 8.6 +.SH "DEPRECATED INTERFACES" +.SS "OLD STRING PROCEDURES" .PP Use of the following procedures (is deprecated since they manipulate the Tcl result as a string. Procedures such as \fBTcl_SetObjResult\fR -that manipulate the result as an object +that manipulate the result as a value can be significantly more efficient. .PP \fBTcl_AppendElement\fR is similar to \fBTcl_AppendResult\fR in @@ -172,16 +197,19 @@ It also sets \fIinterp->freeProc\fR to zero, but does not change \fIinterp->result\fR or clear error state. \fBTcl_FreeResult\fR is most commonly used when a procedure is about to replace one result value with another. -.SH "DIRECT ACCESS TO INTERP->RESULT IS DEPRECATED" +.SS "DIRECT ACCESS TO INTERP->RESULT" .PP It used to be legal for programs to directly read and write \fIinterp->result\fR -to manipulate the interpreter result. -Direct access to \fIinterp->result\fR is now strongly deprecated -because it can make the result's string and object forms inconsistent. -Programs should always read the result -using the procedures \fBTcl_GetObjResult\fR or \fBTcl_GetStringResult\fR, -and write the result using \fBTcl_SetObjResult\fR or \fBTcl_SetResult\fR. +to manipulate the interpreter result. The Tcl headers no longer +permit this access by default, and C code still doing this must +be updated to use supported routines \fBTcl_GetObjResult\fR, +\fBTcl_GetStringResult\fR, \fBTcl_SetObjResult\fR, and \fBTcl_SetResult\fR. +As a migration aid, access can be restored with the compiler directive +.CS +#define USE_INTERP_RESULT +.CE +but this is meant only to offer life support to otherwise dead code. .SH "THE TCL_FREEPROC ARGUMENT TO TCL_SETRESULT" .PP \fBTcl_SetResult\fR's \fIfreeProc\fR argument specifies how @@ -213,12 +241,15 @@ This allows applications to use non-standard storage allocators. When Tcl no longer needs the storage for the string, it will call \fIfreeProc\fR. \fIFreeProc\fR should have arguments and result that match the type \fBTcl_FreeProc\fR: +.PP .CS -typedef void Tcl_FreeProc(char *\fIblockPtr\fR); +typedef void \fBTcl_FreeProc\fR( + char *\fIblockPtr\fR); .CE +.PP When \fIfreeProc\fR is called, its \fIblockPtr\fR will be set to the value of \fIresult\fR passed to \fBTcl_SetResult\fR. .SH "SEE ALSO" Tcl_AddErrorInfo, Tcl_CreateObjCommand, Tcl_SetErrorCode, Tcl_Interp .SH KEYWORDS -append, command, element, list, object, result, return value, interpreter +append, command, element, list, value, result, return value, interpreter |