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Diffstat (limited to 'doc/DictObj.3')
| -rw-r--r-- | doc/DictObj.3 | 82 |
1 files changed, 44 insertions, 38 deletions
diff --git a/doc/DictObj.3 b/doc/DictObj.3 index fb9206e..90ca9e3 100644 --- a/doc/DictObj.3 +++ b/doc/DictObj.3 @@ -4,14 +4,12 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: DictObj.3,v 1.8 2004/10/07 15:15:36 dkf Exp $ -'\" -.so man.macros .TH Tcl_DictObj 3 8.5 Tcl "Tcl Library Procedures" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME -Tcl_NewDictObj, Tcl_DictObjPut, Tcl_DictObjGet, Tcl_DictObjRemove, Tcl_DictObjSize, Tcl_DictObjFirst, Tcl_DictObjNext, Tcl_DictObjDone, Tcl_DictObjPutKeyList, Tcl_DictObjRemoveKeyList \- manipulate Tcl objects as dictionaries +Tcl_NewDictObj, Tcl_DictObjPut, Tcl_DictObjGet, Tcl_DictObjRemove, Tcl_DictObjSize, Tcl_DictObjFirst, Tcl_DictObjNext, Tcl_DictObjDone, Tcl_DictObjPutKeyList, Tcl_DictObjRemoveKeyList \- manipulate Tcl values as dictionaries .SH SYNOPSIS .nf \fB#include <tcl.h>\fR @@ -49,23 +47,23 @@ int .SH ARGUMENTS .AS Tcl_DictSearch "**valuePtrPtr" in/out .AP Tcl_Interp *interp in -If an error occurs while converting an object to be a dictionary object, -an error message is left in the interpreter's result object +If an error occurs while converting a value to be a dictionary value, +an error message is left in the interpreter's result value unless \fIinterp\fR is NULL. .AP Tcl_Obj *dictPtr in/out -Points to the dictionary object to be manipulated. -If \fIdictPtr\fR does not already point to a dictionary object, +Points to the dictionary value to be manipulated. +If \fIdictPtr\fR does not already point to a dictionary value, an attempt will be made to convert it to one. .AP Tcl_Obj *keyPtr in Points to the key for the key/value pair being manipulated within the -dictionary object. +dictionary value. .AP Tcl_Obj **keyPtrPtr out Points to a variable that will have the key from a key/value pair placed within it. May be NULL to indicate that the caller is not interested in the key. .AP Tcl_Obj *valuePtr in -Points to the value for the key/value pair being manipulate within the -dictionary object (or sub-object, in the case of +Points to the value for the key/value pair being manipulated within the +dictionary value (or sub-value, in the case of \fBTcl_DictObjPutKeyList\fR.) .AP Tcl_Obj **valuePtrPtr out Points to a variable that will have the value from a key/value pair @@ -90,24 +88,29 @@ completed, and a zero otherwise. Indicates the number of keys that will be supplied in the \fIkeyv\fR array. .AP "Tcl_Obj *const" *keyv in -Array of \fIkeyc\fR pointers to objects that +Array of \fIkeyc\fR pointers to values that \fBTcl_DictObjPutKeyList\fR and \fBTcl_DictObjRemoveKeyList\fR will use to locate the key/value pair to manipulate within the -sub-dictionaries of the main dictionary object passed to them. +sub-dictionaries of the main dictionary value passed to them. .BE .SH DESCRIPTION .PP -Tcl dictionary objects have an internal representation that supports -efficient mapping from keys to values and which does not guarantee any -particular ordering of keys within the dictionary (the underlying -basic data-structure is a hash table created with \fBTcl_InitObjHashTable\fR). +Tcl dictionary values have an internal representation that supports +efficient mapping from keys to values and which guarantees that the +particular ordering of keys within the dictionary remains the same +modulo any keys being deleted (which removes them from the order) or +added (which adds them to the end of the order). If reinterpreted as a +list, the values at the even-valued indices in the list will be the +keys of the dictionary, and each will be followed (in the odd-valued +index) by the value associated with that key. +.PP The procedures described in this man page are used to -create, modify, index, and iterate over dictionary objects from C code. +create, modify, index, and iterate over dictionary values from C code. .PP -\fBTcl_NewDictObj\fR creates a new, empty dictionary object. The -string representation of the object will be invalid, and the reference -count of the object will be zero. +\fBTcl_NewDictObj\fR creates a new, empty dictionary value. The +string representation of the value will be invalid, and the reference +count of the value will be zero. .PP \fBTcl_DictObjGet\fR looks up the given key within the given dictionary and writes a pointer to the value associated with that key @@ -158,16 +161,20 @@ The order of iteration is implementation-defined. If the \fBTcl_DictObjFirst\fR returns \fBTCL_ERROR\fR and the iteration is not commenced, and otherwise it returns \fBTCL_OK\fR. .PP -If the last call to \fBTcl_DictObjFirst\fR or \fBTcl_DictObjNext\fR -(for a particular \fIsearchPtr\fR) set the variable indicated by the -\fIdonePtr\fR argument to zero but no further key/value pairs are -desired from that particular iteration, the \fIsearchPtr\fR argument -must be passed to \fBTcl_DictObjDone\fR to release any internal locks -held by the searching process. If \fBTcl_DictObjNext\fR is called on -a particular \fIsearchPtr\fR after \fBTcl_DictObjDone\fR is called on -it, the variable pointed to by \fIdonePtr\fR will always be set to 1 -(and nothing else will happen). It is safe to call -\fBTcl_DictObjDone\fR multiple times on the same \fIsearchPtr\fR. +When \fBTcl_DictObjFirst\fR is called upon a dictionary, a lock is placed on +the dictionary to enable that dictionary to be iterated over safely without +regard for whether the dictionary is modified during the iteration. Because of +this, once the iteration over a dictionary's keys has finished (whether +because all values have been iterated over as indicated by the variable +indicated by the \fIdonePtr\fR argument being set to one, or because no +further values are required) the \fBTcl_DictObjDone\fR function must be called +with the same \fIsearchPtr\fR as was passed to \fBTcl_DictObjFirst\fR so that +the internal locks can be released. Once a particular \fIsearchPtr\fR is +passed to \fBTcl_DictObjDone\fR, passing it to \fBTcl_DictObjNext\fR (without +first initializing it with \fBTcl_DictObjFirst\fR) will result in no values +being produced and the variable pointed to by \fIdonePtr\fR being set to one. +It is safe to call \fBTcl_DictObjDone\fR multiple times on the same +\fIsearchPtr\fR for each call to \fBTcl_DictObjFirst\fR. .PP The procedures \fBTcl_DictObjPutKeyList\fR and \fBTcl_DictObjRemoveKeyList\fR are the close analogues of @@ -186,7 +193,7 @@ keys must exist and have dictionaries as their values. .SH EXAMPLE Using the dictionary iteration interface to search determine if there is a key that maps to itself: - +.PP .CS Tcl_DictSearch search; Tcl_Obj *key, *value; @@ -203,26 +210,25 @@ int done; * is performed. However it is safe to try to release the lock * even if we've finished iterating over the loop. */ -if (Tcl_DictObjFirst(interp, objPtr, &search, +if (\fBTcl_DictObjFirst\fR(interp, objPtr, &search, &key, &value, &done) != TCL_OK) { return TCL_ERROR; } -for (; done ; Tcl_DictObjNext(&search, &key, &value, &done)) { +for (; !done ; \fBTcl_DictObjNext\fR(&search, &key, &value, &done)) { /* * Note that strcmp() is not a good way of comparing - * objects and is just used here for demonstration + * values and is just used here for demonstration * purposes. */ if (!strcmp(Tcl_GetString(key), Tcl_GetString(value))) { break; } } -Tcl_DictObjDone(&search); +\fBTcl_DictObjDone\fR(&search); Tcl_SetObjResult(interp, Tcl_NewBooleanObj(!done)); return TCL_OK; .CE - .SH "SEE ALSO" Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_InitObjHashTable .SH KEYWORDS -dict, dict object, dictionary, dictionary object, hash table, iteration, object +dict, dict value, dictionary, dictionary value, hash table, iteration, value |