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| author | dkf <donal.k.fellows@manchester.ac.uk> | 2007-11-20 20:43:08 (GMT) |
|---|---|---|
| committer | dkf <donal.k.fellows@manchester.ac.uk> | 2007-11-20 20:43:08 (GMT) |
| commit | 69ece03dc014b44e93da9576bb02d060b202013b (patch) | |
| tree | b18999bb6907a1311f4eb7808445c05911198c15 /doc/DictObj.3 | |
| parent | 0500cb0762976df7a95232b162dbb09d7876d0ea (diff) | |
| download | tcl-69ece03dc014b44e93da9576bb02d060b202013b.zip tcl-69ece03dc014b44e93da9576bb02d060b202013b.tar.gz tcl-69ece03dc014b44e93da9576bb02d060b202013b.tar.bz2 | |
* generic/tclDictObj.c: Changed the underlying implementation of the
hash table used in dictionaries to additionally keep all entries in
the hash table in a linked list, which is only ever added to at the
end. This makes iteration over all entries in the dictionary in
key insertion order a trivial operation, and so cleans up a great deal
of complexity relating to dictionary representation and stability of
iteration order.
Diffstat (limited to 'doc/DictObj.3')
| -rw-r--r-- | doc/DictObj.3 | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/doc/DictObj.3 b/doc/DictObj.3 index 20d3514..4e72a1c 100644 --- a/doc/DictObj.3 +++ b/doc/DictObj.3 @@ -4,7 +4,7 @@ '\" 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 1.9 2007/06/29 22:37:27 dkf Exp $ +'\" RCS: @(#) $Id: DictObj.3,v 1.10 2007/11/20 20:43:11 dkf Exp $ '\" .so man.macros .TH Tcl_DictObj 3 8.5 Tcl "Tcl Library Procedures" @@ -99,9 +99,14 @@ sub-dictionaries of the main dictionary object passed to them. .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). +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) bu 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. .PP @@ -190,7 +195,7 @@ 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; @@ -225,7 +230,6 @@ for (; done ; \fBTcl_DictObjNext\fR(&search, &key, &value, &done)) { Tcl_SetObjResult(interp, Tcl_NewBooleanObj(!done)); return TCL_OK; .CE - .SH "SEE ALSO" Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_InitObjHashTable .SH KEYWORDS |