of_find

pfcapsrv.pbl   >   pfc_n_cst_list   >   of_find

Name	Datatype
FOUND	integer
lnv_node	n_cst_linkedlistnode
lnv_nonvalid	n_cst_linkedlistnode
NOT_FOUND	integer

public function integer of_find (ref n_cst_linkedlistnode anv_returningnode, n_cst_linkedlistnode anv_keynode, n_cst_linkedlistnode anv_startnode);//////////////////////////////////////////////////////////////////////////////
//
//	Function:  of_find
//
//	Access:  public
//
//	Arguments : 
//	anv_returningnode (by reference) node found and returned from the list.
//	anv_keynode	 Node containing the key to be used to lookup the requested node.
//	anv_startnode	The node to start the searching.
//
//	Returns:  integer
//	 1 : found
//	 0 : not found
//	-1 : failure
//
//	Description:  
//	Finds and returns reference of the next node in the list in which the key
//	meets a specified condition.
//
//	Note:
//	The find operation will not include the valid startnode.  The search starts
//	on the next node.
//	To start a search begining on the Head node call the function with an invalid
//	startnode.
//	
//////////////////////////////////////////////////////////////////////////////
//
//	Revision History
//
//	Version
//	6.0   Initial version
//
//////////////////////////////////////////////////////////////////////////////
//
//	Copyright © 1996-1997 Sybase, Inc. and its subsidiaries.  All rights reserved.
//	Any distribution of the PowerBuilder Foundation Classes (PFC)
//	source code by other than Sybase, Inc. and its subsidiaries is prohibited.
//
//////////////////////////////////////////////////////////////////////////////

constant integer FOUND = 1
constant integer NOT_FOUND = 0
n_cst_linkedlistnode lnv_node
n_cst_linkedlistnode lnv_nonvalid

// Clear return reference.
anv_returningnode = lnv_nonvalid

// Validate required references.
// Validation of anv_startnode is not desired. (an invalid ref means to start at top(head))
if IsNull(anv_keynode) or Not IsValid(anv_keynode) then return FAILURE

// See if this is an empty list.
If of_IsEmpty() Then
	Return NOT_FOUND
End If

// Since the list is not empty, validate the Head node.
if IsNull(inv_head) or Not IsValid(inv_head) then return FAILURE

// Determine the first node to search in.
If IsValid(anv_startnode) Then
	// Start looking in the next node. (skip the startnode)
	anv_startnode.of_getnext(lnv_node)
Else
	lnv_node = inv_head
End If

// if necessary, create the compare object.
if IsNull(inv_compare) or Not IsValid(inv_compare) then
	inv_compare = create n_cst_linkedlistnodecompare
end if

// Loop looking for the node.
do while IsValid(lnv_node)
	choose case inv_compare.of_compare(anv_keynode, lnv_node)
		case inv_compare.EQUAL 
			// Entry has been found.
			anv_returningnode = lnv_node 
			return FOUND
		case inv_compare.LESSTHAN
			// Depending on sort attribute.
			If ib_sorted Then
				// No nodes after the current entry could be a match.
				return NOT_FOUND
			Else
				// Look at next node.				
			End If
		case inv_compare.GREATERTHAN
			// Look at next node.
	end choose

	lnv_node.of_getnext(lnv_node)
loop

Return NOT_FOUND

end function

Name	Owner
pfc_n_cst_list.of_find	pfc_n_cst_list

Name	Owner
systemfunctions.isnull	systemfunctions
systemfunctions.isvalid	systemfunctions
pfc_n_cst_nodecomparebase.of_compare	pfc_n_cst_nodecomparebase
pfc_n_cst_linkedlistbase.of_isempty	pfc_n_cst_linkedlistbase
pfc_n_cst_nodebase.of_getnext	pfc_n_cst_nodebase