| GOLF(2gg) | Development | GOLF(2gg) |
NAME¶
write-list - (linked-list)
PURPOSE¶
Write key/value pair into a linked list.
SYNTAX¶
write-list <list> key <key> \
value <value> \
[ append [ <append> ] ]
DESCRIPTION¶
write-list adds a pair of key/value strings to the linked <list>, specified with <key> and <value> (in "key" and "value" clauses, collectively called an "element").
The key/value pair is added just prior to the list's current position, thus becoming a current element.
If "append" clause is used without boolean variable <append>, or if <append> evaluates to true, then the element is added at the end of the list, and the list's current element becomes the newly added one.
EXAMPLES¶
Add a key/value pair to the end of the list:
new-list mylist write-list mylist key "mykey" value "myvalue" append
The following is a list that is process-scoped, i.e. it is a linked-list server, which can add, delete, read and position to various elements:
%% /llsrv public
// Create linked list just once for the life of the process
do-once
new-list t process-scope
end-do-once
// Get input parameters
get-param op
get-param key
get-param data
if-true op equal "add" // Add data to list
// Make a copy of key,data so they are Golf-allocated
write-list t key (key) value data append
@Added [<<print-out key>>] value [<<print-out data>>]
else-if op equal "delete" // Delete first data and obtain the value deleted
position-list t first
read-list t key (key) value val status st
if-true st equal GG_ERR_EXIST
@Not found
else-if
// If found, then delete key and value
@Deleted key [<<print-out key>>], [<<print-out val>>]
delete-list t
end-if
else-if op equal "next" // Position to next element
position-list t next status st
if-true st equal GG_OKAY
@Okay
else-if
@Not found
end-if
else-if op equal "last" // Position to last element
position-list t last status st
if-true st equal GG_OKAY
@Okay
else-if
@Not found
end-if
else-if op equal "previous" // Position to element
position-list t previous status st
if-true st equal GG_OKAY
@Okay
else-if
@Not found
end-if
else-if op equal "first" // Get first element
position-list t first status st
if-true st equal GG_OKAY
@Okay
else-if
@Not found
end-if
else-if op equal "query" // Get current element
read-list t key (key) value val status st
if-true st equal GG_ERR_EXIST
@Not found
else-if
@Key [<<print-out key>>], value [<<print-out val>>]
end-if
else-if op equal "purge" // remove all, keep the list
purge-list t
end-if %%
Create application:
sudo mgrg -i -u $(whoami) linkserver
Start the server:
mgrg -w 1 linkserver
Try it out:
gg -r --req="/llsrv/op=add/key=1/data=1" --exec --service gg -r --req="/llsrv/op=add/key=2/data=2" --exec --service gg -r --req="/llsrv/op=query" --exec --service gg -r --req="/llsrv/op=previous" --exec --service gg -r --req="/llsrv/op=query" --exec --service
SEE ALSO¶
Linked list
delete-list get-list new-list position-list purge-list read-list write-list See all documentation
| $VERSION | $DATE |