NAME¶

write-array - (array)

PURPOSE¶

Store value into an array.

SYNTAX¶

write-array <array> \


    key <key> \


    value <value> \


    [ old-value <old value> ] 

DESCRIPTION¶

write-array will store a <value> (in "value" clause) under index <key> (in "key" clause) into <array>, which must be created with new-array. <key> is a number from 0 up to (excluding) the currently allocated array size (see new-array). The type of <value> is determined when <array> is created (see "type" clause), and can be either a string, number or a boolean.

<key> and <value> are collectively called an "element".

The old value associated under index <key> is returned in <old value> (in "old-value" clause) and <value> will replace the old value.

If an <array> was created with "process-scope" clause (see new-array), then the element <value> will not be freed when the current request ends, rather it will persist while the process runs, unless deleted (see read-array with delete clause).

EXAMPLES¶

Writing data to an array:

new-array arr
write-array arr key 100 value "some data"

Writing new value with the same key index and obtaining the previous value (which is "some data"):

write-array arr key 100 value "new data" old-value od
@Previous value for this key index is <<print-out od>>

The following is an array service, where a process-scoped array is created. It provides inserting, deleting and querying indexed keys. Maximum number of keys it holds is 10,000,000 (indexed from 0 to 9,999,999). Such a service process can run indefinitely. Create file arrsrv.golf:

%% /arrsrv public


    do-once


    new-array arr max-size 10000000 process-scope type string


    end-do-once


    // Get input parameters


    get-param op


    get-param key


    get-param data


    // Convert string keye to number


    string-number key to key_n


    if-true op equal "add" // Add data to array


        write-array arr key key_n value data old-value old_data 


        delete-string old_data


        @Added [<<print-out key>>]


    else-if op equal "delete" // Delete data and obtain the value deleted


        read-array arr key key_n value val delete 


        @Deleted [<<print-out val>>]


        delete-string val


    else-if op equal "query" // Query hash based on key value


        read-array arr key key_n value val 


        @Value [<<print-out val>>]


    end-if
%%

Create and make the application, then run it as service:

// Create application
gg -k arr
// Make application
gg -q
// Start application (single process key service)
mgrg -w 1 arr

Try it from a command line client (see gg):

// Add data
gg -r --req="/arrsrv/op=add/key=15/data=15" --service --app="/arr" --exec
// Query data
gg -r --req="/arrsrv/op=query/key=15" --service --app="/arr" --exec
// Delete data
gg -r --req="/arrsrv/op=delete/key=15" --service --app="/arr" --exec

See read-array for more examples.

SEE ALSO¶

Array

new-array purge-array read-array write-array See all documentation