verb

describes how a command the user can type is to be interpreted at run time. The general format is

verb "first_command" [, "second_command [, ...] ]
   * ["optional string" or optional_object or optional_attribute  [... ] ]  <verb routine>
   * ["optional string" or optional_object or optional_attribute]/[... ] [...] ]  <verb routine>

It would be used similar to this:

   *                         <verb routine for the verb with no parameters>
   * "word2"                 <verb routine for the verb with this string as a parameter>
   * object                  <verb routine for the verb with an object as a parameter>
   * attribute               <verb routine for the verb with an object as a parameter that has this attribute>
   * "word3"/"word4"         <verb routine for the verb with either string as a parameter>

These can be combined to create very complicated commands. Here is an example:

verb "command"
   *                         DoCommand
   * "word2"                 DoCommand2
   * female                  DoCommand5
   * object                  DoCommand3
   * female "to" "go" object DoCommand6
   * "word3"/"word4"         DoCommand4

The first line means that if the command “command” is typed, and no parameters were given, the routine DoCommand will be run as a verb for that verb. The other lines are routines for the verb with different parameters passed to it, e.g. if the user types the command “command word2” , DoCommand2 will be run; the verb “command” typed in followed by the name of an object as the parameter will cause the routine DoCommand3 to be run, etc.

Consider there is an object named Table that has been defined, and a female_character named Leslie, if the user typed in the verb “Command leslie” would run DoCommand5, but the verb “command table” would run DoCommand3 (table is not female). If the user types in the verb “Command leslie to go north” then command6 would be executed. It would also be executed if the user typed in “Command leslie to go table” which might not make sense in the particular game.

The use of a slash allows either of the parameters to be used interchangeably, e.g. if the user typed the verb “command” followed by either “word3” or “word4” then the verb routine DoCommand4 will run.

While the name of the routine could be anything, it is common practice to name a verb routine beginning with “Do”, followed by the particular verb or the equivalent, to differentiate it from routines used for other purposes, e.g. the standard library defines the verb routine for the “exit” verb as DoExit, the routine for the “look” command as DoLook, etc.

When the user types a verb that has an object as a parameter, the standard library defined variable object will contain the first specified object, which can be tested by comparing it to another object or examining the name property, e.g. if you have the following definition

object wheatstalk "wheat"
{
 ... ...
}

then you can test for whether this was the object referenced with

    if (object.name = "wheat") {
   ...  other code ...
    }

    if (object = wheatstalk) {

    }

If you have a routine which will act on both a command with a parameter or without one, you can test whether an object was given as the parameter through the use in a routine of a reference to object or not object, e.g.

    if (object) {
! code which executes if the user gave an object as a parameter
    }

    if (not object) {
! code which executes if the user did not give an object as a parameter
    }