REBOL Assign command.

All, I don't know if this has ever been done, so I did it myself. Created something similar to the Assign command on the Amiga. Here is the code: ========== REBOL [] Assign: Func [ "Creates an Amiga-like Assign command." Volume [ Word!] "The function that this command will create." Path [ String! File! ] "The directory path that will be assigned to it" ] [ Do Rejoin [ Volume ": Func [ AssignPath ] [ Return to-file Join %" Path " AssignPath ] " ] ] ========== It creates another function that returns the path specified when called. So, for example, to create an Assign to locate REBOL Source code: ASSIGN 'REBSOURCE C:REBOL/SOURCE I can then call it to get source files: DO REBSOURCE HOWDY.R But if I call it to read a directory, I still need to pass a parameter. READ REBSOURCE "." This is slightly cumbersome. So, all that being said, is there a way to make parameters optional in REBOL? So far, in my meager investigations, I have not found a way. I'd like to complete the function so that it can be called like this: READ REBSOURCE, no parameters. -- Sincerely, | The problems of two little people don't amount to Ed Dana | a hill of beans in this crazy mixed-up world! But Software Developer | this is OUR hill, and these are OUR beans! 1Ghz Athlon Amiga | -- Naked Gun via Casablanca.

Ed, You can specify optional parameters. But it can cause confusion inside a script unless you specify the bounds of the evaluation (like inside a block).

>> rebsource: func [dir [any-type!]][if value? 'dir [print dir]] >> rebsource

>> rebsource "."

>>

Hi Ed, ED> So, all that being said, is there a way to make parameters optional in ED> REBOL? So far, in my meager investigations, I have not found a way. I'd ED> like to complete the function so that it can be called like this: READ ED> REBSOURCE, no parameters. In addition to Bo's comment, you could build your function to take a refinement if that seems less cumbersome in your common use. Assign: Func [ "Creates an Amiga-like Assign command." Volume [ Word!] "The function that this commmand will create." Path [ String! File! ] "The path that will be assigned to it." ] [ Do Rejoin [ Volume ": Func [/with AssignPath] [to-file Join %" Path { either with [AssignPath][""] ] } ] ] Then you would use it like this: read REBSOURCE do REBSOURCE/with %hello.r -- Gregg

Excellent! Thank you Bohdan! Here's the updated version: ========== REBOL [] Assign: Func [ "Creates an Amiga-like Assign command." Volume [ Word!] "The function that this command will create." Path [ String! File! ] "The directory path that will be assigned to it" ] [ Do Trim Rejoin [ Volume {: Func [ FilePath [ Any-Type! ] ] [ Return Either (Value? 'FilePath) [ to-file Join %} Path { FilePath ] [ %"} Path {" ] ] } ] ] ========== Much more useful now. :) Bohdan or Rosemary Lechnowsky wrote:

> Ed, > You can specify optional parameters. But it can cause confusion > >> > Have fun!

> I don't know if this has ever been done, so I did it myself. Created > something similar to the Assign command on the Amiga. Here is the code: > So, for example, to create an Assign to locate REBOL Source code: > ASSIGN 'REBSOURCE C:REBOL/SOURCE > > I can then call it to get source files: > DO REBSOURCE HOWDY.R

>> REBSOURCE: %/C/REBOL/SOURCE/

>> REBSOURCE/howdy.r

Ed Dana wrote:

> All, > > I don't know if this has ever been done, so I did it myself. Created > something similar to the Assign command on the Amiga. Here is the code:

Hi Ed, On Saturday, December 28, 2002, 5:03:07 PM, you wrote: ED> So, for example, to create an Assign to locate REBOL Source code: ED> ASSIGN 'REBSOURCE C:REBOL/SOURCE ED> I can then call it to get source files: ED> DO REBSOURCE HOWDY.R

>> rebsource: %/C/REBOL/Script

>> rebsource/anamonitor.r

>> file: %anamonitor.r

>> rebsource/:file

Volker Nitsch wrote:

> Ed Dana wrote: >> All, > you can write > do rebsource/howdy.r