reform, rejoin and separation characters

but

where

refinements?

outrageous!

Hi Terrence, Not sure why you feel that they are resistant. join/with and rejoin/with etc sugestions have been added to the enhancement database. ( /with is a more consistent REBOL term, than sepchar. see 'open, 'write and 'trim for examples) Contact me off list if you would like a copy of that feedback email. Cheers, Allen K

but

There's more to it than that. What the two functions have in common is that they reduce their argument, thereby replacing words supplied to them in a block by the values these words are bound to. However, there are quite a few differences that are due to the fact that rejoin and reform descend from different functions that are intended to accomplish different tasks. In some instances rejoin and reform have similar results. (See the differences documented below.) The rejoin function descends from join, whereas the reform function descends from form. The form function (form is a native function) is used to convert any type of value to a string. The join function (join is a mezzanine function) appends its second argument to its first argument. The join function uses form, if its first argument is not a series! type value. (source form, source join). The behavior you observe (preserving spaces or not) results from the fact that the two functions derive (or extend) essentially different functions. Besides the preservation of spaces there are, however, a few more differences: 1. While reform accepts any datatype you must pass a block to rejoin:

== "3"

** Script Error: rejoin expected block argument of type: block. ** Where: rejoin 3

== "abcdef"

** Script Error: rejoin expected block argument of type: block. ** Where: rejoin "abcdef" This can become relevant when you are using rejoin or reform programmatically, and you don't know for a certainty, whether or not the argument you will supply to the resomething function will be a block or not. Another difference is the return value:

== "/d/ directory"

== %/d/directory

== string!

== file! While reform always returns a string, no matter what it's argument - recall that reform descendants from form, and form's purpose is to convert everything to a string - rejoin returns an argument whose datatype is the datatype of the first element in rejoin's block argument, provided that first element is a series value. After all, rejoin descends from join, and join's purpose is not to convert everything to a string, join's purpose is to join its second argument to its first argument, while preverving the datatype of its first argument, if that datatype is a series! type. If the first element in the block passed to rejoin is a string, or if it is not a series type argument, in these two cases only will rejoin return a value of type string! If you source reform and rejoin, you'll be able to see the difference:

reform: func [ "Forms a reduced block and returns a string." value "Value to reduce and form" ][ form reduce value ]

rejoin: func [ "Reduces and joins a block of values." block [block!] "Values to reduce and join" ][ block: reduce block append either series? first block [copy first block] [ form first block] next block ] In summary, use reform if you would have normally used form, but you must first reduce words contained in a block before the block is converted into a string:

== 1

== "a"

== "1" Use rejoin when you want to append multiple dereferenced words to the leading element, while preserving that leading element's datatype:

== %/d/directory

;- Elan [ : - ) ] author of REBOL: THE OFFICIAL GUIDE REBOL Press: The Official Source for REBOL Books http://www.REBOLpress.com visit me at http://www.TechScribe.com