World: r3wp

>> replace-all b 2 1
== [[1] [[[1]]] [1]]
>> stats/evals
== [219 105 47]

Do you really want to do this:
>> replace-all ["1"] 1 2
== ["2"]
Otherwise, change series? to any-block?

Actually, that is exactly what I want

replace-all: func [series oldval newval /local sub-ic][
        sub-ic: func [sd][
            while [not tail? sd ][  
                case [
                    equal? first sd :oldval [poke sd 1 :newval]
                    series? first sd [sub-ic first sd]
                ]
                sd: next sd
            ]
        ]
        sub-ic series
        series
    ]

CASE is faster than 2 comparisons with EITHER or IF.

I recall you saying that before I never really checked it out.

I profile code patterns to see which is faster.

I think your case is messed up

I think I had that if for a reason but not sure why

in the case of mine both conditions will not be true whereas in your 
case arrangment both can can't they?

Not unless you use case/all. Did you have /case as an option to your 
function at some point?

all yeah I always forget that.

Keep thinking of like switch when I see case and I use case often.

It's more like cond from Lisp.

yeah I never used another language other than REBOL so I wouldn't 
know.

Wow. I've never heard that before.

lol - I'm just a hobbiest with REBOL.

I have no programming education.  Had to self teach me this stuff.

That is why when you use a lot of programming terms I'm lost.

I'm self-taught too, but after more than 20 years you pick up some 
stuff :)

I think that replace function is good Brian.  I would push for that 
to be a mezzanine at this point.

:-)

the reason I like it as series instead of any-block is for using 
it on long strings.

>> str: "this is just a test of replace-all"
== "this is just a test of replace-all"
>> replace-all str #"t" #"d"
== "dhis is jusd a desd of replace-all"

The case did cut it down a bit on the evals:
>> replace-all b 1 2
== [[2] [[[2]]] [2]]
>> stats/evals
== [209 100 42]

I would say that is one heck of a useful function

I've been using timblk to profile, not stats. How useful have you 
found stats to be?

its pretty useful.  Btiffin mentioned timblk also. I will have to 
look for it sometime.

replace-all: func [
    "Replaces all occurences of old value with new value"
    series "Series containing values to replace"
    oldval "Value to be replaced"
    newval "New value to replace old value"
    /local subf
    ][
        subf: func [sd][
            while [not tail? sd ][  
                case [
                    equal? first sd :oldval [poke sd 1 :newval]
                    series? first sd [subf first sd]
                ]
                sd: next sd
            ]
        ]
        subf series
        series
    ]

same function just commented a bit and changed sub-ic to just subf 
meaning subfunction

catch throw-on-error?

Add the [series!] type check to the series parameter of the outer 
function and you'll be set.

oh yeah

catch throw-on-error
 What do you mean?

Should it throw errors to a catch so that it doesn't expose the lower 
code?

not sure how that would behave in this case

You aren't doing anything in the inner code that could generate an 
error, so no need.

If were sure that all the values that it traverses are comptible 
then I agree.  In fact I don't think we need one until it becomes 
known as a problem.

The only problem would be if your blocks have cyclic references and 
you get stack overflow. I'm not sure you can catch that.

replace-all: func [
    "Replaces all occurences of old value with new value"
    series [series!] "Series containing values to replace"
    oldval [any-type!] "Value to be replaced"
    newval [any-type!] "New value to replace old value"
    /local subf
    ][
        subf: func [sd][
            while [not tail? sd ][  
                case [
                    equal? first sd :oldval [poke sd 1 :newval]
                    series? first sd [subf first sd]
                ]
                sd: next sd
            ]
        ]
        subf series
        series
    ]

Don't put [any-type!]. The only difference between that and no type 
spec at all is that your function would be able to accept unset! 
values, and that would require other changes to your code to work 
properly.

here this is better to read:

ahhh good point.

replace-all: func [
    "Replaces all occurences of old value with new value"
    series [series!] "Series containing values to replace"
    old-value  "Value to be replaced"
    new-value  "New value to replace old value"
    /local subf
    ][
        subf: func [sd][
            while [not tail? sd ][  
                case [

                    equal? first sd :old-value [poke sd 1 :new-value]
                    series? first sd [subf first sd]
                ]
                sd: next sd
            ]
        ]
        subf series
        series
    ]

I changed newval to new-value and oldval to old-value

That is the REBOL way :)

hehe - looks good.

In general, I find that it is a good idea to let unset! values be 
erroneous, rather than changing your code to accept them. That makes 
it easier to make a clear distinction between non-values that are 
erroneous (unset!) and non-values that may not be erroneous (none!).

good tip

Is it a good practice to unset series within functions if the series 
is an argument to the function?  Not sure how the garbage handler 
in REBOL works or if it sees it as garbage until the next function 
call.