World: r3wp

http://www.jwz.org/doc/mid.html
	

 In summary, one possible approach to generating a Message-ID would 
 be:

    * Append "<".


    * Get the current (wall-clock) time in the highest resolution to 
    which you have access 

    (most systems can give it to you in milliseconds, but seconds will 
    do);


    * Generate 64 bits of randomness from a good, well-seeded random 
    number generator;


    * Convert these two numbers to base 36 (0-9 and A-Z) and append the 
    first number, 

    a ".", the second number, and an "@". This makes the left hand side 
    of the message ID be only about 21 characters long.


    * Append the FQDN of the local host, or the host name in the user's 
    return address.

    * Append ">".

enbase doesn't accept a value of 36

I used 1'000'000 here .. don't know if it's enough

    generate-messageid: does [

     rejoin [ "<" enbase form now/time/precise "." enbase form random 
     1000000  "@" server-name ">"]
	]

basically you need 13 random characters, don't you?

I"m not sure ...

where does the 13 come from?

a 64 bit number has 64 digits in base 2, and 12-13 digits in base 
36

anyway, since you just need some randomness, a random 12 character 
string will do

so use base 32 ?

>> s
== "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"
>> pool: "" insert/dup pool s 12
== ""
>> random/seed now
>> copy/part random/secure pool 12
== "GQOTTWDZZXNL"
>> copy/part random/secure pool 12
== "JOFF6QY4T2H8"
>> copy/part random/secure pool 12
== "8RJ2MFTQ0IJQ"
>> copy/part random/secure pool 12
== "ZKCS1DX7UTHL"
>> copy/part random/secure pool 12
== "DY3VJH4UTNFF"
>> copy/part random/secure pool 12
== "KWPNQRIJ40KN"

note that "well seeded" usually means you're seeding from some truly 
random value, rather than the current time

I guess since I'm not processing that many email, it doesn't have 
to be truly random.

i think that for your purposes, enbase/base 64 would be just fine

so you could use something like:

which is default for enbase ...

generate-messageid: does [

    rejoin ["<" enbase checksum/secure random/secure mold system/error 
    "@" server-name ">"]
]

you could randomize the message itself and then checksum it, too

what's the mold system/error for ?

get some (long) text to randomize and then checksum

any random data would do

generate-messageid: func [eml [string!] [

    rejoin ["<" enbase checksum/secure random/secure eml "@" server-name 
    ">"]
]

sort of ..

i think that's good for your purposes.

ok, thanks Gabriele

not sure if any char in base 64 could be a problem as a message id 
char, but i think MTAs do use base64 for message ids so probably 
it's fine.

might be better to restrict myself to the first 1000 chars or so 
in case the eml is megabytes long ..

a: make object! [
    b: 4
    c: 6
]

how to remove element b ?

It's not possible to add or remove values within an object.

You can create a new object based on your object that adds or omits 
values, the latter being trickier.

or you can set b to none ....

construct head remove remove find third a to-set-word 'b

:-)

That would fail under the following circumstance:

a: context [c: to-set-word 'b b: 123]

strange result, I would expect obtaining error here?
>> unset in a 'b
>> probe a

make object! [
    b: unset
    c: 6
]
>> a/b
>>

how to add object e: 7 to a ?

you have to clone the object with the new instance variable

a: make a [ e: 7 ]

ok

how to [ d: 5]
word: "d"
integer : "5"

Lookup 'parse for that one..

parse? why parse? What do you mean, Micha?

what do you want to do?

do [ d: 5 ]

>> d
== 5

>> word: "d"
== "d"
>> integer: 5
== 5
>> set to-set-word word integer
== 5
>> d
== 5

Or did you mean something more like...

foreach [word integer] [a 1 b 2 c 3] [
    print ["Word: " to string! word newline "Integer: " integer]
]

I'm getting a confusing error about using paths on a logic! object 
when trying to use the methods of a created object. I figure I'm 
missing something obvious, but I can't figure out what it is:

test-result: make object! [
    run-count: 0
    error-count: 0

    test-started: does [
        run-count: run-count + 1
    ]

    test-failed: does [
        error-count: error-count + 1
    ]

    summary: does [
        return join  run-count [ " run, " error-count " failed" ]
    ]
]


; ...


            ed: make test-result [ ]
            ed/test-started
            ed/test-failed
            assert [ ed/summary == "1 run, 1 failed" ]

; output of code:

[[wisti-:-us1-dhcp-227-65] xUnit]$ rebol xunit.r
** Script Error: Cannot use path on logic! value
** Where: test-failed-result-formatting
** Near: ed/test-started
ed/test-failed
assert [ed/summary == "1 run, 1 failed"]

The code is just me working my way through the book "Test-Driven 
Development" by Kent Beck. I like applying educational exercises 
to new languages as I find them :-)