World: r3wp
[Core] Discuss core issues
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BrianH 25-Apr-2006 [4118x3] | What I was talking about earlier was the allocation quanta. Blocks are allocated with the assumption that you will want to insert stuff into them without having to reallocate them every time. So by that powers of two to multiples of 128, when you want a block length 10, you get 16. When you want 129, you get 256, and so on. On that note, when you want 1000000, you would get 1000064. |
A list may be twice as big, but if you want memory predictability you can't beat it because the allocation quanta is 1 node and the insert/delete is O(1). Indexing and length calculations are O(n) though. | |
Later... | |
Maxim 25-Apr-2006 [4121] | ciao, thanks for all that info :-) |
Henrik 26-Apr-2006 [4122] | wouldn't it make sense for SKIP to support hex values? I'm trying to locate a specific position in a binary and it's tedious having to convert to number! every time. |
Volker 26-Apr-2006 [4123] | what do you convert to number? |
Gregg 26-Apr-2006 [4124] | What is a hex value in REBOL? |
Henrik 26-Apr-2006 [4125] | volker, a specific location in the binary taken from a hex editor |
Volker 26-Apr-2006 [4126x2] | but that conversion could be put in a little function by yourself? |
i think non-system-coders rarely use hex. | |
Maxim 26-Apr-2006 [4128] | skip can be redefined to something which supports hex numbers... |
Henrik 26-Apr-2006 [4129] | I just think it's too obvious and useful to leave out |
Gregg 26-Apr-2006 [4130] | But what is the proper representation of a hex value in REBOL? An issue? An ENBASEd string? |
Henrik 26-Apr-2006 [4131] | it's an issue |
Volker 26-Apr-2006 [4132] | why not write a converter and then skip bin &h #c4d9 |
Gregg 26-Apr-2006 [4133] | Ah, but an issue is really a string, not a number. The TO-HEX function makes it look like this is the recommended approach (it's what I would say, too), but I think it's a type mismatch (unfortunately). |
Henrik 26-Apr-2006 [4134] | I see |
Gregg 26-Apr-2006 [4135x3] | That is, I don't think standard functions should take issue! params for hex values unless RT says, officially, that it's how you do hex values in REBOL. |
Is hex notation something we should propose for R3? I'd bet money Carl thought about it long and hard in the original design, and may even have left some lexical wiggle-room to add it later. | |
propose = request. | |
Henrik 26-Apr-2006 [4138] | well, I can understand it if there is no official way to represent hex values. I think it should be proposed for R3 |
Volker 26-Apr-2006 [4139x2] | Its nearly never needed, but if it is needed, its very usefull. |
hex-editor or ascii or decoding this unix-rights-numbers or such. | |
Gregg 26-Apr-2006 [4141] | REBOL is very high level, and you tend to use hex notation more in low level scenarios, but it's *so* handy to have it there when you need it. |
Maxim 26-Apr-2006 [4142] | yess the kind of thing you need when you are doing projects and the specs are not your own. on the other hand, HTTP 1.1 uses hex values for chunk sizes (stupid design if there is one)... so they are still used. |
Gregg 26-Apr-2006 [4143x3] | Here's what I use: hex: func [ {Returns the base-10 value of a hexadecimal number.} value [integer! string! issue!] "A hexadecimal number" ][ ; Convert to an issue first, so integers can also be translated. to integer! to issue! value ] |
When I first started in REBOL, I also aliased it as &H (as a func name), since that's the hex notation prefix in BASIC and can be used as a func name, unlike "0x" | |
It is a little extra work to use a func to convert values, but not awful. If you need to use it heavily in a particular app, I'd consider using a dialect. | |
Henrik 26-Apr-2006 [4146] | binary tools powerpack then? |
Gregg 26-Apr-2006 [4147] | You bet. Outline the domain and we can cook up a killer dialect. |
Maxim 26-Apr-2006 [4148] | the problem I have with dialects is they are not extensible |
Henrik 26-Apr-2006 [4149] | it would be worthy of its own group, wouldn't it? |
Gregg 26-Apr-2006 [4150] | I think so Henrik, for better focus. |
Henrik 26-Apr-2006 [4151] | I'll create it now |
Maxim 26-Apr-2006 [4152] | I mean without rewriting the original dialect parser itself. |
Gregg 26-Apr-2006 [4153] | Who says Max? |
Volker 26-Apr-2006 [4154] | OT: regarding dialects: could 'any be an option in parse? i often have parse blk [ any[ .. ] ] would like parse/any blk [ .. ] |
Maxim 26-Apr-2006 [4155x2] | when I tried to plug within VID... man it was awfull. |
I ended having to piggy back on top of VID. | |
Gregg 26-Apr-2006 [4157] | The Logo interpreter I did (early in REBOL for me) allowed user defined functions; basically it just added things to the list of parse rules it knew about, naive, but semi-functional. :-) |
Volker 26-Apr-2006 [4158] | it predates the block-parser, and that shows. |
Maxim 26-Apr-2006 [4159] | and that means actually calling the VID parser many many times... |
Volker 26-Apr-2006 [4160] | rebgui looks much cleaner IMHO. |
Gregg 26-Apr-2006 [4161] | Dialects have to be planned for extensibility, just like languages. |
Maxim 26-Apr-2006 [4162] | gregg, exactly... you have to dialect your dialect's dialecting ability ;-) |
Gregg 26-Apr-2006 [4163] | ANY - Not sure what you mean Volker. |
Maxim 26-Apr-2006 [4164] | but that's usually harder than the dialect itself, and there are no ways to ensure that this door, won't corrupt your dialect itself.. |
Henrik 26-Apr-2006 [4165] | group created, lets move binary stuff to there |
Volker 26-Apr-2006 [4166] | i need two nested blocks. nearly everytime i use 'parse. |
Gregg 26-Apr-2006 [4167] | i.e. why would a refinement be better than using PARSEs ANY keyword? |
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