View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000170 | LDMud | Efuns | public | 2004-11-26 21:09 | 2009-10-06 02:02 |
| Reporter | Assigned To | ||||
| Priority | normal | Severity | feature | Reproducibility | N/A |
| Status | new | Resolution | open | ||
| Summary | 0000170: New efun: substitute_string() | ||||
| Description | Short: new efun substitute_string() From: Dave Setty <garpoz@locallink.net> Date: Thu, 10 Dec 1998 02:03:04 -0500 Type: Feature State: Unclassified See also: f-020404 I've also got some various patches around that I'd like to see in there. Lars, if you're interested in any of this let me know... 1) subst(), which is similar to MudOS's replace_string() which in turn is a more refined version of the old implode(explode()) trick. Mine can take two arrays or a mapping of search/replace pairs though. --- Doomdark: If I'm not mistaken, this is similar to 'substitute_string()'-efun I made, which takes 2 string arrays to define the strings to replace. It can be found from 'bugs/doomdark/strutil.c'-file from the ldmud-3.2.5 if you are interested. The extra arguments (min and max length of the aliases to substitute) are just for optimizing the speed; also, the first array is expeceted to be sorted to allow binary search of the substitutions. Finally, the substitution is done by scanning the whole string just once, and by using a static replace buffer (no mallocs except for one used for mallocing room for the returned string, _if_ any substitutions were made). All in all, I tried to do a somewhat optimized version which could be used for alias subsitution in command strings; since this is called for every command players enter, it should be made as fast as possible. ---- Suggestion by Matthew Julius: varargs string strsubst(string, string|mapping|string*, string|string*) String replacement/substitution... Examples, strsubst("abc", "ab", "1") == "1c" strsubst("abc", ({ "a", "b" }), ({ "1", "2" })) == "12c" strsubst("abc", ([ "a": "1" ])) == "1bc" strsubst("abc", ({ "d" }), ({ "1" })) == "abc" The Timewarp mudlib has historically called this subst(). Or call it strreplace(): strreplace("abcdef", "cd", "x") -> "abxef" | ||||
| Tags | No tags attached. | ||||
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| duplicate of | 0000452 | new | replace() efun like in Pike |
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p-990417-1: Daniel Sloan's take on this. Short: New efun replace_string() From: Daniel Sloan Date: 990410 Type: Patch State Unclassified diff-replace : A diff for the efun 'replace_string()', which does the same as implode(explode(X, Y), Z);, but does it faster and without creating an array, of course :-) MudOS uses a very efficient algorithm for it. |
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Hmm, i'm not sure, but cant this be done by regreplace() in a very efficient manner too? Actually replace_string() as known from MudOS allows to replace several strings at once in a easy way. This can be done via regreplace() to, but with regular expression syntax which is not that obvious. |
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We use regreplace to convert umlauts and other characters to ascii. All player input goes through this conversion. It's really fast since it's just a single call to regreplace. (A replacepattern closure gets the replacement characters out of a mapping). No need for a new EFun there. But in this scenario, the regular expression is static (and most likely cached by the driver) and replacement mapping/closure are static too, so there really isn't much to do. Making strsubst()/substitute_string() a simul efun which uses regreplace would be much more difficult to do, because you have to both escape and (in the case of mappings) sort the input strings. Of course you can just use regreplace directly, but that requires knowledge of regexp. It's like saying we don't need inline closures, we have lambda. ;-) |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2004-11-26 21:09 |
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New Issue | |
| 2004-11-26 21:09 |
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File Added: doomdark-strutil.tar.gz | |
| 2004-11-27 00:21 |
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Note Added: 0000224 | |
| 2004-11-27 00:21 |
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File Added: p-990417-1.gz | |
| 2004-12-11 18:49 | Bardioc | Note Added: 0000244 | |
| 2004-12-12 04:51 | menaures | Note Added: 0000248 | |
| 2009-10-06 02:02 | zesstra | Relationship added | duplicate of 0000452 |
