Second Life Wiki - User contributions [en]

User:Vegas Silverweb/vsListFindList

2010-04-21T21:57:15Z

Vegas Silverweb: Created page with 'Like ListFindList but tries for match based on implicit cast to string, so works pretty good for everything except vectors and rotations initialized in-place with integers. <lsl...'

Like ListFindList but tries for match based on implicit cast to string, so works pretty good for everything except vectors and rotations initialized in-place with integers.

<lsl>
integer vsListFindList(list haystack,list needle) {
integer i;
integer j = llGetListLength(haystack);
string s = llList2String(needle,0);
for(i=0;i<j;i++) {
if(llList2String(haystack,i)==s) return i;
}
return -1;
}
</lsl>

User:Vegas Silverweb

2010-04-21T21:44:37Z

Vegas Silverweb:

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[User:Vegas_Silverweb/How to get the SL Time in Chatlog Format|How to get the SL Time in Chatlog Format]]

[[User:Vegas_Silverweb/Fastest And Probably Most Efficient Way To Reverse a List (in Mono)|Fastest And Probably Most Efficient Way To Reverse a List (in Mono)]]

[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)|llHTTPRequest Pro Tip(s)]]
[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)/Matrix URLs|llHTTPRequest Pro Tip(s) (slight return) Matrix URLs]]

[[User:Vegas_Silverweb/LSL to JSON|LSL to JSON]]

[[User:Vegas_Silverweb/vsListFindList|Loose List Find List]]

[https://wiki.secondlife.com/wiki/User:Kelly_Linden/lsl_hacks#Another_javascript_boot_strapping_method_.28Vegas_Silverweb.29 My Prim Media Hack]

User:Vegas Silverweb

2010-04-21T21:42:58Z

Vegas Silverweb:

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[User:Vegas_Silverweb/How to get the SL Time in Chatlog Format|How to get the SL Time in Chatlog Format]]

[[User:Vegas_Silverweb/Fastest And Probably Most Efficient Way To Reverse a List (in Mono)]]

[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)]]
[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)/Matrix URLs]]

[[User:Vegas_Silverweb/LSL to JSON]]

[https://wiki.secondlife.com/wiki/User:Kelly_Linden/lsl_hacks#Another_javascript_boot_strapping_method_.28Vegas_Silverweb.29 My Prim Media Hack]

User:Vegas Silverweb

2010-04-21T21:00:10Z

Vegas Silverweb:

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[User:Vegas_Silverweb/How to get the SL Time in Chatlog Format]]

[[User:Vegas_Silverweb/Fastest And Probably Most Efficient Way To Reverse a List (in Mono)]]

[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)]]
[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)/Matrix URLs]]

[[User:Vegas_Silverweb/LSL to JSON]]

[https://wiki.secondlife.com/wiki/User:Kelly_Linden/lsl_hacks#Another_javascript_boot_strapping_method_.28Vegas_Silverweb.29 My Prim Media Hack]

User:Vegas Silverweb/Fastest And Probably Most Efficient Way To Reverse a List (in Mono)

2010-04-21T04:38:48Z

Vegas Silverweb:

As Seen in Scripts

<lsl>
list newlist;
list oldlist = ["a","b","c"];

while(oldlist !=[]) {newlist+=llList2List(oldlist,-1,-1);oldlist = llDeleteSubList(oldlist,-1,-1);}

// oldlist is now empty, newlist is ["c","b","a"]
</lsl>

(of course the real fastest way to reverse a list is to just iterate over it from end to front)

User:Vegas Silverweb

2010-04-21T04:21:57Z

Vegas Silverweb:

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[User:Vegas_Silverweb/How to get the SL Time in Chatlog Format]]

[[User:Vegas_Silverweb/Fastest And Probably Most Efficient Way To Reverse a List (in Mono)]]

[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)]]

[[User:Vegas_Silverweb/LSL to JSON]]

[https://wiki.secondlife.com/wiki/User:Kelly_Linden/lsl_hacks#Another_javascript_boot_strapping_method_.28Vegas_Silverweb.29 My Prim Media Hack]

User:Vegas Silverweb/LSL to JSON

2010-04-21T04:19:59Z

Vegas Silverweb: Created page with 'JSON's a pleasant way to serialize object representations. At this point basically every general-purpose programming language with some form of object abstraction supports JSON. ...'

JSON's a pleasant way to serialize object representations. At this point basically every general-purpose programming language with some form of object abstraction supports JSON. It's particularly handy in say PHP, where web-to-object is just a json_decode() away.

PHP certainly doesn't speak LSL strided lists, and LSL's list dumping and CSV implementations are rather unique to LSL. With a little trickery, though, you can make use of the fact that the key type in LSL is just a string with delusions of grandeur and construct JSON representations of objects with arbitrary complexity...with some caveats.

Note a few optimizations and shortcuts are omitted for the sake of keeping things a little more readable/understandable.

First let's turn a strided list into a JSON object:
<lsl>
string vsList2JSON(list input) {
list labels;
if(llGetListLength(input) % 2 != 0) {
llSay(DEBUG_CHANNEL,"vsList2JSON must be a 2-strided list!");
return "{}";}

string sTemp = "{";
integer i;
for(i=0;i<llGetListLength(input);i+=2) {
string label = llList2String(input,i);
sTemp += "\""+label+"\":";
integer entryType = llGetListEntryType(input,i+1);
if(entryType>2 && entryType!=4)
sTemp=sTemp+"\""+llList2String(input,i+1)+"\""; else
if(entryType==2)
sTemp=sTemp+(string)llList2Float(input,i+1); else
if(entryType==1)
sTemp=sTemp+(string)llList2Integer(input,i+1); else
if(entryType==4)
sTemp=sTemp+llList2String(input,i+1);
if(llGetListLength(input)>i+2) sTemp=sTemp+",";
}

sTemp += "}";
return sTemp;
}
</lsl>

It's a little ugly, but for most cases works fine. The part that needs a little explaining is how keys are handled (type 4). We want to treat it as a string, but not surround it with quotes. This'll come in handy later...

So we have a strided list in object format. We might need a JSON array, too:

<lsl>
string vsList2JSONArray(list input) {
string sTemp = "[";
integer i;
for(i=0;i<llGetListLength(input);i++) {
integer entryType = llGetListEntryType(input,i);
if(entryType==3)
sTemp=sTemp+"\""+llList2String(input,i)+"\""; else
if(entryType==2)
sTemp=sTemp+(string)llList2Float(input,i); else
if(entryType==4)
sTemp=sTemp+(string)llList2String(input,i); else
sTemp=sTemp+(string)llList2Integer(input,i);
if(llGetListLength(input)>i+1) sTemp=sTemp+",";
}
sTemp += "]";
return sTemp;
}
</lsl>

And there we go, this will wrap and delimit a list so in most cases a JSON parser will treat the list dump as valid JSON. So, let's put them together and make a JSON object of moderate complexity:

<lsl>
default {
state_entry() {
list values = ["Red","Green","Blue"];
llOwnerSay(vsList2JSON(["beer",(key)
vsList2JSON(["Hey","You","Out","There"]),"number",34,"floater",1.232,
"EmbeddedArray",(key)vsList2JSONArray(values)]));
}
}
</lsl>

And the output we get: {"beer":{"Hey":"You","Out":"There"},"number":34,"floater":1.232000,"EmbeddedArray":["Red","Green","Blue"]}

Pop that into your favorite JSON decoder or JSON validator, nice and valid!

Basically all you have to do is preface inner calls of the *2JSON functions with a cast to (key) and the *JSON functions will not wrap the string in quotes, allowing you to construct JSON representations of arbitrary complexity.

Which brings us to the cavaets. JSON's a little finicky, and a number of the characters that could find their way into strings will make fragile JSON parsers, including Javascript interpreters, choke. If there's any chance of forward slashes, backslashes, double quotes, or Unicode characters in your JSON, it's probably wise to let llStringToBase64 wrap the string in a nice, safe encoding. Basically any language that handles JSON probably has facilities to decode base 64 for you as well.

At this point you might be excited about the prospect of serving Javascript objects from HTTP-in scripts, doing some fun stuff with callbacks, and so on. You shouldn't be. The market share leader, IE, refuses to interpret Javascript served with a text/plain content type. Most other browsers are kind enough to do so - including the SL "Media Browser," and 2.0's "Shared Media." If you're want to get mad at Microsoft (about this), don't...they're actually trying to follow standards by expecting application/javascript or application/ecmascript, and allowing text/html fallback for the benefit of nonstandard HTTP servers.

Nevertheless handy particularly for things like [https://wiki.secondlife.com/wiki/User:Kelly_Linden/lsl_hacks#Another_javascript_boot_strapping_method_.28Vegas_Silverweb.29 Shared Media(tm) (heh) hacks].

User:Vegas Silverweb/How to get the SL Time in Chatlog Format

2010-04-21T03:31:28Z

Vegas Silverweb: Created page with 'There's some pretty terrible LSL implementations out there for getting the 24 hour time as reported by Second Life. There's no reason to use a list or conditionals. This one's Go...'

There's some pretty terrible LSL implementations out there for getting the 24 hour time as reported by Second Life. There's no reason to use a list or conditionals. This one's Good.

<lsl>
string vsGetSLClock() {
integer time = (integer) llGetWallclock();
integer hours = time / 3600;
integer minutes = (time / 60) % 60 ;
return llGetSubString("0"+(string)hours,-2,-1)+":"+
llGetSubString("0"+(string)minutes,-2,-1);
}
</lsl>

User:Vegas Silverweb

2010-04-21T03:22:04Z

Vegas Silverweb:

User:Vegas Silverweb/Fastest And Probably Most Efficient Way To Reverse a List (in Mono)

2010-04-21T03:21:00Z

Vegas Silverweb: Created page with 'As Seen in Scripts <lsl> list newlist; list oldlist = ["a","b","c"]; while(oldlist !=[]) {newlist+=llList2List(oldlist,-1,-1);oldlist = llDeleteSubList(oldlist,-1,-1);} // old...'

User:Vegas Silverweb

2010-04-21T03:18:08Z

Vegas Silverweb:

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[User:Vegas_Silverweb/Fastest And Probably Most Efficient Way To Reverse a List (in Mono)]]

[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)]]

[[User:Vegas_Silverweb/LSL to JSON]]

User:Vegas Silverweb

2010-04-16T03:33:01Z

Vegas Silverweb:

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)]]

[[User:Vegas_Silverweb/LSL to JSON]]

User:Vegas Silverweb/llHTTPRequest Pro Tip(s)

2010-04-16T03:31:47Z

Vegas Silverweb: Created page with 'Pro Tip! llHTTPRequest can return null key. Means you're llHTTPRequest-ing too fast, generally. To keep it reliable, you need to do something like this: <lsl> key req; ...'

Pro Tip!

llHTTPRequest can return null key. Means you're llHTTPRequest-ing too fast, generally. To keep it reliable, you need to do something like this:

<lsl>
key req;
while(NULL_KEY == req=llHTTPRequest("http://example.com/",[],"")) {
llOwnerSay("uh oh throttle");
llSleep(5.0);

}
</lsl>

The sleep should probably be longer, perhaps 20 seconds. Even better, defer the HTTP request for 10 or 20 seconds with a timer so your event queue can be serviced while the llHTTPRequest throttle is in effect.

User:Vegas Silverweb

2010-04-16T03:31:00Z

Vegas Silverweb:

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[User:Vegas_Silverweb/llHTTPRequest Pro Tip(s)]]

LlHTTPRequest Pro Tip(s)

2010-04-16T02:05:32Z

User:Vegas Silverweb

2010-04-16T01:32:14Z

Vegas Silverweb: Created page with 'Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters. llHTTPRequest Pro Tip(s)'

Hi. This is where I keep stuff of interest, probably mostly of interest to LSL scripters.

[[llHTTPRequest Pro Tip(s)]]