Luigi's MUSHCoding 201 Class (Second Session)

The second class of four teaching intermediate MUSHCoding concepts, including local registers, application of iter() with local registers, and user-defined functions.

Author: Luigi@8BitMUSH
Category: Softcode
Features: named %q-registers.
Compatibility: PennMUSH.

MUSHCode for Luigi's MUSHCoding 201 Class (Second Session)

CLASS: MUSHCoding 201
DATE: 12/14/2002 TIME: 6 PM
DESCRIPTION: The first class of MUSHCoding 201 PART 2 ever held. Most of
it has been left in its original state, though some parts of the log were
edited to remove spam or clarify points. A '*' has been placed in front of
the speaker's name.


* Luigi says, "Very well. Let us review a little of what we talked about last week."
* Luigi says, "Iteration comes in two forms. Function, and Command."
* Luigi types --> @dolist 1 2 3=say Command Iteration ##!
* Luigi says, "Command Iteration 1!"
* Luigi says, "Command Iteration 2!"
* Luigi says, "Command Iteration 3!"
* Luigi types --> say Function Iteration: [iter(1 2 3,##)]
* Luigi says, "Function Iteration: 1 2 3"
* Luigi says, "The ## is replaced with the current text being iterated on."
* Luigi says, "You will want to use brackets for more than one command in a @Dolist, like so:"
* Luigi types --> @dolist 1 2 3={say hi;say ##}
* Luigi says, "hi"
* Luigi says, "1"
* Luigi says, "hi"
* Luigi says, "2"
* Luigi says, "hi"
* Luigi says, "3"
* Luigi says, "There is also another token which both @dolist and iter() can use. #@"
* Luigi says, "It returns the number of the iteration currently being processed."
* Luigi types --> @dolist red blue green={say ##-#@}
* Luigi says, "red-1"
* Luigi says, "blue-2"
* Luigi says, "green-3"
* Luigi says, "We also discussed Delimiters. Which are what seperates a list of words."
* Luigi says, "1 2 3 (the delimiter is a space)"
* Luigi says, "1|2|3 (the delimiter is a |)"
* Luigi says, "Now, onto today's lesson."
* Luigi says, "We are going to discuss user-defined functions, and user registers."
Rhayden oo!
* Luigi says, "First, we shall overview game registers."
* Luigi says, "Registers, known as Substitutions, are basic and used by builders to determine the appropriate pronouns to use regarding players."
XML raishes hand
* Luigi says, "For instance, someone may set the @OSUCC of an exit to: walks north, %p feet tromp as %s walks away."
XML says, "Are there only %0 %1 %2 %3 %4 %5 %6 %7 %8 and %9? Or are there more?"
* Luigi says, "There are only 10 numbered registers, but there are many more."
* Luigi says, "For instance, %n returns the name of the person who calls it."
* Luigi types --> say %n
* Luigi says, "Luigi"
XML nods.
* Luigi says, "%# returns the DBREF. %p returns 'his', 'her', or 'it' depending on the caller's @SEX."
* Luigi types --> say %# %n %p
* Luigi says, "#1000 Luigi his"
* Luigi says, "So in code, instead of using 'say', you could use @PEMIT combined with %#."
* Luigi types --> @pemit %#=Only %n(%#) is seeing this message.
* Luigi says, "In a $-Command, %# is the DBREF of the person who typed it, so you can @pemit directly to that person this way."
Phil_Laco has arrived.
Mysterious box has left.
Phil_Laco takes Mysterious box.
* Luigi says, "Everyone understand?"
Phil_Laco has left.
Rhayden nods.
XML nods.
XML says, "Hey.."
XML says, "Which should we use?"
XML says, "%n OR %#?"
Faizah prefers %#
XML says, "Is any particular one faster?"
XML says, "Or is it just a personal prefernce?"
* Luigi says, "Only use %#."
XML says, "Oh?"
* Luigi says, "If you're using @pemits. Here's why."
XML says, "Wait, I know why."
XML says, "Objects named the same thing."
XML says, "There can't be more than one dbref"
* Luigi says, "%n may be "Luigi", but if there's an object "Luigi's Puppet" in the same room, @pemit won't know which one to @pemit to."
XML says, "But many things can be named a particular thing."
XML nods.
* Luigi says, "But %n can be useful in exits and such."
* Luigi says, "Now, onward."
* Luigi says, "User-defined registers are % registers than can be set to something, and later recalled."
* Luigi says, "For instance:"
47 is the number
47 times two is 94
Illmuri has disconnected.
* Luigi types --> &test me=$test:say [setr(1,rand(50))] is the number;say %q1 times two is [mul(%q1,2)]
* Luigi types --> test
* Luigi says, "36 is the number"
* Luigi says, "36 times two is 72"
* Luigi says, "29 is the number"
* Luigi says, "29 times two is 58"
* Luigi says, "20 is the number"
* Luigi says, "20 times two is 40"
Rhayden says, "Hey, nifty."
Rhayden says, "It's like algebra."
* Luigi says, "I used the SETR() function to place the value of RAND(50) into user-register "1", and then recalled it twice with "%q1"."
* Luigi says, "The format of SETR() is: SETR(<register>,<value>)"
XML raise hand
XML says, "Can use just use 0-9?"
* Luigi says, "Yes XML?"
XML says, "Or can you use A-Z?"
* Luigi says, "%0 is different from %q0."
XML says, "No, I know."
XML says, "But can you specify more than just 0-9?"
* Luigi says, "I'm getting there, hold up."
XML nods.
Rhayden says, "Could i do setr(foobar,num(me)) ?"
* Luigi says, "The format of the register to recall it is %q<register>. So %q1 recalls "1"."
* Luigi says, "Now, let us discuss <register>."
* Luigi says, "<register> can only be 1 character in length. So "foobar" is too long."
Rhayden nods, ok.
Illmuri has connected.
* Luigi says, "It can be 0-9 on all MU* servers."
* Luigi says, "On PennMUSH and TinyBit, and in the future MUX maybe, it can be A-Z."
* Luigi says, "So.."
* Luigi types --> say [setr(1,rand(100))] [setr(A,rand(100))] [setr(Q,rand(100))] %q1 %qA %qQ
* Luigi says, "74 87 75 74 87 75"
* Luigi says, "It isn't case sensative. There is no difference between 'a' and 'A' in user-registers."
* Luigi says, "However, sometimes in normal game registers there is. %N and %n for example."
* Luigi says, "%N always capitalizes the name of the player, even if it is lowercase. Same with %P."
* Luigi says, "SETR(), or "set register", also has a brother. SETQ()."
Illmuri says, "mux uses va-vz"
* Luigi says, "No it doesn't Illmuri. Not for local-registers."
* Luigi says, "%va-%vz allows you to grab the VA-VZ attributes on an object though."
* Luigi types --> &va me=corndogs
* Luigi types --> say %va
* Luigi says, "corndogs"
Illmuri says, "oh, yeah i see"
* Luigi says, "SETR(), set register, has a brother. SETQ(). The Q most likely stands for 'quiet'."
* Luigi says, "Because it sets the register, without showing it like SETR does."
Illmuri says, "nod"
Illmuri says, "i tried it out just now"
* Luigi types --> say [setq(A,balloon)][setq(B,animals)][setq(C,rule)]%qa %qb %qc
* Luigi says, "balloon animals rule"
* Luigi says, "And if we had used SETR instead.."
* Luigi types --> say [setr(A,balloon)][setr(B,animals)][setr(C,rule)]%qa %qb %qc
* Luigi says, "balloonanimalsruleballoon animals rule"
Rhayden says, "So what is the use of using setr() then?"
* Luigi says, "Saves space sometimes."
* Luigi types --> @swi/first setr(A,rand(100))=>50,{say %qA is greater than 50.},{say %qB is less than 50.}
* Luigi says, "74 is greater than 50."
* Luigi types --> @swi/first [setq(A,rand(100))]%qA=>50,{say %qA is greater than 50.},{say %qB is less than 50.}
* Luigi says, "77 is greater than 50."
* Luigi says, "Both methods work, but the first was shorter."
* Luigi says, "User registers are very useful for storing something you might otherwise have to calculate multiple times in a function."
Rhayden NODS
Rhayden says, "I've run into that before."
* Luigi says, "Function, or a command. Sorry."
* Luigi says, "Now, we learned about ITER() last week. Let's combine both ITER() and user registers."
Shadow-Link has arrived.
Shadow-Link coughs.
* Luigi says, "I'm going to generate 100 random numbers between 1-50 first."
* Luigi types --> say iter(lnum(1,100),rand(50))
* Luigi says, "26 17 9 41 49 4 8 5 1 23 47 35 16 28 22 44 18 37 0 44 13 23 6 9 12 39 46 34 49 40 12 13 15 14 33 13 34 36 16 21 38 19 13 34 33 7 43 37 0 42 36 19 27 11 20 28 18 36 39 25 27 20 21 23 3 29 5 34 1 44 23 47 6 29 18 26 48 2 20 36 31 48 31 39 38 11 37 31 45 10 34 46 0 11 8 5 49 46 35 32"
* Luigi says, "Now, I want to add all of the numbers I generate up into a register, and then show it."
* Luigi types --> say [iter(lnum(1,100),setq(A,add(%qA,rand(50))))]%qA
* Luigi says, " 2146"
Shadow-Link says, "You beast."
Rhayden says, "Why was there all the empty space?"
Illmuri says, "thats how much link gets whipped"
Illmuri says, "cause the spaces of iter"
* Luigi says, "Notice the many spaces. That is because our Delimiter in the Iter defaulted to space, since we didn't tell it otherwise. So now I will add the 3rd and 4th arguments to get rid of the spaces, telling it we want to use nothing as the output seperator."
* Luigi says, "Note: A Delimiter given nothing will assume a space, as a delimiter can not be less than one character in length. An output seperator can be nothing, however."
Illmuri says, "thats all the spaces in between each of 50 numbers"
* Luigi types --> say [iter(lnum(1,100),setq(A,add(%qA,rand(50))),,)]%qA
* Luigi says, "2293"
* Luigi types --> say [iter(lnum(1,100),setq(A,add(%qA,rand(50))),,)]%qA
* Luigi says, "2606"
* Luigi types --> say [iter(lnum(1,100),setq(A,add(%qA,rand(50))),,)]%qA
* Luigi says, "2418"
* Luigi says, "Now that we've seen a good example of Iter() and User Registers, I should let you know that what we just did was not necessary for the following reason: LMATH()."
* Luigi types --> say lmath(add,1 2 3 4 5 6 7 8 9 10)
* Luigi says, "55"
* Luigi says, "But for the sake of example, we didn't use it."
* Luigi says, "Now, any questions before I move on?"
Rhayden says, "Nope, not really."
Faizah is fine.
Illmuri says, "what are common uses?"
* Luigi says, "In Iter()'s as I've described, and @Switches. Consider this.."
* Luigi says, "We usually @Switch on one argument, which would allow us to use #$ to grab what we switched on. But.."
Faizah will speak up if she has questions. But otherwise remain silent to keep log small.
* Luigi types --> @Switch/first [setr(1,rand(100))]|[gt(%q1,50)]=100|*,{say Arg two is equal to 100!},*|1,{say Arg two (%q1) is greater than 50.},{say Arg two (%q1) is not greater than fifty.}
* Luigi says, "Arg two (80) is greater than 50."
* Luigi says, "I put two things on the switch. By placing the random number is %q1, I was more easily able to access it later. I could have also done something like first(#$,|), but this was easier."
* Luigi says, "In more complex coding you'll probably find uses for SETR/SETQ."
Rhayden has a question
* Luigi says, "Yes?"
Rhayden says, "What are you checking against with "100|*" ?"
* Luigi says, "If the random number is equal to 100, and then a |, and then anything else. * is a wildcard."
* Luigi says, "Oh, just for a note, rand(100) will never be equal to 100, because Rand(100) returns a random number in the range of 0 to 99."
* Luigi says, "But that was my oversight."
Rhayden says, "Oh, ok, I get it now."
* Luigi says, "Now, User Defined Functions. We've played with game functions. Our first were the basic math functions if I remember correctly, ADD() and so forth."
* Luigi says, "Functions take arguments, up to 10, which are placed in the %0-%9 registers accordingly."
* Luigi says, "User-Defined Functions that is."
* Luigi says, "A quick example:"
* Luigi types --> &sum me=add(%0,%1)
* Luigi types --> say u(me/sum,10,10)
* Luigi says, "20"
* Luigi says, "The U() function, which is an alias for UFUN(), stands for User Function."
* Luigi says, "It takes an attribute, and calls it as a function. You can pass up to 10 variables to it, which will be placed in %0, %1.. up to %9."
* Luigi says, "There is no error checking for amount of arguments it takes, so.."
* Luigi types --> say u(me/sum,1,2,3)
* Luigi says, "3"
* Luigi says, "It received the third argument, "3", into %2. Even though it never did anything with it."
* Luigi says, "Questions?"
Rhayden says, "I assume the no error-checking goes the other way too?"
* Luigi says, "Hmm?"
Illmuri says, "prolly 0"
XML raises hand
Rhayden says, "As in, if my function requires three arguments and i only give it two, it just adds the first two?"
* Luigi says, "Yes XML?"
XML says, "How big can @switch/switch() es get?"
XML says, "I mean, what's the maximum size"
XML says, "?"
* Luigi says, "Right. It would just pass nothing to %2, and your user-function would try to use a blank %2."
XML says, "I mean, can you have 10, 15, 20 arguements?"
* Luigi says, "Very big, XML."
Rhayden says, "Function invocation limit is 4096, yes?"
Rhayden says, "Er, or am I thinking of function recursion limit"
* Luigi says, "I have never tested, but let's try something quickly"
(Performs a few tests)
* Luigi says, "Interesting. Well, you'll probably never reach that limit, so don't worry about it."
* Luigi says, "Now, let's try a more complex User Function."
XML saves that code for offensive purposes :)
* Luigi types --> &test me=iter(%0,##[setq(T,add(%qT,##))],,+)=%qT
* Luigi types --> say u(me/test,1 2 3)
* Luigi says, "1+2+3=6"
* Luigi types --> say u(me/test,1 2 3 4 5)
* Luigi says, "1+2+3+4+5=15"
* Luigi says, "Now, let's discuss the format of U()."
* Luigi says, "U()'s format is simply this.. U(<target>/<name of attribute>)"
* Luigi says, "Any further arguments after this are sent to the %0 to %9 registers. So up to 10 further arguments can be provided."
* Luigi says, "U(), like SETR and SETQ, has a brother."
* Luigi says, "Perhaps a sister. You can't really tell."
* Luigi says, "ULOCAL()"
* Luigi says, "The difference? User Registers (setr/setq) are passed when a U() calls an attribute. If I set something with SETQ/SETR prior to calling it, it gets passed to the attribute I call with U()."
* Luigi says, "ULOCAL() makes sure the registers effected in the user function called do NOT effect what called it, thus keeping them local."
Rhayden says, "I'm not sure I follow."
Shadow-Link says, "is V() like U()?"
Illmuri says, "u calls a function. v merely shows an attribute"
* Luigi says, "If I set %qL to something while in a "ULOCAL", it doesn't effect what called it."
* Luigi says, "But if it's a U(), it can effect it."
Illmuri says, "u does code, v just displays the code"
* Luigi types --> &red me=[ulocal(me/blue)] %qB
* Luigi types --> &blue me=setq(B,the color blue)
* Luigi types --> say u(me/red)
* Luigi says, " "
* Luigi types --> &red me=[u(me/blue)] %qB
* Luigi types --> say u(me/red)
* Luigi says, " the color blue"
Shadow-Link says, "what about "
XML says, "Yes, what -about- ""
XML ducks :)
Shadow-Link types --> &red me=[get(me/blue)] %qB
Shadow-Link says, "Shtup XML."
* Luigi says, "Link, get() doesn't evaluate what it grabs. U() does."
XML was just joking, sar.
Illmuri says, "help v() help get() help u()"
XML says, "I have to idle for a minute. If Imiss anything important, tell me."
* Luigi says, "So to summarize ULOCAL and U, if you want to use SETR/SETQ in a User Function you are calling, and don't want it to mess up any you have already set, use ULOCAL. Otherwise, use U."
Rhayden says, "Lemme get this straight"
Rhayden says, "I've got a function that sets to blue."
Rhayden says, "I've got a function that sets %qB to blue."
XML re's
Rhayden says, "If I use ulocal(), I could calculate something else using the register %qB, then call %qb and it would still say blue?"
XML nods.
XML says, "case-insensitive."
Rhayden says, "Awright, I think I got it."
* Luigi says, "Correct."
Rhayden says, "Public and private variables, for us Java programmers."
XML says, "It doesn't care about your case."
* Luigi says, "U() and ULOCAL()'s first argument, the <target>/<attribute> one, can also accept simply <attribute>. If you provide u(red) instead of u(me/red), it will default the target to the person who calls it. So it would default to you."
XML says, "Today on Oprah: MUSH functions that don't care about your case."
Rhayden says, "Public and private variables, for us Java programmers."
Rhayden says, "Whoops"
* Luigi says, "If any of you feel like a little extra reading, have a look at U's cousin, UDEFAULT(), and his great-aunt EDEFAULT(). But let's move on. I want to discuss one last topic tonight."
Shadow-Link says, "We just recently started on Java... very repetitive if you don't use loops."
* Luigi says, "The SORT() function. Which is often useful when using ITER() and such."
* Luigi says, "SORT() takes a list, which may be seperated by a Delimiter, and sorts it into an order."
* Luigi types --> say sort(9 5 3 7 10 1 13)
* Luigi says, "1 3 5 7 9 10 13"
* Luigi says, "You can provide a second argument, of a single letter, telling it how to sort it."
* Luigi says, "By providing no second argument, it tries to guess how you wanted it sorted. It usually does a good job. Options for how you can sort it include 'f' for decimal (f = floating point) values, 'a' for lexicographically, and more. See HELP SORT() for this list."
* Luigi says, "The homework for next class is going to combine all of the things we talked about today. You may want to refer to my averaging example."
* Luigi says, "I don't want you using LMATH(), though after this assignment you would probably be best to use LMATH() when possible. :)"
* Luigi says, "For the following assignment, GT() and LT() may come in handy as well. Here it is:"
* Luigi says, "PROJECT 2: Advanced Calculator (15)"
* Luigi says, "Create an object which combines registers, local functions, and"
* Luigi says, "iter() to provide the following commands: 'average <list of numbers>',"
* Luigi says, "'largest <list of numbers>' (returns the largest number), and 'sum"
* Luigi says, "<list of numbers>' (returns the total of the numbers added together)."
* Luigi says, "Also provide a command for sorting a list of decimal numbers, such as"
* Luigi says, "'sort <list of numbers>'."
* Luigi says, "And, for you overacchievers:"
* Luigi says, "EXTRA CREDIT: Calculator Extras (5 points)"
* Luigi says, "Give the calculator a command 'graphlist <list of numbers ranging from"
* Luigi says, "1 to 10>' which shows you an ASCII, ANSI or FANSI display of the list"
* Luigi says, "of numbers given to it."
Illmuri says, "ugh, not math... i got to calculus and that was enough"
* Luigi says, "HELP MATH FUNCTIONS may prove useful. GT() and LT() will be your greatest pals most likely."
Rhayden says, "Mmmm, extra credit. :)"
* Luigi says, "Don't kill yourself over the extra credit, I'm not sure if you guys are up to the level or not yet. It's just something I thought I'd throw out there and see. :)"
XML says, "When's this due?"
Illmuri says, "EC is easy"
* Luigi says, "Does anyone want to meet this Wednesday? Or shall we try next Saturday, or pass for a few weeks in light of the holidays?"
Faizah considers the extra credit... Yeah, I think I could do it. The code might be ugly, but I could do something.
XML says, "sATURDAY"
XML says, "Please... I've got a -ton- of stuff on monday, tuesday and wednesday."
Mysterious box rocks back and forth.
Illmuri says, "sat works"
Rhayden says, "Next Saturday works for me"
Faizah nods.
Illmuri says, "its not too close to holidays"
Illmuri says, "sigh"
* Luigi says, "Alright, next Saturday. Thank you everyone for showing up. My email is if you have questions."
Illmuri says, "sure we have to use iter?"
Illmuri says, "not mean()?"
* Luigi says, "Yep. Look at my example for showing the total."
* Luigi says, "Mean() won't work Illmuri, because they are providing a list of numbers."
Illmuri says, "hmm"
* Luigi says, "You can't do mean(%0). It expects Mean(1,2,3)."
Illmuri says, "oh"
Illmuri says, "thats not all that great then"
Rhayden says, "Heh, got the graph done already. :)"
* Luigi says, "And I want to be able to give it any number of numbers from say.. 2 to 100. So no massive switches. Use ITER() to do it and it'll be slick."
XML nods. Aye,
Illmuri goes home.
Illmuri has left.
Rhayden says, "I like learning to mushcode because: a.), i can do nifty things here."
XML says, "Hey now, I knewe how to mushcode before,"
XML says, "I could get it to pemit "Hi" when you typed sayhi."
* Luigi says, "In my opinion at least. I never knew how to use them until after a long time coding."
XML stands tall.
Rhayden says, "And b.) it helps me put thought into a programming format. Helps me out with other languages, like Java and such."
* Luigi says, "Heh XML"
XML says, "And The IC p... err... project is going to start he coding phase tonight."
Shadow-Link says, "I can't understand why the teacher wants use to use for loops for everything in Java."
XML says, "I can say no more unless I get authorisation."
Link has connected.