This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
This compiles an assembly-like programming language, and runs it. Unlike most assembly code, which is fast, this is very, very, slow. You can't do anything you couldn't do in a tenth the number of lines of LSL, so there are no advantages to using it (besides having fun).
Most of the things I did are really bizarre, and I did it for the sole reason of trying to do something amusing.
I'll try to explain quickly...
There are three registers, 0, 1, and 2. You can save values to 0 and 1. After functions are ran, they put the result into registry 2.
Below are a list of functions.
st0 - Stores the value to registry 0. st1 - Stores the value to registry 1. ty0 - Sets the type of registry 0, "str", "int" or "flo". ty1 - Sets the type of registry 1, "str", "int" or "flo". sv0 - Saves registry 0 to the memory address specified. sv1 - Saves registry 0 to the memory address specified. sv2 - Saves registry 0 to the memory address specified. ld0 - Load the data from the memory address into registry 0. ld1 - Load the data from the memory address into registry 1. jmp - Jump to a line number. jil - Jump to a line number if registry 0 is less than registry 1. jle - Jump to a line number if registry 0 is less than or equal to registry 1. jie - Jump to a line number if registry 0 is equal to registry 1. add - Adds registry 0 and 1, and stores the value into registry 2. sub - Subtracts registry 0 and 1, and stores the value into registry 2. say - Says registry 1 out loud. inp - Waits for user input (chat). rnd - Generates a random number between registry 0 and 1 (inclusive). rem - Comment.
One thing I didn't realize until after I wrote the compiler-type-thing, is that if you use negative numbers as the memory address to save the registries to, you can overwrite the program. This means you can make a self-modifying program fairly easily. You can also read lines of the program by loading a negative number. This works because I load the program into a list, and the variables go after the list, so -1 is the last line of the program, -2 is the second-to-last, etc.
Create a box, and drop this script in it. Then create a note called "prog" and write the program in it. Some example programs follow this script.
list memory;
integer lastProgLine;
string reg0;
string type0;
string reg1;
string type1;
string reg2;
string type2;
integer lstn;
integer i;
err(integer li, string s) {
llOwnerSay("Error on line " + (string)li + ": " + s);
llResetScript();
}
save(string val, integer loc) {
integer add = lastProgLine + (integer)loc;
if (add < llGetListLength(memory)) {
memory = llListReplaceList(memory, [val], add, add);
} else {
integer i = 0;
while (i < add-llGetListLength(memory)) {
memory += "";
i++;
}
memory += val;
}
}
default {
touch_start(integer a) {
llGetNotecardLine("Prog", lastProgLine);
}
changed(integer a) {
if (a & CHANGED_INVENTORY) {
llResetScript();
}
}
dataserver(key qid, string data) {
if (data == EOF) {
state run;
}
memory += data;
llGetNotecardLine("Prog", (lastProgLine += 1));
}
}
state run {
changed(integer a) {
if (a & CHANGED_INVENTORY) {
llResetScript();
}
}
state_entry() {
i = 0;
llSetTimerEvent(.001);
}
timer() {
if (i >= lastProgLine) {
llResetScript();
}
string l = llList2String(memory, i);
string command;
string action;
if (llSubStringIndex(l, " ") != -1) {
list line = [llGetSubString(l, 0, llSubStringIndex(l, " ")-1), llGetSubString(l, llSubStringIndex(l, " ")+1, -1)];
command = llList2String(line, 0);
action = llList2String(line, 1);
} else {
command = l;
}
if (command == "ty0") {
if (!(action == "str" || action == "int" || action == "flo")) {
err(i, "Invalid registry type.");
}
type0 = action;
} else if (command == "ty1") {
if (!(action == "str" || action == "int")) {
err(i, "Invalid registry type.");
}
type1 = action;
} else if (command == "ty2") {
err(i, "Registry two can not be set.");
} else if (command == "st0") {
if (type0 == "") {
err(i, "Registry type has not been defined.");
}
reg0 = action;
} else if (command == "st1") {
if (type1 == "") {
err(i, "Registry type has not been defined.");
}
reg1 = action;
} else if (command == "st2") {
err(i, "Registry two can not be set.");
} else if (command == "jmp") {
i = (integer)action - 1;
} else if (command == "jil") {
if (type0 == "str" || type1 == "str") {
err(i, "Registries may not be of type str to compare.");
}
if ((float)reg0 < (float)reg1)
i = (integer)action - 1;
} else if (command == "jle") {
if (type0 == "str" || type1 == "str") {
err(i, "Registries may not be of type str to compare.");
}
if ((float)reg0 <= (float)reg1)
i = (integer)action - 1;
} else if (command == "jie") {
if (type0 == type1) {
if (reg0 == reg1)
i = (integer)action - 1;
}
} else if (command == "add") {
if (type0 == "str" || type1 == "str") {
type2 = "str";
reg2 = reg0 + reg1;
} else if (type0 == "int" && type1 == "int") {
type2 = "int";
reg2 = (string)((integer)reg0 + (integer)reg1);
} else if (type0 == "flo" && type1 == "flo") {
type2 = "int";
reg2 = (string)((float)reg0 + (float)reg1);
} else if (type0 == "flo" && type1 == "int") {
type2 = "int";
reg2 = (string)((float)reg0 + (integer)reg1);
} else if (type0 == "int" && type1 == "flo") {
type2 = "int";
reg2 = (string)((integer)reg0 + (float)reg1);
} else {
err(i, "Registry type mismatch or invalid.");
}
} else if (command == "sub") {
if (type0 == "int" && type1 == "int") {
type2 = "int";
reg2 = (string)((integer)reg0 - (integer)reg1);
} else {
err(i, "Registry type mismatch or invalid.");
}
} else if (command == "ld0") {
if (type0 == "") {
err(i, "Registry type has not been defined.");
}
reg0 = llList2String(memory, lastProgLine + (integer)action);
} else if (command == "ld1") {
if (type1 == "") {
err(i, "Registry type has not been defined.");
}
reg1 = llList2String(memory, lastProgLine + (integer)action);
} else if (command == "ld2") {
err(i, "Cannot load data into registry two.");
} else if (command == "sv0") {
save(reg0, (integer)action);
} else if (command == "sv1") {
save(reg1, (integer)action);
} else if (command == "sv2") {
save(reg2, (integer)action);
} else if (command == "say") {
llSay(0, reg0);
} else if (command == "inp") {
llSetTimerEvent(0);
lstn = llListen(0, "", "", "");
} else if (command == "rnd") {
if (type0 == "float" || type1 == "float") {
type2 = "flo";
reg2 = (string)(llFrand((float)reg1-(float)reg0)+(float)reg0);
} else if (type1 == "int" && type0 == "int") {
type2 = "int";
reg2 = (string)((integer)llFrand((float)reg1-(float)reg0+1)+(integer)reg0);
}
} else if (command == "rem") {
} else {
err(i, "Invalid command '" + command + "'.");
}
i++;
}
listen(integer i, string n, key id, string m) {
llListenRemove(lstn);
type2 = "str";
reg2 = m;
llSetTimerEvent(.0001);
}
}
Some example programs...
Guess the number
ty0 str ty1 str st0 This is a demo of the assembly-like programming language by Xaviar Czervik. say st0 This is an examle guess-the-number game. say ty0 int ty1 int st0 0 st1 100 sv0 0 sv1 1 ty0 str ty1 str st0 I am thinking of a number between ld1 0 add sv2 2 ld0 2 st1 and add sv2 2 ld0 2 ld1 1 add sv2 2 ld0 2 st1 . Guess what it is. add sv2 2 ld0 2 say ty0 int ty1 int ld0 0 ld1 1 rnd sv2 3 st0 1 sv0 4 ty0 str st0 sv0 5 inp ty0 int ty1 int sv2 5 ld0 3 ld1 5 jie 97 jle 74 ty0 str ty1 str ld0 5 st1 is too low. Guess again. You are on guess # add sv2 6 ty0 int ty1 int ld0 4 st1 1 add sv2 4 ty0 str ty1 str ld0 6 ld1 4 add sv2 6 ld0 6 st1 . add say jmp 40 ty0 str ty1 str ld0 5 st1 is too high. Guess again. You are on guess # add sv2 6 ty0 int ty1 int ld0 4 st1 1 add sv2 4 ty0 str ty1 str ld0 6 ld1 4 add sv2 6 ld0 6 st1 . add say jmp 40 ty0 str ty1 str ld0 5 st1 is correct! It took you add sv2 6 ty0 int ty1 int ld0 4 st1 1 add sv2 4 ty0 str ty1 str ld0 6 ld1 4 add sv2 6 ld0 6 st1 guesses to get my number. add sv2 7 ld0 7 say
Hello world (of sorts)
ty0 int st0 0 ty1 int st1 5 jle 6 jmp 100 sv0 0 ty0 str st0 Hello World. On line: ld1 0 add sv2 1 ld0 1 say ty0 int ld0 0 ty1 int st0 1 add sv2 2 ld0 2 jmp 2
Get user input
ty0 int st0 0 ty1 int st1 3 jle 6 jmp 100 sv0 0 ty0 str st0 Please say something. say inp sv2 1 ty1 str ld1 1 st0 You said: " add sv2 2 ld0 2 st1 " on input number add sv2 2 ld0 2 ld1 0 add sv2 2 ld0 2 st1 . add sv2 2 ld0 2 say ty0 int ld0 0 ty1 int st1 1 add sv2 3 ld0 3 jmp 2