Execute Brain****/D: Difference between revisions
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(Version 2 D updated) |
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}</lang> |
}</lang> |
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== |
===Version 2=== |
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Simpler and faster: |
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<lang d>import core.stdc.stdio |
<lang d>import core.stdc.stdio, core.stdc.stdlib; |
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import core.stdc.stdlib: exit; |
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void brainfuckRun( |
void brainfuckRun(in string code) nothrow { |
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static |
static int[int] matchBraces(in string code) pure nothrow |
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out(result) { |
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foreach (k, v; result) { |
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assert(k >=0 && k < code.length); |
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assert(v >=0 && v < code.length); |
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assert(v in result); |
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} |
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} body { |
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int[int] loops; |
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int[] loopStack; |
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foreach (i, instruction; code) { |
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if (instruction == '[') |
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loopStack ~= i; |
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else if (instruction == ']') { |
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assert(loopStack.length); |
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loops[i] = loopStack[$ - 1]; |
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loopStack.length -= 1; |
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loops[loops[i]] = i; |
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} |
} |
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} |
} |
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} |
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enum char empty = '\0'; |
enum char empty = '\0'; |
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char[30_000] tape = empty; |
char[30_000] tape = empty; |
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case '.': putchar(tape[cell]); break; |
case '.': putchar(tape[cell]); break; |
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case ',': |
case ',': |
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int c = getchar(); |
immutable int c = getchar(); |
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if (c == EOF) |
if (c == EOF) |
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exit(1); |
exit(1); |
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index = loops[index]; |
index = loops[index]; |
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break; |
break; |
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default: |
default: |
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} |
} |
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void main() { |
void main() { |
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brainfuckRun("++++++++++[>+++++++>++++++++++>+++>+<<<<-] |
brainfuckRun("++++++++++[>+++++++>++++++++++>+++>+<<<<-] |
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>++.>+.+++++++..+++.>++.<<+++++++++++++++.>. |
>++.>+.+++++++..+++.>++.<<+++++++++++++++.>. |
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+++.------.--------.>+.>."); |
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}</lang> |
}</lang> |
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Revision as of 23:52, 24 March 2012
Execute Brain****/D is an implementation of Brainf***.
Other implementations of Brainf***.
Execute Brain****/D is part of RCBF. You may find other members of RCBF at Category:RCBF.
Version 1
An implementation of Rosetta Code BrainF*ck interpreter in D.
Implement notes:
- Memory is represented by an associative array, so that negative addresses are allowed, though it is not efficient.
- Input and output are in character mode, rather than in numerical.
- Nesting level is checked during parsing, and if loops/brackets are not matched, an error is thrown before executing the code.
<lang d>import core.stdc.stdio, core.stdc.stdlib, std.file;
alias void delegate() Act;
__gshared char[int] mem; // memory __gshared int ptr; // mem pointer __gshared Act[char] cmd; // bf command except loop-control
static this() {
cmd['>'] = { if (!(++ptr in mem)) mem[ptr] = 0; }; cmd['<'] = { if (!(--ptr in mem)) mem[ptr] = 0; }; cmd['+'] = { mem[ptr]++; }; cmd['-'] = { mem[ptr]--; }; cmd['.'] = { putchar(mem[ptr]); }; cmd[','] = { int c = getc(stdin); if (c == EOF) exit(1); mem[ptr] = cast(char)c; };
}
void bf(in string code) {
int cp = 0; // code pointer int nested = 0; // nested loop level
Act bfAct() { Act[] acts; // store commands of current nesting level char cc;
while (cp < code.length) { // cc get next command and code pointer cp is advanced cc = code[cp]; cp++; switch (cc) { case '[': nested++; acts ~= bfAct(); // begin inner loop break;
case ']': nested--; if (nested < 0) throw new Exception("Unmatched Loops"); return { while (mem[ptr]) { foreach (x; acts) x(); } };
default: if (cc in cmd) acts ~= cmd[cc]; // else ignore other non-command char } }
return { foreach (x; acts) x(); }; }
// reset memory mem = null; mem[0] = 0; ptr = 0;
Act run = bfAct(); if (nested != 0) throw new Exception("Unmatched Loops"); run(); // execute the whole bf program printf("\n");
}
void main(in string[] args) {
// if no argument, demo code will be run, else the first // argument is treated as filename of bf source and executed. if (args.length > 1) { bf(readText(args[1])); } else { bf(">+++++++++[<+++++++++>-]<+.>+++[<----->-] <.-.++++.>++++++[<------>-]<--.>++++++++[ <+++++++++>-]<+.>++[<++>-]<+.>++++++++[<- -------->-]<------.>++++++[<++++++>-]<.>+ ++++[<------->-]<."); }
}</lang>
Version 2
Simpler and faster: <lang d>import core.stdc.stdio, core.stdc.stdlib;
void brainfuckRun(in string code) nothrow {
static int[int] matchBraces(in string code) pure nothrow out(result) { foreach (k, v; result) { assert(k >=0 && k < code.length); assert(v >=0 && v < code.length); assert(v in result); } } body { int[int] loops; int[] loopStack;
foreach (i, instruction; code) { if (instruction == '[') loopStack ~= i; else if (instruction == ']') { assert(loopStack.length); loops[i] = loopStack[$ - 1]; loopStack.length -= 1; loops[loops[i]] = i; } }
assert(!loopStack.length); return loops; }
static void runCode(in string code, in int[int] loops) nothrow { enum char empty = '\0'; char[30_000] tape = empty; int cell, index;
while (index < cast(int)code.length) { immutable int instruction = code[index];
switch (instruction) { case '>': cell++; assert(cell < tape.length); break; case '<': cell--; assert(cell >= 0); break; case '+': tape[cell]++; break; case '-': tape[cell]--; break; case '.': putchar(tape[cell]); break; case ',': immutable int c = getchar(); if (c == EOF) exit(1); tape[cell] = cast(char)c; break; case '[': if (tape[cell] == empty) index = loops[index]; break; case ']': if (tape[cell] != empty) index = loops[index]; break; default: break; }
index++; } }
int[int] loops = matchBraces(code); runCode(code, loops);
}
void main() {
brainfuckRun("++++++++++[>+++++++>++++++++++>+++>+<<<<-] >++.>+.+++++++..+++.>++.<<+++++++++++++++.>. +++.------.--------.>+.>.");
}</lang>
Implementation 3
Faster partially compile-time version (code generated at compile-time, run at run time): <lang d>import core.stdc.stdio, core.stdc.stdlib;
pure string ctbf(in string code) {
string r; foreach (c; code) switch (c) { case '>': r ~= "i++; assert(i < m.length);"; break; case '<': r ~= "i--; assert(i >= 0);"; break; case '+': r ~= "m[i]++;"; break; case '-': r ~= "m[i]--;"; break; case '[': r ~= "while (m[i]) {"; break; case ']': r ~= "}"; break; case '.': r ~= "putchar(m[i]);"; break; case ',': r ~= "int d = getchar(); if (d == EOF) exit(1); m[i] = cast(char)d;"; break; default: break; } return r;
}
void main() {
char[30_000] m = '\0'; size_t i; mixin(ctbf("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++ ++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>."));
}</lang>