19 lines
689 B
D
19 lines
689 B
D
import std.stdio, std.typecons, std.algorithm, std.string, std.array;
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void turing(Sy, St)(in St state, Sy[int] tape, in int pos,
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in Tuple!(Sy, int, St)[Sy][St] rules) {
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if (state.empty) return;
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const r = rules[state][tape[pos] = tape.get(pos, Sy.init)];
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writefln("%-(%s%)", tape.keys.sort()
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.map!(i => format(i == pos ? "(%s)" : " %s ", tape[i])));
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tape[pos] = r[0];
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turing(r[2], tape, pos + r[1], rules);
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}
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void main() {
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turing("a", null, 0,
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["a": [0: tuple(1, 1, "b"), 1: tuple(1, -1, "c")],
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"b": [0: tuple(1, -1, "a"), 1: tuple(1, 1, "b")],
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"c": [0: tuple(1, -1, "b"), 1: tuple(1, 0, "")]]);
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}
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