45 lines
2.1 KiB
Brainfuck
45 lines
2.1 KiB
Brainfuck
[ This program prints "Hello World!" and a newline to the screen, its
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length is 106 active command characters. [It is not the shortest.]
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This loop is an "initial comment loop", a simple way of adding a comment
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to a BF program such that you don't have to worry about any command
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characters. Any ".", ",", "+", "-", "<" and ">" characters are simply
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ignored, the "[" and "]" characters just have to be balanced. This
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loop and the commands it contains are ignored because the current cell
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defaults to a value of 0; the 0 value causes this loop to be skipped.
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]
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++++++++ Set Cell #0 to 8
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[
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>++++ Add 4 to Cell #1; this will always set Cell #1 to 4
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[ as the cell will be cleared by the loop
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>++ Add 2 to Cell #2
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>+++ Add 3 to Cell #3
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>+++ Add 3 to Cell #4
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>+ Add 1 to Cell #5
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<<<<- Decrement the loop counter in Cell #1
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] Loop till Cell #1 is zero; number of iterations is 4
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>+ Add 1 to Cell #2
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>+ Add 1 to Cell #3
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>- Subtract 1 from Cell #4
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>>+ Add 1 to Cell #6
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[<] Move back to the first zero cell you find; this will
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be Cell #1 which was cleared by the previous loop
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<- Decrement the loop Counter in Cell #0
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] Loop till Cell #0 is zero; number of iterations is 8
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The result of this is:
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Cell No : 0 1 2 3 4 5 6
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Contents: 0 0 72 104 88 32 8
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Pointer : ^
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>>. Cell #2 has value 72 which is 'H'
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>---. Subtract 3 from Cell #3 to get 101 which is 'e'
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+++++++..+++. Likewise for 'llo' from Cell #3
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>>. Cell #5 is 32 for the space
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<-. Subtract 1 from Cell #4 for 87 to give a 'W'
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<. Cell #3 was set to 'o' from the end of 'Hello'
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+++.------.--------. Cell #3 for 'rl' and 'd'
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>>+. Add 1 to Cell #5 gives us an exclamation point
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>++. And finally a newline from Cell #6
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