Execute Brain****/Lua: Difference between revisions
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(Fixed bracket matching and made them a bit more robust.) |
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{{implementation|Brainf***}}{{collection|RCBF}} |
{{implementation|Brainf***}}{{collection|RCBF}} |
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{{incorrect|Lua|Instead of jumping to the *next* close bracket when reaching a [ and memory[pointer] == 0, it should jump to the next *matching* close bracket such that embedded loops work}} |
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An implementation of a Brainf*** interpreter in [[Lua]]. |
An implementation of a Brainf*** interpreter in [[Lua]]. |
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<lang lua>memory = {0} --memory is bounded on one side, at 1 |
<lang lua>memory = {0} --memory is bounded on one side, at 1 |
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if memory[pointer] ~= 0 then |
if memory[pointer] ~= 0 then |
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table.insert(retpoints, instruction) |
table.insert(retpoints, instruction) |
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else --if the pointer is zero, jump to the |
else -- if the memory at the pointer is zero, jump to the matching close bracket |
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local b = 1 -- b stores number of unclosed brackets (when b == 0 the match has been found) |
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| ⚫ | |||
while instruction <= #program and b ~= 0 do |
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instruction = instruction + 1 |
instruction = instruction + 1 |
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| ⚫ | |||
b = b + 1 |
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elseif program:sub(instruction, instruction) == "]" |
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b = b - 1 |
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end |
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end |
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if b ~= 0 then |
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error"Missing ']'!" |
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end |
end |
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end |
end |
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end, |
end, |
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["]"] = function() |
["]"] = function() |
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if |
if #retpoints > 0 then |
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if memory[pointer] ~= 0 then |
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instruction = retpoints[#retpoints] |
instruction = retpoints[#retpoints] |
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else |
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| ⚫ | |||
end |
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else |
else |
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error"Missing '['!" |
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| ⚫ | |||
end |
end |
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end, |
end, |
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