Execute SNUSP: Difference between revisions

=={{header|Julia}}==

This Modular SNUSP interpreter uses modular calls to echo the first 2 characters entered. Try typing "Hi" at the prompt.

<lang julia>const echo2 = raw"""

/==!/======ECHO==,==.==#

| |

$==>==@/==@/==<==#"""

@enum Direction dleft dup dright ddown

function snusp(datalength, progstring)

stack = Vector{Tuple{Int, Int, Direction}}()

data = zeros(datalength)

dp = ipx = ipy = 1

direction = dright # default to go to right at beginning

lines = split(progstring, "\n")

lmax = maximum(map(length, lines))

lines = map(x -> rpad(x, lmax), lines)

for (y, li) in enumerate(lines)

if (x = findfirst("\$", li)) != nothing

(ipx, ipy) = (x[1], y)

end

end

right() = (dp += 1)

left() = (dp -= 1; if dp < 0 running = false end)

incr() = (data[dp] += 1)

decr() = (data[dp] -= 1)

readsn() = (data[dp] = read(stdin, UInt8))

writesn() = print(Char(data[dp]))

ruld() = (d = Int(direction); d += (iseven(d) ? 3 : 5); direction = Direction(d % 4))

lurd() = (d = Int(direction); d += (iseven(d) ? 1 : -1); direction = Direction(d))

skip() = ipnext()

skipifz() = if data[dp] == 0 ipnext() end

enter() = (push!(stack, (ipx, ipy, direction)))

leave() = (if length(stack) > 0 (ipx, ipy, direction) = pop!(stack) end)

stop() = (running = false)

instruction = Dict([('>',right), ('<',left), ('+',incr), ('-',decr),

(',',readsn), ('.',writesn), ('/',ruld), ('\\',lurd), ('!',skip),

('?',skipifz), ('@',enter), ('#',leave), ('\n',stop)])

inboundsx(plus) = (plus ? (ipx < lmax) : (ipx > 1)) ? true : exit(data[dp])

inboundsy(plus) = (plus ? (ipy < length(lines)) : (ipy > 1)) ? true : exit(data[dp])

function ipnext()

if direction == dright && inboundsx(true) ipx += 1

elseif direction == dleft && inboundsx(false) ipx -= 1

elseif direction == ddown && inboundsy(true) ipy += 1

elseif direction == dup && inboundsy(false) ipy -= 1

end

end

running = true

while running && (ipx > 0) && (ipy > 0)

cmdcode = lines[ipy][ipx]

if haskey(instruction, cmdcode)

instruction[cmdcode]()

end

ipnext()

end

exit(data[dp])

end

snusp(100, echo2)</lang> {{output}} <pre>

> Hi

Hi

>

</pre>