September Morn Update

Task/Execute-SNUSP/Julia/execute-snusp.julia

@@ -0,0 +1,55 @@
+const echo2 =  raw"""
+       /==!/======ECHO==,==.==#
+       |   |
+$==>==@/==@/==<==#"""
+
+@enum Direction left up right down
+
+function snusp(datalength, progstring)
+    stack = Vector{Tuple{Int, Int, Direction}}()
+    data = zeros(datalength)
+    dp = ipx = ipy = 1
+    direction = right    # 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
+
+    instruction = Dict([('>', ()-> dp += 1),
+        ('<', ()-> (dp -= 1; if dp < 0 running = false end)), ('+', ()-> data[dp] += 1),
+        ('-', ()-> data[dp] -= 1), (',', ()-> (data[dp] = read(stdin, UInt8))),
+        ('.', ()->print(Char(data[dp]))),
+        ('/', ()-> (d = Int(direction); d += (iseven(d) ? 3 : 5); direction = Direction(d % 4))),
+        ('\\', ()-> (d = Int(direction); d += (iseven(d) ? 1 : -1); direction = Direction(d))),
+        ('!', () -> ipnext()), ('?', ()-> if data[dp] == 0 ipnext() end),
+        ('@', ()-> push!(stack, (ipx, ipy, direction))),
+        ('#', ()-> if length(stack) > 0 (ipx, ipy, direction) = pop!(stack) end),
+        ('\n', ()-> (running = false))])
+
+    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 == right && inboundsx(true)     ipx += 1
+        elseif direction == left && inboundsx(false) ipx -= 1
+        elseif direction == down && inboundsy(true)  ipy += 1
+        elseif direction == up && inboundsy(false)   ipy -= 1
+        end
+    end
+
+    running = true
+    while running
+        cmdcode = lines[ipy][ipx]
+        if haskey(instruction, cmdcode)
+            instruction[cmdcode]()
+        end
+        ipnext()
+    end
+    exit(data[dp])
+end
+
+snusp(100, echo2)