--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/rasel_gem/lib/rasel.rb	Fri May 21 17:43:27 2021 +0000
@@ -0,0 +1,91 @@
+Encoding::default_internal = Encoding::default_external = "ASCII-8BIT"
+END { RubyProf::FlatPrinter.new(RubyProf.stop).print STDERR, min_percent: 1 } if ENV["PROFILE"]
+
+def RASEL source, stdout = StringIO.new, stdin = STDIN
+  lines = source.tap{ |_| fail "empty source" if _.empty? }.gsub(/ +$/,"").split(?\n)
+  code = lines.map{ |_| _.ljust(lines.map(&:size).max).bytes }
+  stack = []
+  pop = ->{ stack.pop || 0r }
+  dx, dy = 1, 0
+  x, y = -1, 0
+
+  history = {}
+  move = lambda do
+    y = (y + dy) % code.size
+    x = (x + dx) % code[y].size
+    next unless ENV.key?("DEBUG_HISTORY") && code[y][x] == 32
+    history[[x, y]] ||= 0
+    history[[x, y]] += 1
+  end
+  time = Time.now
+  thread = Thread.new do
+    loop do
+      unless Time.now < time + 1
+        time += 1
+        p history.sort_by(&:last).last(10)
+      end
+      sleep 0.1
+    end
+  end if ENV.key? "DEBUG_HISTORY"
+  if ENV["PROFILE"]
+    require "ruby-prof"
+    RubyProf.start
+  end
+
+  reverse = ->{ dy, dx = -dy, -dx }
+  stringmode = false
+  error = Proc.new{ return Struct.new(:stdout, :stack, :exitcode).new stdout, stack, 255 }
+  loop do
+    move[]
+    byte = code[y][x]
+    char = byte.chr
+    STDERR.puts [char, stringmode, (stack.last Integer ENV["DEBUG"] rescue stack)].inspect if ENV.key? "DEBUG"
+
+    next stack.push byte if stringmode && char != ?"
+    return Struct.new(:stdout, :stack, :exitcode).new stdout, stack, (
+      t = pop[]
+      1 != t.denominator || t < 0 || t > 255 ? 255 : t.to_i
+    ) if char == ?@
+    case char
+      when ?\s
+
+      when ?0..?9, ?A..?Z ; stack.push char.to_i(36).to_r
+      when ?" ; stringmode ^= true
+      when ?# ; move[]
+      when ?$ ; pop[]
+      when ?: ; stack.concat [pop[]] * 2
+      when ?- ; stack.push -(pop[] - pop[])
+      when ?\\ ; stack.concat [pop[], pop[]]
+      when ?/ ; b, a = pop[], pop[]; stack.push (b.zero? ? 0 : a / b)
+      when ?% ; b, a = pop[], pop[]; stack.push (b.zero? ? 0 : a % b)
+      when ?v ; dx, dy =  0,  1
+      when ?> ; dx, dy =  1,  0
+      when ?^ ; dx, dy =  0, -1
+      when ?< ; dx, dy = -1,  0
+      when ?? ; move[] if pop[] > 0
+      when ?a
+        t = pop[]
+        error[] if 0 > t || 1 != t.denominator
+        stack.push t.zero? ? 0 : stack[-t] || 0
+      when ?. ; stdout.print "#{_ = pop[]; 1 != _.denominator ? _.to_f : _.to_i} "
+      when ?, ; stdout.print "#{_ = pop[]; 1 != _.denominator ? error[] : _ < 0 || _ > 255 ? error[] : _.to_i.chr}"
+      when ?~ ; if _ = stdin.getbyte then stack.push _; move[] end
+      when ?&
+        getc = ->{ stdin.getc or throw nil }
+        catch nil do
+          nil until (?0..?9).include? c = getc[]
+          while (?0..?9).include? cc = stdin.getc ; c << cc end
+          stdin.ungetbyte cc if cc
+          stack.push c.to_i
+          move[]
+        end
+      when ?j
+        t = pop[]
+        error[] if 1 != t.denominator
+        y = (y + dy * t.to_i) % code.size
+        x = (x + dx * t.to_i) % code[y].size
+
+      else ; error[]
+    end
+  end
+end