Porting to Python 3 and adding a few tests.

README

@@ -1,32 +0,0 @@
-Horrlang is an esoteric language, you should not try it.
-
-In Horrlang, memory and instructions are mixed, so you can use old instructions
-as new memory places, or do some metaprogramming rewriting your code as it runs.
-
-Just like in LISP but ... without lists ... good luck ...
-
-In Horrlang you have basically 2 pointers, a memory one and an instruction
-one. Both start at 0. The instruction one follows instructions that can move
-the memory pointer. Have a look at the instruction set :
-
-Instruction set :
-
-Lx : Move memory pointer left x chars (defaults to 1).
-Rx : Move memory pointer right x chars (defaults to 1).
-
-Nx : Goto the next char that is x with the instruction pointer.
-Px : Goto the prev char that is x with the instruction pointer.
-O  : Output current value under memory pointer.
-I  : Write from stdin to the current memory pointer.
-K  : Decrement the value under the current memory pointer.
-H  : Increment the value under the current memory pointer.
-Jx : Jump with the instruction pointer to the previous 'x' char if the value under the current memory pointer != 0. (Jumps to the beginning if no 'x' char is found)
-
-The Hello World :
-R9R9R9R4OROROROROROROROROROROROHello World.
-
-Writing a serie of P should like :
-R5OP5P or R3OP3
-
-Write 123456789 using a loop :
-R9R3:ROHLKJ:81

README.md

@@ -0,0 +1,38 @@
+# Horrlang is an esoteric language, you should not try it.
+
+In Horrlang, memory and instructions are mixed, so you can use old instructions
+as new memory places, or do some metaprogramming rewriting your code as it runs.
+
+Just like in LISP but ... without lists ... good luck ...
+
+In Horrlang you have basically 2 pointers, a memory one and an instruction
+one. Both start at 0. The instruction one follows instructions that can move
+the memory pointer. Have a look at the instruction set:
+
+Instruction set:
+
+- Lx: `left`: Move memory pointer on the left for `x` chars (defaults to `1`).
+- Rx: `right`: Move memory pointer on the right for `x` chars (defaults to `1`).
+- Nx: `next`: Forward Jump: Move execution pointer to the first found `x` on the left of its current position.
+- Px: `prev`: Backward Jump: Move execution pointer to the first found `x` on the right of its current position.
+- O: `output`: Copy the current value under memory pointer to stdout.
+- I: `input`: Copy from stdin to the current memory pointer.
+- K: Decrement the value under the current memory pointer.
+- H: Increment the value under the current memory pointer.
+- Jx: `jump` If the value under the current memory pointer is not `0` (0x30): Move the instruction pointer to the previous `x` instruction (like `Px`). (Jumps to the beginning if no `x` char is found).
+
+The Hello World:
+
+    python horrlang.py 'R9R9R9R4OROROROROROROROROROROROHello World.'
+
+Or:
+
+    python horrlang.py 'Hello World0KORJK'
+
+Writing a infinite serie of P:
+
+    R5OP5P or R3OP3
+
+Write 123456789 using a loop:
+
+    R9R3:ROHLKJ:81

horrlang.py

@@ -1,32 +1,17 @@
 #!/usr/bin/env python
-# -*- coding: utf-8 -*-
+"""Horrlang Interpreter."""
 
 import sys
-
-class InfiniteArray:
-    def __init__(self, values=None):
-        self.chunks = {}
-        if values is not None:
-            for key, value in enumerate(values):
-                self[key] = value
-
-    def get_chunk(self, index):
-        if index not in self.chunks:
-            self.chunks[index] = [0 for i in xrange(4096)]
-        return self.chunks[index]
-
-    def __getitem__(self, index):
-        return self.get_chunk(index / 4096)[index % 4096]
-
-    def __setitem__(self, index, value):
-        self.get_chunk(index / 4096)[index % 4096] = value
+import io
+from collections import defaultdict
 
 
 class Machine:
-    def __init__(self, code, read, write, max_cycles=None):
+    def __init__(self, code, read=sys.stdin.read, write=sys.stdout.write, max_cycles=None):
         self.read = read
         self.write = write
-        self.mem = InfiniteArray([ord(char) for char in code])
+        self.mem = defaultdict(int)
+        self.mem.update({i: ord(char) for i, char in enumerate(code)})
         self.exc_ptr = 0
         self.mem_ptr = 0
         self.max_cycles = max_cycles
@@ -41,34 +26,37 @@ class Machine:
 
     def get_integer(self):
         parameter = 0
-        while chr(self.mem[self.exc_ptr + 1]) >= '0' \
-                and chr(self.mem[self.exc_ptr + 1]) <= '9':
+        while self.mem[self.exc_ptr + 1] >= 0x30 and self.mem[self.exc_ptr + 1] <= 0x39:
             self.exc_ptr += 1
             if not self.cycle():
                 return parameter
-            parameter = parameter * 10 + (self.mem[self.exc_ptr] \
-                                              - ord('0'))
+            parameter = parameter * 10 + (self.mem[self.exc_ptr] - ord("0"))
         if parameter == 0:
             parameter = 1
         return parameter
 
     def L(self):
+        """Move memory pointer to the left."""
         self.mem_ptr -= self.get_integer()
         if self.mem_ptr < 0:
             self.mem_ptr = 0
 
     def R(self):
+        """Move memory pointer to the right."""
         self.mem_ptr += self.get_integer()
 
     def O(self):
+        """Output."""
         char = self.mem[self.mem_ptr]
-        if char > 0 and char < 256:
+        if 0 < char < 256:
             self.write(chr(char))
 
     def I(self):
+        """Input."""
         self.mem[self.mem_ptr] = ord(self.read(1))
 
     def N(self):
+        """Forward jump."""
         self.exc_ptr += 1
         search = self.mem[self.exc_ptr]
         while self.mem[self.exc_ptr] != search:
@@ -77,6 +65,7 @@ class Machine:
                 return
 
     def P(self):
+        """Backward jump."""
         search = self.mem[self.exc_ptr + 1]
         self.exc_ptr -= 1
         while self.mem[self.exc_ptr] != search:
@@ -85,7 +74,8 @@ class Machine:
                 return
 
     def J(self):
-        if self.mem[self.mem_ptr] != ord('0'):
+        """Conditional jump."""
+        if self.mem[self.mem_ptr] != ord("0"):
             search = self.mem[self.exc_ptr + 1]
             self.exc_ptr -= 1
             while self.mem[self.exc_ptr] != search:
@@ -94,26 +84,70 @@ class Machine:
                     return
 
     def H(self):
+        """Increment."""
         self.mem[self.mem_ptr] = self.mem[self.mem_ptr] + 1
 
     def K(self):
+        """Decrement."""
         self.mem[self.mem_ptr] = self.mem[self.mem_ptr] - 1
 
+    def _debug(self):
+        print(f"# Cycle {self.cycles}\n")
+        for i, value in sorted(self.mem.items()):
+            marker = ""
+            if i == self.exc_ptr:
+                marker += "← exc ptr"
+                control = chr(self.mem[self.exc_ptr])
+                if hasattr(self, control):
+                    marker += " (" + getattr(self, control).__doc__ + ")"
+            if i == self.mem_ptr:
+                marker += "← mem ptr"
+            printable = ""
+            if chr(value).isprintable():
+                printable = f"{chr(value)}"
+            print(f"{i:3d} | {value:5d} | {printable:5s}", marker)
+        print()
+
     def run(self, debug=False):
         while True:
             if self.mem[self.exc_ptr] == 0:
                 return
             char = self.mem[self.exc_ptr]
-            if char > 0 and char < 256:
+            if 0 < char < 256:
                 control = chr(char)
                 if debug:
-                    print control
+                    self._debug()
                 if hasattr(self, control):
                     getattr(self, control)()
             self.exc_ptr += 1
             if not self.cycle():
                 return
 
-if __name__ == "__main__":
-    Machine(sys.argv[1], sys.stdin.read, sys.stdout.write,
-            int(sys.argv[2]) if len(sys.argv) > 2 else None).run()
+
+def eval(instructions, input="", max_cycles=None):
+    """Convenience, non-interactive wrapper around HorrlangMachine."""
+    stdin = io.StringIO(input)
+    stdout = io.StringIO()
+    machine = Machine(instructions, stdin.read, stdout.write, max_cycles=max_cycles)
+    machine.run()
+    return stdout.getvalue()
+
+
+import argparse
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("code", type=str)
+    parser.add_argument("--debug", action="store_true")
+    parser.add_argument("--max-cycles", type=int, default=None)
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+    Machine(args.code, max_cycles=args.max_cycles,).run(debug=args.debug)
+
+
+if __name__ == '__main__':
+    main()

test_horrlang.py

@@ -0,0 +1,21 @@
+from horrlang import eval
+
+
+def test_hello_world():
+    assert eval("R9R9R9R4OROROROROROROROROROROROHello World.") == "Hello World."
+
+
+def test_short_hello_world():
+    assert eval("Hello World0KORJK") == "Hello World"
+
+
+def test_from_readme():
+    assert eval("R5OP5P", max_cycles=100) == "PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP"
+
+
+def test_from_readme_short():
+    assert eval("R3OP3", max_cycles=100) == "PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP"
+
+
+def test_123456789():
+    assert eval("R9R3:ROHLKJ:91") == "123456789"