added cli compiler

+import argparse, io, pkgutil, ast, types, importlib
+import zinc, zinc.compil, zinc.io.zn
+
+class ListBackends (argparse.Action) :
+    def __call__ (self, parser, namespace, values, option_string=None):
+        names = []
+        for _, name, ispkg in pkgutil.walk_packages(zinc.compil.__path__) :
+            if ispkg :
+                names.append(name)
+        names.sort()
+        width = max(len(n) for n in names)
+        for name in names :
+            try :
+                lang = zinc.compil.getlang(name)
+                print("".join([name.ljust(width + 4), lang.DESCRIPTION]))
+                for opt, (descr, default) in sorted(lang.OPTIONS.items()) :
+                    print(" ", ("--%s=%r" % (opt, default)).ljust(14), "  ", descr)
+            except :
+                pass
+        parser.exit()
+
+parser = argparse.ArgumentParser(prog="zn", description="zinc is the net compiler")
+parser.add_argument("-o", metavar="PATH", dest="output", default=None,
+                    help="output code to PATH")
+parser.add_argument("-n", metavar="NAME", dest="name", default="net",
+                    help="name of the generated module")
+parser.add_argument("-m", metavar="NAME", dest="module", default=None,
+                    help="load SOURCE as a module and use NAME as net variable")
+parser.add_argument("-l", nargs=0, action=ListBackends,
+                    help="show available backends and exit")
+parser.add_argument("source", metavar="SOURCE",
+                    help="source file for the net to compile")
+
+usage = io.StringIO()
+parser.print_usage(usage)
+parser.usage = usage.getvalue().strip() + " [--OPT=VAL ...]"
+parser.epilog = "arguments --OPT=VAL add backend specific options"
+
+args, opts = parser.parse_known_args()
+options = {}
+for o in opts :
+    if not o.startswith("--") :
+        parser.error("expected --OPT=VAL, got %r" % o)
+    try :
+        key, val = o[2:].split("=", 1)
+    except :
+        parser.error("expected --OPT=VAL, got %r" % o)
+    try :
+        options[key] = ast.literal_eval(val)
+    except :
+        options[key] = val
+
+if args.module :
+    mod = importlib.import_module(args.source)
+    net = getattr(mod, args.module)
+else :
+    try :
+        src = open(args.source)
+    except Exception as err :
+        parser.error("could not open %r (%s: %s)"
+                     % (args.source, err.__class__.__name__, err))
+    net = zinc.io.zn.load(src)
+
+net.build(name=args.name, saveto=args.output, **options)

@@ -11,11 +11,11 @@ def getlang (name) :
     module.name = name
     return module
 
-def build (lang, tree, saveto) :
+def build (lang, tree, saveto, **options) :
     if saveto is None :
         out = io.StringIO()
     elif isinstance(saveto, str) :
-        out = open(str, "w+")
+        out = open(saveto, "w+")
     else :
         try :
             saveto.write("hello world!")
@@ -31,12 +31,12 @@ def build (lang, tree, saveto) :
             raise ValueError("%r object does not have expected file-like feature"
                              % saveto.__class__.__name__)
         out = saveto
-    gen = lang.codegen.CodeGenerator(out)
+    gen = lang.codegen.CodeGenerator(out, **options)
     gen.visit(tree)
     out.flush()
     out.seek(0)
     if lang.INMEM :
-        mod = lang.build(tree, out, tree.name + lang.EXT)
+        mod = lang.build(tree, out, tree.name + lang.EXT, **options)
     elif saveto is None :
         try :
             tmp = tempfile.NamedTemporaryFile(mode="w+", suffix=lang.EXT, delete=False)

-import zinc.io.zn, sys
-from . import build, CompilationError
-
-net = zinc.io.zn.load(open(sys.argv[-1]))
-ast = net.__ast__()
-try :
-    build(net.lang, ast, None)
-except CompilationError as err :
-    print(err.message())

@@ -4,6 +4,10 @@ from zinc.compil import CompilationError, BaseDeclare
 from . import codegen as codegen
 from .rename import rename
 
+DESCRIPTION = "CoffeeScript backend (http://coffeescript.org)"
+OPTIONS = {"libpath": ("path to ZINC's CoffeeScript library", "."),
+           "main": ("whether to generate a main function", False)}
+
 NONETYPE = True
 BOOL = "Boolean"
 EXT = ".coffee"
@@ -12,7 +16,7 @@ INMEM = False
 class Declare (BaseDeclare) :
     pass
 
-def build (ast, src, name) :
+def build (ast, src, name, **options) :
     try :
         subprocess.check_output(["coffee", src], stderr=subprocess.STDOUT)
     except Exception as err :

@@ -4,6 +4,9 @@ from zinc.compil import BaseDeclare, CompilationError
 from zinc.compil.go.rename import rename
 from . import codegen
 
+DESCRIPTION = "Golang backend (http://golang.org)"
+OPTIONS = {}
+
 NONETYPE = False
 BOOL = "bool"
 EXT = ".go"
@@ -22,7 +25,7 @@ def update_gopath () :
     elif path not in os.environ["GOPATH"].split(":") :
         os.environ["GOPATH"] = ":".join([path, os.environ["GOPATH"]])
 
-def build (ast, src, name) :
+def build (ast, src, name, **options) :
     update_gopath()
     try :
         subprocess.check_output(["go", "build", src], stderr=subprocess.STDOUT)

@@ -4,6 +4,9 @@ from zinc.compil import CompilationError, BaseDeclare
 from . import codegen as codegen
 from .rename import rename
 
+DESCRIPTION = "Python backend (http://www.python.org)"
+OPTIONS = {}
+
 NONETYPE = True
 BOOL = "bool"
 EXT = ".py"
@@ -12,7 +15,7 @@ INMEM = True
 class Declare (BaseDeclare) :
     pass
 
-def build (ast, src, name) :
+def build (ast, src, name, **options) :
     if isinstance(src, str) :
         src = open(src)
     try :

@@ -98,7 +98,7 @@ class CodeGenerator (ast.CodeGenerator) :
         self.write("\n%s" % inspect.getsource(lts))
         self.write("\n%s" % inspect.getsource(main))
         self.write("\nif __name__ == '__main__':"
-                   "\n    main()")
+                   "\n    main()\n")
     def visit_DefineMarking (self, node) :
         self.fill("from zinc.nets import Marking, mset, dot, hdict")
         self.fill("event = collections.namedtuple('event', "

@@ -16,8 +16,8 @@ class PetriNet (object) :
         self._node = {}
     def __repr__ (self) :
         return "%s(%r, %r)" % (self.__class__.__name__, self.name, self.lang.name)
-    def build (self, name="net", saveto=None) :
-        return zinc.compil.build(self.lang, self.__ast__(name), saveto)
+    def build (self, name="net", saveto=None, **options) :
+        return zinc.compil.build(self.lang, self.__ast__(name), saveto, **options)
     def __ast__ (self, name="net") :
         ctx = zinc.compil.Context(net=self)
         mod = ctx.Module(name,

+#!/bin/sh
+exec python3 -m zinc.cli "$@"