Refactoring the CLI of process, parse and generate

All list-like arguments (nargs='+' and nargs='*') are eliminated
except the file list argument of parse. The rationale behind this
change is to make the usage of the tools less error-prone by
making clear where the argument boundaries are.

README.rst

@@ -80,7 +80,7 @@ Example usage of ``grammarinator-generate``::
 
     grammarinator-generate <generator> -r <start-rule> -d <max-depth> \
     -o <output-pattern> -n <number-of-tests> \
-    -t <one-or-more-transformer>
+    -t <transformer1> -t <transformer2>
 
 **Notes**
 

grammarinator/generate.py

@@ -56,6 +56,12 @@ def import_entity(name):
             steps = name.split('.')
             return getattr(importlib.import_module('.'.join(steps[0:-1])), steps[-1])
 
+        def import_list(lst):
+            lst = lst or []
+            if isinstance(lst, str):
+                lst = json.loads(lst)
+            return [import_entity(item) for item in lst]
+
         def get_boolean(value):
             return value in ['True', True, 1]
 
@@ -83,15 +89,8 @@ def get_boolean(value):
         self.cleanup = get_boolean(cleanup)
         self.encoding = encoding
 
-        tree_transformers = tree_transformers or []
-        if isinstance(tree_transformers, str):
-            tree_transformers = json.loads(tree_transformers)
-        self.tree_transformers = [import_entity(transformer) for transformer in tree_transformers]
-
-        test_transformers = test_transformers or []
-        if isinstance(test_transformers, str):
-            test_transformers = json.loads(test_transformers)
-        self.test_transformers = [import_entity(transformer) for transformer in test_transformers]
+        self.tree_transformers = import_list(tree_transformers)
+        self.test_transformers = import_list(test_transformers)
 
     def __enter__(self):
         return self
@@ -215,17 +214,17 @@ def restricted_float(value):
         created by Grammarinator:Processor.
         """)
     # Settings for generating from grammar.
-    parser.add_argument('generator', metavar='FILE',
-                        help='reference to the generator created by grammarinator-process  (in package.module.class format).')
-    parser.add_argument('--model', default='grammarinator.model.DefaultModel',
-                        help='reference to the decision model (in package.module.class format) (default: %(default)s).')
+    parser.add_argument('generator', metavar='NAME',
+                        help='reference to the generator created by grammarinator-process (in package.module.class format).')
     parser.add_argument('-r', '--rule', metavar='NAME',
                         help='name of the rule to start generation from (default: first parser rule).')
-    parser.add_argument('-t', '--tree-transformers', metavar='LIST', nargs='+', default=[],
-                        help='list of transformers (in package.module.function format) to postprocess the generated tree '
+    parser.add_argument('-m', '--model', metavar='NAME', default='grammarinator.model.DefaultModel',
+                        help='reference to the decision model (in package.module.class format) (default: %(default)s).')
+    parser.add_argument('-t', '--tree-transformer', metavar='NAME', action='append', default=[],
+                        help='reference to a transformer (in package.module.function format) to postprocess the generated tree '
                              '(the result of these transformers will be saved into the serialized tree, e.g., variable matching).')
-    parser.add_argument('--test-transformers', metavar='LIST', nargs='+', default=[],
-                        help='list of transformers (in package.module.function format) to postprocess the generated tree '
+    parser.add_argument('--test-transformer', metavar='NAME', action='append', default=[],
+                        help='reference to a transformer (in package.module.function format) to postprocess the generated tree '
                              '(the result of these transformers will only affect test serialization but won\'t be saved to the '
                              'tree representation, e.g., space insertion).')
     parser.add_argument('-d', '--max-depth', default=inf, type=int, metavar='NUM',
@@ -277,7 +276,7 @@ def restricted_float(value):
     with Generator(generator=args.generator, rule=args.rule, out_format=args.out,
                    model=args.model, max_depth=args.max_depth, cooldown=args.cooldown,
                    population=args.population, generate=args.generate, mutate=args.mutate, recombine=args.recombine, keep_trees=args.keep_trees,
-                   tree_transformers=args.tree_transformers, test_transformers=args.test_transformers,
+                   tree_transformers=args.tree_transformer, test_transformers=args.test_transformer,
                    cleanup=False, encoding=args.encoding) as generator:
         if args.jobs > 1:
             with Pool(args.jobs) as pool:

grammarinator/parse.py

@@ -152,15 +152,15 @@ def execute():
                             compatible tree representations from them and saves them for further
                             reuse.
                             """)
-    parser.add_argument('files', nargs='+',
-                        help='input files to process.')
-    parser.add_argument('-g', '--grammars', nargs='+', metavar='FILE', required=True,
+    parser.add_argument('grammar', metavar='FILE', nargs='+',
                         help='ANTLR grammar files describing the expected format of input to parse.')
+    parser.add_argument('-i', '--input', metavar='FILE', nargs='+', required=True,
+                        help='input files to process.')
     parser.add_argument('-r', '--rule', metavar='NAME',
-                        help='name of the rule to start parsing with (default: first parser rule)')
-    parser.add_argument('-t', '--transformers', metavar='LIST', nargs='+', default=[],
-                        help='list of transformers (in package.module.function format) to postprocess the parsed tree.')
-    parser.add_argument('--hidden', nargs='+', metavar='NAME',
+                        help='name of the rule to start parsing with (default: first parser rule).')
+    parser.add_argument('-t', '--transformer', metavar='NAME', action='append', default=[],
+                        help='reference to a transformer (in package.module.function format) to postprocess the parsed tree.')
+    parser.add_argument('--hidden', metavar='NAME', action='append', default=[],
                         help='list of hidden tokens to be built into the parsed tree.')
     parser.add_argument('--encoding', metavar='ENC', default='utf-8',
                         help='input file encoding (default: %(default)s).')
@@ -179,7 +179,7 @@ def execute():
     add_version_argument(parser)
     args = parser.parse_args()
 
-    for grammar in args.grammars:
+    for grammar in args.grammar:
         if not exists(grammar):
             parser.error('{grammar} does not exist.'.format(grammar=grammar))
 
@@ -191,7 +191,7 @@ def execute():
     process_sys_recursion_limit_argument(args)
     process_antlr_argument(args)
 
-    with ParserFactory(grammars=args.grammars, hidden=args.hidden, transformers=args.transformers, parser_dir=args.parser_dir, antlr=args.antlr,
+    with ParserFactory(grammars=args.grammar, hidden=args.hidden, transformers=args.transformer, parser_dir=args.parser_dir, antlr=args.antlr,
                        max_depth=args.max_depth, cleanup=args.cleanup) as factory:
         if args.jobs > 1:
             with Pool(args.jobs) as pool:

grammarinator/process.py

@@ -630,7 +630,7 @@ def execute():
         creates a fuzzer that can generate randomized content conforming to
         the format described by the grammar.
         """)
-    parser.add_argument('grammars', nargs='+', metavar='FILE',
+    parser.add_argument('grammar', metavar='FILE', nargs='+',
                         help='ANTLR grammar files describing the expected format to generate.')
     parser.add_argument('--no-actions', dest='actions', default=True, action='store_false',
                         help='do not process inline actions.')
@@ -648,14 +648,14 @@ def execute():
     add_version_argument(parser)
     args = parser.parse_args()
 
-    for grammar in args.grammars:
+    for grammar in args.grammar:
         if not exists(grammar):
             parser.error('{grammar} does not exist.'.format(grammar=grammar))
 
     process_log_level_argument(args)
     process_antlr_argument(args)
 
-    FuzzerFactory(args.out, args.antlr).generate_fuzzer(args.grammars, encoding=args.encoding, lib_dir=args.lib, actions=args.actions, pep8=args.pep8)
+    FuzzerFactory(args.out, args.antlr).generate_fuzzer(args.grammar, encoding=args.encoding, lib_dir=args.lib, actions=args.actions, pep8=args.pep8)
 
     if args.cleanup:
         rmtree(join(args.out, 'antlr'), ignore_errors=True)