add `--verbose` option & make warnings comments

fixup! make warnings comments

lark/tools/__init__.py

@@ -1,9 +1,16 @@
 import sys
 from argparse import ArgumentParser, FileType
-from lark import Lark
+try:
+    from textwrap import indent
+except ImportError:
+    def indent(text, prefix):
+        return ''.join(prefix + line for line in text.splitlines(True))
+from logging import DEBUG, INFO, WARN, ERROR
+import warnings
 
-base_argparser = ArgumentParser(add_help=False, epilog='Look at the Lark documentation for more info on the options')
+from lark import Lark, logger
 
+lalr_argparser = ArgumentParser(add_help=False, epilog='Look at the Lark documentation for more info on the options')
 
 flags = [
     ('d', 'debug'),
@@ -16,22 +23,43 @@ flags = [
 
 options = ['start', 'lexer']
 
-base_argparser.add_argument('-s', '--start', action='append', default=[])
-base_argparser.add_argument('-l', '--lexer', default='contextual', choices=('standard', 'contextual'))
-k = {'encoding':'utf-8'} if sys.version_info > (3, 4) else {}
-base_argparser.add_argument('-o', '--out', type=FileType('w', **k), default=sys.stdout, help='the output file (default=stdout)')
-base_argparser.add_argument('grammar_file', type=FileType('r', **k), help='A valid .lark file')
+lalr_argparser.add_argument('-v', '--verbose', action='count', default=0, help="Increase Logger output level, up to three times")
+lalr_argparser.add_argument('-s', '--start', action='append', default=[])
+lalr_argparser.add_argument('-l', '--lexer', default='contextual', choices=('standard', 'contextual'))
+k = {'encoding': 'utf-8'} if sys.version_info > (3, 4) else {}
+lalr_argparser.add_argument('-o', '--out', type=FileType('w', **k), default=sys.stdout, help='the output file (default=stdout)')
+lalr_argparser.add_argument('grammar_file', type=FileType('r', **k), help='A valid .lark file')
 
 for f in flags:
     if isinstance(f, tuple):
         options.append(f[1])
-        base_argparser.add_argument('-' + f[0], '--' + f[1], action='store_true')
+        lalr_argparser.add_argument('-' + f[0], '--' + f[1], action='store_true')
     else:
         options.append(f)
-        base_argparser.add_argument('--' + f, action='store_true')
+        lalr_argparser.add_argument('--' + f, action='store_true')
+
 
 def build_lalr(namespace):
+    logger.setLevel((ERROR, WARN, INFO, DEBUG)[min(namespace.verbose, 3)])
     if len(namespace.start) == 0:
         namespace.start.append('start')
     kwargs = {n: getattr(namespace, n) for n in options}
-    return Lark(namespace.grammar_file, parser='lalr', **kwargs), namespace.out
+    return Lark(namespace.grammar_file, parser='lalr', **kwargs), namespace.out
+
+
+def showwarning_as_comment(message, category, filename, lineno, file=None, line=None):
+    # Based on warnings._showwarnmsg_impl
+    text = warnings.formatwarning(message, category, filename, lineno, line)
+    text = indent(text, '# ')
+    if file is None:
+        file = sys.stderr
+        if file is None:
+            return 
+    try:
+        file.write(text)
+    except OSError:
+        pass
+
+
+def make_warnings_comments():
+    warnings.showwarning = showwarning_as_comment

lark/tools/serialize.py

@@ -5,11 +5,11 @@ import json
 from lark import Lark
 from lark.grammar import RuleOptions, Rule
 from lark.lexer import TerminalDef
-from lark.tools import base_argparser, build_lalr
+from lark.tools import lalr_argparser, build_lalr
 
 import argparse
 
-argparser = argparse.ArgumentParser(prog='python -m lark.tools.serialize', parents=[base_argparser],
+argparser = argparse.ArgumentParser(prog='python -m lark.tools.serialize', parents=[lalr_argparser],
                                     description="Lark Serialization Tool - Stores Lark's internal state & LALR analysis as a JSON file",
                                     epilog='Look at the Lark documentation for more info on the options')
 

lark/tools/standalone.py

@@ -40,7 +40,7 @@ from warnings import warn
 
 import lark
 from lark import Lark
-from lark.tools import base_argparser, build_lalr
+from lark.tools import lalr_argparser, build_lalr, make_warnings_comments
 
 
 from lark.grammar import RuleOptions, Rule
@@ -157,8 +157,9 @@ def gen_standalone(lark_inst, output=None, out=sys.stdout):
 
 
 if __name__ == '__main__':
+    make_warnings_comments()
     parser = ArgumentParser(prog="prog='python -m lark.tools.standalone'", description="Lark Stand-alone Generator Tool",
-                            parents=[base_argparser], epilog='Look at the Lark documentation for more info on the options')
+                            parents=[lalr_argparser], epilog='Look at the Lark documentation for more info on the options')
     parser.add_argument("old_start", nargs='?', help=SUPPRESS)
     ns = parser.parse_args()
     if ns.old_start is not None: