diff options
| author | Cengiz Kaygusuz <cngkaygusuz@gmail.com> | 2017-11-20 20:46:39 -0500 |
|---|---|---|
| committer | Cengiz Kaygusuz <cngkaygusuz@gmail.com> | 2017-11-20 20:46:39 -0500 |
| commit | 27e183a78c8062ed7c2bbb91655a5e56cd697bba (patch) | |
| tree | 88fd355a0cc6da4c130582e092d702836596cbb2 /examples/ebnftest.py | |
| parent | 4ba589cf13588e90992e23deb5a9784340efd2cc (diff) | |
| download | pyparsing-git-27e183a78c8062ed7c2bbb91655a5e56cd697bba.tar.gz | |
Move src to root
Diffstat (limited to 'examples/ebnftest.py')
| -rw-r--r-- | examples/ebnftest.py | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/examples/ebnftest.py b/examples/ebnftest.py new file mode 100644 index 0000000..253404f --- /dev/null +++ b/examples/ebnftest.py @@ -0,0 +1,72 @@ +#
+# ebnftest.py
+#
+# Test script for ebnf.py
+#
+# Submitted 2004 by Seo Sanghyeon
+#
+print('Importing pyparsing...')
+from pyparsing import *
+
+print('Constructing EBNF parser with pyparsing...')
+import ebnf
+
+
+grammar = '''
+syntax = (syntax_rule), {(syntax_rule)};
+syntax_rule = meta_identifier, '=', definitions_list, ';';
+definitions_list = single_definition, {'|', single_definition};
+single_definition = syntactic_term, {',', syntactic_term};
+syntactic_term = syntactic_factor,['-', syntactic_factor];
+syntactic_factor = [integer, '*'], syntactic_primary;
+syntactic_primary = optional_sequence | repeated_sequence |
+ grouped_sequence | meta_identifier | terminal_string;
+optional_sequence = '[', definitions_list, ']';
+repeated_sequence = '{', definitions_list, '}';
+grouped_sequence = '(', definitions_list, ')';
+(*
+terminal_string = "'", character - "'", {character - "'"}, "'" |
+ '"', character - '"', {character - '"'}, '"';
+ meta_identifier = letter, {letter | digit};
+integer = digit, {digit};
+*)
+'''
+
+table = {}
+#~ table['character'] = Word(printables, exact=1)
+#~ table['letter'] = Word(alphas + '_', exact=1)
+#~ table['digit'] = Word(nums, exact=1)
+table['terminal_string'] = sglQuotedString
+table['meta_identifier'] = Word(alphas+"_", alphas+"_"+nums)
+table['integer'] = Word(nums)
+
+print('Parsing EBNF grammar with EBNF parser...')
+parsers = ebnf.parse(grammar, table)
+ebnf_parser = parsers['syntax']
+
+commentcharcount = 0
+commentlocs = set()
+def tallyCommentChars(s,l,t):
+ global commentcharcount,commentlocs
+ # only count this comment if we haven't seen it before
+ if l not in commentlocs:
+ charCount = ( len(t[0]) - len(list(filter(str.isspace, t[0]))) )
+ commentcharcount += charCount
+ commentlocs.add(l)
+ return l,t
+
+#ordinarily, these lines wouldn't be necessary, but we are doing extra stuff with the comment expression
+ebnf.ebnfComment.setParseAction( tallyCommentChars )
+ebnf_parser.ignore( ebnf.ebnfComment )
+
+print('Parsing EBNF grammar with generated EBNF parser...\n')
+parsed_chars = ebnf_parser.parseString(grammar)
+parsed_char_len = len(parsed_chars)
+
+print("],\n".join(str( parsed_chars.asList() ).split("],")))
+
+#~ grammar_length = len(grammar) - len(filter(str.isspace, grammar))-commentcharcount
+
+#~ assert parsed_char_len == grammar_length
+
+print('Ok!')
|