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arpeggio-gm
Commit 6e82b6ca authored by Igor Dejanovic's avatar Igor Dejanovic
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Some PEP-8 fixes.

parent 35c767fc
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Showing with 44 additions and 33 deletions
arpeggio/__init__.py
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# -*- coding: utf-8 -*-
################################################################################
###############################################################################
# Name: arpeggio.py
# Purpose: PEG parser interpreter
# Author: Igor R. Dejanović <igor DOT dejanovic AT gmail DOT com>
# Copyright: (c) 2009 Igor R. Dejanović <igor DOT dejanovic AT gmail DOT com>
# License: MIT License
#
# This is an implementation of packrat parser interpreter based on PEG grammars.
# Grammars are defined using Python language constructs or the PEG textual
# notation.
################################################################################
# This is an implementation of packrat parser interpreter based on PEG
# grammars. Grammars are defined using Python language constructs or the PEG
# textual notation.
###############################################################################
from __future__ import print_function, unicode_literals
import re
......@@ -51,7 +51,8 @@ class NoMatch(Exception):
Args:
value (str): A name of the parsing expression or rule.
position (int): A position in the input stream where exception occurred.
position (int): A position in the input stream where exception
occurred.
parser (Parser): An instance of a parser.
"""
def __init__(self, rule, position, parser):
......@@ -177,7 +178,8 @@ class ParsingExpression(object):
result, new_pos = self.result_cache[c_pos]
parser.position = new_pos
if parser.debug:
print("** Cache hit for [{}, {}] = '{}'".format(self.name, c_pos, str(result)))
print("** Cache hit for [{}, {}] = '{}'"
.format(self.name, c_pos, str(result)))
if parser.debug:
print("<< Leaving rule {}".format(self.name))
return result
......@@ -429,12 +431,12 @@ class Match(ParsingExpression):
@property
def name(self):
return "%s(%s)" % (self.__class__.__name__, self.to_match)
def parse(self, parser):
self._parse_intro(parser)
if parser._in_parse_comment:
return self._parse(parser)
c_pos = parser.position
comments = []
......@@ -472,8 +474,8 @@ class RegExMatch(Match):
This Match class will perform input matching based on Regular Expressions.
Args:
to_match (regex string): A regular expression string to match. It will be
used to create regular expression using re.compile.
to_match (regex string): A regular expression string to match.
It will be used to create regular expression using re.compile.
'''
def __init__(self, to_match, rule=None, flags=None):
super(RegExMatch, self).__init__(rule)
......@@ -529,10 +531,10 @@ class StrMatch(Match):
def __eq__(self, other):
return self.to_match == str(other)
def __hash__(self):
return hash(self.to_match)
# HACK: Kwd class is a bit hackish. Need to find a better way to
# introduce different classes of string tokens.
......@@ -568,7 +570,8 @@ class EndOfFile(Match):
parser._nm_raise(self.name, c_pos, parser)
def EOF(): return EndOfFile()
def EOF():
return EndOfFile()
# ---------------------------------------------------------
......@@ -584,8 +587,10 @@ class ParseTreeNode(object):
Attributes:
rule (str): The name of the rule that created this node or empty
string in case this node is created by a non-root pexpression.
position (int): A position in the input stream where the match occurred.
error (bool): Is this a false parse tree node created during error recovery.
position (int): A position in the input stream where the match
occurred.
error (bool): Is this a false parse tree node created during error
recovery.
comments : A parse tree of comment(s) attached to this node.
"""
def __init__(self, rule, position, error):
......@@ -698,7 +703,8 @@ class SemanticAction(object):
def first_pass(self, parser, node, nodes):
"""
Called in the first pass of tree walk.
This is the default implementation used if no semantic action is defined.
This is the default implementation used if no semantic action is
defined.
"""
# Special case. If only one child exist return it.
if len(nodes)==1:
......@@ -720,7 +726,7 @@ class SemanticAction(object):
else:
# Return the only non-string child
retval = last_non_str
# If there is only one non-string child return
return retval
......@@ -740,7 +746,8 @@ class Parser(object):
debug (bool): If true debugging messages will be printed.
comments_model: parser model for comments.
"""
def __init__(self, skipws=True, ws=DEFAULT_WS, reduce_tree=True, debug=False):
def __init__(self, skipws=True, ws=DEFAULT_WS, reduce_tree=True,
debug=False):
self.skipws = skipws
self.ws = ws
self.reduce_tree = reduce_tree
......@@ -766,9 +773,9 @@ class Parser(object):
Creates Abstract Semantic Graph (ASG) from the parse tree.
Args:
sem_actions (dict): The semantic actions dictionary to use for semantic
analysis. Rule names are the keys and semantic action objects are
values.
sem_actions (dict): The semantic actions dictionary to use for
semantic analysis. Rule names are the keys and semantic action
objects are values.
"""
if not self.parse_tree:
raise Exception("Parse tree is empty. You did call parse(), didn't you?")
......@@ -791,20 +798,23 @@ class Parser(object):
called in the second pass.
"""
if self.debug:
print("Walking down ", node.name, " type:", type(node), "str:", str(node))
print("Walking down ", node.name, " type:",
type(node), "str:", str(node))
children = []
if isinstance(node, NonTerminal):
for n in node:
children.append(tree_walk(n))
if self.debug:
print("Visiting ", node.name, "= '", str(node), "' type:", type(node), \
print("Visiting ", node.name, "= '", str(node),
"' type:", type(node), \
"len:", len(node) if isinstance(node, list) else "")
for i, a in enumerate(children):
print ("\t%d:"%(i+1), str(a), "type:", type(a))
print ("\t%d:" % (i + 1), str(a), "type:", type(a))
if node.rule in sem_actions:
retval = sem_actions[node.rule].first_pass(self, node, children)
retval = sem_actions[node.rule].first_pass(self,
node, children)
if hasattr(sem_actions[node.rule], "second_pass"):
for_second_pass.append((node.rule, retval))
else:
......@@ -857,14 +867,14 @@ class Parser(object):
if self.input[self.line_ends[line - 1]] in '\n\r':
col -= 1
return line + 1, col + 1
def context(self, length=None, position=None):
"""
Returns current context substring, i.e. the substring around current
position.
Args:
length(int): If given used to mark with asterisk a length chars from
current position.
length(int): If given used to mark with asterisk a length chars
from the current position.
position(int): The position in the input stream.
"""
if not position:
......@@ -873,7 +883,7 @@ class Parser(object):
return "{}*{}*{}".format(
str(self.input[max(position - 10, 0):position]),
str(self.input[position:position + length]),
str(self.input[position + length:position+10]))
str(self.input[position + length:position + 10]))
else:
return "{}*{}".format(
str(self.input[max(position - 10, 0):position]),
......@@ -960,7 +970,8 @@ class ParserPython(Parser):
if isinstance(c_rule, CrossRef):
self.__cross_refs += 1
if self.debug:
print("CrossRef usage: {}".format(c_rule.rule_name))
print("CrossRef usage: {}"
.format(c_rule.rule_name))
return c_rule
# Semantic action for the rule
......@@ -977,8 +988,8 @@ class ParserPython(Parser):
# Update cache
__rule_cache[rule] = retval
if self.debug:
print("New rule: {} -> {}".format(rule,
retval.__class__.__name__))
print("New rule: {} -> {}"
.format(rule, retval.__class__.__name__))
elif isinstance(expression, Match):
retval = expression
......
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