Gelatin/compiler/SyntaxCompiler.py
# Copyright (c) 2010-2017 Samuel Abels
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import re
from simpleparse.dispatchprocessor import DispatchProcessor, getString, singleMap
from .Function import Function
from .Grammar import Grammar
from .SkipStatement import SkipStatement
from .WhenStatement import WhenStatement
from .MatchStatement import MatchStatement
from .MatchFieldList import MatchFieldList
from .MatchList import MatchList
from .Number import Number
from .Regex import Regex
from .String import String
from .Context import Context
"""
Indent handling:
o NEWLINE:
- If the amount of indent matches the previous line, parse the \n
and skip all indent.
- If the amount of indent does NOT match the previous line, parse
the \n and stay at the beginning of the new line to let INDENT
or DEDENT figure it out.
o INDENT: Skips all indent, then looks backward to update the indent
count. Checks to make sure that the indent was increased.
o DEDENT: Like INDENT, except it does not check for errors.
"""
class SyntaxCompiler(DispatchProcessor):
"""
Processor sub-class defining processing functions for the productions.
"""
def __init__(self):
self.context = None
def reset(self):
self.context = Context()
def _regex(self, token, buffer):
tag, left, right, sublist = token
regex = Regex()
regex.data = getString(sublist[0], buffer)
return regex
def _string(self, token, buffer):
tag, left, right, sublist = token
string = getString(sublist[0], buffer)
return String(self.context, string)
def _varname(self, token, buffer):
varname = getString(token, buffer)
return self.context.lexicon[varname]
def _number(self, token, buffer):
number = getString(token, buffer)
return Number(int(number))
def _expression(self, token, buffer):
tag = token[0]
if tag == 'string':
return self._string(token, buffer)
elif tag == 'regex':
return self._regex(token, buffer)
elif tag == 'varname':
return self._varname(token, buffer)
elif tag == 'number':
return self._number(token, buffer)
else:
raise Exception('BUG: invalid token %s' % tag)
def _match_field_list(self, token, buffer, flags):
tag, left, right, sublist = token
field_list = MatchFieldList(flags)
for field in sublist:
expression = self._expression(field, buffer)
field_list.expressions.append(expression)
return field_list
def _match_list(self, token, buffer, flags):
tag, left, right, sublist = token
matchlist = MatchList()
for field_list in sublist:
field_list = self._match_field_list(field_list, buffer, flags)
matchlist.field_lists.append(field_list)
return matchlist
def _match_stmt(self, token, buffer, flags=0):
tag, left, right, sublist = token
matcher = MatchStatement()
matcher.matchlist = self._match_list(sublist[0], buffer, flags)
matcher.statements = self._suite(sublist[1], buffer)
return matcher
def _when_stmt(self, token, buffer, flags=0):
tag, left, right, sublist = token
matcher = WhenStatement()
matcher.matchlist = self._match_list(sublist[0], buffer, flags)
matcher.statements = self._suite(sublist[1], buffer)
return matcher
def _skip_stmt(self, token, buffer):
tag, left, right, sublist = token
matcher = SkipStatement()
matcher.match = self._expression(sublist[0], buffer)
return matcher
def _function(self, token, buffer):
tag, left, right, sublist = token
function = Function()
function.name = getString(sublist[0], buffer)
if len(sublist) == 1:
return function
for arg in sublist[1][3]:
expression = self._expression(arg, buffer)
function.args.append(expression)
return function
def _inherit(self, token, buffer):
tag, left, right, sublist = token
return getString(sublist[0], buffer)
def _suite(self, token, buffer):
tag, left, right, sublist = token
statements = []
for token in sublist:
tag = token[0]
if tag == 'match_stmt':
statement = self._match_stmt(token, buffer)
elif tag == 'imatch_stmt':
statement = self._match_stmt(token, buffer, re.I)
elif tag == 'when_stmt':
statement = self._when_stmt(token, buffer)
elif tag == 'skip_stmt':
statement = self._skip_stmt(token, buffer)
elif tag == 'function':
statement = self._function(token, buffer)
else:
raise Exception('BUG: invalid token %s' % tag)
statements.append(statement)
return statements
def define_stmt(self, token, buffer):
tag, left, right, sublist = token
name_tup, value_tup = sublist
value_tag = value_tup[0]
name = getString(name_tup, buffer)
value = getString(value_tup, buffer)
if value_tag == 'regex':
value = self._regex(value_tup, buffer)
elif value_tag == 'varname':
if value not in self.context.lexicon:
_error(buffer, value_tup[1], 'no such variable')
value = self.context.lexicon[value]
else:
raise Exception('BUG: invalid token %s' % value_tag)
self.context.lexicon[name] = value
def grammar_stmt(self, token, buffer):
tag, left, right, sublist = token
map = singleMap(sublist)
grammar = Grammar()
grammar.name = getString(map['varname'], buffer)
grammar.statements = self._suite(map['suite'], buffer)
if 'inherit' in map:
grammar.inherit = self._inherit(map['inherit'], buffer)
self.context.grammars[grammar.name] = grammar