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# This file is part of A Boneless Datastructure Language
# Copyright (C) 2020 Soni L.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
"""[Internal] pyparsing-based Parser.
Provides `BUILT_SYNTAX`.
"""
from pyparsing import Suppress, Literal, Forward, CharsNotIn, StringEnd
from pyparsing import Combine, Optional, Group, Word, srange, Empty
from abdl import exceptions as exc
from abdl import _vm
def _err_str_esc(match_str, pos, toks):
raise exc.PatternError("Error in string escape", pos=pos, toks=toks)
def _err_str_end(match_str, pos, toks):
raise exc.PatternError("Unfinished string", pos=pos, toks=toks)
def _err_re_esc(match_str, pos, toks):
raise exc.PatternError("Error in regex escape", pos=pos, toks=toks)
def _err_re_end(match_str, pos, toks):
raise exc.PatternError("Unfinished regex", pos=pos, toks=toks)
def _err_tok(match_str, pos, toks):
raise exc.PatternError("Unexpected token", pos=pos, toks=toks)
def _build_syntax():
# pylint: disable=too-many-locals
subtree = Forward()
skippable = Optional("?", default="")
escape_char = Literal("%")
any_char = CharsNotIn("", exact=1)
str_token = Literal("'")
re_token = Literal("/")
unexpected_token = any_char.copy().setParseAction(_err_tok)
unexpected_end = StringEnd().setParseAction(_err_tok)
# TODO reformat these
unexpected_str_escape = any_char.copy().setParseAction(_err_str_esc)
str_escape = Suppress(escape_char) + (str_token | escape_char)
str_escape |= escape_char + unexpected_str_escape
str_char = (str_escape | CharsNotIn("%'"))
str_literal = (Combine(Suppress(str_token) + str_char[...]
+ (Suppress(str_token)
| StringEnd().setParseAction(_err_str_end)))
+ skippable)
str_literal.setParseAction(_vm.StringKey.action)
unexpected_re_escape = any_char.copy().setParseAction(_err_re_esc)
re_escape = Suppress(escape_char) + (re_token | escape_char)
re_escape |= escape_char + unexpected_re_escape
re_char = (re_escape | CharsNotIn("%/"))
re_literal = (Combine(Suppress(re_token) + re_char[...]
+ (Suppress(re_token)
| StringEnd().setParseAction(_err_re_end)))
+ skippable)
re_literal.setParseAction(_vm.RegexKey.action)
arrow = Literal("->")
arrow.setParseAction(_vm.Arrow.action)
identifier = Word(srange("[A-Za-z_]"), srange("[A-Za-z0-9_]"))
identifier.setParseAction(_vm.Ident.action)
parameter = (Suppress("$") + skippable + identifier)
parameter.setParseAction(_vm.Param.action)
type_ = (Suppress(":") + skippable + Suppress("$") + identifier)
type_.setParseAction(_vm.ApplyPredicate.action)
# support for objects-as-keys
keysubtree = (Suppress("[") + Group(type_[...] + subtree)
+ (Suppress("]") | unexpected_token | unexpected_end)
+ skippable)
keysubtree.setParseAction(_vm.KeySubtree.action)
# represents key matching - switches from "key" to "value"
tag = ((identifier
+ Optional(parameter | str_literal | re_literal | keysubtree)
| parameter | str_literal | re_literal | keysubtree) + type_[...]
+ Empty().setParseAction(_vm.End.action))
# multiple value matching
valuesubtree = (Suppress("(") + Group(type_[...] + subtree)
+ (Suppress(")") | unexpected_token | unexpected_end)
+ Optional("?", default=""))
valuesubtree.setParseAction(_vm.ValueSubtree.action)
# arrow and tag, value subtree
subtree <<= ((arrow + tag)[...]
+ (valuesubtree
+ Empty().setParseAction(_vm.End.action))[...])
return ((subtree | unexpected_token) + (StringEnd() | unexpected_token)).parseWithTabs()
BUILT_SYNTAX = _build_syntax()
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