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# gzip-like LZSS compressor
# Copyright (C) 2018 Pacien TRAN-GIRARD
#
# 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/>.
type LzssNodeKind* = enum
character,
reference
type LzssNode* = object
case kind*: LzssNodeKind
of character:
character*: uint8
of reference:
length*: int
relativePos*: int
proc lzssCharacter*(value: uint8): LzssNode =
LzssNode(kind: character, character: value)
proc lzssReference*(length, relativePos: int): LzssNode =
LzssNode(kind: reference, length: length, relativePos: relativePos)
proc `==`*(a, b: LzssNode): bool =
if a.kind != b.kind: return false
case a.kind:
of character: a.character == b.character
of reference: a.length == b.length and a.relativePos == b.relativePos
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