DeadEnds

DeadEnds is a C-based genealogical software project.

Introduction

DeadEnds is a collection of libraries and command line programs that support genealogical operations.

DeadEnds is based on the UNIX-based LifeLines program, which I wrote in the early 1990s, before there were genealogical programs available for UNIX. Key features of LifeLines include:

• A B-Tree based database that stores genealogical records in Gedcom format.
• An ncurses-based user interface that provides a terminal-independent, simple windows-based interface.
• Capabilities to create, edit, merge and delete records of persons, families, sources and others. Linkages (to spouses, children, and sources) can be created, deleted and edited.
• LifeLines provides a programming subsystem that lets users write their own report generation programs.

As a followon system from LifeLines, DeadEnds has the following goals:

• Replace the LifeLines B-Tree database with an in-RAM system. When a DeadEnds based program starts up it reads a database from Gedcom files—these provide the backing store for DeadEnds. There are a number of Gedcom standards, one for syntax, and a variety for semantic variants. DeadEnds enforces only syntax standards.
• Embrace Unicode.
• Provide a clean API to genealogical operations to provide developers flexibility. I am imagining a SwiftUI interface.

Repository Structure

The home directory of the DeadEnds repository is named, unsurprisingly, DeadEnds. It contains a number of files and sub-directories. The following sub-directories hold the C code libraries.

Library	Description
Utils	Utility functions. Standard stuff.
DataTypes	Common data types, e.g. hash tables, lists, sets. Nothing specific to genealogy. Abstract data types useful in any context.
Database	In-RAM genealogical database. A database consists of record indexes and a name index. A record index maps record keys to Gedcom record roots. A name index maps name keys to lists of record keys.
Parser	The lexer and parser for the report programming language. The lexer is hand-crafted; the parser is yacc generated.
Interp	The interpreter for the report programming language. The parser builds abstract syntax trees whose nodes are PNodes (program nodes). The interpreter runs programs by interpreting these trees.
Gedcom	Gedcom library. Functions that deal with Gedcom and genealogical records constructed from trees of Gedcom nodes.

Other subdirectories include:

Directory	Description
Test	Test programs. Main programs that test the DeadEnds code base as it is developed.
Gedfiles	Gedcom files useful for testing.
Reports	Report programs useful for testing.
Docs	Documentation.