The DelphiDabbler.Lib.Fractions.pas unit provides a single "Advanced" record, TFraction that encapsulates a fraction and a number of operations on it.

A whole bunch of operator overloads make it straightforward to perform all the usual arithmetic operations on a fraction and to cast a TFraction to and from an integer or floating point value.

For full details of methods and operator overloads see the comprehensive online documentation. There is no help file.

DUnit tests for TFraction are included in the download.

This unit requires Delphi 2009 as a minimum and has been tested on all 32 bit Windows compilers from Delphi 2009 to Delphi XE4 and 64 bit Windows compilers from Delphi XE2 to XE4.

The Fractions Unit, documentation and test suite are supplied in a zip file. Before installing you need to extract all the files from the zip file, preserving the directory structure. The following files will be extracted:

• DelphiDabbler.Lib.Fractions.pas – Main source code.
• README.md – The unit's read-me file.
• MPL-2.txt – Mozilla Public License v2.0.
• CHANGELOG.md – The project's change log.
• Documentation.URL – Short-cut to the online documentation.

In addition to the above files you will find the DUnit tests in the Test sub-directory.

There are four possible ways to use the unit.

1. The simplest way is to add DelphiDabbler.Lib.Fractions.pas to your projects as you need it.
2. To make the unit easier to re-use you can either copy it to a folder on your Delphi search path, or add the folder containing the unit to the Delphi Search path. You then simply use the unit as required without needing to add it to your project.
3. For maximum portability you can add the unit to a Delphi package. If you need help doing this see here.
4. If you use Git you can add the ddablib/fractions GitHub repository as a Git submodule and add it to your project. Obviously, it's safer if you fork the repo and use your copy, just in case ddablib/fractions ever goes away.

A complete change log is provided in CHANGELOG.md that is included in the download.

The Fractions Unit (DelphiDabbler.Lib.Fractions.pas) is released under the terms of the Mozilla Public License v2.0.

All relevant trademarks are acknowledged.

• The information on fractions in the Mathematics Help Facility at https://mathleague.com/ was useful in writing this code.
• The GCD and LCM routines were taken from a UseNet post by Hans van Kruijssen that I found on the now defunct EFG site.
• The DecimalToFraction routine was adapted from the Turbo Pascal code presented in "Algorithm To Convert A Decimal To A Fraction" by John Kennedy, Mathematics Department, Santa Monica College, USA.
• lukas-hribik for reworking the LCM function to reduce the chance of integer overflow [issue #8].

Bugs can be reported or new features requested via the project's Issue Tracker. A GitHub account is required.

Please check if an issue has already been created for a similar report or request. If so then please add a comment containing as much information as you can to the existing issue, or if you've nothing to add, just add a 👍 (:+1:) comment. If there is no suitable existing issue then please add a new issue and give as much information as possible.

I'm Peter Johnson – a hobbyist programmer living in Ceredigion in West Wales, UK, writing mainly in Delphi. My programs and other library code are available from: https://delphidabbler.com/.

This document is copyright © 2013-2023, P D Johnson.