User:Priyanka kapoor


Name: Priyanka Kapoor
Email Address:
IRC Username: priyanka
Brief Background Information:
Final year B. Tech student of Information Technology at Guru Nanak Dev Engineering College, Ludhiana, India.
Had worked on LibreCAD, BRL-CAD, C/C++ and Qt
Phone number: +91 988 890 3138

Project Information

Project Title: Multi-Naap Parser (Support for Multiple Measuring Units)

Brief Summary: This project aims to make LibreCAD supportive for various measuring system. In current status, LibreCAD draws entity in only one unit. In proposed project, it will be able to take user input for dimensions in the form of expression like one foot 12 inch. For this, at back-end, whole expression will be parsed and interpreted and then converted to unit used in LibreCAD.

Detailed Description:


I will divide the project into two parts. Firstly GUI part that will contain all necessary drop downs with various units as options to be used by the user. Secondly coding part that will do pre-parsing, interpreting and evaluating the expressions of mixed units and then passing to mu-parser.

Detailed procedure is:

1. Change the layout of dimension dialog box to add necessary drop downs.
2. Making switch cases for various symbols used for specifying measuring units.
3. Just like, if we have 1’ + 2”
4. Break the string by using arithmetic operators as delimiter and store operator in stack. Now you find symbol of units by checking ASCII code for that.
5. Compare ’ with foot symbol, if true, multiply the operand with 0.3048 (if unit used in LibreCAD is metre)
6. At end, apply all the operators stored on stack one by one on consecutive last two operands and passing on to mu-parser for further arithmetic evaluation.

Development Schedule:

Firstly reviewing the code of existing measuring units. Understanding how the expressions are passed to mu-parser for evaluation. Then I will design a pre-parser that would simplify the expression by converting mixed units to single units and passing back to mu-parser. Then comes the major part of optimizing the code and improving it to the fullest, removing all warnings and bugs if any.


Need to discuss the flowchart of working of pre-parser. All its input, processing and output.


21 April - 19 May Making work flow and to-do lists. Discussion with Mentors.

19 May - 23 June Starting with coding part implementing various symbols recognition, tyeing up with the factors to be multiplied with, re-building the expression in one unit form and then passing to mu-parser.

24 June - 15 July: Discussing with mentors any error, wrong track if any. Unit testing the code.

16 July - 23 July: Pushing the changes to LibreCAD for user testing and evaluations.

24 July - 25 July: Back up days, for any backlogs or pending tasks.

26 July - 29 July: Any pending tasks. Final go through, and preparation for final evaluation.

3 August – 9 August: Fixing bugs, implementing suggested changes, testing.

9 August – 12 August Starting documentation (using LaTeX or any other tool recommended) including developers documentation, user’s documentation.

Future work/Scope (Post GSoC):

Making it more precise in floating point conversions. It can be extended to much more units. We can make LibreCAD's own parser for evaluating mathematical expressions.

Time Availability:

I will be available 35 hours/week, if needed can spend more. No restriction of time.

Why LibreCAD?

LibreCAD is in C++ and Qt which is a source of attraction for me. Moreover LibreCAD code is much more easy to understand and Mentors are much more supportive and helpful. LibreCAD is doing wonders in 2-D CAD. Its much demandable especially for mechanical and civil. Being a Software Engineer, it would be great to help/contribute this software so that it flourish more and more.

Why me?

Programming is my passion. I have good knowledge of C++ and I love maths too. Moreover its my dream to get involve in Google Summer Of Code. Working for my dream would be a much enjoyful and enthusiastic for me. It would be great to interact and work under superior mentors. I will work hard and will surely complete the project under the super guidance of LibreCAD mentors.