Skip to main content

ParseGen - parser generator for FPC

ParseGen is rule driven, parser generator for FPC / Lazarus. ParseGen is design using FPC, FCL and Lazarus and it mainly supports for Windows and Linux operating systems.

ParserGen scanner is slight DFA (deterministic finite automaton) state machine. This scanner can operate on case sensitive or case-insensitive modes and it can easily configure/extend through given class structure. The parser of the ParseGen is recursive descent parser. ParseGen generate this parser using high-level source language and this language is logically similar to EBNF grammar. For example, in ParseGen, definition for "term" and "expression" can be written like this:

define: expression

  optional: "-","+"
  end       

  term       
  loop: "-","+"
    term
  end
 

end

define: term

  factor
  loop: "*","/"
    factor
  end
 
end

This parser generator is mainly design for  FPC / Lazarus, but it can use with Delphi with some minor changes. ParseGen is an open source software project and it is based on GNU General Public License version 3.

Most of the sample scripts and demo applications of this project are based on Niklaus Writh's Algorithms + Data Structures = Programs book and PL/0 programming language. In demo project we implement Writh's PL/0 parser using ParseGen and it is available in main project bundle.

ParseGen is available to download at github.com/dilshan/parsegen and documentation for source language is available in here.

Comments

Popular posts from this blog

CD2003 - yet another simple FM radio receiver

In the last few days, we are looking for some simple FM radio receiver to integrate into one of our ongoing projects. For that, we try several FM radio receiver ICs including TDA7000, CD2003/TA2003/TA8164, CXA1019, and KA22429. Out of all those chips we select CD2003 (or TA2003/TA8164) based receiver for our project because of its simplicity and outstanding performance. Except to CD2003, Sony CXA1019 also perform well but we drop it because of its higher component count. We design our receiver based on Toshiba TA2003 datasheet and later we try TA8164 and CD2003 with the same circuit. Either CD2003 or TA8164 can directly replace TA2003 IC, and as per our observations, TA8164 gives excellent results out of those 3 chips. A prototype version of CD2003 FM radio receiver The PCB design and schematic which we used in our prototype project are available to download at google drive (including pin-outs of crystal filters and inductors ). Except for CD2003 IC, this receiver consist

Arduino superheterodyne receiver

In this project, we extend the shortwave superheterodyne receiver we developed a few years ago . Like the previous design, this receiver operates on the traditional superheterodyne principle.  In this upgrade, we enhanced the local oscillator with Si5351 clock generator module and Arduino control circuit. Compared to the old design, this new receiver uses an improved version of an intermediate frequency amplifier with 3 I.F transformers. In this new design, we divide this receiver into several blocks, which include, mixer with a detector, a local oscillator, and an I.F amplifier. The I.F amplifier builds into one PCB. The filter stage, mixer, and detector stages place in another PCB. Prototype version of 455kHz I.F amplifier. In this prototype build, the Si5351 clock generator drives using an Arduino Uno board. With the given sketch, the user can tune and switch the shortwave meter bands using a rotary encoder. The supplied sketch support clock generation from 5205kHz (tuner frequ

Calculator for audio output transformers

Audio output transformers are heavily used in a vacuum tube and some (older) transistor base audio power amplifiers, but these days output transformer are quite hard to find and expensive item. For homebrew projects, the best option is to construct those transformers by ourselves and this script helps to calculate winding parameters for those transformers. This " AF output transformer calculator " script is written using Python and it works with most of the commonly available Python interpreters . The script is available to download at google drive under the terms of GNU General Public License version 3.0 . Homebrewed 25k: 4 output transformer Once supplied the input parameters this script provides a winding ratio, the number of turns required for primary and secondary winding and required copper wire gauges for both primary and secondary windings, etc. We construct several AF output transformers based on results of this script, which including transformers for M