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Contents

• Overview of the Eiffel Loop libraries
• Library categories
  • Audio management
  • Digital Signal Processing
  • Multi-threading
  • Logging
  • Client-server network
  • Application management
  • GUI
  • File naming and processing
  • Text processing
  • XML processing
  • External Language integration
  • Math
  • Structures
  • OS interaction
• Accessories
  • Development tools
    • Code editing
    • Build tools
  • Applications
• Download

Overview of the Eiffel Loop libraries

The Eiffel Loop library started life in 2002 with the port of a small logging framework written in Java the previous year. As it happened Eiffel was a much more suitable language for implementing this framework. This was a followed followed by a parsing and pattern matching module and then based on this, various utilities and an auto-editing framework. Later came various modules for XML processing and extensions to the logging framework.

The libraries are far from being finished and more work is required to bring them to maturity but I have decided to release them (May 2010) as I believe many programmers would find at least some of the modules quite useful. The EROS network application framework showcases many features of the Eiffel Loop library collection.

The most recent development phase has been Linux centric so some of the digital processing modules developed on Windows have fallen into disrepair but I hope to rectify this soon.

One of the more interesting DSP modules uses Macromedia Flash for the presentation layer. Unfortunately I no longer have access to the Flash development environment to keep it maintained and cannot afford the cost of purchasing a license.

The main goal now is to make all the modules fully implemented on both Linux and Windows.

Library categories

Audio management

• Native Eiffel module to read and write wav audio file headers and data.
• Eiffel interface to the eyeD3 Python library for reading and writing ID3 audio tags.
• Unified Eiffel interface to both the libid3tag (C) and libid3 (C++) for reading and writing ID3 audio tags.

Digital Signal Processing

• Eiffel interface to the Windows sound input API  allowing streaming audio from the microphone to be processed in Eiffel using classes from the producer-consumer thread library. Implemented as a WEL extension.
• Eiffel framework for buffering audio data into the Windows audio output API. Can be used to create audio synthesizers.
  
• Eiffel interface to the Praat sound analysis engine and script interpreter. Praat is an open source tool used by linguists for analyzing speech. The interface allows Praat scripts to be run from Eiffel and the resulting values of script variables to be retrieved. 
  
• Eiffel/ActionScript 2.0 framework for building applications that analyze microphone input in real-time in the Praat speech analysis engine and visually representing the results in Macromedia Flash. The microphone status is presented in an Eiffel GUI as an overlay to a Flash presentation. Synchronized opening and closing of Flash/Eiffel applications gives the illusion of a single application.

Multi-threading

• A generic producer-consumer thread communication framework where a producing thread places products onto a queue for consumption by a consumer thread.
  

Features:


• Implementation of a single consumer thread consuming the products of a single worker thread.
• Implementation of multiple consumer threads consuming the products of a single worker thread.
• Vision2 extension allowing products of a thread to be consumed by the main GUI application thread.
• Specialized consumer-producer thread classes for agent action consuming.
• A Vision2 extension framework for building proxy interfaces to GUI components that are callable from non-GUI threads. Allows non-GUI threads to asynchronously call routines that call Vision2 routines.
• Intermittent timed event framework
• Specialized "action loop" thread classes with a number of variations:
• Intermittently repeat an action with a specified sleep interval until signaled to stop.
• Continuously repeat an action until signaled to stop.
• Continuously repeat an action until receiving a signal to suspend or exit. Remains suspended unless signaled to resume or exit.
  
• A generic synchronization monitor allowing synchronization on an object to be protected with a contract requiring that the object is locked before being referenced. It is integrated with the logging framework to help detect deadlock conditions. If a thread needs to wait for a lock on a synchronized object, both the waiting and acquiring of the lock is logged in the thread's log.
• Container cell class for numeric types shared across threads. Features thread safe increment, decrement, add and subtract operations.
• Thread safe queue and stack container classes.
  

Logging

Logging framework with the following features:

• Output is indented to reflect the state of the call stack. Shows the entry and exit from routines in a way that is designed to mimic the routines code definition.
• Global filtering mechanism to restrict output to selected classes and routines. A wildcard character can be used to log all routines for a particular class.
• Integrated with UI component to switch thread context visible in console.
  
• Features:
• Support for both Vision2 and WEL GUI toolkits.
• Thread contexts selectable from a dialog drop down list
• Thread selection history navigation buttons with browser style ALT left/right arrow keyboard shortcuts

Client-server network

• EROS, an XML orientated remote procedure call application framework with an original protocol based purely on XML processing instructions rather that any special XML tags.
  

Features:

• Easily create multi threaded XML-RPC applications in Eiffel.
• Allows standard XML documents (SVG, XHTML etc) to be turned into procedure calls with the addition of a single processing instruction.
• Based on framework that allows flexible mapping of XML data to native Eiffel objects. Represent your XML data in Eiffel any way you want. Skim off as little or as much data from the document as you need. Much more efficient than DOM based approach.
• Deserialization (XML->Eiffel) uses declarative xpath to setter mapping arrays. Multi context mapping greatly simplifies deserialization of complex documents and eliminating the need for very long absolute XPaths. Instead define a number of XML contexts with shorter relative xpaths.
• Serialization (Eiffel->XML) uses Evolicity the Eiffel Loop templating mini language (Similar to Apache Velocity). Evolicity supports multi context serialization to simplify serialization of complex Eiffel structures.
• Develop your remotely accessible application components on single threaded console test harness and deploy on multi-threaded server with thread output and performance monitor.
• Demo application to calculate Fourier transformations based on Greg Lee's Numeric Eiffel Library.
• Server GUI to control startup/shutdown and thread log output context switching in command console. Easily see whats happening with a large number of threads with browser like navigation controls.
• Server GUI monitors 11 different performance characteristics.
• Eiffel/Flash ActionScript framework allowing Eiffel to make asynchronous calls to ActionScript procedures in a Flash application using simple XML messages. Also allows Flash button clicks to be actioned in Eiffel application.
• Extension to Eiffel Software FTP_PROTOCOL class making it easy to upload files, create remote directories and perform other common FTP operations.

Application management

• Eiffel binding to Windows dll for creating and editing Windows short cuts.
• Eiffel binding to Python library for creating and editing Gnome menus.
• Framework for creating installer applications for Windows.
  
• Framework for creating self installing multi-mode applications on Linux/Gnome (Windows version to follow). Features:
• Define application sub menus
• Define application menu launchers
• Define launcher as file context Nautilus action script.
• Framework design is multi-platform. 
• Framework for managing multiple applications in a single Eiffel project. Applications are selected for launch by a command line switch. Useful for managing many experimental variants of a single application. Integrated with "self installing app" framework.

GUI

• An Windows application configuration framework integrating user editions with command line parameter options. Features:
• MVC style binding of edit controls to textual, numeric and file name field containers.
• Possible to register listeners for field containers value changes.

• A UI framework based on WEL library for creating applications that do directory tree file processing.
  

Features:

• Input and output directory selection
• Files processed count monitor
• Cancel batch button
• Framework for managing installed application graphics integrated with scons application build process.
• Various UI components based on Vision2 GUI library including:
• Panel with On/Off status lights and configurable bulb icons.
• Text box specialized for user selected directory paths
• Slider control for integer interval with proportional setter procedure
• Task completion bar display component for worker threads.
• Grid of radio buttons component
• Various UI components based on WEL GUI library including:
• Audio input level indicator
• Panel with On/Off status lights

File naming and processing

• A framework for processing file trees.
• A memory efficient file and directory name list container
• Library of routines for managing file and directory paths.
  

Text processing

• A parsing and lexing library that allow grammars and text patterns to be completely specified in Eiffel without precompilation.
  

Features:

• Navigate of grammar structures in EiffelStudio.
• agent based pattern match handling
  
• A total of 21 kernel patterns constructs and 18 derived patterns.
  
• For readability patterns are described textually in preference to regular expressions.
  
• Same pattern matching engine is used for both text strings and token strings.
• Collection of patterns to search for Eiffel code fragments.
• Collection of patterns to search for C code fragments.
• Collection of patterns to search for XML code fragments.
• A framework for creating automated text file editors operating on directory source trees. Based on the Eiffel Loop parsing and lexing library, it is able find and replace complex patterns with equally complex editions. It is both simpler and more powerful than the Unix sed utility. Programs are more readable than Perl scripts and equally powerful. Suited to creating tools for migrating a source tree to a different platform or compiler. If a new version of the source tree comes a long the migration tool you created for the previous version will probably still work.
  
• Evolicity, an Eiffelized version of the Apache Velocity text substitution scripting language allowing Eiffel data to be easily interpolated into plain text. Evolicity was created using the Eiffel Loop parsing and lexing framework.
  

XML processing

• Eiffel interface to the VTD-XML XML parser. VTD-XML is arguably the world's top performing XML parser and xpath 1.0 implementation both in terms of speed and memory efficiency. The Eiffel interface actually represents an improvement over the original C and Java API. It supports nested xpath queries and is much more developer friendly requiring fewer objects to manage.
• Eiffel interface to the Expat XML parser that is significantly faster than the GOBO parser.
• High performance XPath event processor based on declarative mapping of xpaths to Eiffel agents using a minimal subset of xpath query language.
• An XML deserialization framework based on declarative mapping of relative xpaths to Eiffel builder agents. A builder agent is a routine that constructs some part of an Eiffel object.
  

Key features:


• Ability to define many mapping contexts for a single document. All Xpaths defined within a context are relative to a parent context.
• Allows flexible mapping of XML documents to Eiffel models composed of an arbitrary number of classes.
• Supports recursive data models.
• Uses a small subset of the xpath query language.
• Supports xpath mapping based on attribute value predicates, i.e. Expressions of the form AAA/BBB[@x='y'] may be used to map building agents.
• A framework for serializing Eiffel objects as XML based on the Eiffel Loop text substitution scripting language, Evolicity.
• A DOM like mini framework for modeling XML in Eiffel.
• A parser for an alternate "Pythonized" XML syntax called Pyxis (Acronym for PYthonic Xml Ideal Source). The goal is to have a more readable text for XML configuration files. 
  

External Language integration

• An advanced framework for wrapping Java classes that adds a layer of abstraction to Eiffel Software's Java2Eiffel library. It is based on the concept of a Java agent in Eiffel (JAVA_FUNCTION or JAVA_PROCEDURE inheriting JAVA_ROUTINE) that is analogous to an Eiffel agent. JAVA_ROUTINE's automatically generate correct JNI call signatures. Allows the creation of recursively wrapped classes where the arguments and return types to wrapped routines are themselves wrapped classes.
• An extension to the PEPE framework for wrapping Python libraries that automates the process of converting Eiffel types to Python types and vice-versa.
• A framework for calling Matlab scripts and Matlab scripts that have been compiled into C, and processing the results in Eiffel.
• A framework for running Praat speech analysis scripts in Eiffel and processing the results.
• Container library for sharing data with C/C++ programs including:
• C strings covering all permutations of little and big endian 8, 16 and 32 bit characters.
• Wrapper for C numeric arrays.
  

Math

• Basic column and row vector implementation
  

Structures

• An extension to the standard Elks ARRAY class that allows memory area sharing on sub arrays. Possible to see up to a 100% performance increase on digital processing applications which make heavy use of ARRAYs. (Standard Elks subarray function makes a copy of the subarray. Safe but not very efficient.)
• Memory efficient form of numeric lists with many repeats implemented as run length encoded arrayed lists.
• Numeric array serialization.
  

OS interaction

• Cross platform Eiffel interface to various OS file system commands including:
  
• File listing
• Directory listing
• Directory moving, copying and deleting.
• File moving, copying and deleting.
• A command string variable substitution component

Accessories

Development tools

Code editing

• Automatic code editor that operates on the gcc source code tree of the Praat linguistics tool. The editor adds hooks for an Eiffel interface and modifications allowing compilation with the MS VC++ compiler.
• Build tool for commenting out logging lines in Eiffel source code.
• Tool for normalizing Eiffel source code file names to match class names.
• Eiffel class renaming tool that is faster than EiffelStudio.

Build tools

• A script to manage OS environments from a project Python script and launch EiffelStudio.
• An extension to scons build system for Eiffel projects with the following features:
• Select freeze or finalize build
• Builds any Eiffel library precompiles using a standard SConstruct
  
• Checks for existence of SConstruct to build C dependencies
• Installs application graphics specified with an extra ECF tag into standardized directories locatable by an Eiffel class.
  
• Migration tool to translate an Eiffel configuration file written in the Pyxis data format to XML format. Pyxis is an alternate "Pythonized" XML syntax devised by Finnian Reilly.

Applications

• Documentation tool to create a class inventory in HTML format from an Eiffel source tree.
• A web publishing application configured by an XML script to create multiple views of HTML documents created in the Thunderbird email client HTML editor.
• An application to perform off-site archiving of project files featuring:
• Backups scripted with XML.
• File filtering and wildcards.
• Optional cyclical versioning upto a maximum version.
• Optional gpg encryption for selected directories.
• Archive compression.
• Offsite transfer of all archives via ftp.

Download

http://www.eiffel-loop.com/download/Eiffel-Loop.1.0.tar.gz