APL#

[eɪ p

h

iː ɛl ʃɑ:p]

Morten Kromberg CTO, Dyalog Ltd.

[email protected]

SDC 2011

Agenda

• • • • • Some Well Rationalized History Try to convince you that my personal addiction is ”reasonable” Develop a couple of small DSL’s ”on the fly” Introduce APL#, a modern dialect of APL targeting the Microsoft.Net Framework Demonstrate Dyalog APL and APL# working together to produce a SilverLight App APL# SDC 2011 2

History

APL# SDC 2011 3

Who Stole The Mainframe?

• • • • • APL users felt that the Mainframe was a high productivity environment for personal computing – in 1970!

APL was used to prototype every component of current ERP systems and experienced its First Golden Age APL vendors and users were all convinced those obviously impractical Personal Computers would disappear fast 40 years later, everyone is starting to agree APL users don’t enjoy studying the computer, they have work to do!

APL# SDC 2011 4

Customer Profile

• • • • APL# Domain Expert (Financial Analyst, Bond Trader, Chemical Engineer, Biologist, Health Care Provider, ...) – Sometimes a ”semi-computer litterate” friend Build a sometimes Hideous, but Uniquely Competitive and Timely Product If Successful, Build a Company – Learn to combine APL with ”Software Engineering” Today, 8 of our 10 largest customers are ”Software Vendors” employing many Software Engineers, but...

– ... in markets where product enhancements require active participation by Domain Experts SDC 2011 5

Some Examples …

APL# SDC 2011 6

Production Planning

GUI Examples Dyalog APL 7

Largest Patient Journal System in Sweden

GUI Examples Dyalog APL 8

Nutrition Management (Windows Mobile - handheld)

APL Borealis - Canada

GUI Examples Dyalog APL 9

Job Ads (1)

APL# SDC 2011 10

Job Ads (2)

APL# SDC 2011 11

APL Intro ...

• • • • APL is a General-Purpose DSL (Domain = Arrays) (Everything is a Nail an Array) It’s interactive, and highly addictive...

APL# SDC 2011 12

Data Exploration with APL

• A Tool of Thought for exploring data and algorithms interactively...

– Knowledge Acquisition • APL provides a framework for the Domain Expert to extend APL with his or her own more specific DSL ...

• A day in the life of a Historian ...

APL# SDC 2011 13

The APL Vendors Task

• • • Support ALL steps from prototyping to deployment of high performance commercial software Provide easy access to all the tools in the environment – So the Software Engineer CAN • • Use them Build wrappers for Domain Experts – But WITHOUT demanding that the Domain Expert master them Maintain the unique selling points of the Notation as a Tool of Thought APL# SDC 2011 14

Recent History

• • • • • v11.0 Object Orientation + .Net Integration – Full (but ”unmanaged”) integration with .Net Class Hierarchies: Consume, Provide, Inherit – WPF, WCF, MS Office Plugins, ASP.Net ...

v11.0: 64-bit Version v12.0: Full Unicode Support – APL code in mainstream source code mgt tools v13.0: RegExs V13.0: Complex Nums & 128-bit Decimal FP APL# SDC 2011 15

The Next Challenge

• • • APL has been ”fully managed” since 1966 – Self-describing arrays, no pointers, garbage collection Now Microsoft and Sun Oracle want to do the managing (on some platforms) – – But with a different view of data types and what ”stack” is In particular: No efficient mutable arrays with value semantics, and no way to ”cheat” in order to provide them  – No way to make names visible to all called functions We could wait for the next generation of VMs and hope, but decided to ”engage” now APL# SDC 2011 16

• • • •

What is APL#

An attempt to design a new dialect which is… A first-class citizen of the CLR (JVM, etc) • • • Dyalog APL has full “.Net Interop” but is unmanaged We want to run in the browser, have a zero footprint Seamlessly integrated with all available tools Make Software Engineers more comfortable BUT: Must be as good a Tool of Thought as APL • • Value rather than Reference semantics for Arrays Illusion that there is only one numeric type (OK, possibly TWO: “Exact” and “Inexact” numbers, but 2 = +/ TRUE FALSE TRUE ) APL# SDC 2011 17

Implementation Goals

• • • • • APL# should be a fully-paid-up citizen of the Microsoft.Net platform, BUT No

language feature

may DEPEND on .NET

APL# must be portable to other AVMs It should be possible to compile “native” versions of APL# for use on high performance hardware APL# is expected to outlive the current generation of AVMs (.NET, JVM) APL# SDC 2011 18

Initial Target Platforms

• • • •

Microsoft.Net

under Microsoft Windows

Mono

(Open Source .Net Linux and other ‘Nixes)

SilverLight

(Web Browser plug-in for Windows and Mac OS/X)

MoonLight

(Open Source Web Browser plug-in) • APL# will be available as an interpreter, but there will also be a compiler for code which does not use ⍎ . This will produce code which is faster, and can run on embedded/mobile platforms which do not support dynamic code generation.

APL# SDC 2011 19

APL# vs Dyalog APL

• • • • •

Key Differences:

APL# uses lexical (static) scoping rules “Functional” is the default function style (with procedural extensions) ABLE to pass arrays “by reference” Fixes index origin at zero (at least on the .NET framework). THIS DOES interfere with the “Tool of Thoughtness”.

Does not guarantee order-of-execution of primitive parallel higher-order functions (each, rank) APL# SDC 2011 20

APL# + Dyalog APL

• • • • • •

Integration / Migration

A single new IDE will service both systems – Visual Studio required to debug compiled APL# Full interop via existing Microsoft.Net Bridge Will share the Dyalog APL “Object Store” (aka “Component Files”) Share values of APL arrays via TCP sockets We expect users to build systems using APL# on the Client and Dyalog APL on the server Time for a final demo… APL# SDC 2011 21

Rules of ”Go Fish” (English)

• • • • • • A standard 52 card deck is used. The dealer deals 5 cards to each player (7 each for 2 players). The remaining cards are placed face down to form a stock. A turn consists of asking a specific player for a specific rank. For example, if it is my turn I might say: 'Mary, please give me your jacks'. The player who asks must already hold at least one card of the requested rank.

If the player who was asked (Mary) has cards of the named rank (jacks in this case), she must give

all

her cards of this rank to the player who asked for them. That player then gets another turn and may again ask any player for any rank already held by the asker. If the person asked does not have any cards of the named rank, they say 'Go fish!'. The asker must then draw the top card of the undealt stock. If the drawn card is the rank asked for, the asker shows it and gets another turn. If the drawn card is not the rank asked for, the asker keeps it, but the turn now passes to the player who said 'Go fish!'. As soon as a player collects a book of 4 cards of the same rank, this must be shown and discarded face down.

The game continues until either someone has no cards left in their hand or the stock runs out. The winner is the player who then has the most books. APL# SDC 2011 22

APL# In Action...

APL# SDC 2011 23

Clientside Code (APL#)

APL# SDC 2011 24

Clientside Code (APL#)

APL# SDC 2011 25

What was that again ...?

• • • • Prototype of APL# embedded in our ”Light Execution Module” (LEM) LEM talks to HTTP server written in Dyalog APL, which downloads packages of XAML + APL# Script GoFishGame runs in Dyalog APL on server, downloads game data Results of simulation viewed ”off line” APL# SDC 2011 26

•

Wrapping Up...

– Need for “Tools of Thought” is greater than ever • APL integrates Functional, Array and Object Oriented paradigms into a single package Choose the best one for each task – – APL is a natural language for many Domain Experts – APL# makes it possible for APL to run in new environments; in the browser, on cell phones, as SQL stored procedures, etc.

• Prototypes available “after the summer” Dyalog APL available now  APL# SDC 2011 27

Other APL Futures

• • • • – – Compiled (Optionally Typed) APL shows promise as a tool for harnessing highly parallel hardware: “Map” is the default way to apply functions in APL Many different forms of “Reduce” are available (APL has used the name “Reduce” for the / in ( +/) since the 1960’s) – We are hoping to work with Robert Bernecky and Sven-Bodo Scholz on compiling APL to Single Assignment C (SAC) Greater emphasis on functional programming style More Integration: Mono an Java Bridges for Dyalog APL “Plugins” for Eclipse and Visual Studio APL# SDC 2011 28

50

th

Anniversary Kenneth E. Iverson's book “A Programming Language” in 2012 APL: Still an Emerging Technology

APL# SDC 2011 29

More Reading

• • • • • • “Arrays of Objects” (OOPSLA DSL paper) DLS '07 Proceedings of the 2007 symposium on Dynamic languages http://www.aplsharp.com

http://forums.dyalog.com

Twitter & Facebook: dyalogapl Apply for a non commercial licence in the “Download Zone” at dyalog.com and mention “SDC 2011” Come to Dyalog’11 in Boston, October 2-5 APL# SDC 2011 30