xtext project and phds in gemany

T.Baar: NSU TechTalk, The framework Xtext. 2015-11-24 1

Xtext: Eclipse-based framework for defining

Domain-Specific Languages (DSLs)

Thomas [email protected] (temporary *)

NSU Tech Talk; Akademgorodok, 2015-11-24

Guest Lecturer at:

Home University:

* My stay at Novosibirsk State University is supported by DAAD (German Academic Exchange Service).


Domain-Specific Language (DSL)

A DSL is a notation for expressing observations, facts, algorithms

in an elegant way. The notation can be

- textual

- graphical

- table-oriented

or a mixture of the above.



Compared to general-purpose modeling languages (e.g. UML) or

programming languages (e.g. Java), DSLs have usually a (much)

less complex syntax while being expressive enough for the

domains they target!



Compared to general-purpose modeling languages (e.g. UML) or

programming languages (e.g. Java), DSLs have usually a (much)

less complex syntax while being expressive enough for the

domains they target!

Domain-specific models/programs are typically less complex

than models/programs written in a general purpose language.

Thus, they are easier to understand and to maintain.


DSL ExamplesDomain

Typesetting

Language

Latex

Source: Britannica kids. kid.eb.com


DSL ExamplesDomain

Automatic Software Build

Language

make


DSL ExamplesDomain

Chemistry

Language

Mendeleev's periodic

system of chemical

elements


DSL ExamplesDomain

Process Description

Language

Harel's statecharts


- Что такое?

• Eclipse-framework for defining textual DSLs

- actually, Xtext is the heart of Eclipse bundle "Eclipse for Java

and DSL developers"





and DSL developers"

• Open source, but professionally developed and maintained by

start-up company Itemis (Kiel, Germany)

- matured code, release 2.9 expected early Dec 2015

- nice documentation/tutorials

- active forum, fast bug-fixes





and DSL developers"

• Open source, but professionally developed and maintained by

start-up company Itemis (Kiel, Germany)

- matured code, release 2.9 expected early Dec 2015

- nice documentation/tutorials

- active forum, fast bug-fixes

• Very informative website www.eclipse.org/xtext

- short video tutorials explaining each editor feature

- links to what community has implemented using Xtext


Xtext: Mission & Workflow

Mission: Make the Definition and Usage of textual DSLs as easy as possible.


Overview on DSL DefinitionDSL-Part Defined in Purpose

Grammar EBNF-inspired Grammar language

specify lexer, parser

Validator Xtend * filter out non-intended input models; trigger error-markers in editor

Scope definitions Xtend resolve cross-references

Editor configurations (Overview pane, content assist/auto-completion, font-selection, tooltips, etc.)

Xtend adjust editor features

Code generator Xtend specify code generator

Tests Xtend execute test cases for lexer, parser, validator, scope provider, editor, eclipse integration, etc.

* Xtend - An extension of Java invented from Xtext-team in order to make typical programming tasks (e.g. AST traversion, code templates) much easier.


More detailed DSL-Definition Workflow


Example Project

Beans


A Simple Example: Beans-- Create an Xtext Project --


A Simple Example: Beans-- Define the Grammar --



Header

Start Rule

Feature in generatedEMF class

Cross-reference

Keyword

Optional Occurence


Xtext is build on top of the parser generator ANTLR. For the above grammar,

much longer input files for ANTLR have been generated (299 LOC, 24 LOC).


Header

Start Rule

Feature in generatedEMF class

Cross-reference

Keyword

Optional Occurence

The formalism for defining a grammar is a DSL! This DSL has been implemented by Xtext itself ;-)


A Simple Example: Beans-- Testing the Parser using JUnit --

Pre-definedhelper classes

String templates(enclosed by ''' )

Extension method(actually definedin ParserHelper andnot in String)


A Simple Example: Beans-- Adding a Validator: Making the syntax more precise --

class BeansDslValidator extends AbstractBeansDslValidator {

public static val INVALID_NAME = 'invalidName'

@Checkdef checkBeannameStartsWithCapital(Bean bean) {

if (!Character.isUpperCase(bean.name.charAt(0))) {error('Name must start with a capital',

BeansDslPackage.Literals.BEAN__NAME, INVALID_NAME)

}}

}

Mark input text as erroneousunder certain circumstances


A Simple Example: Beans-- Testing the Validator using JUnit --


A Simple Example: Beans-- Enjoy the Editor :-) --

Content assist(aka auto-completion)

Grammar error (missing ';')

Validation error (no capital letter)


A Simple Example: Beans-- Specify a Code Generator using Xtend --

class BeansDslGenerator implements IGenerator {override void doGenerate(Resource resource, IFileSystemAccess fsa) {

resource.allContents.toIterable.filter(typeof(Bean)).forEach[fsa.generateFile('''beans/«name».java''', compile)

]}

def compile(Bean bean) {'''public class «bean.name» «IF bean.superType != null»extends «bean.superType.name» «ENDIF»{

«FOR att : bean.attributes»private «att.type.typeToString» «att.name»;«ENDFOR»

«FOR att : bean.attributes»public «att.type.typeToString» get«att.name.toFirstUpper»() {

return «att.name»;}

public void set«att.name.toFirstUpper»(«att.type.typeToString» _arg) {this.«att.name» = _arg;

}«ENDFOR»

}'''}

def typeToString(BasicType type) {if (type.literal.equals("string")) "String" else type}

}

Output written in .java file

Each bean becomes a Java class

Each bean attribute is mapped to Java attribute, getter- and setter-method


A Simple Example: Beans-- Enjoy the Code Generator :-) --

One input file(written in ourDSL)

Location of generatedartifacts

Three output files(written in targetlanguage)


A Simple Example: Beans-- Testing Code Generator using JUnit --

class BeansGeneratorTests {@Rule@Inject public TemporaryFolder temporaryFolder

@Inject extension CompilationTestHelper@Inject extension ReflectExtensions

@Testdef void testTwoCompiledClasses() {

'''bean Person{string name;}bean Student extends Person{

boolean isMaster; studentID; // implicitely typed as int

}}

'''.compile [getCompiledClass("Person").assertNotNullgetCompiledClass("Student").assertNotNull

]}

}

both classes has been compiledsuccessfully


A Simple Example: Beans-- Testing Code Generator using JUnit --

@Testdef void playWithGeneratedJavaCode() {

'''bean Person{string name;}bean Student extends Person{

boolean isMaster; studentID; // implicitely typed as int

}}

'''.compile [getCompiledClass("Student").newInstance => [

assertNull(it.invoke("getName"))val aName = "Johnson"it.invoke("setName", aName) // invoking inherit methodassertEquals(aName, it.invoke("getName"))val anInt = 1234it.invoke("setStudentID", anInt)

assertEquals(anInt, it.invoke("getStudentID"))]

]}

create instanceof Student and invoke setter/getterby reflection


Summary

• Differences of domain-specific and general-purpose

languages

• Short overview on purpose and architecture of

Xtext

• Gone through small example (hopefully) showing the

efficiency gain


Summary

• Differences of domain-specific and general-purpose

languages

• Short overview on purpose and architecture of

Xtext

• Gone through small example (hopefully) showing the

efficiency gain

Try it out by yourself! Xtext is very versatile and stable.


Thank you!

T.Baar: NSU TechTalk, Writing a PhD Thesis in Germany. 2015-11-24 1

How to write a PhD thesis in Germany

Thomas [email protected] (temporary *)

NSU Tech Talk; Akademgorodok, 2015-11-24

Guest Lecturer at:

Home University:

* My stay at Novosibirsk State University is supported by DAAD (German Academic Exchange Service).


What do you like Germany for?

Source of map: "Deutschland topo" by Botaurus-stellaris - Own work. Licensed under CC BY-SA 3.0 via Commons -

https://commons.wikimedia.org/wiki/File:Deutschland_topo.jpg#/media/File:Deutschland_topo.jpg


What do you like Germany for?

Source of map: "Deutschland topo" by Botaurus-stellaris - Own work. Licensed under CC BY-SA 3.0 via Commons -

https://commons.wikimedia.org/wiki/File:Deutschland_topo.jpg#/media/File:Deutschland_topo.jpg

Cultural heritage(literature, music,

architecture)

Social welfare

Innovative companies

High-quality products(„Made in (West-)Germany“)

Efficiency

German beer :-)


Up-/Downsides of Efficiency



Ups

- high wages

- cheap products/food

- as a country: strong

economic position

(much more export

than import)



Ups

- high wages

- cheap products/food

- as a country: strong

economic position

(much more export

than import)

Downs

- high unemployment

rate

- expensive workplaces

do not call a

craftsman ...

- high pressure on

employees

Diesel Gate at VW


Efficiency also in Academia

• Comparing Student/Employee ratio of

- Hochschule für Technik und Wirtschaft (HTW) Berlin

University of Applied Sciences

- Humboldt-University (HU) Berlin

- Novosibirsk State University (NSU)

0

5000

10000

15000

20000

25000

30000

35000

HTW Berlin HU Berlin NSU

Size of Universities

Employees Students








0

5

10

15

20

25

30


Students per Employee

0

5000

10000

15000

20000

25000

30000

35000



Employees Students








0

5

10

15

20

25

30


Students per Employee

0

5000

10000

15000

20000

25000

30000

35000



Employees Students

This is the paradise !!!


My Career

1990-97 Study of Computer Science at HU Berlin

1997-99 Research Assistent at HU Berlin

1999 How to continue? Hard decision!

1999-03 Doctoral Student at University of Karlsruhe

(today: KIT)

2003-07 Post-Doc, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland

2007-11 Senior Engineer in small software company, Berlin

2011 -- Professor at HTW Berlin


My Period of Writing PhD Thesis

• 2 years preliminary research work at HU Berlin

• my group in Karlsruhe

- 2 professors

- 2 post-docs

- 4 phd students

funding from DFG (Deutsche Forschungsgemeinschaft): salary,

equipement, travelling

basically no teaching obligations

- appr. 5-10 student assistents





- 2 professors

- 2 post-docs

- 4 phd students





We have the worst PhD supervisor ever, because he does not supervise us!





- 2 professors

- 2 post-docs

- 4 phd students





We have the worst PhD supervisor ever, because he does not supervise us!

We have the best PhD supervisor ever, because he does not supervise us!


How to find open Research Position?

• Ask your professor/supervisor here in Nsk

- people meet at conferences/workshops and

disseminate open positions

• Go to www.academics.de

- offers alert service

- informative links


Types of PhD Positions• assistent position at university (Landesstelle)

+ contract extension no problem

- sometimes time-consuming teaching obligations

• research position at university (e.g. DFG financed)

+ focus on research; no teaching

- sometimes hard to get project extension

• position at research institute (Fraunhofer, Leibniz)

+ working on industry problems

- overloaded with work to reach next milestone

• research position in industry (Daimler Benz, Siemens)

+ working on industry problems

- no strong supervision; danger to become 'ordinary' project member


Initiative for Academic Excellence

• Initiated by chancellor Gerhard Schröder

Idea: Universities and clusters can apply for

special status "Place of Excellence"

- selected universities get huge research money from

Federal budget

- highly competitive (only 5-10 universities got status)

- only already renowned universities have chance to

become successful

Rational: Germany wants to "become better" in world-

wide rankings


Consequences of Excellence Initiative

• currently a lot of money "in the system"

• many interesting projects

• a lot of open positions :-)

- also due to the current very good job market

many talented graduates go to industry


Consequences of Excellence Initiative

• currently a lot of money "in the system"

• many interesting projects

• a lot of open positions :-)

- also due to the current very good job market

many talented graduates go to industry

!!! However !!!

- still only non-permanent positions

- becoming a professor after PhD project became

even more difficult (due to many qualified colleages

that completed PhD as well)


Will I have enough money to survive?• as a PhD student: no fees to be paid



• Salary usually according to Tv-L 13: currently 3500 € per month

- from this appr. 50% reduction for taxes, health insurance,

pension plan

- !Attention! some research projects offer only 50% jobs

"officially" 50% workload, but for sure only 50% payment



• Salary usually according to Tv-L 13: currently 3500 € per month

- from this appr. 50% reduction for taxes, health insurance,

pension plan

- !Attention! some research projects offer only 50% jobs

"officially" 50% workload, but for sure only 50% payment

• Some prices:

- lunch in cafeteria: appr. 4 €

- food from supermarket: appr. 150 € per month

- 1-room flat in Berlin: from 400 € per month


Final Recommendations• Do not worry about German language skills

- helpful in private life, but not mandatory at university

• my favourite position: research at university with professor

having 3-4 PhD students

• getting an 1-year-contract initially is rather normal

• publications

- do not wait too long with your first one

- write only if you found out something worth to be told

- also read books/articles on "How to write a good paper?/How to give a good talk?"


Final Recommendations

Prof. Tom Henzinger: „Strive always to be as good as you can!“ (when writing applications,writing papers, giving talks)


Thank you!