Building DSLs with Eclipse

Building DSLs with Eclipse • Peter Friese, itemis • @peterfriese • @xtext (c) 2009 Peter Friese. Distributed under the EDL V1.0 - http://www.eclipse.org/org/documents/edl-v10.php More info: http://www.peterfriese.de / http://www.itemis.com

Suppose...

You’d want to core an apple...

... for your kids.

? Right tool for the job?

Your trusty swiss army knife!

Because you can use it for other stuff, too. E.g., opening a bottle of wine.

Suppose...

You’d want to core a few more apples...

... for an apple cake.

Still the best tool for the job?

Better use this one.

and this one:

BUT avoid the unitasker!

... a DSL is ...

A specific tool for a specific job

Samples for DSLs

SQL

select name, salary from employees where salary > 2000 order by salary

ANT

<project name="MyProject" default="dist" basedir="."> <property name="src" location="src"/> <property name="build" location="build"/> <property name="dist" location="dist"/> <target name="init"> <mkdir dir="${build}"/> </target> <target name="compile" depends="init"> <javac srcdir="${src}" destdir="${build}"/> </target> <target name="dist" depends="compile"> <mkdir dir="${dist}/lib"/> <jar jarfile="${dist}/lib/MyProject.jar" basedir="${build}"/> </target> <target name="clean"> <delete dir="${build}"/> <delete dir="${dist}"/> </target></project>

Building DSLs

Create ANTLR grammar • Generate lexer / parser • Parser will create parse tree • Transform parse tree to semantic model • Iterate model • Pass model element(s) to template

Complicated

Why not use a DSL... ... for building DSLs?

Building DSLs with Eclipse