Rascal Devnology Code Fest

Rascal Codefest

Jurgen Vinju&& Tijs van der Storm && Bas Basten && Jeroen van den Bos && Mark Hills

Woensdag 3 maart 2010

Thursday, March 4, 2010

Installation artEclipse Galileo 3.5 for RCP/Plugin developers

32-bit version (yes, also on 64-bit machine)

32-bit Java run-time (JRE >= version 1.5)

Install plugins

http://download.eclipse.org/technology/imp/updates

IMP run-time & IMP analysis features

http://www.meta-environment.org/updates

Rascal feature

go ahead!






http://www.rascal-mpl.org/releases/Prefuse.zip

Example open source Java project

http://www.prefuse.org


http://www.rascal-mpl/releases/Prefuse.zip








Rascal TeamPaulKlint

JurgenVinju

Tijsv/d Storm

ArnoldLankamp

BertLisser Bas

BastenMarkHills

Jeroenvan den Bos

BobFuhrer

IBM

EmilieBalland

INRIACWI/INRIA


Codefest

Lightning intro

Coding Game

analysis

visualization

transformation

Disclaimers/Advertisements

No Parsing

today

Analysis!!

Visualization!!

No Generation today


Meta SoftwareDead code detection

Slicing/Dependence

Metrics

Reverse engineering

Verification

Architecture recovery

Code-to-model

...

Goto elimination

Dialect transformation

Aspect weaving

DSL compilers

API migration

Model-to-code

...

(Static)

AnalysisProgram Transformation


Challenges

Diversity

languages, dialects, frameworks, api, ...

Multi-disciplinary

parsing, static analysis, transformation, ...

Efficiency versus precision

trade-off must be programmable


Metaprogramming

Source Code

Models

Pictures

GenerationExtraction

FormalizationVisualization

Transformation

Conversion

Analysis

Input

Abstraction

Output

Extract

Analyze

SYnthesize

EASY


So, Rascal is a domain specific languagefor

source codeanalysis

andtransformation

andvisualization

andgeneration

andnothing less

(and nothing more)Thursday, March 4, 2010

Use

File extension: .rsc

Open “Rascal Persective”

Use “New Rascal Project” wizard

Use “New Rascal File” wizard

Context-menu on Rascal projects

Start Console


Read-Eval-Print

rascal>1 + 1int: 2rascal>[1,2,3]list[int]: [1,2,3]rascal>{1,1,1}set[int]: {1}rascal>{ <i,i*i> | i <- [1..10]}rel[int,int]: {<1,1>,<2,4>,<3,9>,...


Read-Eval-Printrascal>import IO;okrascal>for (i <- [1..10]) {>>>>>>> println("<i> * <i> = <i * i>");>>>>>>>}1 * 1 = 12 * 2 = 43 * 3 = 94 * 4 = 165 * 5 = 256 * 6 = 367 * 7 = 498 * 8 = 649 * 9 = 8110 * 10 = 100list[void]: []rascal>


module path::to::Examplesimport IO;

public int fac(int n) { if (n == 0) { return 1; } return n * fac(n - 1);}

Modules


list[int] even(int max) { list[int] result = []; for (int i <- [0..max]) { if (i % 2 == 0) { result += i; } } return result;}

From coding to declaring


list[int] even(int max) { list[int] result = []; for (int i <- [0..max], i%2 == 0) { result += i; } return result;}



list[int] even(int max) { result = []; for (i <- [0..max], i%2 == 0) { result += i; } return result;}



list[int] even(int max) { return for (i <- [0..max], i%2 == 0) append i;}



list[int] even(int max) { return [i | i <- [0..max], i%2 == 0];}



Immutable values

WYSIWYG values

true, false

1, 2, 3, ...

1.0, 1.1, 1.11111111

[1,2,3]

{1,2,3}

(“1”:1, “2”:2)

name(“Y.T.”)

<1,2>, <1,2,1.0>

{<1,2>,2,1>}

Nest any way you like


Types

list[void]: []

list[int]: [1]

list[value]: [1, “1”]

set[int]: {1}

set[value]: {1,”1”}

value

void

int str list[value] ...


Sub-typesvalue

intreal

bool

list[value]

list[int] list[real]

“A sub-type is a sub-set”


node myNode = “person”(“Y.T”, 18);

data Person = person(str name, int age) | person(str first, str last);

Person YT = person(“Y.T”, 18);Person MC = person(“Hiro”, “Protagonist”);

Trees and Data


node myNode = “person”(“Y.T”, 18);

data Person = person(str name, int age) | person(str first, str last);

Person YT = person(“Y.T”, 18);Person MC = person(“Hiro”, “Protagonist”);

node

Person

Trees and Data


bool isPerson(node t) { switch (t) case person(_,_) : return true; case person(_,_,_) : return true; default: return false; }}

Switch


set[Person] personTrafo(set[Person] s) { return visit(s) { case person(str f, str l) => person(“<l>,<f>”, 0) case person(str f, str l) : { name = “<l>, <f>”; println(name); insert name; } } }

Visit


Booleans & Patternstrue && false, true || false, !true

true ==> false, true <==> false

all( i <- [2,4,6,8], i % 2 == 0)

int i := x

<int i, int j> := <1,”2”>

person(str name) <- {person(“x”)}

/<word:[a-z]+>/ <- [“123”,”abc”]


Quoting & Antiquoting“Hello, I’m <myAge> year<s(myAge)> old”

“class <className> { <for (<type, name> <- fields) {> <type> <name>; public <type> get<capitalize(name)>() { return this.<name>; } <}>}”


Concrete Syntax

import lang::ansiC::CompilationUnit...visit(s) { case `if(!<expr>) <stat1> else <stat2>` => `if(<expr>) <stat2> else <stat1>`}

Unfinished


Finally! Coding

Warm-up

Analyze & visualize a Java project

Extension Pie Chart / Histogram

Make a word cloud for Java code

Compute deepest inherited classes

Visualize a type hierarchy

Visualize source code metrics


Warm-up1 + 1, 4 / 2, 2 * 2

int a = 1;

b = 2;

import Set;

max({1,2,3})

{ i | i <- [0..100]}

int a := b

<a,b> = <1,2>;

if (1 > 2) println(“x”);

int fac(int n) { if (n == 0 ) return 1; return n * f(n - 1); }

prime numbers?


Extension Charts


Extension Charts

Import Resources, viz::Figure::Render, viz::Figure::Core, viz::Figure::Chart

|project://Prefuse|

loc l = ...; l.extension == “java”

Make a map[str, int]

myMap[elem]?0 += 1;


Word cloud

Pick a single class, or it’s probably too slow


Word cloud

import Resources

|project://myProjectName|

/file(loc l) := myResource

visit(myResource) { case file(l) : ... }

import IO;

readFileLines

/<myWord:[A-Za-z0-9]+>/ := line

Import viz::Figure::Core and Render

render, align, text, fontSize

|project://Prefuse/src/prefuse/data/parser/ByteParser.java|


Deep Inheritance


Deep InheritanceImport JDT, Java, Resources, Set;

Compute set[str], “deepest inherited” classes

facts = extractProject(project);

rel[Entity, Entity] x = facts@extends;

x+; // transitive closure

str readable(Entity e);

int size(set[&T] s);

viz::Basic, treeView(...)


Subtype graph


Subtype graph

Use viz::Figure::Core, viz::Figure::Render, JDT, Java, Resources, Set, Relation, and Graph modules

Visualize (a part of) the type hierarchy:

subtypes = facts@extends + facts@implements;

subtypes += top(subtypes) * makeClass(“java.lang.Object”);

filter on prefuse.data.expression.FunctionExpression using reach(...)

graph([width(600),height(600)],[text([id(name)],name)|name <- ... ],[edge(from,to) | <from,to> <- ... ])


Metrics


Metricsconstruct a view with a box for each class:

classes: rel[loc,Entity] x = fact@types;

height is #methods: facts@declaredMethods

width is #fields: facts@declaredFields

color is #implemented interface, less is red, more is blue.

use loc.length

fillColor(Color c)

colorRange([...],color(“red”),color(“blue”);

use pack([width(x),height(x)],[...])Thursday, March 4, 2010

Thank you!http://www.rascal-mpl.org

Feedback is welcome

Look out for more alpha releases:

static (type) checker

concrete syntax features

IDE generation

Cases

DSL implementation

Refactoring implementation

...

Tip: http://www.eclipse.org/imp

Read ! s"rce!


http://www.rascal-mpl.org

http://www.rascal-mpl.org

http://www.eclipse.org/imp




















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Rascal Devnology Code Fest