Groovy Update - Guillaume Laforge - Greach 2011

Whatʼs new in Groovy 1.8 and beyond?Guillaume LaforgeGroovy Project ManagerSpringSource, a division of VMwareTwitter: @glaforgeBlog: http://glaforge.appspot.comGoogle+: http://gplus.to/glaforge

Guillaume Laforge• Groovy Project Manager at VMware • Initiator of the Grails framework • Creator of the Gaelyk toolkit• Co-author of Groovy in Action• Speaking worldwide w/ a French accent• Follow me on... • My blog: http://glaforge.appspot.com • Twitter: @glaforge • Google+: http://gplus.to/glaforge @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 2

Groovy 1.7 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

Groovy 1.7185 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

Groovy 1.7185k @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

Groovy 1.7185k FIRST MONTH AFTER RELEASE @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

Groovy 1.7 k @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

Groovy 1.7177k SECOND MONTH AFTER RELEASE @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

Groovy 1.7 k @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

Groovy 1.7362k USERS? @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 3

?TIP OFTHEICEBERG

Guesstimate 1/2 Users Million@glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 5

Agenda @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 6

Agenda• Whatʼs new in Groovy 1.8? – Nicer DSLs with command chains expressions – Runtime performance improvements – GPars bundled for taming your multicores – Closure enhancements – Builtin JSON support – New AST transformations @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 6

Agenda• Whatʼs new in Groovy 1.8? – Nicer DSLs with command chains expressions – Runtime performance improvements – GPars bundled for taming your multicores – Closure enhancements – Builtin JSON support – New AST transformations• Whatʼs cooking for Groovy 1.9? – Continued runtime performance improvements – Alignments with JDK 7 • Project Coin (small language changes) • Static type checking • InvokeDynamic @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 6

Command chains expressions @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 7

Command chains expressions• A grammar improvement allowing you to drop dots & parens when chaining method calls – an extended version of top-level statements like println @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 7

Command chains expressions• A grammar improvement allowing you to drop dots & parens when chaining method calls – an extended version of top-level statements like println• Less dots, less parens allow you to – write more readable business rules – in almost plain English sentences • (or any language, of course) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 7

Command chains expressions• A grammar improvement allowing you to drop dots & parens when chaining method calls – an extended version of top-level statements like println• Less dots, less parens allow you to – write more readable business rules – in almost plain English sentences • (or any language, of course)• Letʼs have a look at some examples @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 7

Command chains expressions turn left then right @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 8

Command chains expressions Alternation of method names turn left then right @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 8

Command chains expressions Alternation of method names turn left then right and parameters (even named ones) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 8

Command chains expressions turn left then right @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 8

Command chains expressions Equivalent to: ( ). ( ) turn left then right @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 8

LookM a!N op are ns,no do ts!

Command chains expressions Before... we used to do... take 2.pills, of: chloroquinine, after: 6.hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 10

Command chains expressions Before... we used to do... take 2.pills, of: chloroquinine, after: 6.hours Normal argument @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 10

Command chains expressions Before... we used to do... take 2.pills, of: chloroquinine, after: 6.hours Normal argument Named arguments @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 10

Command chains expressions Before... we used to do... take 2.pills, of: chloroquinine, after: 6.hours Normal argument Named arguments Woud call: def take(Map m, Quantity q) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 10

Command chains expressions Now, even less punctuation! take 2.pills of chloroquinine after 6.hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 11

Command chains expressions Now, even less punctuation! ( ). ( ). ( ) take 2.pills of chloroquinine after 6.hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 11

Command chains expressions // environment initialization Integer.metaClass.getPills { ‐> delegate } Integer.metaClass.getHours { ‐> delegate } // variable injection def chloroquinine = /*...*/ { } // implementing the DSL logic def take(n) { [of: { drug ‐> [after: { time ‐> /*...*/ }] }] } // ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ take 2.pills of chloroquinine after 6.hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 12

Command chains expressions take 2.pills of chloroquinine after 6.hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 13

Command chains expressions take 2.pills of chloroquinine after 6.hours ... some dots remain ... @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 13

Command chains expressions Yes, we can... get rid of them :-) take 2 pills of chloroquinine after 6 hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 14

Command chains expressions Yes, we can... get rid of them :-) ( ). ( ). ( ). ( ) take 2 pills of chloroquinine after 6 hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 14

Command chains expressions // variable injection def (of, after, hours) = /*...*/ // implementing the DSL logic { } def take(n) { [pills: { of ‐> [chloroquinine: { after ‐> [6: { time ‐> }] }] }] } // ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ take 2 pills of chloroquinine after 6 hours @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 15

Command chains expressions @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation check that: margarita tastes good @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation check that: margarita tastes good // closure parameters for new control structures @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation check that: margarita tastes good // closure parameters for new control structures given {} when {} then {} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation check that: margarita tastes good // closure parameters for new control structures given {} when {} then {} // zero‐arg methods require parens @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation check that: margarita tastes good // closure parameters for new control structures given {} when {} then {} // zero‐arg methods require parens select all unique() from names @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation check that: margarita tastes good // closure parameters for new control structures given {} when {} then {} // zero‐arg methods require parens select all unique() from names // possible with an odd number of terms @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor // leverage named‐args as punctuation check that: margarita tastes good // closure parameters for new control structures given {} when {} then {} // zero‐arg methods require parens select all unique() from names // possible with an odd number of terms take 3 cookies @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor ( ). ( ). ( ) // leverage named‐args as punctuation check that: margarita tastes good // closure parameters for new control structures given {} when {} then {} // zero‐arg methods require parens select all unique() from names // possible with an odd number of terms take 3 cookies @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor ( ). ( ). ( ) // leverage named‐args as punctuation check that: margarita tastes good ( ). ( ) // closure parameters for new control structures given {} when {} then {} // zero‐arg methods require parens select all unique() from names // possible with an odd number of terms take 3 cookies @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor ( ). ( ). ( ) // leverage named‐args as punctuation check that: margarita tastes good ( ). ( ) // closure parameters for new control structures given {} when {} then {} ( ). ( ). ( ) // zero‐arg methods require parens select all unique() from names // possible with an odd number of terms take 3 cookies @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor ( ). ( ). ( ) // leverage named‐args as punctuation check that: margarita tastes good ( ). ( ) // closure parameters for new control structures given {} when {} then {} ( ). ( ). ( ) // zero‐arg methods require parens select all unique() from names ( ). . ( ) // possible with an odd number of terms take 3 cookies @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Command chains expressions // methods with multiple arguments (commas) take coffee with sugar, milk and liquor ( ). ( ). ( ) // leverage named‐args as punctuation check that: margarita tastes good ( ). ( ) // closure parameters for new control structures given {} when {} then {} ( ). ( ). ( ) // zero‐arg methods require parens select all unique() from names ( ). . ( ) // possible with an odd number of terms take 3 cookies ( ). @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 16

Runtime performance improvements• Signiﬁcant runtime improvements for primitive type operations – classical Fibonacci example x13 faster! – almost as fast as Java• Some direct method calls on this @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 17

GPars bundled• GPars is bundled in the Groovy distribution• GPars covers a wide range of parallel and concurrent paradigms – actors, fork/join, map/ﬁlter/reduce, dataﬂow, agents, STM – parallel arrays, executors, and more... @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 18

Closure enhancements• Closure annotation parameters• Some more functional ﬂavor – composition – trampoline – memoization• Currying improvements @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 19

Closure annotation parameters @Retention(RetentionPolicy.RUNTIME) @interface Invariant { Class value() // a closure class } { @Invariant({ number >= 0 }) class Distance { float number String unit } def d = new Distance(number: 10, unit: "meters") def anno = Distance.getAnnotation(Invariant) def check = anno.value().newInstance(d, d) assert check(d) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 20

Closure annotation parameters @Retention(RetentionPolicy.RUNTIME) @interface Invariant { Class value() // a closure class } { @Invariant({ number >= 0 }) class Distance { float number an’s G Cont racts String unit P oor-m } def d = new Distance(number: 10, unit: "meters") def anno = Distance.getAnnotation(Invariant) def check = anno.value().newInstance(d, d) assert check(d) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 20

Closure composition def plus2 = { it + 2 } def times3 = { it * 3 } { def times3plus2 = plus2 << times3 assert times3plus2(3) == 11 assert times3plus2(4) == plus2(times3(4)) { def plus2times3 = times3 << plus2 assert plus2times3(3) == 15 assert plus2times3(5) == times3(plus2(5)) // reverse composition{ assert times3plus2(3) == (times3 >> plus2)(3) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 21

Closure trampoline @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 22

Closure trampoline def factorial factorial = { int n, BigInteger accu = 1G ‐> if (n < 2) return accu factorial.trampoline(n ‐ 1, n * accu) }.trampoline() assert factorial(1) == 1 assert factorial(3) == 1 * 2 * 3 assert factorial(1000) == 402387260... @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 22

Closure memoization @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms assert plus(2, 2) == 4 // return immediately @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms assert plus(2, 2) == 4 // return immediately // at least 10 invocations cached @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms assert plus(2, 2) == 4 // return immediately // at least 10 invocations cached def plusAtLeast = { ... }.memoizeAtLeast(10) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms assert plus(2, 2) == 4 // return immediately // at least 10 invocations cached def plusAtLeast = { ... }.memoizeAtLeast(10) // at most 10 invocations cached @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms assert plus(2, 2) == 4 // return immediately // at least 10 invocations cached def plusAtLeast = { ... }.memoizeAtLeast(10) // at most 10 invocations cached def plusAtMost = { ... }.memoizeAtMost(10) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms assert plus(2, 2) == 4 // return immediately // at least 10 invocations cached def plusAtLeast = { ... }.memoizeAtLeast(10) // at most 10 invocations cached def plusAtMost = { ... }.memoizeAtMost(10) // between 10 and 20 invocations cached @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Closure memoization def plus = { a, b ‐> sleep 1000; a + b }.memoize() assert plus(1, 2) == 3 // after 1000ms assert plus(1, 2) == 3 // return immediately assert plus(2, 2) == 4 // after 1000ms assert plus(2, 2) == 4 // return immediately // at least 10 invocations cached def plusAtLeast = { ... }.memoizeAtLeast(10) // at most 10 invocations cached def plusAtMost = { ... }.memoizeAtMost(10) // between 10 and 20 invocations cached def plusAtLeast = { ... }.memoizeBetween(10, 20) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 23

Currying improvements @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 24

Currying improvements // right currying def divide = { a, b ‐> a / b } def halver = divide.rcurry(2) assert halver(8) == 4 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 24

Currying improvements // right currying def divide = { a, b ‐> a / b } def halver = divide.rcurry(2) assert halver(8) == 4 // currying n‐th parameter def joinWithSeparator = { one, sep, two ‐> one + sep + two } def joinWithComma = joinWithSeparator.ncurry(1, , ) assert joinWithComma(a, b) == a, b @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 24

Builtin JSON support• Consuming• Producing• Pretty-printing @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 25

Builtin JSON supportimport groovy.json.* def payload = new URL( "http://github.../json/commits/...").text def slurper = new JsonSlurper()def doc = slurper.parseText(payload) doc.commits.message.each { println it } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 26

Builtin JSON support import groovy.json.* def json = new JsonBuilder() json.person { name "Guillaume" age 33 pets "Hector", "Felix" } println json.toString() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 27

Builtin JSON support import groovy.json.* println JsonOutput.prettyPrint( {"person":{"name":"Guillaume","age":33, + "pets":["Hector","Felix"]}}) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 28

Builtin JSON support import groovy.json.* println JsonOutput.prettyPrint( {"person":{"name":"Guillaume","age":33, + "pets":["Hector","Felix"]}}) { "person": { "name": "Guillaume", "age": 33, "pets": [ "Hector", "Felix" ] } } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 28

New AST transformations• @Log • @Canonical – @ToString,• @Field – @EqualsAndHashCode, – @TupleConstructor• @AutoClone• @AutoExternalizable • @InheritConstructor • @WithReadLock• Controlling the execution of your code • @WithWriteLock – @ThreadInterrupt, – @TimedInterrupt, • @ListenerList – @ConditionalInterrupt @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 29

@Log• Four different loggers can be injected – @Log, @Commons, @Log4j, @Slf4j• Possible to implement your own strategy import groovy.util.logging.* @Log class Car { Car() { log.info Car constructed } } def c = new Car() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 30

@Log• Four different loggers can be injected – @Log, @Commons, @Log4j, @Slf4j• Possible to implement your own strategy import groovy.util.logging.* @Log class Car { Guarded Car() { w/ an if log.info Car constructed } } def c = new Car() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 30

@Field• Surprising scoping rules in scripts – variables are local to the run() method – variables arenʼt visible in methods • although visually the variable is in a surrounding scope• @Field creates a ﬁeld in the script class @Field List awe = [1, 2, 3] def awesum() { awe.sum() } assert awesum() == 6 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 31

Controlling code execution• Your application may run userʼs code – what if the code runs in inﬁnite loops or for too long? – what if the code consumes too many resources? @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 32

Controlling code execution• Your application may run userʼs code – what if the code runs in inﬁnite loops or for too long? – what if the code consumes too many resources?• 3 new transforms at your rescue – @ThreadInterrupt: adds Thread#isInterrupted checks so your executing thread stops when interrupted – @TimedInterrupt: adds checks in method and closure bodies to verify itʼs run longer than expected – @ConditionalInterrupt: adds checks with your own conditional logic to break out from the user code @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 32

Controlling code execution• Your application may run userʼs code – what if the code runs in inﬁnite loops or for too long? – what if the code consumes too many resources?• 3 new transforms at your rescue – @ThreadInterrupt: adds Thread#isInterrupted checks so your executing thread stops when interrupted – @TimedInterrupt: adds checks in method and closure bodies to verify itʼs run longer than expected – @ConditionalInterrupt: adds checks with your own conditional logic to break out from the user code• Also see compilation customizers later on @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 32

@ThreadInterrupt @ThreadInterrupt import groovy.transform.ThreadInterrupt while (true) { // eat lots of CPU } 33 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 33

@ThreadInterrupt @ThreadInterrupt import groovy.transform.ThreadInterrupt while (true) { { if (Thread.currentThread.isInterrupted()) throw new InterruptedException() } // eat lots of CPU } 33 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 33

@ThreadInterrupt @ThreadInterrupt import groovy.transform.ThreadInterrupt while (true) { { if (Thread.currentThread.isInterrupted()) throw new InterruptedException() } // eat lots of CPU }• Two optional annotation parameters available – checkOnMethodStart (true by default) – applyToAllClasses (true by default) 33 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 33

@TimedInterrupt @TimedInterrupt(10) import groovy.transform.TimedInterrupt while (true) { // eat lots of CPU }• InterruptedException thrown when checks indicate code ran longer than desired• Optional annotation parameters available – same as @ThreadInterrupt – value: for an amount of time duration – unit: for the time duration unit (TimeUnit.SECONDS) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 34

@ConditionalInterrupt• Specify your own condition to be inserted at the start of method and closure bodies – check for available resources, number of times run, etc.• Leverages closure annotation parameters from Groovy 1.8 @ConditionalInterrupt({ counter++ > 2 }) import groovy.transform.ConditionalInterrupt import groovy.transform.Field @Field int counter = 0 100.times { println executing script method... } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 35

@ToString• Provides a default toString() method to your types• Available annotation options – includeNames, includeFields, includeSuper, excludes import groovy.transform.ToString @ToString class Person { String name int age } println new Person(name: Pete, age: 15) // => Person(Pete, 15) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 36

@EqualsAndHashCode• Provides default implementations for equals() and hashCode() methods import groovy.transform.EqualsAndHashCode @EqualsAndHashCode class Coord { int x, y } def c1 = new Coord(x: 20, y: 5) def c2 = new Coord(x: 20, y: 5) assert c1 == c2 assert c1.hashCode() == c2.hashCode() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 37

@TupleConstructor• Provides a «classical» constructor with all properties• Several annotation parameter options available import groovy.transform.TupleConstructor @TupleConstructor class Person { String name int age } def m = new Person(Marion, 3) assert m.name == Marion assert m.age == 3 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 38

@Canonical• One annotation to rule them all! – @Canonical mixes together • @ToString • @EqualsAndHashCode • @TupleConstructor• You can customize behavior by combining @Canonical and one of the other annotations @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 39

@InheritConstructor• Classes like Exception are painful when extended, as all the base constructors should be replicatedclass CustomException extends Exception { CustomException() { super() } CustomException(String msg) { super(msg) } CustomException(String msg, Throwable t) { super(msg, t) } CustomException(Throwable t) { super(t) }} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 40

@InheritConstructor• Classes like Exception are painful when extended, as all the base constructors should be replicatedimport groovy.transform.*@InheritConstructorsclass CustomException extends Exception { CustomException() { super() } CustomException(String msg) { super(msg) } CustomException(String msg, Throwable t) { super(msg, t) } CustomException(Throwable t) { super(t) }} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 40

@WithReadLock, @WithWriteLock import groovy.transform.* class ResourceProvider { private final Map<String, String> data = new HashMap<>() @WithReadLock String getResource(String key) { return data.get(key) } @WithWriteLock void refresh() { //reload the resources into memory } } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 41

@WithReadLock, @WithWriteLock import groovy.transform.* class ResourceProvider { private final Map<String, String> data = new HashMap<>() { @WithReadLock String getResource(String key) { return data.get(key) } { @WithWriteLock void refresh() { //reload the resources into memory } } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 41

Miscelanous• Compilation customizers• Java 7 diamond operator• Slashy and dollar slashy strings• New GDK methods• (G)String to Enum coercion @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 42

Compilation customizers• Ability to apply some customization to the Groovy compilation process• Three available customizers – ImportCustomizer – ASTTransformationCustomizer – SecureASTCustomizer• But you can implement your own @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 43

Imports customizer def configuration = new CompilerConfiguration() def custo = new ImportCustomizer() custo.addStaticStar(Math.name) configuration.addCompilationCustomizers(custo) def result = new GroovyShell(configuration) .evaluate(" cos PI/3 ") @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 44

Applying an AST transformation def configuration = new CompilerConfiguration() configuration.addCompilationCustomizers( new ASTTransformationCustomizer(Log)) new GroovyShell(configuration).evaluate(""" class Car { Car() { log.info Car constructed } } log.info Constructing a car def c = new Car() """) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 45

Secure AST customizer Idea: Implement an «arithmetic shell» Being able control what a user script is allowed to do: only arithmetic expressions• Letʼs setup our environment – some imports – an import customizer to import java.lang.Math.* – prepare a secure AST customizerimport org.codehaus.groovy.control.customizers.*import org.codehaus.groovy.control.*import static org.codehaus.groovy.syntax.Types.* def imports = new ImportCustomizer().addStaticStars(java.lang.Math)def secure = new SecureASTCustomizer() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 46

Secure AST customizer ... secure.with { // disallow closure creation closuresAllowed = false // disallow method definitions methodDefinitionAllowed = false // empty white list => forbid imports importsWhitelist = [] staticImportsWhitelist = [] // only allow the java.lang.Math.* static import staticStarImportsWhitelist = [java.lang.Math ... @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 47

Secure AST customizer... // language tokens allowed tokensWhitelist = [ PLUS, MINUS, MULTIPLY, DIVIDE, MOD, POWER, PLUS_PLUS, MINUS_MINUS, COMPARE_EQUAL, COMPARE_NOT_EQUAL, COMPARE_LESS_THAN, COMPARE_LESS_THAN_EQUAL, COMPARE_GREATER_THAN, COMPARE_GREATER_THAN_EQUAL ] // types allowed to be used (including primitive types) constantTypesClassesWhiteList = [ Integer, Float, Long, Double, BigDecimal, Integer.TYPE, Long.TYPE, Float.TYPE, Double.TYPE ] // classes who are allowed to be receivers of method calls receiversClassesWhiteList = [ Math, Integer, Float, Double, Long, BigDecimal ]}... @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 48

Secure AST customizer• Ready to evaluate our arithmetic expressions! ... def config = new CompilerConfiguration() config.addCompilationCustomizers(imports, secure) def shell = new GroovyShell(config) shell.evaluate cos PI/3• But the following would have failed: shell.evaluate System.exit(0) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 49

Slashy and dollar slashy strings• Slashy strings are now multiline – particularly handy for multi-line regexs• Dollar slashy string notation introduced – a multiline GString with different escaping rules def (name, date) = ["Guillaume", "Oct, 26th"] def dollarSlashy = $/ Hello $name, today were ${date} $ dollar‐sign $$ dollar‐sign backslash / slash $/ slash /$ @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 50

New GDK methods @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures def map = [a: 1, bbb: 4, cc: 5, dddd: 2] @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures def map = [a: 1, bbb: 4, cc: 5, dddd: 2] assert map.max { it.key.size() }.key == dddd @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures def map = [a: 1, bbb: 4, cc: 5, dddd: 2] assert map.max { it.key.size() }.key == dddd assert map.min { it.value }.value == 1 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures def map = [a: 1, bbb: 4, cc: 5, dddd: 2] assert map.max { it.key.size() }.key == dddd assert map.min { it.value }.value == 1 // map withDefault() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures def map = [a: 1, bbb: 4, cc: 5, dddd: 2] assert map.max { it.key.size() }.key == dddd assert map.min { it.value }.value == 1 // map withDefault() def words = "one two two three three three".split() @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures def map = [a: 1, bbb: 4, cc: 5, dddd: 2] assert map.max { it.key.size() }.key == dddd assert map.min { it.value }.value == 1 // map withDefault() def words = "one two two three three three".split() def freq = [:].withDefault { k ‐> 0 } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

New GDK methods // count assert [2,4,2,1,3,5,2,4,3].count { it % 2 == 0 } == 5 // count by assert [0:2, 1:3] == [1,2,3,4,5].countBy{ it % 2 } assert [(true):2, (false):4] == Groovy.toList().countBy{ it == o } // min/max for maps with closures def map = [a: 1, bbb: 4, cc: 5, dddd: 2] assert map.max { it.key.size() }.key == dddd assert map.min { it.value }.value == 1 // map withDefault() def words = "one two two three three three".split() def freq = [:].withDefault { k ‐> 0 } words.each { freq[it] += 1 } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 51

(G)String to Enum coercion @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue } // coercion with as @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue } // coercion with as def r = "red" as Color @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue } // coercion with as def r = "red" as Color // implicit coercion @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue } // coercion with as def r = "red" as Color // implicit coercion Color b = "blue" @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue } // coercion with as def r = "red" as Color // implicit coercion Color b = "blue" // with GStrings too @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

(G)String to Enum coercion enum Color { red, green, blue } // coercion with as def r = "red" as Color // implicit coercion Color b = "blue" // with GStrings too def g = "${green}" as Color @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 52

Customizing the Groovysh prompt @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 53

Launching remote scripts• With the Groovy command, you can launch remote scripts > groovy http://groovyconsole.appspot.com/raw/110001• Be careful to what youʼre executing :-) @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 54

What’scookingfor 1.9?

Groovy 1.9 roadmap• Java 7 alignements: Project Coin – binary literals – underscore in literals – multicatch• JDK 7: InvokeDynamic• Towards a more modular Groovy• Static type checking and compilation• Miscelanous• What else? Your call! @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 56

Java 7 / JDK 7• Project Coin and InvokeDynamic @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 57

Binary literals• We had decimal, octal and hexadecimal notations for number literals• We can now use binary representations too int x = 0b10101111 assert x == 175 byte aByte = 0b00100001 assert aByte == 33 int anInt = 0b1010000101000101 assert anInt == 41285 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 58

Underscore in literals• Now we can also add underscores in number literals for more readability long creditCardNumber = 1234_5678_9012_3456L long socialSecurityNumbers = 999_99_9999L float monetaryAmount = 12_345_132.12 long hexBytes = 0xFF_EC_DE_5E long hexWords = 0xFFEC_DE5E long maxLong = 0x7fff_ffff_ffff_ffffL long alsoMaxLong = 9_223_372_036_854_775_807L long bytes = 0b11010010_01101001_10010100_10010010 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 59

Multicatch• One block for multiple exception caught – rather than duplicating the block try { /* ... */ } catch(IOException | NullPointerException e) { /* one block to treat 2 exceptions */ } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 60

InvokeDynamic• Groovy 1.9 will support JDK 7ʼs invokeDynamic – an «indy» branch started recently – compiler will have a ﬂag for compiling against JDK 7• Beneﬁts – more runtime performance! – in the long run, will allow us to get rid of code! • call site caching, thanks to MethodHandles • metaclass registry, thanks to ClassValues • will let the JIT inline calls more easily @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 61

Groovy Modularity• Groovyʼs «all» JAR weighs in at 4MB• Nobody needs everything – Template engine, Ant scripting, Swing UI building...• Provide a smaller core – and several smaller JARs per feature• Provide hooks for setting up EMCs / DGM methods, etc. @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 62

Static Type Checking• Goal: make the Groovy compiler «grumpy»! – and throw compilation errors (not at runtime)• Not everybody needs dynamic features all the time – think Java libraries scripting• Grumpy should... – tell you about your method or variable typos – complain if you call methods that donʼt exist – shout on assignments of wrong types – infer the types of your variables – ﬁgure out GDK methods – etc... @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 63

A typo in your variable or method namesimport groovy.transform.StaticTypes void method() {} @TypeChecked test() { // Cannot find matching method metthhoood() metthhoood() def name = "Guillaume" // variable naamme is undeclared println naamme} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 64

A typo in your variable or method namesimport groovy.transform.StaticTypes void method() {} @TypeChecked test() { // Cannot find matching method metthhoood() metthhoood() def name = "Guillaume" // variable naamme is undeclared Compilation println naamme errors!} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 64

Complain on wrong assignments// cannot assign value of type... to variable...int x = new Object()Set set = new Object() def o = new Object()int x = o String[] strings = [a,b,c]int str = strings[0] // cannot find matching method plus()int i = 0i += 1 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 65

Complain on wrong assignments// cannot assign value of type... to variable...int x = new Object()Set set = new Object() Compilation errors!def o = new Object()int x = o String[] strings = [a,b,c]int str = strings[0] // cannot find matching method plus()int i = 0i += 1 @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 65

Complain on wrong return typesString method() { String }// cannot assign value of type String...int x = method()// checks if/else branch return valuesint method() { if (true) { String } else { 42 }}// works for switch/case & try/catch/finally // transparent toString() impliedString greeting(String name) { def sb = new StringBuilder() sb << "Hi" << name} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 66

Complain on wrong return typesString method() { String }// cannot assign value of type String...int x = method() Compilation errors!// checks if/else branch return valuesint method() { if (true) { String } else { 42 }}// works for switch/case & try/catch/finally // transparent toString() impliedString greeting(String name) { def sb = new StringBuilder() sb << "Hi" << name} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 66

Type inference @TypeChecked test() { def name = " Guillaume " // String type infered (even inside GString) println "NAME = ${name.toUpperCase()}" // Groovy GDK method support // (GDK operator overloading too) println name.trim() int[] numbers = [1, 2, 3] // Element n is an int for (int n in numbers) { println n } } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 67

Staticly checked method & dynamic method @TypeChecked String greeting(String name) { // call method with dynamic behavior // but with proper signature generateMarkup(name.toUpperCase()) } // usual dynamic behavior String generateMarkup(String name) { def sw = new StringWriter() new MarkupBuilder(sw).html { body { div name } } sw.toString() } @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 68

Bytecode viewer• Groovy Consoleʼs bytecode viewer from the AST browser window – select class generation phase – select a class node @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 69

Disable Global AST transformations// witout a specific configuration, the AST builder worksdef shell = new GroovyShell()shell.evaluate(script) // passesdef config = new CompilerConfiguration()config.disabledGlobalASTTransformations = [org.codehaus.groovy.ast.builder.AstBuilderTransformation]def script = import org.codehaus.groovy.ast.builder.AstBuilder new AstBuilder().buildFromCode { "Hello" } // now with the configuration in place,// the AST builder transform is not appliedshell = new GroovyShell(config) // <‐‐ with the configurationshouldFail { shell.evaluate(script) // fails} @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 70

Summary @glaforge — http://glaforge.appspot.com ROCKS! — http://gplus.to/glaforge 71

Thank you! e L aforg pment aume vy Develo Guill Groo m Hea d of g mail.co aforge@ mail: gl glaforge e E @ o /glaforg T witter : http://gplus.t Go ogle+: @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 72

Q&A — Got questions, Really?

Image credits• Iceberg: http://hqworld.net/gallery/data/media/20/tip_of_the_iceberg.jpg• Bicycle: http://drunkcyclist.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=2131&g2_serialNumber=2• Pills: http://www.we-ew.com/wp-content/uploads/2011/01/plan-b-pills.jpg• Chains: http://2.bp.blogspot.com/-GXDVqUYSCa0/TVdBsON4tdI/AAAAAAAAAW4/EgJOUmAxB28/s1600/breaking-chains5_copy9611.jpg• Cooking: http://www.ﬂickr.com/photos/eole/449958332/sizes/l/• Oui nide iou: http://desencyclopedie.wikia.com/wiki/Fichier:Superdupont_we_need_you.jpg• Guitar: http://www.lelitteraire.com/IMG/breveon323.jpg• Trampoline: http://www.ﬁtness-online.fr/images/trampoline-1-m.jpg• Curry: http://www.pot-a-epices.com/wp-content/uploads/2009/02/curry1.jpg• Slurp: http://www.ohpacha.com/218-532-thickbox/gamelle-slurp.jpg• Caution: http://www.jeunes-epinay-sur-seine.fr/wp-content/uploads/2010/11/caution-colocation.jpg• Grumpy: http://mafeuilledechou.fr/__oneclick_uploads/2010/05/grumpy.jpg• Modularity: http://php.jglobal.com/blog/wp-content/uploads/2009/11/modularity.jpg• Agenda: http://www.plombiereslesbains.fr/images/stories/agenda.jpg• Java 7: http://geeknizer.com/wp-content/uploads/java7.jpg• WIP: http://www.connetport.com/wp-content/uploads/Work_in_progress.svg_.png• Grumpy 2: http://grumpy.division-par-zero.fr/wp-content/images/grumpy.jpg• @glaforge — http://glaforge.appspot.com — http://gplus.to/glaforge 74

Groovy Update - Guillaume Laforge - Greach 2011

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Groovy Update - Guillaume Laforge - Greach 2011 Presentation Transcript

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