Groovy update at SpringOne2GX 2012

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

What’s new in Groovy 2.0?
Guillaume Laforge
...

Guillaume Laforge
• Groovy Project Manager at VMware
• Initiator of the Grails framework
• Creator of the ...

Agenda (1/2)
• What’s in Groovy 1.8?
–Nicer DSLs with command chains
–Runtime performance improvements
...

Agenda (2/2)
• What’s new in Groovy 2.0?
–Alignments with JDK 7
• Project Coin (small language changes)
...

Command chains
• A grammar improvement allowing you
to drop dots & parens when chaining method calls
–an e...

Command chains

pull
request

on
github

6

Command chains
Alternation of
method names

pull
request

on
...

Command chains
Alternation of
method names

pull
request

on
...

Command chains

pull
request

on
github

6

Command chains

Equivalent to:

(

).

(

...

Command chains

7

Command chains
//
methods
with
multiple
arguments
(commas)

7

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

Command chains
//
methods
with
multiple
arguments
(commas)
take
coffee

with
...

GPars bundled
• GPars is bundled in the Groovy distribution

• GPars covers a wide range of parallel
and con...

Closure enhancements
• Closure annotation parameters

• Some more functional ﬂavor
–composition
• comp...

Closure annotation parameters
@Retention(RetentionPolicy.RUNTIME)
@interface
Invariant
{
...

Closure annotation parameters
@Retention(RetentionPolicy.RUNTIME)
@interface
Invariant
{
...

Closure memoization

11

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Closure memoization
def
plus
=
{
a,
b
-‐>
sleep
1000;
a
+
b
}.memoize()...

Builtin JSON support

• Consuming

• Producing

• Pretty-printing

12

Builtin JSON support

import
groovy.json.*

def
payload
=
new
URL(

...

Builtin JSON support

import
groovy.json.*

def
json
=
new
JsonBuilder()

...

Builtin JSON support

import
groovy.json.*

def
json
=
new
JsonBuilder()

...

Builtin JSON support
import
groovy.json.*

println
JsonOutput.prettyPrint(

...

New AST transformations
• @Log • Controlling execution
– @ThreadI...

@Log

• Four different loggers can be injected
–@Log import
groovy.util.logging.*...

@Log

• Four different loggers can be injected
–@Log import
groovy.util.logging.*...

Controlling code execution
• Your application may run user’s code
– what if the code runs in inﬁnite loops or ...

@ThreadInterrupt

@ThreadInterrupt
import
groovy.transform.ThreadInterrupt

...

@ThreadInterrupt

@ThreadInterrupt
import
groovy.transform.ThreadInterrupt

...

@ToString

• Provides a default
toString() method import
groovy.transform.ToString

...

@EqualsAndHashCode

• Provides default import
groovy.transform.EqualsAndHashCode

implementations ...

@TupleConstructor

• Provides a « classical » import
groovy.transform.TupleConstructor

constructor wi...

@InheritConstructors

• Classes like Exception are painful when extended,
as all the base constructors should ...

@InheritConstructors

• Classes like Exception are painful when extended,
as all the base constructors should ...

Miscellaneous
• Compilation customizers
• Java 7 diamond operator
• Slashy and dollar slashy strings
•...

Compilation customizers
• Ability to apply some customization to the Groovy compilation
process

• Three ...

Imports customizer

def
configuration
=
new
CompilerConfiguration()

def ...

What’s
in store
for 2.0?

Groovy 2.0 bird’s eye view

A more Java 7 Static Type
Project Coin Check...

Groovy 2.0 bird’s eye view

A more
modular
Groovy
29

Groovy Modularity
• Groovy’s « all » JAR weighs in at 6 MB

• Nobody needs everything
–Template engine, A...

The new JARs
• A smaller JAR: 3MB

• Modules
– console – jsr-223 – test
...

Extension modules
• Create your own module
–contribute instance extension methods

package
foo

...

Extension modules
• Create your own module Same structure
–contrib...

Extension modules
• Create your own module
–contribute class extension methods

package ...

Extension module descriptor
• Descriptor in: META-INF/services/
org.codehaus.groovy.runtime.ExtensionModule

...

Groovy 2.0 bird’s eye view

A more Java 7 Static Type
Project Coin Check...

Groovy 2.0 bird’s eye view

Java 7
Project Coin

I...

Java 7 / JDK 7

• Project Coin and InvokeDynamic

37

Binary literals
• We had decimal, octal and hexadecimal
notations for number literals
• We can now use bi...

Underscore in literals
• Now we can also add underscores
in number literals for more readability

l...

Multicatch
• One block for multiple exception caught
–rather than duplicating the block

try
{
...

InvokeDynamic
• Groovy 2.0 supports JDK 7’s invokeDynamic
–compiler has a ﬂag for compiling against JDK 7
...

Groovy 2.0 bird’s eye view

A more Java 7 Static Type
Project Coin Check...

Groovy 2.0 bird’s eye view

Static Type
Checking
Sta...

Static Type Checking
• Goal: make the Groovy compiler « grumpy »!
–and throw compilation errors (not at runtim...

Typos in a variable or method

import
groovy.transform.TypeChecked

...

Typos in a variable or method

import
groovy.transform.TypeChecked

...

Typos in a variable or method

Annotation can be at import
groovy.transform.TypeChecked

...

Wrong assignments

//
cannot
assign
value
of
type...
to
variable...
int
x
...

Wrong assignments

//
cannot
assign
value
of
type...
to
variable...
int
x
...

Wrong return types
//
checks
if/else
branch
return
values
@TypeChecked
...

Wrong return types
//
checks
if/else
branch
return
values
@TypeChecked
...

Type inference
@TypeChecked
test()
{

def
name
=
"

Guillaum...

Statically checked & dynamic methods
@TypeChecked
String
greeting(String
name)
{
...

Instanceof checks
@TypeChecked

void
test(Object
val)
{

if
(...

Instanceof checks
@TypeChecked

void
test(Object
val)
{

if
(...

Instanceof checks
@TypeChecked

void
test(Object
val)
{

if
(...

Lowest Upper Bound
• Represents the lowest « super » type classes have in common
–may be virtual (aka « non-de...

Lowest Upper Bound
• Represents the lowest « super » type classes have in common
–may be virtual (aka « non-de...

Lowest Upper Bound
• Represents the lowest « super » type classes have in common
–may be virtual (aka « non-de...

Flow typing
• Static type checking shouldn’t complain even for bad coding
practicies which work without type c...

Gotcha: static checking vs dynamic
• Type checking works at compile-time
–adding @TypeChecked doesn’t change b...

Gotcha: runtime metaprogramming

@TypeChecked

void
test()
{

...

Gotcha: runtime metaprogramming

@TypeChecked

void
test()
{

...

Gotcha: runtime metaprogramming

@TypeChecked

void
test()
{

...

Gotcha: explicit type for closures

@TypeChecked
test()
{

["a",
"b",
"c"].coll...

Gotcha: explicit type for closures

@TypeChecked
test()
{

["a",
"b",
"c"].coll...

Closure shared variables

@TypeChecked
test()
{

def
var
=...

Closure shared variables
var assigned in the closure:
...

Closure shared variables
var assigned in the closure:
...

Closure shared variables
var assigned in the closure:
...

Closure shared variables
class
A

{
void
foo()
{}
}
...

Closure shared variables
class
A

{
void
foo()
{}
}
...

Static Compilation
• Given your Groovy code can be type checked...
we can as well compile it « statically »

...

Static Compilation: advantages
• You gain:

–Type safety
• thanks to static type checking
...

Static Compilation: disadvantages
• But you loose:

–Dynamic features
• metaclass changes, categories...

Statically compiled & dynamic methods
@CompileStatic
String
greeting(String
name)
{
...

What about performance?
• Comparisons between:

–Java

–Groovy static compilation (Groovy 2.0)
–Gro...

What about performance?

Pi (π) Binary
...

Summary: Groovy 2.0 themes
• Modularity

• Embark the JDK 7 enhancements
–Project Coin
–Invoke Dyn...

Thank you!

e
e Laforg velopment
...

Questions & Answers
• Got questions, really?
Q&A

66

Image credits
• Bugs bunny: http://storage.canalblog.com/63/56/517188/47634843.jpeg
• Pills: http://www.we...

Share Slideshare

LinkedIn
Facebook
Twitter

Embed

Size (px)

Show related Slideshows at end

WordPress Shortcode

Link

Share
Email

Groovy Domain Specific Languages - ... by Guillaume Laforge 5108 views

View on Slideshare

1 of 120 Ad

View on Slideshare

1 of 120 Ad