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Posted to notifications@groovy.apache.org by keeganwitt <gi...@git.apache.org> on 2015/08/21 06:55:51 UTC
[GitHub] incubator-groovy pull request: Document primitive autowrapping
GitHub user keeganwitt opened a pull request:
https://github.com/apache/incubator-groovy/pull/94
Document primitive autowrapping
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/keeganwitt/incubator-groovy doc-primitives
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/incubator-groovy/pull/94.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #94
----
commit 4de0b6176142c63581f3807ba794db795e89bd87
Author: Keegan Witt <ke...@gmail.com>
Date: 2015-08-21T04:51:35Z
document primitive autowrapping
----
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[GitHub] incubator-groovy pull request: Document primitive autowrapping
Posted by keeganwitt <gi...@git.apache.org>.
Github user keeganwitt commented on a diff in the pull request:
https://github.com/apache/incubator-groovy/pull/94#discussion_r37699872
--- Diff: src/spec/doc/core-differences-java.adoc ---
@@ -260,6 +260,19 @@ with exception.
include::{projectdir}/src/spec/test/DifferencesFromJavaTest.groovy[tags=chars_c_vs_groovy_cast,indent=0]
----
+== Primitives and wrappers
+
+Because uses Objects for everything, it link:core-object-orientation.html#_primitive_types[autowraps] references
--- End diff --
Oops. Yes I did, thank you.
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[GitHub] incubator-groovy pull request: Document primitive autowrapping
Posted by shils <gi...@git.apache.org>.
Github user shils commented on a diff in the pull request:
https://github.com/apache/incubator-groovy/pull/94#discussion_r37697087
--- Diff: src/spec/doc/core-differences-java.adoc ---
@@ -260,6 +260,19 @@ with exception.
include::{projectdir}/src/spec/test/DifferencesFromJavaTest.groovy[tags=chars_c_vs_groovy_cast,indent=0]
----
+== Primitives and wrappers
+
+Because uses Objects for everything, it link:core-object-orientation.html#_primitive_types[autowraps] references
--- End diff --
Did you mean 'Because Groovy uses Objects for everything..' ?
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[GitHub] incubator-groovy pull request: Document primitive autowrapping
Posted by keeganwitt <gi...@git.apache.org>.
Github user keeganwitt commented on a diff in the pull request:
https://github.com/apache/incubator-groovy/pull/94#discussion_r37699868
--- Diff: src/spec/doc/core-object-orientation.adoc ---
@@ -35,6 +35,51 @@ Groovy supports the same primitive types as those defined by the {jls}[Java Lang
* `boolean` type (exactly `true` or `false`)
* `char` type (16 bit, usable as a numeric type, representing an UTF-16 code)
+While Groovy declares and stores primitive fields and variables as primitives, because it uses Objects for
+everything, it autowraps references to primitives. Just like Java, the wrappers it uses are
+
+[cols="1,1" options="header"]
+.primitive wrappers
+|====
+| Primitive type
+| Wrapper class
+
+| boolean
+| Boolean
+
+| char
+| Character
+
+| short
+| Short
+
+| int
+| Integer
+
+| long
+| Long
+
+| float
+| Float
+
+| double
+| Double
+|====
+
+Here's an example using `int`
+
+[source,groovy]
+----
+include::{projectdir}/src/spec/test/PrimitiveTest.groovy[tags=primitive_references,indent=0]
+----
+
+Now you may be concerned that this means every time you use a mathematical operator on a reference to a primitive
+that you'll incur the cost of unboxing and reboxing the primitive. But this is not the case, as Groovy will compile
+your operators into their link:core-operators.html#_operator-overloading[method equivalents] and uses those instead.
+Additionally, Groovy will automatically unbox to a primitive when calling Java that takes a primitive parameter and
--- End diff --
Yes, that is what I meant. I'll make this change.
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[GitHub] incubator-groovy pull request: Document primitive autowrapping
Posted by asfgit <gi...@git.apache.org>.
Github user asfgit closed the pull request at:
https://github.com/apache/incubator-groovy/pull/94
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[GitHub] incubator-groovy pull request: Document primitive autowrapping
Posted by shils <gi...@git.apache.org>.
Github user shils commented on a diff in the pull request:
https://github.com/apache/incubator-groovy/pull/94#discussion_r37697139
--- Diff: src/spec/doc/core-object-orientation.adoc ---
@@ -35,6 +35,51 @@ Groovy supports the same primitive types as those defined by the {jls}[Java Lang
* `boolean` type (exactly `true` or `false`)
* `char` type (16 bit, usable as a numeric type, representing an UTF-16 code)
+While Groovy declares and stores primitive fields and variables as primitives, because it uses Objects for
+everything, it autowraps references to primitives. Just like Java, the wrappers it uses are
+
+[cols="1,1" options="header"]
+.primitive wrappers
+|====
+| Primitive type
+| Wrapper class
+
+| boolean
+| Boolean
+
+| char
+| Character
+
+| short
+| Short
+
+| int
+| Integer
+
+| long
+| Long
+
+| float
+| Float
+
+| double
+| Double
+|====
+
+Here's an example using `int`
+
+[source,groovy]
+----
+include::{projectdir}/src/spec/test/PrimitiveTest.groovy[tags=primitive_references,indent=0]
+----
+
+Now you may be concerned that this means every time you use a mathematical operator on a reference to a primitive
+that you'll incur the cost of unboxing and reboxing the primitive. But this is not the case, as Groovy will compile
+your operators into their link:core-operators.html#_operator-overloading[method equivalents] and uses those instead.
+Additionally, Groovy will automatically unbox to a primitive when calling Java that takes a primitive parameter and
--- End diff --
'when calling a Java method that takes a primitive parameter..' ?
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