This is an automated email from the ASF dual-hosted git repository.
asf-gitbox-commits pushed a commit to branch asf-site
in repository https://gitbox.apache.org/repos/asf/groovy-dev-site.git
The following commit(s) were added to refs/heads/asf-site by this push:
new bcb2c3c 2026/05/20 10:09:42: Generated dev website from
groovy-website@a5e1814
bcb2c3c is described below
commit bcb2c3c443e02c93e279a0c9a9e688a0f230bd17
Author: jenkins <[email protected]>
AuthorDate: Wed May 20 10:09:42 2026 +0000
2026/05/20 10:09:42: Generated dev website from groovy-website@a5e1814
---
search/search-index.json | 2 +-
wiki/GEP-19.html | 40 +++++++++++++++++++++-------------------
2 files changed, 22 insertions(+), 20 deletions(-)
diff --git a/search/search-index.json b/search/search-index.json
index 7268724..a0c8ced 100644
--- a/search/search-index.json
+++ b/search/search-index.json
@@ -905,7 +905,7 @@
{
"id": "wiki/GEP-19.html",
"title": "The Apache Groovy programming language - Developer docs -
GEP-19",
- "content": "The Apache Groovy programming language - Developer docs -
GEP-19 Socialize Discuss on the mailing list Groovy on X Groovy on Bluesky
Groovy on Mastodon Groovy on LinkedIn Events and conferences Source code on
GitHub Report issues in Jira Stack Overflow questions Slack Community You are
using an outdated browser. Please upgrade your browser to improve your
experience. Apache Groovy™ Learn Documentation Download Support
Contribute Ecosystem Blog posts Socialize GE [...]
+ "content": "The Apache Groovy programming language - Developer docs -
GEP-19 Socialize Discuss on the mailing list Groovy on X Groovy on Bluesky
Groovy on Mastodon Groovy on LinkedIn Events and conferences Source code on
GitHub Report issues in Jira Stack Overflow questions Slack Community You are
using an outdated browser. Please upgrade your browser to improve your
experience. Apache Groovy™ Learn Documentation Download Support
Contribute Ecosystem Blog posts Socialize GE [...]
"url": "wiki/GEP-19.html",
"site": "dev"
},
diff --git a/wiki/GEP-19.html b/wiki/GEP-19.html
index bb3c868..ac70eb5 100644
--- a/wiki/GEP-19.html
+++ b/wiki/GEP-19.html
@@ -172,15 +172,14 @@ We welcome feedback and discussion, but please keep in
mind that the details are
<div class="sectionbody">
<div class="paragraph">
<p>This GEP extends Groovy’s <code>switch</code> expression with
structural pattern
-matching for lists, maps, and types, building on the record patterns
-introduced in 5.0 and aligning with Java’s pattern-matching trajectory
-(JEPs 440, 441, 456, 507).</p>
+matching for lists, maps, records, and types, aligning with Java’s
+pattern-matching trajectory (JEPs 440, 441, 456, 507).</p>
</div>
<div class="paragraph">
<p>The proposal adds list patterns (<code>[var h, var…​
t]</code>), map patterns
-(<code>[name: var n, var…​ rest]</code>), type patterns with
binding (<code>String s</code>),
-guard clauses (<code>when</code>), and a unified wildcard form (<code>_</code>
inside record
-patterns; <code>var _</code> elsewhere). The same pattern grammar is also
accepted
+(<code>[name: var n, var…​ rest]</code>), record patterns
(<code>Type(var x, var y)</code>),
+type patterns with binding (<code>String s</code>), guard clauses
(<code>when</code>), and a
+unified wildcard form (<code>_</code> inside record patterns; <code>var
_</code> elsewhere). The same pattern grammar is also accepted
in <code>def […​] = …​</code> bracket-form
declarations, providing a consistent
destructuring grammar between switch case labels and assignment for
users who want it. The everyday parens form (<code>def (…​) =
…​</code>) is
@@ -200,9 +199,11 @@ markers that distinguish a structural pattern from a
legacy case label.</p>
<div class="paragraph">
<p>Groovy’s <code>switch</code> already exceeds Java’s classic
switch through the
<code>isCase</code> protocol — case labels can be classes, ranges, regex
patterns,
-collections, and closures. Groovy 5.0 added record patterns aligned with
-Java 21’s JEP 440. What remains absent is structural decomposition of
-the most common data shapes: lists, maps, and arrays.</p>
+collections, and closures. What remains absent is structural
+decomposition: type-narrowing bindings, record deconstruction, and the
+destructuring of the most common data shapes (lists and maps). This
+proposal adds all four together, aligned with Java’s pattern-matching
+trajectory (JEPs 440, 441, 456, 507).</p>
</div>
<div class="paragraph">
<p>Languages that have shipped this — Scala, Rust, Swift, Kotlin (limited),
@@ -305,16 +306,15 @@ type, binding a new local variable in the case body:</p>
<div class="paragraph">
<p>The bound name is narrowed to the declared type within the case body
and any <code>when</code> guard. <code>@CompileStatic</code> and
<code>@TypeChecked</code> see the
-narrowed type via the same flow analysis already used for record
-patterns.</p>
+narrowed type within the binding’s scope.</p>
</div>
</div>
<div class="sect2">
<h3 id="_record_patterns">Record patterns</h3>
<div class="paragraph">
-<p>Record patterns (introduced in Groovy 5.0) deconstruct record-typed
-values positionally. Component positions accept nested patterns,
-including the unnamed pattern <code>_</code>:</p>
+<p>Record patterns deconstruct record-typed values positionally.
+Component positions accept nested patterns, including the unnamed
+pattern <code>_</code>:</p>
</div>
<div class="listingblock">
<div class="content">
@@ -838,8 +838,10 @@ key-set difference for rest),</p>
</ul>
</div>
<div class="paragraph">
-<p>Record patterns reuse the lowering already present in 5.0. When Java’s
-deconstructor JEP ships, surface forms like
+<p>Record patterns lower via the same <code>Deconstructable</code> strategy: a
type
+check on the record class, component extraction via the record’s
+accessor methods, and recursive lowering for nested component patterns.
+When Java’s deconstructor JEP ships, surface forms like
<code>case List.of(var h, var…​ t) -></code> and
<code>case Map.of("name", var n) -></code> are accepted as additional
spellings
that lower to the same <code>Deconstructable</code> calls — no
re-architecture.</p>
@@ -893,12 +895,12 @@ side effects.</p>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Pattern
matching for <code>instanceof</code> (JEP 394, 16)</p></td>
<td class="tableblock halign-left valign-top"><p
class="tableblock">Shipped</p></td>
-<td class="tableblock halign-left valign-top"><p class="tableblock">Type and
record patterns valid in <code>instanceof</code></p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Type and
record patterns in <code>instanceof</code> added in this proposal</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Record
patterns (JEP 440, 21)</p></td>
<td class="tableblock halign-left valign-top"><p
class="tableblock">Shipped</p></td>
-<td class="tableblock halign-left valign-top"><p class="tableblock">Already in
Groovy 5.0; extended in this proposal</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Added in
this proposal</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Pattern
matching for <code>switch</code> (JEP 441, 21)</p></td>
@@ -1065,7 +1067,7 @@ triggered only by syntactic forms that currently fail to
parse:</p>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>case
String s →</code></p></td>
-<td class="tableblock halign-left valign-top"><p class="tableblock">No — new
(5.0 supported only <code>Type(…​)</code>)</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">No —
new</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>def
[var h, var…​ t] = list</code></p></td>
