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https://issues.apache.org/jira/browse/GROOVY-12724?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18140930#comment-18140930
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ASF GitHub Bot commented on GROOVY-12724:
-----------------------------------------
blackdrag commented on code in PR #3259:
URL: https://github.com/apache/groovy/pull/3259#discussion_r4509525415
##########
subprojects/groovy-ginq/src/main/groovy/org/apache/groovy/ginq/provider/collection/runtime/Queryable.java:
##########
@@ -516,6 +518,42 @@ default Queryable<T> union(Queryable<? extends T>
queryable) {
*/
List<T> toList();
+ /**
+ * Iterates the materialized elements. A static {@code for} loop calls this
+ * rather than wrapping the query as a single value.
+ *
+ * @return an iterator over the elements
+ * @since 7.0.0
+ */
+ default Iterator<T> iterator() {
+ return toList().iterator();
+ }
+
+ /**
+ * Coerces this query. Implementations that know the target type override
it.
+ *
+ * @param type the requested type
+ * @return the coerced value
+ * @since 7.0.0
+ */
+ default Object asType(Class<?> type) {
+ if (type == Queryable.class || List.class == type || Collection.class
== type || Iterable.class == type) {
+ return type == Queryable.class ? this : toList();
+ }
+ return this;
Review Comment:
if I do `def foo = queryable as Foo` then this code does not ensure `foo`
will be compatible with `Foo`. After the special casing is done you should
instead delegate to DGM or throw a GroovyCastException here.
> GINQ: support static compilation and a fluent query API
> -------------------------------------------------------
>
> Key: GROOVY-12724
> URL: https://issues.apache.org/jira/browse/GROOVY-12724
> Project: Groovy
> Issue Type: Improvement
> Components: GINQ
> Reporter: Daniel Sun
> Assignee: Daniel Sun
> Priority: Major
>
> Under @CompileStatic / @TypeChecked, GQ, GQL, and @GQ currently rely on
> dynamic lowering. This improvement makes those entry points usable from a
> statically checked scope while keeping the SQL-like syntax lowered to the
> in-memory collection runtime.
> h3. Goals
> * Allow GQ / GQL / @GQ from @CompileStatic and @TypeChecked without forcing
> the lowered tree through static checking at the expression site.
> * Defer pipeline construction with LazyQueryable until a terminal read
> (toList, count, etc.), copying locals at the expression site (same binding as
> dynamic GQ).
> * Add Ginq.from(...) as a deferred, generic fluent chain on the same runtime,
> with @ClosureParams so where/select/join/aggregate closures can infer element
> types where inference is sound.
> * Preserve default lazy/deferred evaluation and dynamic GQ behavior for map
> rows and other intentionally dynamic cases.
> h3. Non-goals / known limits
> * Stored untyped Closure variables still need a SAM target type for parameter
> inference (same as Java/C#).
> * Raw Query parameters/fields cannot recover a safe element type.
> * Names bound by from inside GQ / GQL / @GQ stay dynamic by design; callers
> that need checked element types use Ginq.from.
> h3. Related work
> GitHub PR: https://github.com/apache/groovy/pull/3259
> Stacked on GEP-26 SQL window work (PR #3167 / gep26-sql-window).
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