[GROOVY-7274] Improve type inference for hash map -> Map<?, ?>

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 4.0.0-alpha-3, 3.0.20
• Component/s: Static compilation
• Assignee: Eric Milles
• Reporter: Hendy Irawan
• Created: 23/Jan/15 22:34
• Updated: 02/Dec/23 16:21
• Resolved: 31/Mar/21 01:09

Description

Currently we have to do this:

@CompileStatic
...
inserter.createNode([v: it.value, l: it.language] as Map<String, Object>, labelLabel)

If not we'll get:

Error:(81, 37) Groovyc: [Static type checking] - Cannot call org.neo4j.unsafe.batchinsert.BatchInserter#createNode(java.util.Map <java.lang.String, java.lang.Object>, org.neo4j.graphdb.Label[]) with arguments [java.util.LinkedHashMap <java.lang.String, java.lang.String>, org.neo4j.graphdb.Label]

But since the caller requests Map<String, Object>, Groovy can create the hashmap as <String, Object> instead of <String, String>... saving us from explicit type coercion even with @CompileStatic. (similar to Java7's diamond operator)

Issue Links

• is related to: GROOVY-7106 Improve coercion / implicit cast of map literals for @CompileStatic