Upgrade to riddl 2.0.0-rc.10-57-e012ebb9

Pin bumped to match ../bin/riddlc, then `sbt extractGrammar`.

The grammar gains the optional second binder on `foreach`, which
destructures a mapping into key and value. Arity against the collection's
type is a validation rule rather than a grammatical one, so both shapes
parse and the diagnostic can name the actual type.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: reid-spencer

build.sbt

@@ -24,7 +24,7 @@ lazy val root = Root(
   // Keep these two lines in step: bumping the riddl version may require
   // bumping this one to whatever riddl built with.
   With.Scala3.configure(version = Some("3.9.0-RC4")),
-  With.Riddl.library(version = "2.0.0-rc.10-46-286ef815", nonJVMDependency = false)
+  With.Riddl.library(version = "2.0.0-rc.10-57-e012ebb9", nonJVMDependency = false)
 ).settings(
   resolvers += "GitHub Package Registry" at "https://maven.pkg.github.com/ossuminc/riddl",
 

sites/riddl/docs/references/riddl-grammar.ebnf

@@ -277,8 +277,11 @@ match_subject = get_value | literal_string | value_ref ;
 match_case = "case" match_pattern ["when" boolean_expression] "{" {statement} "}" ;
 match_pattern = comparison_operator comparand | literal_string | type_ref ;
 (* A25: `foreach <element> in <collection> { <statements> }`; `field <path>` collection is a
-   FieldRef, a bare identifier is a `let`-bound local *)
-foreach_statement = "foreach" identifier "in" (field_ref | identifier) "{" {statement} "}" ;
+   FieldRef, a bare identifier is a `let`-bound local. The optional second identifier destructures
+   a mapping into key and value; arity against the collection's type is a validation rule, not a
+   grammatical one, so both forms parse here. *)
+foreach_statement = "foreach" identifier ["," identifier] "in" (field_ref | identifier)
+                    "{" {statement} "}" ;
 
 (* Message operations. A54: the message operand is a bare ref or an inline constructor. *)
 message_value = constructor | message_ref ;