isCombined (schema -- isCombined)

Inputs

• schema: Object or Ref object whose dereferenced schema is tested for the Struct group.

Outputs

• isCombined: Known Cond result that is TRUE when schema dereferences to any Struct.

isCombined is a dereferenced-schema predicate. It tests whether the dereferenced schema is any Struct.

isCombined reports the Struct schema group: a Dict, List, or Tuple, including the empty (). It is a schema-group test, not a field-count or nonempty-container test; current value contents do not participate.

Behavior

• Dict, List, and Tuple schemas produce TRUE, including the empty Tuple ().
• All non-Struct schemas produce FALSE.

Example

{} 0 {} [
  dict: { x: 1; };

  "-- Dict and Ref --" printCompilerMessage
  dict isCombined printStack _:;
  @dict isCombined printStack _:;
  dict fieldCount printStack _:;

  "-- empty Tuple --" printCompilerMessage
  () isCombined printStack _:;
  () fieldCount printStack _:;

  "-- non-Struct values --" printCompilerMessage
  0 isCombined printStack _:;
  [] isCombined printStack _:;

  0
] "main" exportFunction

Expected Output During Compilation

-- Dict and Ref --
TRUE
TRUE
1
-- empty Tuple --
TRUE
0
-- non-Struct values --
FALSE
FALSE

See also

• alignment builtin (schema -- alignment) Returns the storage alignment requirement of the dereferenced schema.
• code? builtin (schema -- isBlock) Historical Block dereferenced-schema test.
• codeRef? builtin (schema -- isCode) Code dereferenced-schema test.
• fieldCount builtin (schema -- itemCount) Item count of a Struct schema.
• has builtin (schema itemName -- hasName) Known-name presence test on a Struct schema.
• managed? builtin (schema -- isManaged) Managed-lifetime dereferenced-schema test.
• same builtin (leftSchema rightSchema -- isSameSchema) Exact dereferenced-schema equality test.
• schemaName builtin (schema -- reportedName) Reported name of the dereferenced schema.
• storageSize builtin (schema -- size) Returns the storage size of the dereferenced schema.
• virtual? builtin (schema -- isMeta) Historical Meta dereferenced-schema test.