unknownStable? (value -- isUnknownStable)

Builtins

Name introduction, declaration modifiers, and module binding: NAME: ...;, codeRef, def, exportFunction, importFunction, importVariable, overload, private, static, use, and virtual.
Struct construction forms: (...), {...}, and array.
Selection forms: source-text selection with NAME and .NAME, read-only source-text selection with @NAME and .@NAME, and ordinal or known-name data-input selection with @, callField, and fieldRead.
Writing forms: source-text selection with !NAME and .!NAME, ordinal selection with ! and fieldWrite, and already-selected destination replacement with set.
Calling and control flow: call, if, loop, ucall, and uif.
Text operations: &, LF, attribute, textSize, and textSplit.
Condition constants, value comparison, and logical operators: <, =, >, DEBUG, FALSE, TRUE, and, is, lshift, or, rshift, xor, and ~.
Arithmetic and numeric transforms: *, +, -, /, ^, cast, ceil, cos, floor, log, log10, mod, neg, sin, and sqrt.
Reference, creation, and value-state operations: const, dynamic, isConst, isDirty, isDynamic, isRef, isStatic, known?, new, newVarOfTheSameType, stable?, unconst, and unknownStable?.
Schema and struct introspection: code?, codeRef?, fieldCount, fieldIndex, fieldIsRef, fieldIsVirtual, fieldName, has, isCombined, managed?, same, schemaName, and virtual?.
Storage and manual lifetime operations: addressToReference, alignment, manuallyDestroyVariable, manuallyInitVariable, storageAddress, and storageSize.
Diagnostics and compile-time failure: failCompilation, getCallTrace, printCompilerMessage, printStack, printStackTrace, and raiseStaticError.

unknownStable? (value -- isUnknownStable)

Inputs

value: Current stack value whose unknown-stability is tested.

Outputs

isUnknownStable: Known Cond result that is TRUE when the current stack value stays stable after concrete contents are forgotten.

unknownStable? is the current stack-value forgotten-contents predicate. It tests whether current stability survives after concrete contents are forgotten.

This predicate follows the referenced target for known non-NIL Ref values. It is the same predicate as isDynamic. Fully known In-place values therefore report FALSE. Text, Code, and Meta values also report FALSE, including callable non-NIL Code values.

Behavior

A fully known In-place value reports FALSE.

An In-place value whose concrete contents have been forgotten, for example by dynamic, reports TRUE.

A known non-NIL Ref value reports TRUE only when its referenced target stays stable in that forgotten-contents state.

Known NIL Ref values and unknown Ref values report FALSE.

Text values report FALSE.

Code values report FALSE.

Meta values report FALSE.

Example

{} 0 {} [ value: 7; codeLocal: {} () {} codeRef; unknownValue: 0 dynamic; unknownText: 0 ("") dynamic @; [] !codeLocal "-- stable? versus unknownStable? for In-place values --" printCompilerMessage 7 stable? printStack _:; 7 unknownStable? printStack _:; 7 isDynamic printStack _:; unknownValue stable? printStack _:; unknownValue unknownStable? printStack _:; unknownValue isDynamic printStack _:; "-- stable? versus unknownStable? for references --" printCompilerMessage @value stable? printStack _:; @value unknownStable? printStack _:; @value isDynamic printStack _:; @value dynamic stable? printStack _:; @value dynamic unknownStable? printStack _:; @value dynamic isDynamic printStack _:; 0nx value addressToReference stable? printStack _:; 0nx value addressToReference unknownStable? printStack _:; 0nx value addressToReference isDynamic printStack _:; "-- stable? versus unknownStable? for text, code, meta --" printCompilerMessage "hi" stable? printStack _:; "hi" unknownStable? printStack _:; "hi" isDynamic printStack _:; unknownText stable? printStack _:; unknownText unknownStable? printStack _:; unknownText isDynamic printStack _:; {} () {} codeRef stable? printStack _:; {} () {} codeRef unknownStable? printStack _:; {} () {} codeRef isDynamic printStack _:; @codeLocal stable? printStack _:; @codeLocal unknownStable? printStack _:; @codeLocal isDynamic printStack _:; () stable? printStack _:; () unknownStable? printStack _:; () isDynamic printStack _:; 0 ] "main" exportFunction

Expected Output During Compilation

-- stable? versus unknownStable? for In-place values -- TRUE FALSE FALSE TRUE TRUE TRUE -- stable? versus unknownStable? for references -- TRUE FALSE FALSE TRUE TRUE TRUE FALSE FALSE FALSE -- stable? versus unknownStable? for text, code, meta -- TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE