lshift (value shiftCount -- shiftedValue)

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.

lshift (value shiftCount -- shiftedValue)

Inputs

value: Whole-number value to shift.

shiftCount: Whole-number shift amount.

Outputs

shiftedValue: Left-shift result in the same schema.

lshift consumes two Whole values. value provides the bits to shift and the schema of the result. shiftCount provides the shift amount and may use a different Whole schema.

The bits of value move to the left. Zero bits are inserted at the low end and bits shifted past the high end are discarded.

The result always keeps the same schema as value.

Behavior

For Nat and Int, zero bits are inserted at the low end.

If shiftCount uses an Int schema, its bit pattern is first reinterpreted as the matching Nat width. Non-negative Int shift counts therefore behave the same as equal-valued Nat shift counts.

For Int, the shifted bit pattern is interpreted again as the same signed schema. In Int32, 1 31 lshift therefore produces -2147483648.

If both inputs are known at compile time, the result is computed at compile time.

If value is known zero, the result is known zero even when shiftCount is unknown.

Otherwise, an unknown input produces an unknown result of the same schema as value.

Example

{} () {} [ "-- nat32 --" printCompilerMessage 3n32 2 lshift printStack _:; 3n32 1i8 lshift printStack _:; "-- nat8 dropped bits --" printCompilerMessage 0x80n8 1 lshift printStack _:; "-- zero and unknown shift --" printCompilerMessage unknownShift: 0n32 dynamic; 0n32 unknownShift lshift printStack _:; "-- unknown value and zero shiftCount --" printCompilerMessage unknownNat: 0n32 dynamic; unknownNat 0 lshift printStack _:; "-- int32 --" printCompilerMessage 5 1 lshift printStack _:; 1 31 lshift printStack _:; ] "main" exportFunction

Expected Output During Compilation

-- nat32 -- 12n32 6n32 -- nat8 dropped bits -- 0n8 -- zero and unknown shift -- 0n32 -- unknown value and zero shiftCount -- Nat32 -- int32 -- 10 -2147483648