This module implements an interface to Nim's runtime type information (RTTI). See the marshal module for an example of what this allows you to do.

Note: Even though Any and its operations hide the nasty low level details from its users, it remains inherently unsafe! Also, Nim's runtime type information will evolve and may eventually be deprecated. As an alternative approach to programmatically understanding and manipulating types, consider using the macros module to work with the types' AST representation at compile time. See for example the getTypeImpl proc. As an alternative approach to storing arbitrary types at runtime, consider using generics.

Example:

import std/typeinfo
var x: Any

var i = 42
x = i.toAny
assert x.kind == akInt
assert x.getInt == 42

var s = @[1, 2, 3]
x = s.toAny
assert x.kind == akSequence
assert x.len == 3

Imports

strimpl

Types

Any = object value: pointer when defined(js): rawType: PNimType else: rawTypePtr: pointer: A type that can represent any nim value.
Danger: The wrapped value can be modified with its wrapper! This means that Any keeps a non-traced pointer to its wrapped value and must not live longer than its wrapped value.
Source Edit
AnyKind = enum akNone = 0, ## invalid akBool = 1, ## bool akChar = 2, ## char akEnum = 14, ## enum akArray = 16, ## array akObject = 17, ## object akTuple = 18, ## tuple akSet = 19, ## set akRange = 20, ## range akPtr = 21, ## ptr akRef = 22, ## ref akSequence = 24, ## sequence akProc = 25, ## proc akPointer = 26, ## pointer akString = 28, ## string akCString = 29, ## cstring akInt = 31, ## int akInt8 = 32, ## int8 akInt16 = 33, ## int16 akInt32 = 34, ## int32 akInt64 = 35, ## int64 akFloat = 36, ## float akFloat32 = 37, ## float32 akFloat64 = 38, ## float64 akFloat128 = 39, ## float128 akUInt = 40, ## uint akUInt8 = 41, ## uint8 akUInt16 = 42, ## uin16 akUInt32 = 43, ## uint32 akUInt64 = 44 ## uint64: The kind of Any. Source Edit

Procs

proc `[]=`(x, y: Any) {....raises: [], tags: [].}: Dereference operator for Any. x needs to represent a ptr or a ref. Source Edit
proc `[]=`(x: Any; fieldName: string; value: Any) {....raises: [ValueError], tags: [].}: Sets a field of x. x needs to represent an object or a tuple. Source Edit
proc `[]=`(x: Any; i: int; y: Any) {....raises: [ValueError], tags: [].}: Accessor for an any x that represents an array or a sequence. Source Edit
proc `[]`(x: Any): Any {....raises: [], tags: [].}: Dereference operator for Any. x needs to represent a ptr or a ref. Source Edit
proc `[]`(x: Any; fieldName: string): Any {....raises: [ValueError], tags: [].}: Gets a field of x. x needs to represent an object or a tuple. Source Edit
proc `[]`(x: Any; i: int): Any {....raises: [ValueError], tags: [].}: Accessor for an any x that represents an array or a sequence. Source Edit
proc assign(x, y: Any) {....raises: [], tags: [].}: Copies the value of y to x. The assignment operator for Any does NOT do this; it performs a shallow copy instead! Source Edit
proc base(x: Any): Any {....raises: [], tags: [].}: Returns the base type of x (useful for inherited object types). Source Edit
proc baseTypeKind(x: Any): AnyKind {.inline, ...raises: [], tags: [].}: Gets the base type's kind. If x has no base type, akNone is returned. Source Edit
proc baseTypeSize(x: Any): int {.inline, ...raises: [], tags: [].}: Returns the size of x's base type. If x has no base type, 0 is returned. Source Edit
proc extendSeq(x: Any) {....raises: [], tags: [].}: Performs setLen(x, x.len+1). x needs to represent a seq. Source Edit
proc getBiggestFloat(x: Any): BiggestFloat {....raises: [], tags: [].}: Retrieves the float value out of x. x needs to represent some float. The value is extended to BiggestFloat. Source Edit
proc getBiggestInt(x: Any): BiggestInt {....raises: [], tags: [].}: Retrieves the integer value out of x. x needs to represent some integer, a bool, a char, an enum or a small enough bit set. The value might be sign-extended to BiggestInt. Source Edit
proc getBiggestUint(x: Any): uint64 {....raises: [], tags: [].}: Retrieves the unsigned integer value out of x. x needs to represent an unsigned integer. Source Edit
proc getBool(x: Any): bool {....raises: [], tags: [].}: Retrieves the bool value out of x. x needs to represent a bool. Source Edit
proc getChar(x: Any): char {....raises: [], tags: [].}: Retrieves the char value out of x. x needs to represent a char. Source Edit
proc getCString(x: Any): cstring {....raises: [], tags: [].}: Retrieves the cstring value out of x. x needs to represent a cstring. Source Edit
proc getEnumField(x: Any): string {....raises: [], tags: [].}: Gets the enum field name as a string. x needs to represent an enum. Source Edit
proc getEnumField(x: Any; ordinalValue: int): string {....raises: [], tags: [].}: Gets the enum field name as a string. x needs to represent an enum but is only used to access the type information. The field name of ordinalValue is returned. Source Edit
proc getEnumOrdinal(x: Any; name: string): int {....raises: [], tags: [].}: Gets the enum field ordinal from name. x needs to represent an enum but is only used to access the type information. In case of an error low(int) is returned. Source Edit
proc getFloat(x: Any): float {....raises: [], tags: [].}: Retrieves the float value out of x. x needs to represent a float. Source Edit
proc getFloat32(x: Any): float32 {....raises: [], tags: [].}: Retrieves the float32 value out of x. x needs to represent a float32. Source Edit
proc getFloat64(x: Any): float64 {....raises: [], tags: [].}: Retrieves the float64 value out of x. x needs to represent a float64. Source Edit
proc getInt(x: Any): int {....raises: [], tags: [].}: Retrieves the int value out of x. x needs to represent an int. Source Edit
proc getInt8(x: Any): int8 {....raises: [], tags: [].}: Retrieves the int8 value out of x. x needs to represent an int8. Source Edit
proc getInt16(x: Any): int16 {....raises: [], tags: [].}: Retrieves the int16 value out of x. x needs to represent an int16. Source Edit
proc getInt32(x: Any): int32 {....raises: [], tags: [].}: Retrieves the int32 value out of x. x needs to represent an int32. Source Edit
proc getInt64(x: Any): int64 {....raises: [], tags: [].}: Retrieves the int64 value out of x. x needs to represent an int64. Source Edit
proc getPointer(x: Any): pointer {....raises: [], tags: [].}: Retrieves the pointer value out of x. x needs to be of kind akString, akCString, akProc, akRef, akPtr, akPointer or akSequence. Source Edit
proc getString(x: Any): string {....raises: [], tags: [].}: Retrieves the string value out of x. x needs to represent a string. Source Edit
proc getUInt(x: Any): uint {....raises: [], tags: [].}: Retrieves the uint value out of x. x needs to represent a uint. Source Edit
proc getUInt8(x: Any): uint8 {....raises: [], tags: [].}: Retrieves the uint8 value out of x. x needs to represent a uint8. Source Edit
proc getUInt16(x: Any): uint16 {....raises: [], tags: [].}: Retrieves the uint16 value out of x. x needs to represent a uint16. Source Edit
proc getUInt32(x: Any): uint32 {....raises: [], tags: [].}: Retrieves the uint32 value out of x. x needs to represent a uint32. Source Edit
proc getUInt64(x: Any): uint64 {....raises: [], tags: [].}: Retrieves the uint64 value out of x. x needs to represent a uint64. Source Edit
proc inclSetElement(x: Any; elem: int) {....raises: [], tags: [].}: Includes an element elem in x. x needs to represent a Nim bitset. Source Edit
proc invokeNew(x: Any) {....raises: [], tags: [].}: Performs new(x). x needs to represent a ref. Source Edit
proc invokeNewSeq(x: Any; len: int) {....raises: [], tags: [].}: Performs newSeq(x, len). x needs to represent a seq. Source Edit
proc isNil(x: Any): bool {....raises: [], tags: [].}: isNil for an x that represents a cstring, proc or some pointer type. Source Edit
proc kind(x: Any): AnyKind {.inline, ...raises: [], tags: [].}: Gets the type kind. Source Edit
proc len(x: Any): int {....raises: [], tags: [].}: len for an any x that represents an array or a sequence. Source Edit
proc setBiggestFloat(x: Any; y: BiggestFloat) {....raises: [], tags: [].}: Sets the float value of x. x needs to represent some float. Source Edit
proc setBiggestInt(x: Any; y: BiggestInt) {....raises: [], tags: [].}: Sets the integer value of x. x needs to represent some integer, a bool, a char, an enum or a small enough bit set. Source Edit
proc setBiggestUint(x: Any; y: uint64) {....raises: [], tags: [].}: Sets the unsigned integer value of x. x needs to represent an unsigned integer. Source Edit
proc setObjectRuntimeType(x: Any) {....raises: [], tags: [].}: This needs to be called to set x's runtime object type field. Source Edit
proc setPointer(x: Any; y: pointer) {....raises: [], tags: [].}: Sets the pointer value of x. x needs to be of kind akString, akCString, akProc, akRef, akPtr, akPointer or akSequence. Source Edit
proc setString(x: Any; y: string) {....raises: [], tags: [].}: Sets the string value of x. x needs to represent a string. Source Edit
proc size(x: Any): int {.inline, ...raises: [], tags: [].}: Returns the size of x's type. Source Edit
proc skipRange(x: Any): Any {....raises: [], tags: [].}: Skips the range information of x. Source Edit
proc toAny[T](x: var T): Any {.inline.}: Constructs an Any object from x. This captures x's address, so x can be modified with its Any wrapper! The caller needs to ensure that the wrapper does not live longer than x! Source Edit

Iterators

iterator elements(x: Any): int {....raises: [], tags: [].}: Iterates over every element of x. x needs to represent a set. Source Edit
iterator fields(x: Any): tuple[name: string, any: Any] {....raises: [], tags: [].}: Iterates over every active field of x. x needs to represent an object or a tuple. Source Edit