nix_value type and core operations for working with Nix values More...

Data Structures
struct	nix_value
	A Nix language value, or thunk that may evaluate to a value. More...

Enumerations
enum	ValueType { NIX_TYPE_THUNK , NIX_TYPE_INT , NIX_TYPE_FLOAT , NIX_TYPE_BOOL , NIX_TYPE_STRING , NIX_TYPE_PATH , NIX_TYPE_NULL , NIX_TYPE_ATTRS , NIX_TYPE_LIST , NIX_TYPE_FUNCTION , NIX_TYPE_EXTERNAL , NIX_TYPE_FAILED }
	Represents the state of a Nix value. More...

Functions
nix_err	nix_value_incref (nix_c_context context, nix_value value)
	Increment the garbage collector reference counter for the given nix_value.
nix_err	nix_value_decref (nix_c_context context, nix_value value)
	Decrement the garbage collector reference counter for the given object.

Detailed Description

nix_value type and core operations for working with Nix values

See also: Value Creation; Value Extraction

Enumeration Type Documentation

◆ ValueType

enum ValueType

Represents the state of a Nix value.

Thunk values (NIX_TYPE_THUNK) change to their final, unchanging type when forced.

See also: https://nix.dev/manual/nix/latest/language/evaluation.html

Enumerator
NIX_TYPE_THUNK	Unevaluated expression Thunks often contain an expression and closure, but may contain other representations too. Their state is mutable, unlike that of the other types.
NIX_TYPE_INT	A 64 bit signed integer.
NIX_TYPE_FLOAT	IEEE 754 double precision floating point number. See also https://nix.dev/manual/nix/latest/language/types.html#type-float
NIX_TYPE_BOOL	Boolean true or false value. See also https://nix.dev/manual/nix/latest/language/types.html#type-bool
NIX_TYPE_STRING	String value with context. String content may contain arbitrary bytes, not necessarily UTF-8. See also https://nix.dev/manual/nix/latest/language/types.html#type-string
NIX_TYPE_PATH	Filesystem path. See also https://nix.dev/manual/nix/latest/language/types.html#type-path
NIX_TYPE_NULL	Null value. See also https://nix.dev/manual/nix/latest/language/types.html#type-null
NIX_TYPE_ATTRS	Attribute set (key-value mapping). See also https://nix.dev/manual/nix/latest/language/types.html#type-attrs
NIX_TYPE_LIST	Ordered list of values. See also https://nix.dev/manual/nix/latest/language/types.html#type-list
NIX_TYPE_FUNCTION	Function (lambda or builtin). See also https://nix.dev/manual/nix/latest/language/types.html#type-function
NIX_TYPE_EXTERNAL	External value from C++ plugins or C API. See also Externals

Function Documentation

◆ nix_value_decref()

nix_err nix_value_decref	(	nix_c_context *	context,
		nix_value *	value )

Decrement the garbage collector reference counter for the given object.

When the counter reaches zero, the nix_value object becomes invalid. The data referenced by nix_value may not be deallocated until the memory garbage collector has run, but deallocation is not guaranteed.

Parameters

[out]	context	Optional, stores error information
[in]	Value	The object to stop referencing

◆ nix_value_incref()

nix_err nix_value_incref	(	nix_c_context *	context,
		nix_value *	value )

Increment the garbage collector reference counter for the given nix_value.

The Nix language evaluator C API keeps track of alive objects by reference counting. When you're done with a refcounted pointer, call nix_value_decref().