nix_api_value.h File Reference

libexpr C bindings dealing with values More...

#include "nix_api_util.h"
#include "nix_api_store.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Go to the source code of this file.

Typedefs
typedef struct nix_value	nix_value
typedef struct EvalState	EvalState
typedef nix_value	Value
typedef struct BindingsBuilder	BindingsBuilder
	Stores an under-construction set of bindings.
typedef struct ListBuilder	ListBuilder
	Stores an under-construction list.
typedef struct PrimOp	PrimOp
	PrimOp function.
typedef struct ExternalValue	ExternalValue
	External Value.
typedef struct nix_realised_string	nix_realised_string
	String without placeholders, and realised store paths.
typedef void(*	PrimOpFun) (void *user_data, nix_c_context *context, EvalState *state, nix_value **args, nix_value *ret)
	Function pointer for primops.

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 }

Functions
PrimOp *	nix_alloc_primop (nix_c_context *context, PrimOpFun fun, int arity, const char *name, const char **args, const char *doc, void *user_data)
	Allocate a PrimOp.
nix_err	nix_register_primop (nix_c_context *context, PrimOp *primOp)
	add a primop to the builtins attribute set
nix_value *	nix_alloc_value (nix_c_context *context, EvalState *state)
	Allocate a Nix value.
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.
BindingsBuilder *	nix_make_bindings_builder (nix_c_context *context, EvalState *state, size_t capacity)
	Create a bindings builder.
nix_err	nix_bindings_builder_insert (nix_c_context *context, BindingsBuilder *builder, const char *name, nix_value *value)
	Insert bindings into a builder.
void	nix_bindings_builder_free (BindingsBuilder *builder)
	Free a bindings builder.
nix_realised_string *	nix_string_realise (nix_c_context *context, EvalState *state, nix_value *value, bool isIFD)
	Realise a string context.
const char *	nix_realised_string_get_buffer_start (nix_realised_string *realised_string)
	Start of the string.
size_t	nix_realised_string_get_buffer_size (nix_realised_string *realised_string)
	Length of the string.
size_t	nix_realised_string_get_store_path_count (nix_realised_string *realised_string)
	Number of realised store paths.
const StorePath *	nix_realised_string_get_store_path (nix_realised_string *realised_string, size_t index)
	Get a store path. The store paths are stored in an arbitrary order.
void	nix_realised_string_free (nix_realised_string *realised_string)
	Free a realised string.
Getters
ValueType	nix_get_type (nix_c_context *context, const nix_value *value)
	Get value type.
const char *	nix_get_typename (nix_c_context *context, const nix_value *value)
	Get type name of value as defined in the evaluator.
bool	nix_get_bool (nix_c_context *context, const nix_value *value)
	Get boolean value.
nix_err	nix_get_string (nix_c_context *context, const nix_value *value, nix_get_string_callback callback, void *user_data)
	Get the raw string.
const char *	nix_get_path_string (nix_c_context *context, const nix_value *value)
	Get path as string.
unsigned int	nix_get_list_size (nix_c_context *context, const nix_value *value)
	Get the length of a list.
unsigned int	nix_get_attrs_size (nix_c_context *context, const nix_value *value)
	Get the element count of an attrset.
double	nix_get_float (nix_c_context *context, const nix_value *value)
	Get float value in 64 bits.
int64_t	nix_get_int (nix_c_context *context, const nix_value *value)
	Get int value.
ExternalValue *	nix_get_external (nix_c_context *context, nix_value *value)
	Get external reference.
nix_value *	nix_get_list_byidx (nix_c_context *context, const nix_value *value, EvalState *state, unsigned int ix)
	Get the ix'th element of a list.
nix_value *	nix_get_attr_byname (nix_c_context *context, const nix_value *value, EvalState *state, const char *name)
	Get an attr by name.
bool	nix_has_attr_byname (nix_c_context *context, const nix_value *value, EvalState *state, const char *name)
	Check if an attribute name exists on a value.
nix_value *	nix_get_attr_byidx (nix_c_context *context, const nix_value *value, EvalState *state, unsigned int i, const char **name)
	Get an attribute by index in the sorted bindings.
const char *	nix_get_attr_name_byidx (nix_c_context *context, const nix_value *value, EvalState *state, unsigned int i)
	Get an attribute name by index in the sorted bindings.
Initializers
Values are typically "returned" by initializing already allocated memory that serves as the return value. For this reason, the construction of values is not tied their allocation. Nix is a language with immutable values. Respect this property by only initializing Values once; and only initialize Values that are meant to be initialized by you. Failing to adhere to these rules may lead to undefined behavior.
nix_err	nix_init_bool (nix_c_context *context, nix_value *value, bool b)
	Set boolean value.
nix_err	nix_init_string (nix_c_context *context, nix_value *value, const char *str)
	Set a string.
nix_err	nix_init_path_string (nix_c_context *context, EvalState *s, nix_value *value, const char *str)
	Set a path.
nix_err	nix_init_float (nix_c_context *context, nix_value *value, double d)
	Set a float.
nix_err	nix_init_int (nix_c_context *context, nix_value *value, int64_t i)
	Set an int.
nix_err	nix_init_null (nix_c_context *context, nix_value *value)
	Set null.
nix_err	nix_init_apply (nix_c_context *context, nix_value *value, nix_value *fn, nix_value *arg)
	Set the value to a thunk that will perform a function application when needed.
nix_err	nix_init_external (nix_c_context *context, nix_value *value, ExternalValue *val)
	Set an external value.
nix_err	nix_make_list (nix_c_context *context, ListBuilder *list_builder, nix_value *value)
	Create a list from a list builder.
ListBuilder *	nix_make_list_builder (nix_c_context *context, EvalState *state, size_t capacity)
	Create a list builder.
nix_err	nix_list_builder_insert (nix_c_context *context, ListBuilder *list_builder, unsigned int index, nix_value *value)
	Insert bindings into a builder.
void	nix_list_builder_free (ListBuilder *list_builder)
	Free a list builder.
nix_err	nix_make_attrs (nix_c_context *context, nix_value *value, BindingsBuilder *b)
	Create an attribute set from a bindings builder.
nix_err	nix_init_primop (nix_c_context *context, nix_value *value, PrimOp *op)
	Set primop.
nix_err	nix_copy_value (nix_c_context *context, nix_value *value, const nix_value *source)
	Copy from another value.

Detailed Description

libexpr C bindings dealing with values