Sratom 0.6.22 documentation

# Sratom

Sratom is a small library for serializing LV2 atoms. Sratom reads/writes atoms from/to RDF, allowing them to be converted between binary and text or stored in a model.

## Overview

The complete API is declared in `sratom.h`:

    #include <sratom/sratom.h>

## Sratom C API

typedef struct SratomImpl Sratom

  Atom serializer.

enum SratomObjectMode

  Mode for reading resources to LV2 Objects.

  This affects how resources (which are either blank nodes or have URIs) are read by `sratom_read()`, since they may be read as simple references (a URI or blank node ID) or a complete description (an atom “Object”).

  Currently, blank nodes are always read as Objects, but support for reading blank node IDs may be added in the future.

  enumerator SRATOM_OBJECT_MODE_BLANK

    Read blank nodes as Objects, and named resources as URIs.

  enumerator SRATOM_OBJECT_MODE_BLANK_SUBJECT

    Read blank nodes and the main subject as Objects.

    Any other named resources are read as URIs. The “main subject” is the subject parameter passed to `sratom_read()`; if this is a resource it will be read as an Object, but all other named resources encountered will be read as URIs.

LV2_Atom *sratom_forge_deref(LV2_Atom_Forge_Sink_Handle handle, LV2_Atom_Forge_Ref ref)

  The corresponding deref function for sratom_forge_sink.

LV2_Atom_Forge_Ref sratom_forge_sink(LV2_Atom_Forge_Sink_Handle handle, const void *buf, uint32_t size)

  A convenient resizing sink for LV2_Atom_Forge.

  The handle must point to an initialized SerdChunk.

void sratom_free(Sratom *sratom)

  Free an Atom serializer.

LV2_Atom *sratom_from_turtle(Sratom *sratom, const char *base_uri, const SerdNode *subject, const SerdNode *predicate, const char *str)

  Read an Atom from a Turtle string.

  The returned atom must be free()’d by the caller.

Sratom *sratom_new(LV2_URID_Map *map)

  Create a new Atom serializer.

void sratom_read(Sratom *sratom, LV2_Atom_Forge *forge, SordWorld *world, SordModel *model, const SordNode *node)

  Read an Atom from RDF.

  The resulting atom will be written to `forge`.

void sratom_set_env(Sratom *sratom, SerdEnv *env)

  Set the environment for reading or writing Turtle.

  This can be used to set namespace prefixes and a base URI for `sratom_to_turtle()` and `sratom_from_turtle()`.

void sratom_set_object_mode(Sratom *sratom, SratomObjectMode object_mode)

  Configure how resources will be read to form LV2 Objects.

void sratom_set_pretty_numbers(Sratom *sratom, bool pretty_numbers)

  Write pretty numeric literals.

  If `pretty_numbers` is true, numbers will be written as pretty Turtle literals, rather than string literals with precise types. The cost of this is that the types might get fudged on a round-trip to RDF and back.

void sratom_set_sink(Sratom *sratom, const char *base_uri, SerdStatementSink sink, SerdEndSink end_sink, void *handle)

  Set the sink(s) where sratom will write its output.

  This must be called before calling `sratom_write()`.

char *sratom_to_turtle(Sratom *sratom, LV2_URID_Unmap *unmap, const char *base_uri, const SerdNode *subject, const SerdNode *predicate, uint32_t type, uint32_t size, const void *body)

  Serialize an Atom to a Turtle string.

  The returned string must be free()’d by the caller.

int sratom_write(Sratom *sratom, LV2_URID_Unmap *unmap, uint32_t flags, const SerdNode *subject, const SerdNode *predicate, uint32_t type_urid, uint32_t size, const void *body)

  Write an Atom to RDF.

  The serialized atom is written to the sink set by `sratom_set_sink()`.

  Returns:

    0 on success, or a non-zero error code otherwise.