5.12.2 Reader

enum SerdReaderFlag

Reader options.

enumerator SERD_READ_LAX

Tolerate invalid input where possible.

This will attempt to ignore invalid input and continue reading. Invalid Unicode characters will be replaced with the replacement character, and various other syntactic problems will be ignored. If there are more severe problems, the reader will try to skip the statement and continue parsing. This should work reasonably well for line-based syntaxes like NTriples and NQuads, but abbreviated Turtle or TriG may not recover.

Note that this flag should be used carefully, since it can result in data loss.

enumerator SERD_READ_VARIABLES

Support reading variable nodes.

As an extension, serd supports reading variables nodes with SPARQL-like syntax, for example “?foo” or “$bar”. This can be used for storing graph patterns and templates.

enumerator SERD_READ_RELATIVE

Read relative URI references exactly without resolving them.

Normally, the reader expands all relative URIs against the base URI. This flag disables that, so that URI references are passed to the sink exactly as they are in the input.

enumerator SERD_READ_GLOBAL

Read blank node labels without adding a prefix unique to the document.

Normally, the reader adds a prefix like “f1”, “f2”, and so on, to blank node labels, to separate the namespaces from separate input documents. This flag disables that, so that blank node labels will be read without any prefix added.

Note that this flag should be used carefully, since it can result in data corruption. Specifically, if data from separate documents parsed with this flag is combined, the IDs from each document may clash.

enumerator SERD_READ_GENERATED

Read generated blank node labels exactly without adjusting them.

Normally, the reader will adapt blank node labels in the input that clash with its scheme for generating new ones, for example mapping “_:b123” to “_:B123”. This flag disables that, so that blank node labels are passed to the sink exactly as they are in the input.

Note that this flag should be used carefully, since it can result in data corruption. Specifically, if the input is a syntax like Turtle with anonymous nodes, the generated IDs for those nodes may clash with IDs from the input document.

typedef struct SerdReaderImpl SerdReader

Streaming parser that reads a text stream and writes to a statement sink.

typedef uint32_t SerdReaderFlags

Bitwise OR of SerdReaderFlag values.

SerdReader *serd_reader_new(SerdWorld *world, SerdSyntax syntax, SerdReaderFlags flags, SerdEnv *env, const SerdSink *sink, size_t stack_size)

Create a new RDF reader.

SerdStatus serd_reader_start(SerdReader *reader, SerdInputStream *input, const SerdNode *input_name, size_t block_size)

Prepare to read some input.

This sets up the reader to read from the given input, but will not read any bytes from it. This should be followed by serd_reader_read_chunk() or serd_reader_read_document() to actually read the input.

Parameters

• reader – The reader.

• input – An opened input stream to read from.

• input_name – The name of the input stream for error messages.

• block_size – The number of bytes to read from the stream at once.

SerdStatus serd_reader_read_chunk(SerdReader *reader)

Read a single “chunk” of data during an incremental read.

This function will read a single top level description, and return. This may be a directive, statement, or several statements; essentially it reads until a ‘.’ is encountered. This is particularly useful for reading directly from a pipe or socket.

SerdStatus serd_reader_read_document(SerdReader *reader)

Read a complete document from the source.

This function will continue pulling from the source until a complete document has been read. Note that this may block when used with streams, for incremental reading use serd_reader_read_chunk().

SerdStatus serd_reader_finish(SerdReader *reader)

Finish reading from the source.

This should be called before starting to read from another source.

void serd_reader_free(SerdReader *reader)

Free reader.

The reader will be finished via serd_reader_finish() if necessary.