/* Copyright 2011-2017 David Robillard Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /** @file serd.h API for Serd, a lightweight RDF syntax library. */ #ifndef SERD_SERD_H #define SERD_SERD_H #include #include #include #include #include #ifdef SERD_SHARED # ifdef _WIN32 # define SERD_LIB_IMPORT __declspec(dllimport) # define SERD_LIB_EXPORT __declspec(dllexport) # else # define SERD_LIB_IMPORT __attribute__((visibility("default"))) # define SERD_LIB_EXPORT __attribute__((visibility("default"))) # endif # ifdef SERD_INTERNAL # define SERD_API SERD_LIB_EXPORT # else # define SERD_API SERD_LIB_IMPORT # endif #else # define SERD_API #endif #ifdef __cplusplus extern "C" { #endif /** @defgroup serd Serd A lightweight RDF syntax library. @{ */ /** World. The World represents all library state shared between various objects. */ typedef struct SerdWorldImpl SerdWorld; /** Statement. A subject, predicate, and object, with optional graph context. */ typedef struct SerdStatementImpl SerdStatement; /** Cursor, the origin of a statement in a document. */ typedef struct SerdCursorImpl SerdCursor; /** Environment. Represents the state required to resolve a CURIE or relative URI, e.g. the base URI and set of namespace prefixes at a particular point. */ typedef struct SerdEnvImpl SerdEnv; /** RDF reader. Parses RDF by calling user-provided sink functions as input is consumed (much like an XML SAX parser). */ typedef struct SerdReaderImpl SerdReader; /** RDF writer. Provides a number of functions to allow writing RDF syntax out to some stream. These functions are deliberately compatible with the sink functions used by SerdReader, so a reader can be directly connected to a writer to re-serialise a document with minimal overhead. */ typedef struct SerdWriterImpl SerdWriter; /** An interface that receives a stream of RDF data. */ typedef struct SerdSinkImpl SerdSink; /** Return status code. */ typedef enum { SERD_SUCCESS, /**< No error */ SERD_FAILURE, /**< Non-fatal failure */ SERD_ERR_UNKNOWN, /**< Unknown error */ SERD_ERR_BAD_SYNTAX, /**< Invalid syntax */ SERD_ERR_BAD_ARG, /**< Invalid argument */ SERD_ERR_NOT_FOUND, /**< Not found */ SERD_ERR_ID_CLASH, /**< Encountered clashing blank node IDs */ SERD_ERR_BAD_CURIE, /**< Invalid CURIE (e.g. prefix does not exist) */ SERD_ERR_INTERNAL, /**< Unexpected internal error (should not happen) */ SERD_ERR_OVERFLOW /**< Stack overflow */ } SerdStatus; /** RDF syntax type. */ typedef enum { /** Turtle - Terse RDF Triple Language (UTF-8). @see Turtle */ SERD_TURTLE = 1, /** NTriples - Line-based RDF triples (ASCII). @see NTriples */ SERD_NTRIPLES = 2, /** NQuads - Line-based RDF quads (UTF-8). @see NQuads */ SERD_NQUADS = 3, /** TriG - Terse RDF quads (UTF-8). @see Trig */ SERD_TRIG = 4 } SerdSyntax; /** Flags indicating inline abbreviation information for a statement. */ typedef enum { SERD_EMPTY_S = 1 << 1, /**< Empty blank node subject */ SERD_EMPTY_O = 1 << 2, /**< Empty blank node object */ SERD_ANON_S_BEGIN = 1 << 3, /**< Start of anonymous subject */ SERD_ANON_O_BEGIN = 1 << 4, /**< Start of anonymous object */ SERD_ANON_CONT = 1 << 5, /**< Continuation of anonymous node */ SERD_LIST_S_BEGIN = 1 << 6, /**< Start of list subject */ SERD_LIST_O_BEGIN = 1 << 7, /**< Start of list object */ SERD_LIST_CONT = 1 << 8 /**< Continuation of list */ } SerdStatementFlag; /** Bitwise OR of SerdStatementFlag values. */ typedef uint32_t SerdStatementFlags; /** Type of a syntactic RDF node. This is more precise than the type of an abstract RDF node. An abstract node is either a resource, literal, or blank. In syntax there are two ways to refer to a resource (by URI or CURIE) and two ways to refer to a blank (by ID or anonymously). Anonymous (inline) blank nodes are expressed using SerdStatementFlags rather than this type. */ typedef enum { /** The type of a nonexistent node. This type is useful as a sentinel, but is never emitted by the reader. */ SERD_NOTHING = 0, /** Literal value. A literal optionally has either a language, or a datatype (not both). */ SERD_LITERAL = 1, /** URI (absolute or relative). Value is an unquoted URI string, which is either a relative reference with respect to the current base URI (e.g. "foo/bar"), or an absolute URI (e.g. "http://example.org/foo"). @see RFC3986. */ SERD_URI = 2, /** CURIE, a shortened URI. Value is an unquoted CURIE string relative to the current environment, e.g. "rdf:type". @see CURIE Syntax 1.0 */ SERD_CURIE = 3, /** A blank node. Value is a blank node ID, e.g. "id3", which is meaningful only within this serialisation. @see Turtle nodeID */ SERD_BLANK = 4 } SerdType; /** Flags indicating certain string properties relevant to serialisation. */ typedef enum { SERD_HAS_NEWLINE = 1, /**< Contains line breaks ('\\n' or '\\r') */ SERD_HAS_QUOTE = 1 << 1, /**< Contains quotes ('"') */ SERD_HAS_DATATYPE = 1 << 2, /**< Literal node has datatype */ SERD_HAS_LANGUAGE = 1 << 3 /**< Literal node has language */ } SerdNodeFlag; /** Field in a statement. */ typedef enum { SERD_SUBJECT = 0, /**< Subject */ SERD_PREDICATE = 1, /**< Predicate ("key") */ SERD_OBJECT = 2, /**< Object ("value") */ SERD_GRAPH = 3 /**< Graph ("context") */ } SerdField; /** Bitwise OR of SerdNodeFlag values. */ typedef uint32_t SerdNodeFlags; /** A syntactic RDF node. */ typedef struct SerdNodeImpl SerdNode; /** An unterminated immutable slice of a string. */ typedef struct { const char* buf; /**< Start of chunk */ size_t len; /**< Length of chunk in bytes */ } SerdStringView; /** A mutable buffer in memory. */ typedef struct { void* buf; /**< Buffer */ size_t len; /**< Size of buffer in bytes */ } SerdBuffer; /** An error description. */ typedef struct { SerdStatus status; /**< Error code */ const SerdCursor* cursor; /**< Origin of error, or NULL */ const char* fmt; /**< Message format string (printf style) */ va_list* args; /**< Arguments for fmt */ } SerdError; /** A parsed URI. This struct directly refers to slices in other strings, it does not own any memory itself. Thus, URIs can be parsed and/or resolved against a base URI in-place without allocating memory. */ typedef struct { SerdStringView scheme; /**< Scheme */ SerdStringView authority; /**< Authority */ SerdStringView path_base; /**< Path prefix if relative */ SerdStringView path; /**< Path suffix */ SerdStringView query; /**< Query */ SerdStringView fragment; /**< Fragment */ } SerdURI; /** Syntax style options. The style of the writer output can be controlled by ORing together values from this enumeration. Note that some options are only supported for some syntaxes (e.g. NTriples does not support abbreviation and is always ASCII). */ typedef enum { SERD_STYLE_ASCII = 1 << 0, /**< Escape all non-ASCII characters. */ SERD_STYLE_BULK = 1 << 1 /**< Write output in pages. */ } SerdStyle; /** Bitwise OR of SerdStyle values. */ typedef uint32_t SerdStyleFlags; /** Free memory allocated by Serd. This function exists because some systems require memory allocated by a library to be freed by code in the same library. It is otherwise equivalent to the standard C free() function. */ SERD_API void serd_free(void* ptr); /** @name String Utilities @{ */ /** Return a string describing a status code. */ SERD_API const char* serd_strerror(SerdStatus status); /** Measure a UTF-8 string. @return Length of `str` in bytes. @param str A null-terminated UTF-8 string. @param flags (Output) Set to the applicable flags. */ SERD_API size_t serd_strlen(const char* str, SerdNodeFlags* flags); /** Parse a string to a double. The API of this function is similar to the standard C strtod function, except this function is locale-independent and always matches the lexical format used in the Turtle grammar (the decimal point is always "."). The end parameter is an offset from the start of `str` to avoid the const-correctness issues of the strtod API. */ SERD_API double serd_strtod(const char* str, size_t* end); /** Decode a base64 string. This function can be used to deserialise a blob node created with serd_new_blob(). @param str Base64 string to decode. @param len The length of `str`. @param size Set to the size of the returned blob in bytes. @return A newly allocated blob which must be freed with serd_free(). */ SERD_API void* serd_base64_decode(const char* str, size_t len, size_t* size); /** @} @name Byte Streams @{ */ /** Function to detect I/O stream errors. Identical semantics to `ferror`. @return Non-zero if `stream` has encountered an error. */ typedef int (*SerdStreamErrorFunc)(void* stream); /** Source function for raw string input. Identical semantics to `fread`, but may set errno for more informative error reporting than supported by SerdStreamErrorFunc. @param buf Output buffer. @param size Size of a single element of data in bytes (always 1). @param nmemb Number of elements to read. @param stream Stream to read from (FILE* for fread). @return Number of elements (bytes) read, which is short on error. */ typedef size_t (*SerdReadFunc)(void* buf, size_t size, size_t nmemb, void* stream); /** Sink function for raw string output. Identical semantics to `fwrite`, but may set errno for more informative error reporting than supported by SerdStreamErrorFunc. @param buf Input buffer. @param size Size of a single element of data in bytes (always 1). @param nmemb Number of elements to read. @param stream Stream to write to (FILE* for fread). @return Number of elements (bytes) written, which is short on error. */ typedef size_t (*SerdWriteFunc)(const void* buf, size_t size, size_t nmemb, void* stream); /** @} @name Syntax Utilities @{ */ /** Get a syntax by name. Case-insensitive, supports "Turtle", "NTriples", "NQuads", and "TriG". Zero is returned if the name is not recognized. */ SERD_API SerdSyntax serd_syntax_by_name(const char* name); /** Guess a syntax from a filename. This uses the file extension to guess the syntax of a file. Zero is returned if the extension is not recognized. */ SERD_API SerdSyntax serd_guess_syntax(const char* filename); /** Guess a syntax from a filename. This uses the file extension to guess the syntax of a file. Zero is returned if the extension is not recognized. */ SERD_API bool serd_syntax_has_graphs(SerdSyntax syntax); /** @} @name URI @{ */ static const SerdURI SERD_URI_NULL = { {NULL, 0}, {NULL, 0}, {NULL, 0}, {NULL, 0}, {NULL, 0}, {NULL, 0} }; /** Get the unescaped path and hostname from a file URI. @param uri A file URI. @param hostname If non-NULL, set to the hostname, if present. @return The path component of the URI. The returned path and `*hostname` must be freed with serd_free(). */ SERD_API char* serd_file_uri_parse(const char* uri, char** hostname); /** Return true iff `utf8` starts with a valid URI scheme. */ SERD_API bool serd_uri_string_has_scheme(const char* utf8); /** Parse `utf8`, writing result to `out`. */ SERD_API SerdStatus serd_uri_parse(const char* utf8, SerdURI* out); /** Set target `t` to reference `r` resolved against `base`. @see http://tools.ietf.org/html/rfc3986#section-5.2.2 */ SERD_API void serd_uri_resolve(const SerdURI* r, const SerdURI* base, SerdURI* t); /** Serialise `uri` with a series of calls to `sink`. */ SERD_API size_t serd_uri_serialise(const SerdURI* uri, SerdWriteFunc sink, void* stream); /** Serialise `uri` relative to `base` with a series of calls to `sink`. The `uri` is written as a relative URI iff if it a child of `base` and @c root. The optional `root` parameter must be a prefix of `base` and can be used keep up-references ("../") within a certain namespace. */ SERD_API size_t serd_uri_serialise_relative(const SerdURI* uri, const SerdURI* base, const SerdURI* root, SerdWriteFunc sink, void* stream); /** @} @name Node @{ */ /** Create a new plain literal string node from `str`. */ SERD_API SerdNode* serd_new_string(const char* str); /** Create a new plain literal node from `str`. A plain literal has no datatype, but may have a language tag. The `lang` may be NULL, in which case this is equivalent to `serd_new_string()`. */ SERD_API SerdNode* serd_new_plain_literal(const char* str, const char* lang); /** Create a new typed literal node from `str`. A typed literal has no language tag, but may have a datatype. The `datatype` may be NULL, in which case this is equivalent to `serd_new_string()`. */ SERD_API SerdNode* serd_new_typed_literal(const char* str, const SerdNode* datatype); /** Create a new blank node. */ SERD_API SerdNode* serd_new_blank(const char* str); /** Create a new CURIE node. */ SERD_API SerdNode* serd_new_curie(const char* str); /** Return a deep copy of `node`. */ SERD_API SerdNode* serd_node_copy(const SerdNode* node); /** Return true iff `a` is equal to `b`. */ SERD_API bool serd_node_equals(const SerdNode* a, const SerdNode* b); /** Create a new URI from a string. */ SERD_API SerdNode* serd_new_uri(const char* str); /** Create a new URI from a string, resolved against a base URI. */ SERD_API SerdNode* serd_new_resolved_uri(const char* str, const SerdNode* base); /** Resolve `node` against `base`. If `node` is not a relative URI, an equivalent new node is returned. */ SERD_API SerdNode* serd_node_resolve(const SerdNode* node, const SerdNode* base); /** Create a new file URI node from a file system path and optional hostname. Backslashes in Windows paths will be converted, and other characters will be percent encoded as necessary. If `path` is relative, `hostname` is ignored. If `out` is not NULL, it will be set to the parsed URI. */ SERD_API SerdNode* serd_new_file_uri(const char* path, const char* hostname); /** Create a new URI from a string, relative to a base URI. @param str URI string. @param base Base URI to make `str` relative to, if possible. @param root Optional root URI for resolution. The URI is made relative iff if it a child of `base` and `root`. The optional `root` parameter must be a prefix of `base` and can be used keep up-references ("../") within a certain namespace. */ SERD_API SerdNode* serd_new_relative_uri(const char* str, const SerdNode* base, const SerdNode* root); /** Create a new node by serialising `d` into an xsd:decimal string. The resulting node will always contain a `.', start with a digit, and end with a digit (i.e. will have a leading and/or trailing `0' if necessary). It will never be in scientific notation. A maximum of `frac_digits` digits will be written after the decimal point, but trailing zeros will automatically be omitted (except one if `d` is a round integer). Note that about 16 and 8 fractional digits are required to precisely represent a double and float, respectively. @param d The value for the new node. @param frac_digits The maximum number of digits after the decimal place. @param datatype Datatype of node, may be NULL in which case the node has type xsd:decimal. */ SERD_API SerdNode* serd_new_decimal(double d, unsigned frac_digits, const SerdNode* datatype); /** Create a new node by serialising `i` into an xsd:integer string. @param i Integer value to serialise. @param datatype Datatype of node, may be NULL in which case the node has type xsd:integer. */ SERD_API SerdNode* serd_new_integer(int64_t i, const SerdNode* datatype); /** Create a node by serialising `buf` into an xsd:base64Binary string. This function can be used to make a serialisable node out of arbitrary binary data, which can be decoded using serd_base64_decode(). @param buf Raw binary input data. @param size Size of `buf`. @param wrap_lines Wrap lines at 76 characters to conform to RFC 2045. @param datatype Datatype of node, may be NULL in which case the node has type xsd:base64Binary. */ SERD_API SerdNode* serd_new_blob(const void* buf, size_t size, bool wrap_lines, const SerdNode* datatype); /** Return the type of a node (SERD_URI, SERD_BLANK, or SERD_LITERAL). */ SERD_API SerdType serd_node_get_type(const SerdNode* node); /** Return the string value of a node. */ SERD_API const char* serd_node_get_string(const SerdNode* node); /** Return the length of the string value of a node in bytes. */ SERD_API size_t serd_node_get_length(const SerdNode* node); /** Return the datatype of a literal node, or NULL. */ SERD_API const SerdNode* serd_node_get_datatype(const SerdNode* node); /** Return the language tag of a literal node, or NULL. */ SERD_API const SerdNode* serd_node_get_language(const SerdNode* node); /** Return the flags (string properties) of a node. */ SERD_API SerdNodeFlags serd_node_get_flags(const SerdNode* node); /** Free any data owned by `node`. Note that if `node` is itself dynamically allocated (which is not the case for nodes created internally by serd), it will not be freed. */ SERD_API void serd_node_free(SerdNode* node); /** @} @name Event Handlers @{ */ /** Sink (callback) for errors. @param handle Handle for user data. @param error Error description. */ typedef SerdStatus (*SerdErrorSink)(void* handle, const SerdError* error); /** Sink (callback) for base URI changes. Called whenever the base URI of the serialisation changes. */ typedef SerdStatus (*SerdBaseSink)(void* handle, const SerdNode* uri); /** Sink (callback) for namespace definitions. Called whenever a prefix is defined in the serialisation. */ typedef SerdStatus (*SerdPrefixSink)(void* handle, const SerdNode* name, const SerdNode* uri); /** Sink (callback) for statements. Called for every RDF statement in the serialisation. */ typedef SerdStatus (*SerdStatementSink)(void* handle, SerdStatementFlags flags, const SerdStatement* statement); /** Sink (callback) for anonymous node end markers. This is called to indicate that the anonymous node with the given `value` will no longer be referred to by any future statements (i.e. the anonymous serialisation of the node is finished). */ typedef SerdStatus (*SerdEndSink)(void* handle, const SerdNode* node); /** @} @name World @{ */ /** Create a new Serd World. It is safe to use multiple worlds in one process, though no objects can be shared between worlds. */ SERD_API SerdWorld* serd_world_new(void); /** Free `world`. */ SERD_API void serd_world_free(SerdWorld* world); /** Return a unique blank node. The returned node is valid only until the next time serd_world_get_blank() is called or the world is destroyed. */ SERD_API const SerdNode* serd_world_get_blank(SerdWorld* world); /** Set a function to be called when errors occur. The `error_sink` will be called with `handle` as its first argument. If no error function is set, errors are printed to stderr. */ SERD_API void serd_world_set_error_sink(SerdWorld* world, SerdErrorSink error_sink, void* handle); /** @} @name Environment @{ */ /** Create a new environment. */ SERD_API SerdEnv* serd_env_new(const SerdNode* base_uri); /** Free `ns`. */ SERD_API void serd_env_free(SerdEnv* env); /** Get the current base URI. */ SERD_API const SerdNode* serd_env_get_base_uri(const SerdEnv* env); /** Set the current base URI. */ SERD_API SerdStatus serd_env_set_base_uri(SerdEnv* env, const SerdNode* uri); /** Set a namespace prefix. */ SERD_API SerdStatus serd_env_set_prefix(SerdEnv* env, const SerdNode* name, const SerdNode* uri); /** Set a namespace prefix. */ SERD_API SerdStatus serd_env_set_prefix_from_strings(SerdEnv* env, const char* name, const char* uri); /** Qualify `uri` into a CURIE if possible. Returns null if `node` can not be qualified. */ SERD_API SerdNode* serd_env_qualify(const SerdEnv* env, const SerdNode* uri); /** Expand `node`, which must be a CURIE or URI, to a full URI. Returns null if `node` can not be expanded. */ SERD_API SerdNode* serd_env_expand(const SerdEnv* env, const SerdNode* node); /** Call `func` for each prefix defined in `env`. */ SERD_API void serd_env_foreach(const SerdEnv* env, SerdPrefixSink func, void* handle); /** @} @name Sink @{ */ /** Create a new sink. Initially, the sink has no set functions and will do nothing. Use the serd_sink_set_*_func functions to set handlers for various events. @param handle Opaque handle that will be passed to sink functions. */ SERD_API SerdSink* serd_sink_new(void* handle); /** Free `sink`. */ SERD_API void serd_sink_free(SerdSink* sink); /** Set a function to be called when the base URI changes. */ SERD_API SerdStatus serd_sink_set_base_func(SerdSink* sink, SerdBaseSink base_func); /** Set a function to be called when a namespace prefix is defined. */ SERD_API SerdStatus serd_sink_set_prefix_func(SerdSink* sink, SerdPrefixSink prefix_func); /** Set a function to be called when a statement is emitted. */ SERD_API SerdStatus serd_sink_set_statement_func(SerdSink* sink, SerdStatementSink statement_func); /** Set a function to be called when an anonymous node ends. */ SERD_API SerdStatus serd_sink_set_end_func(SerdSink* sink, SerdEndSink end_func); /** Set the base URI. Simple wrapper for the `SerdBaseSink` of `sink`. */ SERD_API SerdStatus serd_sink_write_base(const SerdSink* sink, const SerdNode* uri); /** Set a namespace prefix. Simple wrapper for the `SerdPrefixSink` of `sink`. */ SERD_API SerdStatus serd_sink_write_prefix(const SerdSink* sink, const SerdNode* name, const SerdNode* uri); /** Write a statement. Simple wrapper for the `SerdStatementSink` of `sink`. */ SERD_API SerdStatus serd_sink_write_statement(const SerdSink* sink, SerdStatementFlags flags, const SerdStatement* statement); /** Write a statement from individual nodes. Simple wrapper for the `SerdStatementSink` of `sink`. */ SERD_API SerdStatus serd_sink_write(const SerdSink* sink, SerdStatementFlags flags, const SerdNode* subject, const SerdNode* predicate, const SerdNode* object, const SerdNode* graph); /** Mark the end of an anonymous node. Simple wrapper for the `SerdEndSink` of `sink`. */ SERD_API SerdStatus serd_sink_write_end(const SerdSink* sink, const SerdNode* node); /** @} @name Reader @{ */ /** Create a new RDF reader. */ SERD_API SerdReader* serd_reader_new(SerdWorld* world, SerdSyntax syntax, const SerdSink* sink, size_t stack_size); /** Enable or disable strict parsing. The reader is non-strict (lax) by default, which will tolerate URIs with invalid characters. Setting strict will fail when parsing such files. An error is printed for invalid input in either case. */ SERD_API void serd_reader_set_strict(SerdReader* reader, bool strict); /** Set a prefix to be added to all blank node identifiers. This is useful when multiple files are to be parsed into the same output (e.g. a store, or other files). Since Serd preserves blank node IDs, this could cause conflicts where two non-equivalent blank nodes are merged, resulting in corrupt data. By setting a unique blank node prefix for each parsed file, this can be avoided, while preserving blank node names. */ SERD_API void serd_reader_add_blank_prefix(SerdReader* reader, const char* prefix); /** Set the URI of the default graph. If this is set, the reader will emit quads with the graph set to the given node for any statements that are not in a named graph (which is currently all of them since Serd currently does not support any graph syntaxes). */ SERD_API void serd_reader_set_default_graph(SerdReader* reader, const SerdNode* graph); /** Prepare to read from the file at a local file `uri`. */ SERD_API SerdStatus serd_reader_start_file(SerdReader* reader, const char* uri, bool bulk); /** Prepare to read from a stream. The `read_func` is guaranteed to only be called for `page_size` elements with size 1 (i.e. `page_size` bytes). */ SERD_API SerdStatus serd_reader_start_stream(SerdReader* reader, SerdReadFunc read_func, SerdStreamErrorFunc error_func, void* stream, const SerdNode* name, size_t page_size); /** Prepare to read from a string. */ SERD_API SerdStatus serd_reader_start_string(SerdReader* reader, const char* utf8, const SerdNode* name); /** 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. */ SERD_API SerdStatus serd_reader_read_chunk(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(). */ SERD_API SerdStatus serd_reader_read_document(SerdReader* reader); /** Finish reading from the source. This will close the open file, if applicable, and ensure the reader has processed all input. */ SERD_API SerdStatus serd_reader_finish(SerdReader* reader); /** Free `reader`. The reader will be finished via `serd_reader_finish()` if necessary. */ SERD_API void serd_reader_free(SerdReader* reader); /** @} @name Writer @{ */ /** Create a new RDF writer. */ SERD_API SerdWriter* serd_writer_new(SerdWorld* world, SerdSyntax syntax, SerdStyleFlags style, SerdEnv* env, SerdWriteFunc ssink, void* stream); /** Free `writer`. */ SERD_API void serd_writer_free(SerdWriter* writer); /** Return a sink interface that emits statements via `writer`. */ SERD_API const SerdSink* serd_writer_get_sink(SerdWriter* writer); /** Return the env used by `writer`. */ SERD_API SerdEnv* serd_writer_get_env(SerdWriter* writer); /** A convenience sink function for writing to a string. This function can be used as a SerdSink to write to a SerdBuffer which is resized as necessary with realloc(). The `stream` parameter must point to an initialized SerdBuffer. When the write is finished, the string should be retrieved with serd_buffer_sink_finish(). */ SERD_API size_t serd_buffer_sink(const void* buf, size_t size, size_t nmemb, void* stream); /** Finish a serialisation to a buffer with serd_buffer_sink(). The returned string is the result of the serialisation, which is NULL terminated (by this function) and owned by the caller. */ SERD_API char* serd_buffer_sink_finish(SerdBuffer* stream); /** Set a prefix to be removed from matching blank node identifiers. */ SERD_API void serd_writer_chop_blank_prefix(SerdWriter* writer, const char* prefix); /** Set the current output base URI (and emit directive if applicable). Note this function can be safely casted to SerdBaseSink. */ SERD_API SerdStatus serd_writer_set_base_uri(SerdWriter* writer, const SerdNode* uri); /** Set the current root URI. The root URI should be a prefix of the base URI. The path of the root URI is the highest path any relative up-reference can refer to. For example, with root and base , will be written as <../>, but will be written non-relatively as . If the root is not explicitly set, it defaults to the base URI, so no up-references will be created at all. */ SERD_API SerdStatus serd_writer_set_root_uri(SerdWriter* writer, const SerdNode* uri); /** Finish a write. */ SERD_API SerdStatus serd_writer_finish(SerdWriter* writer); /** @} @name Statement @{ */ /** Return the given node in `statement`. */ SERD_API const SerdNode* serd_statement_get_node(const SerdStatement* statement, SerdField field); /** Return the subject in `statement`. */ SERD_API const SerdNode* serd_statement_get_subject(const SerdStatement* statement); /** Return the predicate in `statement`. */ SERD_API const SerdNode* serd_statement_get_predicate(const SerdStatement* statement); /** Return the object in `statement`. */ SERD_API const SerdNode* serd_statement_get_object(const SerdStatement* statement); /** Return the graph in `statement`. */ SERD_API const SerdNode* serd_statement_get_graph(const SerdStatement* statement); /** Return the source location where `statement` originated, or NULL. */ SERD_API const SerdCursor* serd_statement_get_cursor(const SerdStatement* statement); /** @} @name Cursor @{ */ /** Create a new cursor Note that, to minimise model overhead, the cursor does not own the name node, so `name` must have a longer lifetime than the cursor for it to be valid. That is, serd_cursor_get_name() will return exactly the pointer `name`, not a copy. For cursors from models, this is the lifetime of the model. For user-created cursors, the simplest way to handle this is to use `SerdNodes`. @param name The name of the document or stream (usually a file URI) @param line The line number in the document (1-based) @param col The column number in the document (1-based) @return A new cursor that must be freed with serd_cursor_free() */ SERD_API SerdCursor* serd_cursor_new(const SerdNode* name, unsigned line, unsigned col); /// Return a copy of `cursor` SERD_API SerdCursor* serd_cursor_copy(const SerdCursor* cursor); /// Free `cursor` SERD_API void serd_cursor_free(SerdCursor* cursor); /// Return true iff `lhs` is equal to `rhs` SERD_API bool serd_cursor_equals(const SerdCursor* lhs, const SerdCursor* rhs); /** Return the document name. This is typically a file URI, but may be a descriptive string node for statements that originate from streams. */ SERD_API const SerdNode* serd_cursor_get_name(const SerdCursor* cursor); /** Return the one-relative line number in the document. */ SERD_API unsigned serd_cursor_get_line(const SerdCursor* cursor); /** Return the zero-relative column number in the line. */ SERD_API unsigned serd_cursor_get_column(const SerdCursor* cursor); /** @} @} */ #ifdef __cplusplus } /* extern "C" */ #endif #endif /* SERD_SERD_H */