Factor out NTriples reader

1 files changed, 186 insertions, 0 deletions

diff --git a/src/read_ntriples.h b/src/read_ntriples.h
new file mode 100644
index 00000000..bc76fed6
--- /dev/null
+++ b/src/read_ntriples.h
@@ -0,0 +1,186 @@
+// Copyright 2011-2021 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#ifndef SERD_SRC_READ_NTRIPLES_H
+#define SERD_SRC_READ_NTRIPLES_H
+
+#include "serd/node.h"
+#include "serd/reader.h"
+#include "serd/status.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+
+// Utilities
+
+/**
+   Return true if the codepoint `c` is a valid PN_CHARS_BASE character.
+
+   RDF 1.1 NTriples: [157s] PN_CHARS_BASE
+*/
+bool
+is_PN_CHARS_BASE(uint32_t c);
+
+/**
+   Read one (possibly multi-byte) character.
+
+   The caller must have already eaten the first byte, `c`.
+*/
+SerdStatus
+read_character(SerdReader* reader, SerdNode* dest, uint8_t c);
+
+/**
+   Read one string literal escape.
+
+   The caller must have already eaten the first byte, a backslash.
+*/
+SerdStatus
+read_string_escape(SerdReader* reader, SerdNode* ref);
+
+// Terminals
+
+/**
+   Read a language tag starting after the '@'.
+
+   RDF 1.1 NTriples: [144s] LANGTAG
+*/
+SerdStatus
+read_LANGTAG(SerdReader* reader);
+
+/**
+   Read an end of line.
+
+   RDF 1.1 NTriples: [7] EOL
+*/
+SerdStatus
+read_EOL(SerdReader* reader);
+
+/**
+   Read an absolute IRI.
+
+   This is a stricter subset of [8] IRIREF in the NTriples grammar, since a
+   scheme is required.  Handling this in the parser results in better error
+   messages.
+*/
+SerdStatus
+read_IRI(SerdReader* reader, SerdNode** dest);
+
+/**
+   Read an IRI reference suffix into an existing node.
+
+   RDF 1.1 NTriples: [8] IRIREF
+*/
+SerdStatus
+read_IRIREF_suffix(SerdReader* reader, SerdNode* node);
+
+/**
+   Read a string that is single-quoted with the given character.
+
+   RDF 1.1 NTriples: [9]  STRING_LITERAL_QUOTE
+   RDF 1.1 Turtle:   [23] STRING_LITERAL_SINGLE_QUOTE
+*/
+SerdStatus
+read_STRING_LITERAL(SerdReader* reader, SerdNode* ref, uint8_t q);
+
+/**
+   Read a blank node label that comes after "_:".
+
+   RDF 1.1 NTriples: [141s] BLANK_NODE_LABEL
+*/
+SerdStatus
+read_BLANK_NODE_LABEL(SerdReader* reader, SerdNode** dest, bool* ate_dot);
+
+/**
+   Read an escape like "u201C", starting after the initial backslash.
+
+   RDF 1.1 NTriples: [10] UCHAR
+*/
+SerdStatus
+read_UCHAR(SerdReader* reader, SerdNode* node, uint32_t* code_point);
+
+/**
+   Read an escape like "n", starting after the initial backslash.
+
+   RDF 1.1 NTriples: [153s] ECHAR
+*/
+SerdStatus
+read_ECHAR(SerdReader* reader, SerdNode* dest);
+
+/**
+   Read a basic prefixed name character.
+
+   RDF 1.1 NTriples: [157s] PN_CHARS_BASE
+*/
+SerdStatus
+read_PN_CHARS_BASE(SerdReader* reader, SerdNode* dest);
+
+/**
+   Read any prefixed name character.
+
+   RDF 1.1 NTriples: [160s] PN_CHARS
+*/
+SerdStatus
+read_PN_CHARS(SerdReader* reader, SerdNode* dest);
+
+/**
+   Read a single hexadecimal digit.
+
+   RDF 1.1 NTriples: [162s] HEX
+*/
+uint8_t
+read_HEX(SerdReader* reader);
+
+// Nonterminals
+
+/**
+   Read a comment that starts with '#' and ends with the line.
+
+   Not described by a rule in the grammar since RDF 1.1.
+*/
+SerdStatus
+read_comment(SerdReader* reader);
+
+/**
+   Read a subject (IRI or blank).
+
+   RDF 1.1 NTriples: [3] subject
+*/
+SerdStatus
+read_nt_subject(SerdReader* reader, SerdNode** dest);
+
+/**
+   Read a predicate (IRI).
+
+   RDF 1.1 NTriples: [4] predicate
+*/
+SerdStatus
+read_nt_predicate(SerdReader* reader, SerdNode** dest);
+
+/**
+   Read an object (IRI or blank or literal).
+
+   RDF 1.1 NTriples: [5] object
+*/
+SerdStatus
+read_nt_object(SerdReader* reader, SerdNode** dest, bool* ate_dot);
+
+/**
+   Read a variable that starts with '?' or '$'.
+
+   This is an extension that serd uses in certain contexts to support
+   patterns.
+
+   Restricted version of SPARQL 1.1: [108] Var
+*/
+SerdStatus
+read_Var(SerdReader* reader, SerdNode** dest);
+
+/**
+   Read a complete NTriples document.
+
+   RDF 1.1 NTriples: [1] ntriplesDoc
+*/
+SerdStatus
+read_ntriplesDoc(SerdReader* reader);
+
+#endif // SERD_SRC_READ_NTRIPLES_H