Factor out syntax-specific reader implementation

1 files changed, 1490 insertions, 0 deletions

diff --git a/src/n3.c b/src/n3.c
new file mode 100644
index 00000000..06fc8e80
--- /dev/null
+++ b/src/n3.c
@@ -0,0 +1,1490 @@
+/*
+  Copyright 2011-2017 David Robillard <http://drobilla.net>
+
+  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.
+*/
+
+#include "serd_internal.h"
+
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "reader.h"
+
+#define TRY_THROW(exp) if (!(exp)) goto except;
+#define TRY_RET(exp)   if (!(exp)) return 0;
+
+static inline bool
+fancy_syntax(const SerdReader* reader)
+{
+	return reader->syntax == SERD_TURTLE || reader->syntax == SERD_TRIG;
+}
+
+static bool
+read_collection(SerdReader* reader, ReadContext ctx, Ref* dest);
+
+static bool
+read_predicateObjectList(SerdReader* reader, ReadContext ctx, bool* ate_dot);
+
+static inline uint8_t
+read_HEX(SerdReader* reader)
+{
+	const uint8_t c = peek_byte(reader);
+	if (is_xdigit(c)) {
+		return eat_byte_safe(reader, c);
+	}
+	return r_err(reader, SERD_ERR_BAD_SYNTAX,
+	             "invalid hexadecimal digit `%c'\n", c);
+}
+
+// Read UCHAR escape, initial \ is already eaten by caller
+static inline bool
+read_UCHAR(SerdReader* reader, Ref dest, uint32_t* char_code)
+{
+	const uint8_t b      = peek_byte(reader);
+	unsigned      length = 0;
+	switch (b) {
+	case 'U':
+		length = 8;
+		break;
+	case 'u':
+		length = 4;
+		break;
+	default:
+		return false;
+	}
+	eat_byte_safe(reader, b);
+
+	uint8_t buf[9] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+	for (unsigned i = 0; i < length; ++i) {
+		if (!(buf[i] = read_HEX(reader))) {
+			return false;
+		}
+	}
+
+	uint32_t code;
+	sscanf((const char*)buf, "%X", &code);
+
+	unsigned size = 0;
+	if (code < 0x00000080) {
+		size = 1;
+	} else if (code < 0x00000800) {
+		size = 2;
+	} else if (code < 0x00010000) {
+		size = 3;
+	} else if (code < 0x00110000) {
+		size = 4;
+	} else {
+		r_err(reader, SERD_ERR_BAD_SYNTAX,
+		      "unicode character 0x%X out of range\n", code);
+		push_bytes(reader, dest, replacement_char, 3);
+		*char_code = 0xFFFD;
+		return true;
+	}
+
+	// Build output in buf
+	// (Note # of bytes = # of leading 1 bits in first byte)
+	uint32_t c = code;
+	switch (size) {
+	case 4:
+		buf[3] = 0x80 | (uint8_t)(c & 0x3F);
+		c >>= 6;
+		c |= (16 << 12);  // set bit 4
+	case 3:
+		buf[2] = 0x80 | (uint8_t)(c & 0x3F);
+		c >>= 6;
+		c |= (32 << 6);  // set bit 5
+	case 2:
+		buf[1] = 0x80 | (uint8_t)(c & 0x3F);
+		c >>= 6;
+		c |= 0xC0;  // set bits 6 and 7
+	case 1:
+		buf[0] = (uint8_t)c;
+	}
+
+	push_bytes(reader, dest, buf, size);
+	*char_code = code;
+	return true;
+}
+
+// Read ECHAR escape, initial \ is already eaten by caller
+static inline bool
+read_ECHAR(SerdReader* reader, Ref dest, SerdNodeFlags* flags)
+{
+	const uint8_t c = peek_byte(reader);
+	switch (c) {
+	case 't':
+		eat_byte_safe(reader, 't');
+		push_byte(reader, dest, '\t');
+		return true;
+	case 'b':
+		eat_byte_safe(reader, 'b');
+		push_byte(reader, dest, '\b');
+		return true;
+	case 'n':
+		*flags |= SERD_HAS_NEWLINE;
+		eat_byte_safe(reader, 'n');
+		push_byte(reader, dest, '\n');
+		return true;
+	case 'r':
+		*flags |= SERD_HAS_NEWLINE;
+		eat_byte_safe(reader, 'r');
+		push_byte(reader, dest, '\r');
+		return true;
+	case 'f':
+		eat_byte_safe(reader, 'f');
+		push_byte(reader, dest, '\f');
+		return true;
+	case '\\': case '"': case '\'':
+		push_byte(reader, dest, eat_byte_safe(reader, c));
+		return true;
+	default:
+		return false;
+	}
+}
+
+static inline SerdStatus
+bad_char(SerdReader* reader, const char* fmt, uint8_t c)
+{
+	// Skip bytes until the next start byte
+	for (uint8_t b = peek_byte(reader); (b & 0x80);) {
+		eat_byte_safe(reader, b);
+		b = peek_byte(reader);
+	}
+
+	r_err(reader, SERD_ERR_BAD_SYNTAX, fmt, c);
+	return reader->strict ? SERD_ERR_BAD_SYNTAX : SERD_FAILURE;
+}
+
+static SerdStatus
+read_utf8_bytes(SerdReader* reader, uint8_t bytes[4], uint32_t* size, uint8_t c)
+{
+	*size = utf8_num_bytes(c);
+	if (*size <= 1 || *size > 4) {
+		return bad_char(reader, "invalid UTF-8 start 0x%X\n", c);
+	}
+
+	bytes[0] = c;
+	for (unsigned i = 1; i < *size; ++i) {
+		if (((bytes[i] = peek_byte(reader)) & 0x80) == 0) {
+			return bad_char(reader, "invalid UTF-8 continuation 0x%X\n",
+			                bytes[i]);
+		}
+		eat_byte_safe(reader, bytes[i]);
+	}
+
+	return SERD_SUCCESS;
+}
+
+static SerdStatus
+read_utf8_character(SerdReader* reader, Ref dest, uint8_t c)
+{
+	uint32_t   size;
+	uint8_t    bytes[4];
+	SerdStatus st = read_utf8_bytes(reader, bytes, &size, c);
+	if (st) {
+		push_bytes(reader, dest, replacement_char, 3);
+	} else {
+		push_bytes(reader, dest, bytes, size);
+	}
+	return st;
+}
+
+static SerdStatus
+read_utf8_code(SerdReader* reader, Ref dest, uint32_t* code, uint8_t c)
+{
+	uint32_t   size;
+	uint8_t    bytes[4];
+	SerdStatus st = read_utf8_bytes(reader, bytes, &size, c);
+	if (st) {
+		push_bytes(reader, dest, replacement_char, 3);
+		return st;
+	}
+
+	push_bytes(reader, dest, bytes, size);
+	*code = parse_counted_utf8_char(bytes, size);
+	return st;
+}
+
+// Read one character (possibly multi-byte)
+// The first byte, c, has already been eaten by caller
+static inline SerdStatus
+read_character(SerdReader* reader, Ref dest, SerdNodeFlags* flags, uint8_t c)
+{
+	if (!(c & 0x80)) {
+		switch (c) {
+		case 0xA: case 0xD:
+			*flags |= SERD_HAS_NEWLINE;
+			break;
+		case '"': case '\'':
+			*flags |= SERD_HAS_QUOTE;
+			break;
+		}
+		push_byte(reader, dest, c);
+		return SERD_SUCCESS;
+	}
+	return read_utf8_character(reader, dest, c);
+}
+
+// [10] comment ::= '#' ( [^#xA #xD] )*
+static void
+read_comment(SerdReader* reader)
+{
+	eat_byte_safe(reader, '#');
+	uint8_t c;
+	while (((c = peek_byte(reader)) != 0xA) && (c != 0xD) && c) {
+		eat_byte_safe(reader, c);
+	}
+}
+
+// [24] ws ::= #x9 | #xA | #xD | #x20 | comment
+static inline bool
+read_ws(SerdReader* reader)
+{
+	const uint8_t c = peek_byte(reader);
+	switch (c) {
+	case 0x9: case 0xA: case 0xD: case 0x20:
+		eat_byte_safe(reader, c);
+		return true;
+	case '#':
+		read_comment(reader);
+		return true;
+	default:
+		return false;
+	}
+}
+
+static inline bool
+read_ws_star(SerdReader* reader)
+{
+	while (read_ws(reader)) {}
+	return true;
+}
+
+static inline bool
+peek_delim(SerdReader* reader, const char delim)
+{
+	read_ws_star(reader);
+	return peek_byte(reader) == delim;
+}
+
+static inline bool
+eat_delim(SerdReader* reader, const char delim)
+{
+	if (peek_delim(reader, delim)) {
+		eat_byte_safe(reader, delim);
+		return read_ws_star(reader);
+	}
+	return false;
+}
+
+// STRING_LITERAL_LONG_QUOTE and STRING_LITERAL_LONG_SINGLE_QUOTE
+// Initial triple quotes are already eaten by caller
+static Ref
+read_STRING_LITERAL_LONG(SerdReader* reader, SerdNodeFlags* flags, uint8_t q)
+{
+	Ref ref = push_node(reader, SERD_LITERAL, "", 0);
+	while (!reader->status) {
+		const uint8_t c = peek_byte(reader);
+		uint32_t      code;
+		switch (c) {
+		case '\\':
+			eat_byte_safe(reader, c);
+			if (!read_ECHAR(reader, ref, flags) &&
+			    !read_UCHAR(reader, ref, &code)) {
+				r_err(reader, SERD_ERR_BAD_SYNTAX,
+				      "invalid escape `\\%c'\n", peek_byte(reader));
+				return pop_node(reader, ref);
+			}
+			break;
+		default:
+			if (c == q) {
+				eat_byte_safe(reader, q);
+				const uint8_t q2 = eat_byte_safe(reader, peek_byte(reader));
+				const uint8_t q3 = peek_byte(reader);
+				if (q2 == q && q3 == q) {  // End of string
+					eat_byte_safe(reader, q3);
+					return ref;
+				}
+				*flags |= SERD_HAS_QUOTE;
+				push_byte(reader, ref, c);
+				read_character(reader, ref, flags, q2);
+			} else {
+				read_character(reader, ref, flags, eat_byte_safe(reader, c));
+			}
+		}
+	}
+	return ref;
+}
+
+// STRING_LITERAL_QUOTE and STRING_LITERAL_SINGLE_QUOTE
+// Initial quote is already eaten by caller
+static Ref
+read_STRING_LITERAL(SerdReader* reader, SerdNodeFlags* flags, uint8_t q)
+{
+	Ref ref = push_node(reader, SERD_LITERAL, "", 0);
+	while (!reader->status) {
+		const uint8_t c    = peek_byte(reader);
+		uint32_t      code = 0;
+		switch (c) {
+		case '\n': case '\r':
+			r_err(reader, SERD_ERR_BAD_SYNTAX, "line end in short string\n");
+			return pop_node(reader, ref);
+		case '\\':
+			eat_byte_safe(reader, c);
+			if (!read_ECHAR(reader, ref, flags) &&
+			    !read_UCHAR(reader, ref, &code)) {
+				r_err(reader, SERD_ERR_BAD_SYNTAX,
+				      "invalid escape `\\%c'\n", peek_byte(reader));
+				return pop_node(reader, ref);
+			}
+			break;
+		default:
+			if (c == q) {
+				eat_byte_check(reader, q);
+				return ref;
+			} else {
+				read_character(reader, ref, flags, eat_byte_safe(reader, c));
+			}
+		}
+	}
+	eat_byte_check(reader, q);
+	return ref;
+}
+
+static Ref
+read_String(SerdReader* reader, SerdNodeFlags* flags)
+{
+	const uint8_t q1 = peek_byte(reader);
+	eat_byte_safe(reader, q1);
+
+	const uint8_t q2 = peek_byte(reader);
+	if (q2 != q1) {  // Short string (not triple quoted)
+		return read_STRING_LITERAL(reader, flags, q1);
+	}
+
+	eat_byte_safe(reader, q2);
+	const uint8_t q3 = peek_byte(reader);
+	if (q3 != q1) {  // Empty short string ("" or '')
+		return push_node(reader, SERD_LITERAL, "", 0);
+	}
+
+	if (!fancy_syntax(reader)) {
+		return r_err(reader, SERD_ERR_BAD_SYNTAX,
+		             "syntax does not support long literals\n");
+	}
+
+	eat_byte_safe(reader, q3);
+	return read_STRING_LITERAL_LONG(reader, flags, q1);
+}
+
+static inline bool
+is_PN_CHARS_BASE(const uint32_t c)
+{
+	return ((c >= 0x00C0 && c <= 0x00D6) || (c >= 0x00D8 && c <= 0x00F6) ||
+	        (c >= 0x00F8 && c <= 0x02FF) || (c >= 0x0370 && c <= 0x037D) ||
+	        (c >= 0x037F && c <= 0x1FFF) || (c >= 0x200C && c <= 0x200D) ||
+	        (c >= 0x2070 && c <= 0x218F) || (c >= 0x2C00 && c <= 0x2FEF) ||
+	        (c >= 0x3001 && c <= 0xD7FF) || (c >= 0xF900 && c <= 0xFDCF) ||
+	        (c >= 0xFDF0 && c <= 0xFFFD) || (c >= 0x10000 && c <= 0xEFFFF));
+}
+
+static SerdStatus
+read_PN_CHARS_BASE(SerdReader* reader, Ref dest)
+{
+	uint32_t      code;
+	const uint8_t c  = peek_byte(reader);
+	SerdStatus    st = SERD_SUCCESS;
+	if (is_alpha(c)) {
+		push_byte(reader, dest, eat_byte_safe(reader, c));
+	} else if (!(c & 0x80)) {
+		return SERD_FAILURE;
+	} else if ((st = read_utf8_code(reader, dest, &code,
+	                                eat_byte_safe(reader, c)))) {
+		return st;
+	} else if (!is_PN_CHARS_BASE(code)) {
+		r_err(reader, SERD_ERR_BAD_SYNTAX,
+		      "invalid character U+%04X in name\n", code);
+		if (reader->strict) {
+			return SERD_ERR_BAD_SYNTAX;
+		}
+	}
+	return st;
+}
+
+static inline bool
+is_PN_CHARS(const uint32_t c)
+{
+	return (is_PN_CHARS_BASE(c) || c == 0xB7 ||
+	        (c >= 0x0300 && c <= 0x036F) || (c >= 0x203F && c <= 0x2040));
+}
+
+static SerdStatus
+read_PN_CHARS(SerdReader* reader, Ref dest)
+{
+	uint32_t      code;
+	const uint8_t c = peek_byte(reader);
+	SerdStatus    st = SERD_SUCCESS;
+	if (is_alpha(c) || is_digit(c) || c == '_' || c == '-') {
+		push_byte(reader, dest, eat_byte_safe(reader, c));
+	} else if (!(c & 0x80)) {
+		return SERD_FAILURE;
+	} else if ((st = read_utf8_code(reader, dest, &code,
+	                                eat_byte_safe(reader, c)))) {
+		return st;
+	} else if (!is_PN_CHARS(code)) {
+		r_err(reader, (st = SERD_ERR_BAD_SYNTAX),
+		      "invalid character U+%04X in name\n", code);
+	}
+	return st;
+}
+
+static bool
+read_PERCENT(SerdReader* reader, Ref dest)
+{
+	push_byte(reader, dest, eat_byte_safe(reader, '%'));
+	const uint8_t h1 = read_HEX(reader);
+	const uint8_t h2 = read_HEX(reader);
+	if (h1 && h2) {
+		push_byte(reader, dest, h1);
+		push_byte(reader, dest, h2);
+		return true;
+	}
+	return false;
+}
+
+static SerdStatus
+read_PLX(SerdReader* reader, Ref dest)
+{
+	uint8_t c = peek_byte(reader);
+	switch (c) {
+	case '%':
+		if (!read_PERCENT(reader, dest)) {
+			return SERD_ERR_BAD_SYNTAX;
+		}
+		return SERD_SUCCESS;
+	case '\\':
+		eat_byte_safe(reader, c);
+		if (is_alpha(c = peek_byte(reader))) {
+			// Escapes like \u \n etc. are not supported
+			return SERD_ERR_BAD_SYNTAX;
+		}
+		// Allow escaping of pretty much any other character
+		push_byte(reader, dest, eat_byte_safe(reader, c));
+		return SERD_SUCCESS;
+	default:
+		return SERD_FAILURE;
+	}
+}
+
+static SerdStatus
+read_PN_LOCAL(SerdReader* reader, Ref dest, bool* ate_dot)
+{
+	uint8_t    c  = peek_byte(reader);
+	SerdStatus st = SERD_SUCCESS;
+	switch (c) {
+	case '0': case '1': case '2': case '3': case '4': case '5':
+	case '6': case '7': case '8': case '9': case ':': case '_':
+		push_byte(reader, dest, eat_byte_safe(reader, c));
+		break;
+	default:
+		if ((st = read_PLX(reader, dest)) > SERD_FAILURE) {
+			return st;
+		} else if (st != SERD_SUCCESS && read_PN_CHARS_BASE(reader, dest)) {
+			return SERD_FAILURE;
+		}
+	}
+
+	while ((c = peek_byte(reader))) {  // Middle: (PN_CHARS | '.' | ';')*
+		if (c == '.' || c == ':') {
+			push_byte(reader, dest, eat_byte_safe(reader, c));
+		} else if ((st = read_PLX(reader, dest)) > SERD_FAILURE) {
+			return st;
+		} else if (st != SERD_SUCCESS && (st = read_PN_CHARS(reader, dest))) {
+			break;
+		}
+	}
+
+	SerdNode* const n = deref(reader, dest);
+	if (n->buf[n->n_bytes - 1] == '.') {
+		// Ate trailing dot, pop it from stack/node and inform caller
+		--n->n_bytes;
+		serd_stack_pop(&reader->stack, 1);
+		*ate_dot = true;
+	}
+
+	return (st > SERD_FAILURE) ? st : SERD_SUCCESS;
+}
+
+// Read the remainder of a PN_PREFIX after some initial characters
+static SerdStatus
+read_PN_PREFIX_tail(SerdReader* reader, Ref dest)
+{
+	uint8_t c;
+	while ((c = peek_byte(reader))) {  // Middle: (PN_CHARS | '.')*
+		if (c == '.') {
+			push_byte(reader, dest, eat_byte_safe(reader, c));
+		} else if (read_PN_CHARS(reader, dest)) {
+			break;
+		}
+	}
+
+	const SerdNode* const n = deref(reader, dest);
+	if (n->buf[n->n_bytes - 1] == '.' && read_PN_CHARS(reader, dest)) {
+		r_err(reader, SERD_ERR_BAD_SYNTAX, "prefix ends with `.'\n");
+		return SERD_ERR_BAD_SYNTAX;
+	}
+
+	return SERD_SUCCESS;
+}
+
+static SerdStatus
+read_PN_PREFIX(SerdReader* reader, Ref dest)
+{
+	if (!read_PN_CHARS_BASE(reader, dest)) {
+		return read_PN_PREFIX_tail(reader, dest);
+	}
+	return SERD_FAILURE;
+}
+
+static Ref
+read_LANGTAG(SerdReader* reader)
+{
+	uint8_t c = peek_byte(reader);
+	if (!is_alpha(c)) {
+		return r_err(reader, SERD_ERR_BAD_SYNTAX, "unexpected `%c'\n", c);
+	}
+	Ref ref = push_node(reader, SERD_LITERAL, "", 0);
+	push_byte(reader, ref, eat_byte_safe(reader, c));
+	while ((c = peek_byte(reader)) && is_alpha(c)) {
+		push_byte(reader, ref, eat_byte_safe(reader, c));
+	}
+	while (peek_byte(reader) == '-') {
+		push_byte(reader, ref, eat_byte_safe(reader, '-'));
+		while ((c = peek_byte(reader)) && (is_alpha(c) || is_digit(c))) {
+			push_byte(reader, ref, eat_byte_safe(reader, c));
+		}
+	}
+	return ref;
+}
+
+static bool
+read_IRIREF_scheme(SerdReader* reader, Ref dest)
+{
+	uint8_t c = peek_byte(reader);
+	if (!isalpha(c)) {
+		return r_err(reader, SERD_ERR_BAD_SYNTAX,
+		             "bad IRI scheme start `%c'\n", c);
+	}
+
+	while ((c = peek_byte(reader))) {
+		if (c == '>') {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX, "missing IRI scheme\n");
+		} else if (!is_uri_scheme_char(c)) {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX,
+			             "bad IRI scheme char `%X'\n", c);
+		}
+
+		push_byte(reader, dest, eat_byte_safe(reader, c));
+		if (c == ':') {
+			return true;  // End of scheme
+		}
+	}
+
+	return false;
+}
+
+static Ref
+read_IRIREF(SerdReader* reader)
+{
+	TRY_RET(eat_byte_check(reader, '<'));
+	Ref ref = push_node(reader, SERD_URI, "", 0);
+	if (!fancy_syntax(reader) && !read_IRIREF_scheme(reader, ref)) {
+		return pop_node(reader, ref);
+	}
+
+	uint32_t code = 0;
+	while (!reader->status) {
+		const uint8_t c = eat_byte_safe(reader, peek_byte(reader));
+		switch (c) {
+		case '"': case '<': case '^': case '`': case '{': case '|': case '}':
+			r_err(reader, SERD_ERR_BAD_SYNTAX,
+			      "invalid IRI character `%c'\n", c);
+			return pop_node(reader, ref);
+		case '>':
+			return ref;
+		case '\\':
+			if (!read_UCHAR(reader, ref, &code)) {
+				r_err(reader, SERD_ERR_BAD_SYNTAX, "invalid IRI escape\n");
+				return pop_node(reader, ref);
+			}
+			switch (code) {
+			case 0: case ' ': case '<': case '>':
+				r_err(reader, SERD_ERR_BAD_SYNTAX,
+				      "invalid escaped IRI character %X %c\n", code, code);
+				return pop_node(reader, ref);
+			}
+			break;
+		default:
+			if (c <= 0x20) {
+				if (isprint(c)) {
+					r_err(reader, SERD_ERR_BAD_SYNTAX,
+					      "invalid IRI character `%c' (escape %%%02X)\n", c, c);
+				} else {
+					r_err(reader, SERD_ERR_BAD_SYNTAX,
+					      "invalid IRI character (escape %%%02X)\n", c, c);
+				}
+				if (reader->strict) {
+					return pop_node(reader, ref);
+				}
+				reader->status = SERD_FAILURE;
+				push_byte(reader, ref, c);
+			} else if (!(c & 0x80)) {
+				push_byte(reader, ref, c);
+			} else if (read_utf8_character(reader, ref, c)) {
+				if (reader->strict) {
+					return pop_node(reader, ref);
+				}
+				reader->status = SERD_FAILURE;
+			}
+		}
+	}
+	return pop_node(reader, ref);
+}
+
+static bool
+read_PrefixedName(SerdReader* reader, Ref dest, bool read_prefix, bool* ate_dot)
+{
+	if (read_prefix && read_PN_PREFIX(reader, dest) > SERD_FAILURE) {
+		return false;
+	} else if (peek_byte(reader) != ':') {
+		return false;
+	}
+
+	push_byte(reader, dest, eat_byte_safe(reader, ':'));
+	return read_PN_LOCAL(reader, dest, ate_dot) <= SERD_FAILURE;
+}
+
+static bool
+read_0_9(SerdReader* reader, Ref str, bool at_least_one)
+{
+	unsigned count = 0;
+	for (uint8_t c; is_digit((c = peek_byte(reader))); ++count) {
+		push_byte(reader, str, eat_byte_safe(reader, c));
+	}
+	if (at_least_one && count == 0) {
+		r_err(reader, SERD_ERR_BAD_SYNTAX, "expected digit\n");
+	}
+	return count;
+}
+
+static bool
+read_number(SerdReader* reader, Ref* dest, Ref* datatype, bool* ate_dot)
+{
+	#define XSD_DECIMAL NS_XSD "decimal"
+	#define XSD_DOUBLE  NS_XSD "double"
+	#define XSD_INTEGER NS_XSD "integer"
+	Ref     ref         = push_node(reader, SERD_LITERAL, "", 0);
+	uint8_t c           = peek_byte(reader);
+	bool    has_decimal = false;
+	if (c == '-' || c == '+') {
+		push_byte(reader, ref, eat_byte_safe(reader, c));
+	}
+	if ((c = peek_byte(reader)) == '.') {
+		has_decimal = true;
+		// decimal case 2 (e.g. '.0' or `-.0' or `+.0')
+		push_byte(reader, ref, eat_byte_safe(reader, c));
+		TRY_THROW(read_0_9(reader, ref, true));
+	} else {
+		// all other cases ::= ( '-' | '+' ) [0-9]+ ( . )? ( [0-9]+ )? ...
+		TRY_THROW(is_digit(c));
+		read_0_9(reader, ref, true);
+		if ((c = peek_byte(reader)) == '.') {
+			has_decimal = true;
+
+			// Annoyingly, dot can be end of statement, so tentatively eat
+			eat_byte_safe(reader, c);
+			c = peek_byte(reader);
+			if (!is_digit(c) && c != 'e' && c != 'E') {
+				*dest    = ref;
+				*ate_dot = true;  // Force caller to deal with stupid grammar
+				return true;  // Next byte is not a number character, done
+			}
+
+			push_byte(reader, ref, '.');
+			read_0_9(reader, ref, false);
+		}
+	}
+	c = peek_byte(reader);
+	if (c == 'e' || c == 'E') {
+		// double
+		push_byte(reader, ref, eat_byte_safe(reader, c));
+		switch ((c = peek_byte(reader))) {
+		case '+': case '-':
+			push_byte(reader, ref, eat_byte_safe(reader, c));
+		default: break;
+		}
+		TRY_THROW(read_0_9(reader, ref, true));
+		*datatype = push_node(reader, SERD_URI,
+		                      XSD_DOUBLE, sizeof(XSD_DOUBLE) - 1);
+	} else if (has_decimal) {
+		*datatype = push_node(reader, SERD_URI,
+		                      XSD_DECIMAL, sizeof(XSD_DECIMAL) - 1);
+	} else {
+		*datatype = push_node(reader, SERD_URI,
+		                      XSD_INTEGER, sizeof(XSD_INTEGER) - 1);
+	}
+	*dest = ref;
+	return true;
+except:
+	pop_node(reader, *datatype);
+	pop_node(reader, ref);
+	return r_err(reader, SERD_ERR_BAD_SYNTAX, "bad number syntax\n");
+}
+
+static bool
+read_iri(SerdReader* reader, Ref* dest, bool* ate_dot)
+{
+	switch (peek_byte(reader)) {
+	case '<':
+		*dest = read_IRIREF(reader);
+		return true;
+	default:
+		*dest = push_node(reader, SERD_CURIE, "", 0);
+		return read_PrefixedName(reader, *dest, true, ate_dot);
+	}
+}
+
+static bool
+read_literal(SerdReader* reader, Ref* dest,
+             Ref* datatype, Ref* lang, SerdNodeFlags* flags, bool* ate_dot)
+{
+	Ref str = read_String(reader, flags);
+	if (!str) {
+		return false;
+	}
+
+	switch (peek_byte(reader)) {
+	case '@':
+		eat_byte_safe(reader, '@');
+		TRY_THROW(*lang = read_LANGTAG(reader));
+		break;
+	case '^':
+		eat_byte_safe(reader, '^');
+		eat_byte_check(reader, '^');
+		TRY_THROW(read_iri(reader, datatype, ate_dot));
+		break;
+	}
+	*dest = str;
+	return true;
+except:
+	*datatype = pop_node(reader, *datatype);
+	*lang     = pop_node(reader, *lang);
+	pop_node(reader, str);
+	return r_err(reader, SERD_ERR_BAD_SYNTAX, "bad literal syntax\n");
+}
+
+inline static bool
+is_token_end(uint8_t c)
+{
+	switch (c) {
+	case 0x9: case 0xA: case 0xD: case 0x20: case '\0':
+	case '#': case '.': case ';': case '<':
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool
+read_verb(SerdReader* reader, Ref* dest)
+{
+	if (peek_byte(reader) == '<') {
+		return (*dest = read_IRIREF(reader));
+	}
+
+	/* Either a qname, or "a".  Read the prefix first, and if it is in fact
+	   "a", produce that instead.
+	*/
+	*dest = push_node(reader, SERD_CURIE, "", 0);
+	SerdNode*        node    = deref(reader, *dest);
+	const SerdStatus st      = read_PN_PREFIX(reader, *dest);
+	bool             ate_dot = false;
+	if (!st && node->n_bytes == 1 && node->buf[0] == 'a' &&
+	    is_token_end(peek_byte(reader))) {
+		pop_node(reader, *dest);
+		return (*dest = push_node(reader, SERD_URI, NS_RDF "type", 47));
+	} else if (st > SERD_FAILURE ||
+	           !read_PrefixedName(reader, *dest, false, &ate_dot) ||
+	           ate_dot) {
+		*dest = pop_node(reader, *dest);
+		return r_err(reader, SERD_ERR_BAD_SYNTAX, "bad verb\n");
+	}
+
+	return true;
+}
+
+static Ref
+read_BLANK_NODE_LABEL(SerdReader* reader, bool* ate_dot)
+{
+	eat_byte_safe(reader, '_');
+	eat_byte_check(reader, ':');
+	Ref ref = push_node(reader, SERD_BLANK,
+	                    reader->bprefix ? (char*)reader->bprefix : "",
+	                    reader->bprefix_len);
+
+	uint8_t c = peek_byte(reader);  // First: (PN_CHARS | '_' | [0-9])
+	if (is_digit(c) || c == '_') {
+		push_byte(reader, ref, eat_byte_safe(reader, c));
+	} else if (read_PN_CHARS(reader, ref)) {
+		r_err(reader, SERD_ERR_BAD_SYNTAX, "invalid name start character\n");
+		return pop_node(reader, ref);
+	}
+
+	while ((c = peek_byte(reader))) {  // Middle: (PN_CHARS | '.')*
+		if (c == '.') {
+			push_byte(reader, ref, eat_byte_safe(reader, c));
+		} else if (read_PN_CHARS(reader, ref)) {
+			break;
+		}
+	}
+
+	SerdNode* n = deref(reader, ref);
+	if (n->buf[n->n_bytes - 1] == '.' && read_PN_CHARS(reader, ref)) {
+		// Ate trailing dot, pop it from stack/node and inform caller
+		--n->n_bytes;
+		serd_stack_pop(&reader->stack, 1);
+		*ate_dot = true;
+	}
+
+	if (reader->syntax == SERD_TURTLE) {
+		if (is_digit(n->buf[reader->bprefix_len + 1])) {
+			if ((n->buf[reader->bprefix_len]) == 'b') {
+				((char*)n->buf)[reader->bprefix_len] = 'B';  // Prevent clash
+				reader->seen_genid = true;
+			} else if (reader->seen_genid &&
+			           n->buf[reader->bprefix_len] == 'B') {
+				r_err(reader, SERD_ERR_ID_CLASH,
+				      "found both `b' and `B' blank IDs, prefix required\n");
+				return pop_node(reader, ref);
+			}
+		}
+	}
+	return ref;
+}
+
+static Ref
+read_blankName(SerdReader* reader)
+{
+	eat_byte_safe(reader, '=');
+	if (eat_byte_check(reader, '=') != '=') {
+		return r_err(reader, SERD_ERR_BAD_SYNTAX, "expected `='\n");
+	}
+
+	Ref  subject = 0;
+	bool ate_dot = false;
+	read_ws_star(reader);
+	read_iri(reader, &subject, &ate_dot);
+	return subject;
+}
+
+static bool
+read_anon(SerdReader* reader, ReadContext ctx, bool subject, Ref* dest)
+{
+	const SerdStatementFlags old_flags = *ctx.flags;
+	bool empty;
+	eat_byte_safe(reader, '[');
+	if ((empty = peek_delim(reader, ']'))) {
+		*ctx.flags |= (subject) ? SERD_EMPTY_S : SERD_EMPTY_O;
+	} else {
+		*ctx.flags |= (subject) ? SERD_ANON_S_BEGIN : SERD_ANON_O_BEGIN;
+		if (peek_delim(reader, '=')) {
+			if (!(*dest = read_blankName(reader)) ||
+			    !eat_delim(reader, ';')) {
+				return false;
+			}
+		}
+	}
+
+	if (!*dest) {
+		*dest = blank_id(reader);
+	}
+	if (ctx.subject) {
+		TRY_RET(emit_statement(reader, ctx, *dest, 0, 0));
+	}
+
+	ctx.subject = *dest;
+	if (!empty) {
+		*ctx.flags &= ~(SERD_LIST_CONT);
+		if (!subject) {
+			*ctx.flags |= SERD_ANON_CONT;
+		}
+		bool ate_dot_in_list = false;
+		read_predicateObjectList(reader, ctx, &ate_dot_in_list);
+		if (ate_dot_in_list) {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX, "`.' inside blank\n");
+		}
+		read_ws_star(reader);
+		if (reader->end_sink) {
+			reader->end_sink(reader->handle, deref(reader, *dest));
+		}
+		*ctx.flags = old_flags;
+	}
+	return (eat_byte_check(reader, ']') == ']');
+}
+
+/* If emit is true: recurses, calling statement_sink for every statement
+   encountered, and leaves stack in original calling state (i.e. pops
+   everything it pushes). */
+static bool
+read_object(SerdReader* reader, ReadContext* ctx, bool emit, bool* ate_dot)
+{
+	static const char* const XSD_BOOLEAN     = NS_XSD "boolean";
+	static const size_t      XSD_BOOLEAN_LEN = 40;
+
+#ifndef NDEBUG
+	const size_t orig_stack_size = reader->stack.size;
+#endif
+
+	bool          ret      = false;
+	bool          simple   = (ctx->subject != 0);
+	SerdNode*     node     = NULL;
+	Ref           o        = 0;
+	Ref           datatype = 0;
+	Ref           lang     = 0;
+	uint32_t      flags    = 0;
+	const uint8_t c        = peek_byte(reader);
+	if (!fancy_syntax(reader)) {
+		switch (c) {
+		case '"': case ':': case '<': case '_': break;
+		default: return r_err(reader, SERD_ERR_BAD_SYNTAX,
+		                      "expected: ':', '<', or '_'\n");
+		}
+	}
+	switch (c) {
+	case '\0': case ')':
+		return r_err(reader, SERD_ERR_BAD_SYNTAX, "expected object\n");
+	case '[':
+		simple = false;
+		TRY_THROW(ret = read_anon(reader, *ctx, false, &o));
+		break;
+	case '(':
+		simple = false;
+		TRY_THROW(ret = read_collection(reader, *ctx, &o));
+		break;
+	case '_':
+		TRY_THROW(ret = (o = read_BLANK_NODE_LABEL(reader, ate_dot)));
+		break;
+	case '<': case ':':
+		TRY_THROW(ret = read_iri(reader, &o, ate_dot));
+		break;
+	case '+': case '-': case '.': case '0': case '1': case '2': case '3':
+	case '4': case '5': case '6': case '7': case '8': case '9':
+		TRY_THROW(ret = read_number(reader, &o, &datatype, ate_dot));
+		break;
+	case '\"':
+	case '\'':
+		TRY_THROW(ret = read_literal(reader, &o, &datatype, &lang, &flags, ate_dot));
+		break;
+	default:
+		/* Either a boolean literal, or a qname.  Read the prefix first, and if
+		   it is in fact a "true" or "false" literal, produce that instead.
+		*/
+		node = deref(reader, o = push_node(reader, SERD_CURIE, "", 0));
+		while (!read_PN_CHARS_BASE(reader, o)) {}
+		if ((node->n_bytes == 4 && !memcmp(node->buf, "true", 4)) ||
+		    (node->n_bytes == 5 && !memcmp(node->buf, "false", 5))) {
+			node->type = SERD_LITERAL;
+			datatype   = push_node(
+				reader, SERD_URI, XSD_BOOLEAN, XSD_BOOLEAN_LEN);
+			ret = true;
+		} else if (read_PN_PREFIX_tail(reader, o) > SERD_FAILURE) {
+			ret = false;
+		} else {
+			if (!(ret = read_PrefixedName(reader, o, false, ate_dot))) {
+				r_err(reader, SERD_ERR_BAD_SYNTAX, "expected prefixed name\n");
+			}
+		}
+	}
+
+	if (simple && o) {
+		deref(reader, o)->flags = flags;
+	}
+
+	if (ret && emit && simple) {
+		ret = emit_statement(reader, *ctx, o, datatype, lang);
+	} else if (ret && !emit) {
+		ctx->object   = o;
+		ctx->datatype = datatype;
+		ctx->lang     = lang;
+		return true;
+	}
+
+except:
+	pop_node(reader, lang);
+	pop_node(reader, datatype);
+	pop_node(reader, o);
+#ifndef NDEBUG
+	assert(reader->stack.size == orig_stack_size);
+#endif
+	return ret;
+}
+
+static bool
+read_objectList(SerdReader* reader, ReadContext ctx, bool* ate_dot)
+{
+	TRY_RET(read_object(reader, &ctx, true, ate_dot));
+	if (!fancy_syntax(reader) && peek_delim(reader, ',')) {
+		return r_err(reader, SERD_ERR_BAD_SYNTAX,
+		             "syntax does not support abbreviation\n");
+	}
+
+	while (!*ate_dot && eat_delim(reader, ',')) {
+		TRY_RET(read_object(reader, &ctx, true, ate_dot));
+	}
+	return true;
+}
+
+static bool
+read_predicateObjectList(SerdReader* reader, ReadContext ctx, bool* ate_dot)
+{
+	while (read_verb(reader, &ctx.predicate) &&
+	       read_ws_star(reader) &&
+	       read_objectList(reader, ctx, ate_dot)) {
+		ctx.predicate = pop_node(reader, ctx.predicate);
+		if (*ate_dot) {
+			return true;
+		}
+
+		bool    ate_semi = false;
+		uint8_t c;
+		do {
+			read_ws_star(reader);
+			switch (c = peek_byte(reader)) {
+			case 0:
+				return r_err(reader, SERD_ERR_BAD_SYNTAX,
+				             "unexpected end of file\n");
+			case '.': case ']': case '}':
+				return true;
+			case ';':
+				eat_byte_safe(reader, c);
+				ate_semi = true;
+			}
+		} while (c == ';');
+
+		if (!ate_semi) {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX, "missing ';' or '.'\n");
+		}
+	}
+
+	return pop_node(reader, ctx.predicate);
+}
+
+static bool
+end_collection(SerdReader* reader, ReadContext ctx, Ref n1, Ref n2, bool ret)
+{
+	pop_node(reader, n2);
+	pop_node(reader, n1);
+	*ctx.flags &= ~SERD_LIST_CONT;
+	return ret && (eat_byte_safe(reader, ')') == ')');
+}
+
+static bool
+read_collection(SerdReader* reader, ReadContext ctx, Ref* dest)
+{
+	eat_byte_safe(reader, '(');
+	bool end = peek_delim(reader, ')');
+	*dest = end ? reader->rdf_nil : blank_id(reader);
+	if (ctx.subject) {
+		// subject predicate _:head
+		*ctx.flags |= (end ? 0 : SERD_LIST_O_BEGIN);
+		TRY_RET(emit_statement(reader, ctx, *dest, 0, 0));
+		*ctx.flags |= SERD_LIST_CONT;
+	} else {
+		*ctx.flags |= (end ? 0 : SERD_LIST_S_BEGIN);
+	}
+
+	if (end) {
+		return end_collection(reader, ctx, 0, 0, true);
+	}
+
+	/* The order of node allocation here is necessarily not in stack order,
+	   so we create two nodes and recycle them throughout. */
+	Ref n1   = push_node_padded(reader, genid_size(reader), SERD_BLANK, "", 0);
+	Ref n2   = 0;
+	Ref node = n1;
+	Ref rest = 0;
+
+	ctx.subject = *dest;
+	while (!(end = peek_delim(reader, ')'))) {
+		// _:node rdf:first object
+		ctx.predicate = reader->rdf_first;
+		bool ate_dot = false;
+		if (!read_object(reader, &ctx, true, &ate_dot) || ate_dot) {
+			return end_collection(reader, ctx, n1, n2, false);
+		}
+
+		if (!(end = peek_delim(reader, ')'))) {
+			/* Give rest a new ID.  Done as late as possible to ensure it is
+			   used and > IDs generated by read_object above. */
+			if (!rest) {
+				rest = n2 = blank_id(reader);  // First pass, push
+			} else {
+				set_blank_id(reader, rest, genid_size(reader));
+			}
+		}
+
+		// _:node rdf:rest _:rest
+		*ctx.flags |= SERD_LIST_CONT;
+		ctx.predicate = reader->rdf_rest;
+		TRY_RET(emit_statement(reader, ctx,
+		                       (end ? reader->rdf_nil : rest), 0, 0));
+
+		ctx.subject = rest;         // _:node = _:rest
+		rest        = node;         // _:rest = (old)_:node
+		node        = ctx.subject;  // invariant
+	}
+
+	return end_collection(reader, ctx, n1, n2, true);
+}
+
+static Ref
+read_subject(SerdReader* reader, ReadContext ctx, Ref* dest, char* s_type)
+{
+	bool ate_dot = false;
+	switch ((*s_type = peek_byte(reader))) {
+	case '[':
+		read_anon(reader, ctx, true, dest);
+		break;
+	case '(':
+		read_collection(reader, ctx, dest);
+		break;
+	case '_':
+		*dest = read_BLANK_NODE_LABEL(reader, &ate_dot);
+		break;
+	default:
+		TRY_RET(read_iri(reader, dest, &ate_dot));
+	}
+	return ate_dot ? pop_node(reader, *dest) : *dest;
+}
+
+static Ref
+read_labelOrSubject(SerdReader* reader, ReadContext ctx)
+{
+	Ref  subject = 0;
+	bool ate_dot = false;
+	switch (peek_byte(reader)) {
+	case '[':
+		eat_byte_safe(reader, '[');
+		read_ws_star(reader);
+		TRY_RET(eat_byte_check(reader, ']'));
+		return blank_id(reader);
+	case '_':
+		return read_BLANK_NODE_LABEL(reader, &ate_dot);
+	default:
+		read_iri(reader, &subject, &ate_dot);
+	}
+	return subject;
+}
+
+static bool
+read_triples(SerdReader* reader, ReadContext ctx, bool* ate_dot)
+{
+	bool ret = false;
+	if (ctx.subject) {
+		read_ws_star(reader);
+		switch (peek_byte(reader)) {
+		case '.':
+			*ate_dot = eat_byte_safe(reader, '.');
+			return r_err(reader, SERD_ERR_BAD_SYNTAX, "syntax error\n");
+		case '}':
+			return false;
+		}
+		ret = read_predicateObjectList(reader, ctx, ate_dot);
+	}
+	ctx.subject = ctx.predicate = 0;
+	return ret;
+}
+
+static bool
+read_base(SerdReader* reader, bool sparql, bool token)
+{
+	if (token) {
+		TRY_RET(eat_string(reader, "base", 4));
+	}
+
+	Ref uri;
+	read_ws_star(reader);
+	TRY_RET(uri = read_IRIREF(reader));
+	if (reader->base_sink) {
+		reader->base_sink(reader->handle, deref(reader, uri));
+	}
+	pop_node(reader, uri);
+
+	read_ws_star(reader);
+	if (!sparql) {
+		return eat_byte_check(reader, '.');
+	} else if (peek_byte(reader) == '.') {
+		return r_err(reader, SERD_ERR_BAD_SYNTAX,
+		             "full stop after SPARQL BASE\n");
+	}
+	return true;
+}
+
+static bool
+read_prefixID(SerdReader* reader, bool sparql, bool token)
+{
+	if (token) {
+		TRY_RET(eat_string(reader, "prefix", 6));
+	}
+
+	read_ws_star(reader);
+	bool ret  = true;
+	Ref  name = push_node(reader, SERD_LITERAL, "", 0);
+	if (read_PN_PREFIX(reader, name) > SERD_FAILURE) {
+		return pop_node(reader, name);
+	}
+
+	if (eat_byte_check(reader, ':') != ':') {
+		return pop_node(reader, name);
+	}
+
+	read_ws_star(reader);
+	const Ref uri = read_IRIREF(reader);
+	if (!uri) {
+		pop_node(reader, name);
+		return false;
+	}
+
+	if (reader->prefix_sink) {
+		ret = !reader->prefix_sink(reader->handle,
+		                           deref(reader, name),
+		                           deref(reader, uri));
+	}
+	pop_node(reader, uri);
+	pop_node(reader, name);
+	if (!sparql) {
+		read_ws_star(reader);
+		return eat_byte_check(reader, '.');
+	}
+	return ret;
+}
+
+static bool
+read_directive(SerdReader* reader)
+{
+	const bool sparql = peek_byte(reader) != '@';
+	if (!sparql) {
+		eat_byte_safe(reader, '@');
+		switch (peek_byte(reader)) {
+		case 'B': case 'P':
+			return r_err(reader, SERD_ERR_BAD_SYNTAX,
+			             "uppercase directive\n");
+		}
+	}
+
+	switch (peek_byte(reader)) {
+	case 'B': case 'b': return read_base(reader, sparql, true);
+	case 'P': case 'p': return read_prefixID(reader, sparql, true);
+	default:
+		return r_err(reader, SERD_ERR_BAD_SYNTAX, "invalid directive\n");
+	}
+
+	return true;
+}
+
+static bool
+read_wrappedGraph(SerdReader* reader, ReadContext* ctx)
+{
+	bool ate_dot = false;
+	char s_type  = 0;
+	TRY_RET(eat_byte_check(reader, '{'));
+	read_ws_star(reader);
+	while (peek_byte(reader) != '}') {
+		ctx->subject = 0;
+		Ref subj = read_subject(reader, *ctx, &ctx->subject, &s_type);
+		if (!subj && ctx->subject) {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX, "bad subject\n");
+		} else if (!subj) {
+			return false;
+		} else if (!read_triples(reader, *ctx, &ate_dot) && s_type != '[') {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX,
+			             "missing predicate object list\n");
+		}
+		pop_node(reader, subj);
+		read_ws_star(reader);
+		if (peek_byte(reader) == '.') {
+			eat_byte_safe(reader, '.');
+		}
+		read_ws_star(reader);
+	}
+	return eat_byte_check(reader, '}');
+}
+
+static int
+tokcmp(SerdReader* reader, Ref ref, const char* tok, size_t n)
+{
+	SerdNode* node = deref(reader, ref);
+	if (!node || node->n_bytes != n) {
+		return -1;
+	}
+	return serd_strncasecmp((const char*)node->buf, tok, n);
+}
+
+bool
+read_n3_statement(SerdReader* reader)
+{
+	SerdStatementFlags flags   = 0;
+	ReadContext        ctx     = { 0, 0, 0, 0, 0, 0, &flags };
+	Ref                subj    = 0;
+	bool               ate_dot = false;
+	char               s_type  = 0;
+	bool               ret     = true;
+	read_ws_star(reader);
+	switch (peek_byte(reader)) {
+	case '\0':
+		reader->source.eof = true;
+		return reader->status <= SERD_FAILURE;
+	case '@':
+		if (!fancy_syntax(reader)) {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX,
+			             "syntax does not support directives\n");
+		}
+		TRY_RET(read_directive(reader));
+		read_ws_star(reader);
+		break;
+	case '{':
+		if (reader->syntax == SERD_TRIG) {
+			TRY_RET(read_wrappedGraph(reader, &ctx));
+			read_ws_star(reader);
+		} else {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX,
+			             "syntax does not support graphs\n");
+		}
+		break;
+	default:
+		subj = read_subject(reader, ctx, &ctx.subject, &s_type);
+		if (!tokcmp(reader, ctx.subject, "base", 4)) {
+			ret = read_base(reader, true, false);
+		} else if (!tokcmp(reader, ctx.subject, "prefix", 6)) {
+			ret = read_prefixID(reader, true, false);
+		} else if (!tokcmp(reader, ctx.subject, "graph", 5)) {
+			read_ws_star(reader);
+			TRY_RET((ctx.graph = read_labelOrSubject(reader, ctx)));
+			read_ws_star(reader);
+			TRY_RET(read_wrappedGraph(reader, &ctx));
+			read_ws_star(reader);
+		} else if (read_ws_star(reader) && peek_byte(reader) == '{') {
+			if (s_type == '(' || (s_type == '[' && !*ctx.flags)) {
+				return r_err(reader, SERD_ERR_BAD_SYNTAX,
+				             "invalid graph name\n");
+			}
+			ctx.graph   = subj;
+			ctx.subject = subj = 0;
+			TRY_RET(read_wrappedGraph(reader, &ctx));
+			read_ws_star(reader);
+		} else if (!subj) {
+			ret = r_err(reader, SERD_ERR_BAD_SYNTAX, "bad subject\n");
+		} else if (!read_triples(reader, ctx, &ate_dot)) {
+			ret = (s_type == '[');
+		} else if (!ate_dot) {
+			read_ws_star(reader);
+			ret = (eat_byte_check(reader, '.') == '.');
+		}
+		pop_node(reader, subj);
+		break;
+	}
+	return ret;
+}
+
+static void
+skip_until(SerdReader* reader, uint8_t byte)
+{
+	for (uint8_t c = 0; (c = peek_byte(reader)) && c != byte;) {
+		eat_byte_safe(reader, c);
+	}
+}
+
+bool
+read_turtleTrigDoc(SerdReader* reader)
+{
+	while (!reader->source.eof) {
+		if (!read_n3_statement(reader)) {
+			if (reader->strict) {
+				return 0;
+			}
+			skip_until(reader, '\n');
+			reader->status = SERD_SUCCESS;
+		}
+	}
+	return reader->status <= SERD_FAILURE;
+}
+
+bool
+read_nquadsDoc(SerdReader* reader)
+{
+	while (!reader->source.eof) {
+		SerdStatementFlags flags   = 0;
+		ReadContext        ctx     = { 0, 0, 0, 0, 0, 0, &flags };
+		bool               ate_dot = false;
+		char               s_type  = false;
+		read_ws_star(reader);
+		if (peek_byte(reader) == '\0') {
+			reader->source.eof = true;
+			break;
+		} else if (peek_byte(reader) == '@') {
+			return r_err(reader, SERD_ERR_BAD_SYNTAX,
+			             "syntax does not support directives\n");
+		}
+
+		// subject predicate object
+		if (!(ctx.subject = read_subject(reader, ctx, &ctx.subject, &s_type)) ||
+		    !read_ws_star(reader) ||
+		    !(ctx.predicate = read_IRIREF(reader)) ||
+		    !read_ws_star(reader) ||
+		    !read_object(reader, &ctx, false, &ate_dot)) {
+			return false;
+		}
+
+		if (!ate_dot) {  // graphLabel?
+			TRY_RET(read_ws_star(reader));
+			switch (peek_byte(reader)) {
+			case '.':
+				break;
+			case '_':
+				ctx.graph = read_BLANK_NODE_LABEL(reader, &ate_dot);
+				break;
+			default:
+				if (!(ctx.graph = read_IRIREF(reader))) {
+					return false;
+				}
+			}
+
+			// Terminating '.'
+			TRY_RET(read_ws_star(reader));
+			eat_byte_check(reader, '.');
+		}
+
+		TRY_RET(emit_statement(reader, ctx, ctx.object, ctx.datatype, ctx.lang));
+		pop_node(reader, ctx.graph);
+		pop_node(reader, ctx.lang);
+		pop_node(reader, ctx.datatype);
+		pop_node(reader, ctx.object);
+	}
+	return reader->status <= SERD_FAILURE;
+}