diff options
| -rw-r--r-- | src/n3.c | 195 |
1 files changed, 108 insertions, 87 deletions
@@ -814,7 +814,7 @@ read_subject(SerdReader* const reader, st = read_BLANK_NODE_LABEL(reader, dest, &ate_dot); break; default: - st = read_iri(reader, dest, &ate_dot); + TRY(st, read_iri(reader, dest, &ate_dot)); } if (ate_dot) { @@ -938,33 +938,6 @@ read_prefixID(SerdReader* const reader, const bool sparql, const bool token) } static SerdStatus -read_directive(SerdReader* const reader) -{ - const bool sparql = peek_byte(reader) != '@'; - if (!sparql) { - skip_byte(reader, '@'); - switch (peek_byte(reader)) { - case 'B': - case 'P': - return r_err(reader, SERD_BAD_SYNTAX, "uppercase directive"); - } - } - - 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: - break; - } - - return r_err(reader, SERD_BAD_SYNTAX, "invalid directive"); -} - -static SerdStatus read_wrappedGraph(SerdReader* const reader, ReadContext* const ctx) { SerdStatus st = SERD_SUCCESS; @@ -1003,84 +976,132 @@ read_wrappedGraph(SerdReader* const reader, ReadContext* const ctx) } static int -tokcmp(SerdNode* const node, const char* const tok, const size_t n) +tokcmp(const SerdNode* const node, const char* const tok, const size_t n) { return ((!node || node->length != n) ? -1 : serd_strncasecmp(serd_node_string(node), tok, n)); } +static SerdStatus +read_turtle_directive(SerdReader* const reader) +{ + skip_byte(reader, '@'); + + switch (peek_byte(reader)) { + case 'b': + return read_base(reader, false, true); + case 'p': + return read_prefixID(reader, false, true); + default: + break; + } + + return r_err(reader, SERD_BAD_SYNTAX, "expected \"base\" or \"prefix\""); +} + +static SerdStatus +read_sparql_directive(SerdReader* const reader, + ReadContext* const ctx, + const SerdNode* const token) +{ + if (!tokcmp(token, "base", 4)) { + return read_base(reader, true, false); + } + + if (!tokcmp(token, "prefix", 6)) { + return read_prefixID(reader, true, false); + } + + if (!tokcmp(token, "graph", 5)) { + SerdStatus st = SERD_SUCCESS; + read_ws_star(reader); + TRY(st, read_labelOrSubject(reader, &ctx->graph)); + read_ws_star(reader); + return read_wrappedGraph(reader, ctx); + } + + return SERD_FAILURE; +} + +static SerdStatus +read_block(SerdReader* const reader, ReadContext* const ctx) +{ + SerdStatus st = SERD_SUCCESS; + + // Try to read a subject, though it may actually be a directive or graph name + SerdNode* token = NULL; + int s_type = 0; + if ((st = read_subject(reader, *ctx, &token, &s_type)) > SERD_FAILURE) { + return st; + } + + // Try to interpret as a SPARQL "PREFIX" or "BASE" directive + if (st && (st = read_sparql_directive(reader, ctx, token)) != SERD_FAILURE) { + return st; + } + + // Try to interpret as a named TriG graph like "graphname { ..." + read_ws_star(reader); + if (peek_byte(reader) == '{') { + if (s_type == '(' || (s_type == '[' && !*ctx->flags)) { + return r_err(reader, SERD_BAD_SYNTAX, "invalid graph name"); + } + + ctx->graph = token; + return read_wrappedGraph(reader, ctx); + } + + if (st) { + return r_err(reader, SERD_BAD_SYNTAX, "expected directive or subject"); + } + + // Our token is really a subject, read some triples + bool ate_dot = false; + ctx->subject = token; + if ((st = read_triples(reader, *ctx, &ate_dot)) > SERD_FAILURE) { + return st; + } + + // "Failure" is only allowed for anonymous subjects like "[ ... ] ." + if (st && s_type != '[') { + return r_err(reader, SERD_BAD_SYNTAX, "expected triples"); + } + + // Ensure that triples are properly terminated + return ate_dot ? st : eat_byte_check(reader, '.'); +} + SerdStatus read_n3_statement(SerdReader* const reader) { - SerdStatementFlags flags = 0; - ReadContext ctx = {0, 0, 0, 0, &flags}; - bool ate_dot = false; - int s_type = 0; - SerdStatus st = SERD_SUCCESS; + SerdStatementFlags flags = 0; + ReadContext ctx = {0, 0, 0, 0, &flags}; + + // Handle nice cases we can distinguish from the next byte read_ws_star(reader); switch (peek_byte(reader)) { - case '\0': - skip_byte(reader, '\0'); - return SERD_FAILURE; case EOF: return SERD_FAILURE; + + case '\0': + eat_byte(reader); + return SERD_FAILURE; + case '@': - TRY(st, read_directive(reader)); - read_ws_star(reader); - break; - case '{': - if (reader->syntax == SERD_TRIG) { - TRY(st, read_wrappedGraph(reader, &ctx)); - read_ws_star(reader); - } else { - return r_err(reader, SERD_BAD_SYNTAX, "syntax does not support graphs"); - } - break; - default: - TRY_FAILING(st, read_subject(reader, ctx, &ctx.subject, &s_type)); - - if (!tokcmp(ctx.subject, "base", 4)) { - st = read_base(reader, true, false); - } else if (!tokcmp(ctx.subject, "prefix", 6)) { - st = read_prefixID(reader, true, false); - } else if (!tokcmp(ctx.subject, "graph", 5)) { - ctx.subject = NULL; - read_ws_star(reader); - TRY(st, read_labelOrSubject(reader, &ctx.graph)); - read_ws_star(reader); - TRY(st, read_wrappedGraph(reader, &ctx)); - ctx.graph = 0; - read_ws_star(reader); - } else if (!tokcmp(ctx.subject, "true", 4) || - !tokcmp(ctx.subject, "false", 5)) { - return r_err(reader, SERD_BAD_SYNTAX, "expected subject"); - } else if (read_ws_star(reader) && peek_byte(reader) == '{') { - if (s_type == '(' || (s_type == '[' && !*ctx.flags)) { - return r_err(reader, SERD_BAD_SYNTAX, "invalid graph name"); - } - ctx.graph = ctx.subject; - ctx.subject = NULL; - TRY(st, read_wrappedGraph(reader, &ctx)); - read_ws_star(reader); - } else if ((st = read_triples(reader, ctx, &ate_dot))) { - if (st == SERD_FAILURE && s_type == '[') { - return SERD_SUCCESS; - } + return read_turtle_directive(reader); - if (ate_dot && (reader->strict || (s_type != '('))) { - return r_err(reader, SERD_BAD_SYNTAX, "unexpected end of statement"); - } + case '{': + return (reader->syntax == SERD_TRIG) + ? read_wrappedGraph(reader, &ctx) + : r_err(reader, SERD_BAD_SYNTAX, "syntax does not support graphs"); - return st > SERD_FAILURE ? st : SERD_BAD_SYNTAX; - } else if (!ate_dot) { - read_ws_star(reader); - st = eat_byte_check(reader, '.'); - } + default: break; } - return st; + // No such luck, figure out what to read from the first token + return read_block(reader, &ctx); } SerdStatus |