# Rasqal RDF Query Library - Release Notes

## Rasqal 0.9.13 Changes

### General Changes

Added a new `rasqal_query_results_formatter` class.

Many internal query engine changes, mostly to separate query and query_results internals so that eventually the run-time execution context is entirely separated from the static query structure.

Added query features system with one initial feature `RASQAL_FEATURE_NO_NET`.

### Configuration and Build Changes

Allow shell variable `LEX` to be set to things that aren't exactly `flex` Recommend flex 2.5.33 and update configure to point at the main flex site whichq finally gets 2.5.33 after 9 years.

`PKGCONFIG` vars not substituted correctly in configure.ac. Remove @LDFLAGS from rasqal.pc.in. Fixes Issue#0000098.

Win32 build fixes.Correct win32 static linking of rasqal. (Fixes Issue#0000100) and include float.h and `#define isnan` on win32. (Fixes Issue#0000111).

In maintainer mode, add all the supported compiler `-W` warning flags to the CFLAGS.

Declare several rasqal functions with GCC printf-formatting attributes when using a new enough GCC.

Remove broken debug messages. #0000131.

### SPARQL Query Language Changes

Added labels to grammar tokens using bison to give better error messages.

Fix looking for EOF in an unsigned variable since it may be negative on some systems.

The query engine now implements SPARQL `GRAPH` matching.

### RDQL Query Language Changes

Added labels to grammar tokens using bison to give better error messages.

Fix looking for EOF in an unsigned variable since it may be negative on some systems.

### Query Engine Changes

The query engine now implements SPARQL `GRAPH` matching.

Merge only all adjacent sequences of basic graph pattern triples, not anything with triples such as optional BGP triples. Fixes Issue#0000080.

When an exact triple match is present, do not execute a query forever. Fixes Issue#0000094.

Fail if a variable argument to `LANG()` has an undefined value rather than try to execute a NULL pointer. Fixes Issue#0000113.

Add query / query_results link early so reference counting is done right. Fixes Issue#0000095.

Report failure as well as query finished when an error occurs during making results. Fixes Issue#0000118.

Added a hack to check an outer constraint expression. Fixes Issue#0000129.

Free origins (`GRAPH` nodes) in triples to prevent memory leak. Fixes Issue#0000133.

### Query API Changes

Added a new `rasqal_query_results_formatter` class to format `librdf_query_results` into a syntax. Also added a `rasqal_query_results_formats_enumerate()` function to enumerate all the supported formats. The query results method `rasqal_query_results_write()` was changed to use this class internally.

Added a new feature system to allow setting parameters on the query parser/engine. Initially have one feature `RASQAL_FEATURE_NO_NET` that prevents network requests during a query execution. Added functions: `rasqal_features_enumerate`, `rasqal_get_feature_count`, `rasqal_feature_from_uri`, `rasqal_feature_value_type`, `rasqal_query_set_feature`, `rasqal_query_set_feature_string`, `rasqal_query_get_feature`, `rasqal_query_get_feature_string`.

`roqet` gained a `-f` / `--feature` option to set query features.

## Rasqal 0.9.12 Changes

### General Changes

Added JSON as a query results format based on the Serializing SPARQL Query Results in JSON draft.

Added query writing to a `raptor_iostream` which allows reading in one query language and writing in another. The only useful consequence of this now is that it enables `roqet` to become an RDQL to SPARQL translator.

Rasqal now requires raptor 1.4.9 or newer.

### Configuration and Build Changes

Now using subversion.

### `roqet` utility Changes

Altered the `-d` (`--dump-query`) option to now take an argument of the query format to dump. The values it can take are `debug`, `structure` or `sparql`.

To convert a query from RDQL to SPARQL, use:

    roqet -q -i rdql -d sparql -n query.rdql > query.sparql

Added `-r json` for JSON query results output based on the draft defined in the Serializing SPARQL Query Results in JSON draft

### SPARQL Query Language Changes

Updated to match SPARQL Query Language for RDF, W3C Candidate Recommendation 6 April 2006. All DAWG syntax tests now pass. The update includes near alignment with SPARQL grammar term names except where the flex/bison approach diverged.

Updated SPARQL tests from DAWG CVS

Finally removed long deprecated `ASC[]` and `DESC[]` syntax.

### RDQL Query Language Changes

Handle empty regex `//` Fixes Issue#0000071

### Query Engine Changes

Some updates to handle latest changes to SPARQL grammar.

Added `RASQAL_EXPR_REGEX` 3-arg operation to match the SPARQL `regex()` 2/3-arg function.

Many internal changes to move more of the query execution state from inside `rasqal_query` to inside `rasqal_query_results` and related structures. This is not yet complete but when done, you will be able to execute the same query more than once at the same time.

### Query API Changes

Added `rasqal_query_write` to write a query structure into a syntax onto a raptor_iostream. Implements writing SPARQL format with format URI NULL, http://www.w3.org/TR/rdf-sparql-query/ or http://www.w3.org/TR/2006/CR-rdf-sparql-query-20060406/

Added a JSON SPARQL query results format with format URI identifier http://www.w3.org/2001/sw/DataAccess/json-sparql/ based on the draft defined in http://www.w3.org/2001/sw/DataAccess/json-sparql/ Implemented document with version `alt-ser-sparql.rst,v 1.3 2006/02/16 16:03:08 k Exp`.

`rasqal_query_get_all_variable_sequence` was corrected to match the definition - return all variables, not just the bound (`SELECT`ed) ones. Fixes Issue#00000079.

Added `rasqal_query_get_anonymous_variable_sequence` to return only anonymous variables after change above.

Added `rasqal_graph_pattern_get_index` to get the absolute index of a graph pattern in a graph.

### IOstream class Changes

Added `rasqal_query_iostream_write_escaped_counted_string` and `rasqal_query_escape_counted_string` to format an escaped string suitable for using inside a query.

### Documentation Changes

Updated `roqet.1` for --exec option and new usages.

## Rasqal 0.9.11 Changes

### General Changes

Duplicated `SELECT` variables are now detected, give a warning and are removed.

Rasqal now requires raptor 1.4.8 or newer to get the guess parser that uses URI/name and mime type returned from protocol request (if available) to choose the correct parser.

Added an internal `rasqal_map` key : value map for use with result duplicate detection and ordering.

A major source code regoranisation moved all library source code to the `src/` dir, roqet to `utils/` and other documentation to `docs/`. This should only affect packagers, not any functionality.

Many more function documentation were added to the sources for use by gtk-doc.

### SPARQL Query Language Changes

Updated to the SPARQL Query Language for RDF W3C Working Draft 23 November 2005:

- Added `isIRI` keywords.
- Updated the name definitions to allow initial _ in variable names.
- Changed the decimal and double literal syntax.
- Allow negative numeric literals.
- Change the AND and OR logic when an error is present.

Added a post 2005-11-23 SPARQL WD syntax change: added `langMatches` operator and initial query engine support.

Invalid `\u`HHHH and `\U`HHHHHHHH hex escapes and floating point number formats are detected and warned.

Updates to the query engine make `DISTINCT` and `ORDER BY` now work, including with `LIMIT`.

The lexer now counts line numbers correctly over multi-line comments.

Updated changes to the valid characters allowed in SPARQL names for variable, prefix and QNames.

### RDQL Query Language Changes

The lexer now counts line numbers correctly over multi-line comments.

### Query Engine Changes

When query result sorting is used with limit (SPARQL `LIMIT`) and offset, they now work correctly, performing the limit and offset after ordering the result. This matches the SPARQL query result semantics.

The query engine now implements distinct results (SPARQL `DISTINCT`) including with ordering (SPARQL `ORDER BY`).

More cases with optional graph patterns (SPARQL `OPTIONAL`s) are now executed correctly. Note: this does not mean all cases work, there are known problems with executing optional clauses.

Added types for `xsd:float` (C float) and `xsd:double` (C double); `xsd:decimal` (handled as a string) and `xsd:datetime` (as a string).

Fixed (a compare b) between integers and doubles to be the right sign.

Do not promote literals early on in comparisons to strings "perl style" but do the best type-based comparsion as late as possible.

### Query API Changes

Added `rasqal_new_double_literal`.

Added `rasqal_graph_pattern_visit` and type for visitor function `rasqal_graph_pattern_visit_fn`.

Added `rasqal_new_expression_from_expression`.

Added `rasqal_expression_visit` and type for visitor function `rasqal_expression_visit_fn`.

Deprecated function `rasqal_new_floating_literal` replaced by new `rasqal_new_double_literal`.

Deprecated function `rasqal_expression_foreach`, replaced by new `rasqal_expression_visit`.

Function `rasqal_expression_evaluate` gains a flag argument of new enum `rasqal_compare_flags`.

Added enum `rasqal_compare_flags` flags for `rasqal_expression_evaluate` or `rasqal_literal_compare`. Type `RASQAL_COMPARE_XQUERY` can be used with to ask for use of XQuery comparison and type promotions.

Added `rasqal_literal` types: `RASQAL_LITERAL_DECIMAL`, `RASQAL_LITERAL_DATETIME`, `RASQAL_LITERAL_DOUBLE` (replacing deprecated `RASQAL_LITERAL_FLOATING`) and `RASQAL_LITERAL_FLOAT`. Reordered the `rasqal_literal` types in the enum.

The enum types in `rasqal_literal_type` were reordered to make them match sparql type promotion.

### `roqet` utility program changes

`roqet` gains -e/--exec option to execute a query string directly rather than via a file or URI containing the query.

Now writes out XML results format in format with version URI `http://www.w3.org/2005/06/sparqlResults` and short name "xml". The previous version is available with short name "xml-v2". The latest version now writes `ordered` and `distinct` boolean-valued attributes on the `results` element.

### Configuration Changes

The autogen.sh script for building from CVS was revamped to be more modular.

`configure` now takes an `--enable-gtk-doc` option to enable building of the documentation using the `gtk-doc` utility. It is by default enabled only if the utility is available.

### Documentation Changes

The GNOME `gtk-doc` program is now used to automatically extract documentation from source comments into reference documentation. This is then merged with templates and additional documentation to provide a reference manual for rasqal as XML document which is turned into HTML along with GNOME devhelp support.

This new documentation intended to replace the librasqal manual page/web page as easier to read document with scope for better expanding with more detail of rasqal including examples and tutorial information. The librasqal manual page will continue to contain the summary information for the present.

## Rasqal 0.9.10 Changes

### General Changes

The query engine now supports ordering query results, in SPARQL this is the `ORDER BY` clause.

### SPARQL Query Language Changes

The SPARQL parser now passes (accepts) all the 70+ SyntaxFull tests in the RDF Data Access Working Group (DAWG) test suite for SPARQL. This mostly means accepting optional punctuation in some places.

Sorting results with `ORDER BY` now partially works however comparison is not done with the SPARQL literal comparison rules (after XQuery) but using the existing RDQL-style "string-y" comparisons.

Allow `<>` as a URI.

The SPARQL parser now accepts some changes made by the DAWG after the last published working draft: SPARQL Query Language for RDF, W3C Working Draft, 19 April 2005. This includes:

- In `ORDER BY` `ASC(`expression`)` replaces `ASC[...]`, `DESC(`expression`)` replaces `DESC[...]`, and it also accepts `ORDER BY (`expression`)`. `ORDER BY` func()`` is accepted although at present no extension function support is available that could use it.
- `[]` can be used in the triple predicate position as an anonymous existential variable
- Enforce that ASK queries cannot use `ORDER BY`, `LIMIT` or `OFFSET`

Omitting `WHERE` gives a warning. Don't do that!

### Query Engine Changes

The query engine now allows sorting of results (`ORDER BY` in SPARQL). It performs comparisons using the existing RDQL style and does not yet support the SPARQL literal comparison rules. Sorting can be done by a sequence of expressions, ascending or descending. If the final result is equality, the object pointers are used.

Note: removal of duplicates is not supported yet.

Some test code for datatypes support was added, not enabled by default and not yet useful.

### Query API Changes

Removed functions deprecated in 0.9.9.

Added `rasqal_graph_pattern_operator` enumeration with values for the main SPARQL graph patterns, graph pattern class method `rasqal_graph_pattern_get_operator` and graph pattern utility function `rasqal_graph_pattern_operator_as_string`

Modified the type of the final argument of `rasqal_new_graph_pattern_from_sequence` and `rasqal_graph_pattern_add_triples` from an integer to a `rasqal_graph_pattern_operator` enumeration.

Deprecated function `rasqal_graph_pattern_get_flags` now always returning 0 replaced by the graph pattern operator functions listed above .

### `roqet` utility program changes

Removed deprecated flags -f and -o

## Rasqal 0.9.9 Changes

### General Changes

SPARQL is now the default query language

Added a signing memory debugging system to aid checking when rasqal-allocated memory is freed in another library or vice-versa enabled by `--with-memory-signing` configure option (defaults to on in maintainer mode).

Fixed a few internal malloc/frees to use RASQAL_MALLOC / RASQAL_FREE so that the above signed memory system worked.

### SPARQL Query Language Changes

Grammar updated to follow the SPARQL Query Language for RDF, W3C Working Draft, 19 April 2005. This changes many parts of the syntax:

- Turtle/N3 style for triples with abbreviations
- `{` ... `}` around triple patterns
- `OPTIONAL` instead of `[]`
- `GRAPH` replaces `SOURCE`
- `FROM NAMED` replaces `LOAD`
- `FILTER` replaces `AND`
- `REGEX` replaces `?var =~ /match/flags` and `!~`
- Added `LIMIT`, `OFFSET` and `ORDER BY` with `ASC[]` and `DESC[]`
- Changed function syntax to remove `&`
- Removed old operator tokens: `ne`, `eq`, `==`

(Note: the query engine does not support sorting amongst other recently added SPARQL features)

SPARQL keywords are now case independent rather than just upper or lowercase.

Added """long literals""" after N3 (and soon, Turtle) and '''long literals''' for SPARQL only.

Added many SPARQL tests from DAWG most not yet approved by the working group. Not all pass either because not implemented or known bugs.

Added the revised SPARQL Query Results XML Format (the latest version not yet published) support to `rasqal_query_results_write` when called with format URI `http://www.w3.org/2001/sw/DataAccess/rf1/result2`.

### Query Engine Changes

Uses the query results limit and offset information to skip initial results (offset) and provide a maximum number of results (limit).

Moved some engine-specific operations from RDQL and SPARQL parser.

Added internal `rasqal_formula` class for the Turtle part of the SPARQL parser

Deprecated the `rasqal_triples_source` factory method `new_triples_match`. It is replaced by a new method `init_triples_match` and will be removed from the next release.

### Query API Changes

Added bnode identifier generation functions: `rasqal_query_set_default_generate_bnodeid_parameters`, `rasqal_query_set_generate_bnodeid_handler` based on the raptor API for generating blank node identifiers in the Turtle/N3 triple style.

Added `order_conditions_sequence` to the query structure to store query ordering conditions and added access methods `rasqal_query_get_order_conditions_sequence` and `rasqal_query_get_order_condition` to read the resulting expressions.

Added expressions for SPARQL ordering conditions: `RASQAL_EXPR_ORDER_COND_ASC`, `RASQAL_EXPR_ORDER_COND_DESC` and `RASQAL_EXPR_ORDER_COND_NONE`.

Added types for variables in two version - normal and anonymous with an new enum `rasqal_variable_type` and `rasqal_new_variable_typed` to allow creating them.

Completed the distinct/limit and offset get/set methods by adding: `rasqal_query_set_distinct`, `rasqal_query_set_limit`, `rasqal_query_get_offset` and `rasqal_query_set_offset`

Deprecated the `rasqal_triple` flags field - the value `RASQAL_TRIPLE_FLAGS_EXACT` was only used in internals of the execution engine. The value `RASQAL_TRIPLE_FLAGS_OPTIONAL` was never used. Optionals are now noted on graph patterns. Deprecated `rasqal_triple_set_flags` and `rasqal_triple_get_flags`.

Added enum `rasqal_query_verb` for the main query verbs: `RASQAL_QUERY_VERB_SELECT` `RASQAL_QUERY_VERB_CONSTRUCT` `RASQAL_QUERY_VERB_DESCRIBE` and `RASQAL_QUERY_VERB_ASK`. Added method `rasqal_query_get_verb` to access the verb.

Added `rasqal_query_get_query_graph_pattern` to get the top graph pattern.

Added `rasqal_query_get_wildcard` to get the query verb wildcard flag such as with SPARQL `SELECT *`

Added `rasqal_query_get_construct_triples_sequence` and `rasqal_query_get_construct_triple` to get the triples made from a SPARQL `CONSTRUCT` query.

### `roqet` utility program changes

Updated roqet to include better query structure walking with `-w` / `--walk` including listing query verb, distinct, limit, offset flags, construct triples and easier to read groupings of graph patterns and triples.

Deprecated roqet arguments `-f` / `--format` and `-o` / `--output` in place of `-r` / `--results` as both choose the query results format.

SPARQL is now the default query language for roqet.

## Rasqal 0.9.8 Changes

### SPARQL Query Language Changes

Grammar updated to follow the SPARQL Query Language for RDF, W3C Working Draft, 17 February 2005.

Added support for casting in constraint expresions for datatyped literals with the syntax qname`(`literal`)` such as `xsd:decimal("10")`.

Added named graphs parsing with `LOAD` and note that `UNION` cannot be handled yet, `SOURCE` and `[`...`]` syntax for optionals are deprecated.

### Query Engine Changes

Engine now operates over a hierarchy of `rasqal_graph_pattern` objects, where at the root the query has a single query graph rather than a sequence of graph patterns. The query graph contains the former sequence of graph patterns.

Constraints can be applied to any graph pattern, not just at the top level of a query.

Added casting expressions type `RASQAL_EXPR_CAST` and constructor `rasqal_new_cast_expression`.

Fixed setting of a triple origin (SPARQL `GRAPH`) which was not working in 0.9.7

`xsd:boolean` RDF literals are now promoted into internal `RASQAL_LITERAL_BOOLEAN` typed `rasqal_literal` like for XSD integer and double.

The query engine uses the named graph information when evaluating queries, passing it to the `rasqal_triples_match` factory methods either implemented with raptor or redland as a `rasqal_triples_source_factory` and returning them as results of variable bindings.

### Query API Changes

Added no-arg constructor `rasqal_new_graph_pattern`

Added method `rasqal_graph_pattern_add_triples` to add triples to an existing graph pattern.

Added methods `rasqal_graph_pattern_add_constraint`, `rasqal_graph_pattern_get_constraint_sequence` and `rasqal_graph_pattern_get_constraint` to add constraints to a graph pattern.

Added method `rasqal_graph_pattern_add_sub_graph_pattern` to add a sub-graph pattern to a graph pattern.

Added a Data Graph class with constructor `rasqal_new_data_graph`, destructor `rasqal_free_data_graph` and debug method `rasqal_data_graph_print`.

Added query methods for data graphs: `rasqal_query_add_data_graph`, `rasqal_query_get_data_graph_sequence`, `rasqal_query_get_data_graph`.

Deprecated query methods `rasqal_query_add_constraint`, `rasqal_query_get_constraint_sequence` `rasqal_query_get_constraint`, `rasqal_query_add_source`, `rasqal_query_get_source_sequence` and `rasqal_query_get_source`. These will be removed in the next release.

Removed functions deprecated in previous version: `rasqal_query_get_variable_sequence` and `rasqal_query_add_triple`.

## Rasqal 0.9.7 Changes

### General Changes

Fix a resource clean up when query results are either not read at all or not fully exhausted. This caused a problem in Redland when it held on to MySQL database handles despite a query having ended.

Added option `-n/--dryrun` to `roqet` to stop after preparing the query. Added option `-w/--walk-query` to walk and print the query using the graph API.

New build configuration and portability fixes for win32 (John Barstow)

Portability fixes for win32 - define `RASQAL_INLINE` and use it as for raptor. (Dave Viner)

Make rasqal tests work when building against raptor in a sibling source tree.

### Query Engine Changes

Added a graph pattern API with `rasqal_graph_pattern` typedef and `rasqal_pattern_flags` enum with value `RASQAL_PATTERN_FLAGS_OPTIONAL` to allow complete walking of the query structure.

Two new methods to the query class were added to support this: `rasqal_query_get_graph_pattern_sequence` to get the raptor_sequence of graph patterns in a query and `rasqal_query_get_graph_pattern` to get individual an graph pattern by index.

The new graph pattern methods added are:

- `rasqal_graph_pattern_get_triple` to get a `raptor_triple` inside a graph pattern.
- `rasqal_graph_pattern_get_sub_graph_pattern_sequence` to get the raptor_sequence of sub-graph patterns.
- `rasqal_graph_pattern_get_sub_graph_pattern` to get a sub-graph pattern inside a graph pattern by index.
- `rasqal_graph_pattern_get_flags` to get a graph pattern's flags.
- `rasqal_graph_pattern_print` to print a graph pattern in a debug form.

Deprecated `rasqal_query_add_triple` as it doesn't construct the graph patterns and is of little use as it does not build the correct query structures.

Added query API methods to get the bound and all variables in a query: `rasqal_query_get_bound_variable_sequence` and `rasqal_query_get_all_variable_sequence` respectively. Deprecated `rasqal_query_get_variable_sequence` as too ambiguous.

With the aid of gcc `-Wswitch-enum`, found and fixed cases where switch on enumerated values were missing cases. The remaining cases return failure or an error message rather than abort(). This fixed a crash when comparing for equality a variable ?x with a blank node value and an interger.

Deleted `RASQAL_EXPR_PATTERN` as it was never used.

Added `rasqal_query_get_distinct` to get a query-specified distinct results flag.

Added `rasqal_query_get_limit` to get a query-specified limit on the number of results.

### SPARQL Query Language Changes

Updated some of the SPARQL syntax to match the changes in the SPARQL Query Language for RDF W3C Working Draft of 17 February 2005. Added `GRAPH` replacing `SOURCE` and `WITH` replacing `FROM`. Added warnings about using the older forms and about using `[`...`]` instead of `OPTIONAL`.

Added recording of `DISTINCT` and `LIMIT` in the query structures but not yet used by the query engine.

### RDQL Query Language Changes

None.

## Rasqal 0.9.6 Changes

### General Changes

Fix a bug in writing a query result to XML when blank nodes are used. Now also correctly uses the base URI when pass in to the writing method.

Added support for three types of query result - bindings (the only one in previous versions), an RDF graph and a boolean. Added `rasqal_query_results` methods to test the type of the result: `rasqal_query_results_is_bindings`, `rasqal_query_results_is_boolean` and `rasqal_query_results_is_graph`.

Added `rasqal_query_results_get_triple` to get current triple as a `raptor_statement` and `rasqal_query_results_next_triple` to move to the next triple.

Added `rasqal_query_results_get_boolean` to get a boolean query result value.

Added `rasqal_triple` copy constructor `rasqal_new_triple_from_triple`.

### Query Engine Changes

Constructs an RDF graph result as a sequence of triples. This enables the SPARQL `CONSTRUCT` form to work.

Can return a boolean result indicating that there were variable binding results, but not returning them. This enables the SPARQL `ASK` form to work.

Added a new function expression - rasqal_op enum value `RASQAL_EXPR_FUNCTION`, added new `name` and `args` fields to the `rasqal_expression` structure and added `rasqal_new_function_expression` to construct this expression.

Added new 1-argument expression `RASQAL_EXPR_STR` returning a string version of the expression.

Added new 1-argument expressions operating on RDF literals: `RASQAL_EXPR_LANG` returning the language string of an RDF literal, `RASQAL_EXPR_DATATYPE` returning the datatype URI of an RDF literal.

Added new 1-argument testing expressions returning booleans: `RASQAL_EXPR_BOUND` true if the variable argument is bound to a value, `RASQAL_EXPR_ISURI` true if the argument is a URI, `RASQAL_EXPR_ISBLANK` true if the argument is a blank node and `RASQAL_EXPR_ISLITERAL` true if the argument is an RDF literal.

Fixed a problem in optional results returning extra results with no new bindings.

### SPARQL Query Language Changes

The SPARQL Parser now allows UTF-8 and \u, \U in prefixes and QNames.

Now supports `CONSTRUCT` and `ASK` queries using the updated query engine features.

`OPTIONAL` can now be used wherever `[` ... `]` could be used (parser bug fix).

Now supports the SPARQL built-in functions `STR()` returning a string version of the expression, `LANG()` returning the language string of an RDF literal, `DATATYPE()` returning the datatype URI of an RDF literal, `BOUND()` testing if a variable is bound, `ISURI()` testing if an expression is a URI, `ISBLANK()` testing if an expression is a blank node and `ISLITERAL()` testing if an expression is an RDF literal.

Now supports SPARQL `BASE` directive for setting the base URI of a query. This is experimental and may not be in the next version or may not be in the final SPARQL language.

The parser now expands QNames correctly when used in literals like `"blah"^^xsd:string`.

### RDQL Query Language Changes

The RDQL Parser now allows UTF-8 and \u, \U in prefixes and QNames. This makes RDQL testsuite tests S-03, S-04 and S-05 work.

## Rasqal 0.9.5 Changes

A release with major changes internal to the query engine to operate over graph patterns instead of sequences of triple patterns and to add execution of optional graph patterns. Additionally the query results can now be written in a recognised XML format.

This version of Rasqal requires Raptor 1.4.4.

### Core Changes

Added a `rasqal_graph_pattern` class for handling matching a graph pattern (set of triple patterns) in an `rasqal_query`. RDQL only has one of these wheras SPARQL may have many, and they may be nested (this may change, as SPARQL is under development).

Added `rasqal_query_results_write` method to write variable binding query results to a `raptor_iostream` in the XML format defined by SPARQL Variable Binding Results XML Format, W3C Working Draft, 21 December 2004.

### Query Engine Changes

Updated the query engine to operate over graph patterns rather than a single sequence of triple patterns. The graph patterns may be optional, which is used to implement SPARQL optionals. Nested graph patterns are constructed but cannot yet be executed.

Added a unary minus expression type.

Improved the type promotion for expression evaluation. Try to evaluate strings as doubles or integers if the operation contains one double or integer respectively.

Fixed a memory leak with string matches/non-matches.

### SPARQL Query Language Changes

Optional graph patterns `OPTIONAL` and `[` ... `]` now work.

Added the `{` ... `}` group syntax and removed the `(` ... `)` form.

`$` was added as an allowed variable prefixes.

A warning was added to show `SOURCE *` is ignored.

Added the `UNION` keyword, unsupported.

Rasqal now passes the DAWG SPARQL test cases: Optional triples (dawg-opt-query-001, dawg-opt-query-002, dawg-opt-query-003, dawg-opt-query-004) and examples from query WD (sparql-query-example-2.1a, sparql-query-example-2.2a, sparql-query-example-2.3a, sparql-query-example-2.4a, sparql-query-example-3)

Allow UTF-8 qname prefixes and check name against XML name constraints.

Recover lexer state from errors in regexes.

Terminate the lexer on a syntax error, rather than produce multiple errors.

### RDQL Query Language Changes

The lexer now handles UTF-8 qname prefixes, enabling RDQL testsuite test S-02 to pass.

Allow UTF-8 qname prefixes and check name against XML name constraints.

Recover lexer state from errors in regexes.

Terminate the lexer on a syntax error, rather than produce multiple errors.

## Rasqal 0.9.4 Changes

Pass on raptor parser errors to rasqal's error routines and upwards.

Clean up several memory allocations when a query fails to prepare or execute fully.

Fixed lexer jams when a query contained an illegal variable name after a '?'.

Fixed lexer crashes when a query ended in a regex pattern like `/abc/`.

Tidied up the testing framework so 'make distcheck' works.

## Rasqal 0.9.3 Changes

Rasqal's License was changed from LGPL 2.1/MPL 1.1 to LGPL 2.1/Apache 2

Added support for the SPARQL Query Language for RDF, W3C Working Draft, 12 October 2004 from the W3C RDF Data Access Working Group (DAWG). The support is at the basic syntax level - token lexer and grammar parser which passes the first simple tests from the proposed DAWG testcases. No additional query engine support has been added for SPARQL features that are not supported by RDQL. The Rasqal to do list contains full details of the implementation state.

Queries can now be prepared and then executed multiple times.

Added configure `--enable-query-languages` option with `rdql` and `sparql` as the choices.

Thanks to Chris Pointon for several patches to make Rasqal easier to build under Win32. Applied with some modifications. Renamed the RDQL and SPARQL syntax tokens ERROR to ERROR_TOKEN to help.

Added experimental support for querying multiple sources; the same query is executed over each source in turn. Also added some support for returning the source URI which is not yet enabled as this feature is in flux in the DAWG work. This may change or be removed in future versions.

`roqet` can specify a data source URI on the command line with `-s` / `--source`) URI for queries executing against an implicit model.

Added the DAWG SPARQL test cases driven from the manifest.n3 format. Created tests from the examples in the working draft.

Added an experimental XML result format for bindings, based on DAWG work. Enabled in `roqet` with `-o xml`. This is very likely to change or replaced in future versions.

Added `roqet` argument `-d` / `--dump-query` to dump the processed query, rather than do it by default (0.9.2 and earlier).

`roqet` can now read queries from URIs, using the `raptor_www` class to do the retrieval.

Fixed the `configure` checks for a posix regex function regcomp to correctly discover it is present.

### Internal changes

Added support for declaring prefixes for XML-style QNames both before and after their use.

The struct `rasqal_prefix` gained a `declared` field.

The struct `rasqal_triple` gained an origin field; not used at present but intended to support work on tracking triple provenance such as provided by Redland Contexts.

Added methods `rasqal_triple_set_origin` and `rasqal_triple_get_origin` to support the above.

struct `rasqal_triple_meta` now takes a 4-array of bindings, the fourth being the origin.

Exported function `rasqal_set_triples_source_factory` publically as originally intended.

## Rasqal 0.9.2 Changes

This release made minor portability fixes for building with C++ and Win32 (untested).

Several functions changed their parameters or return values from char* to unsigned char* or const unsigned char* to reflect the actual use.

Changed to return a `const unsigned char*`:
`rasqal_literal_as_string`

Changed to take `const unsigned char*` (or add `const`):
`rasqal_new_floating_literal`
`rasqal_new_pattern_literal`
`rasqal_new_prefix`
`rasqal_new_simple_literal`
`rasqal_new_string_literal`
`rasqal_new_variable`
`rasqal_query_has_variable`
`rasqal_query_results_get_binding_name`
`rasqal_query_results_get_binding_value_by_name`
`rasqal_query_results_get_bindings`
`rasqal_query_set_variable`

## Rasqal 0.9.1 Changes

This release changed the way that results were returned. A new `rasqal_query_results` class was created. This allows for a clean separation of the two concepts allowing multiple form of the results to be retrieved as methods of the query_results class, rather than the query class. The only form of results currently available is variable bindings, but RDF graphs will be returned in future, as a set of triples in a serialised form.

The execution method `rasqal_query_execute` was changed to return a new object of that class rather than an `int` success or failure.

The following methods of the `rasqal_query` class were renamed and moved to the new `rasqal_query_results` class:

0.9.0 name | 0.9.1+ name
--- | ---
`rasqal_query_get_result_count` | `rasqal_query_results_get_count`
`rasqal_query_next_result` | `rasqal_query_results_next`
`rasqal_query_results_finished` | `rasqal_query_results_finished`
`rasqal_query_get_result_bindings` | `rasqal_query_results_get_bindings`
`rasqal_query_get_result_binding_value` | `rasqal_query_results_get_binding_value`
`rasqal_query_get_result_binding_name` | `rasqal_query_results_get_binding_name`
`rasqal_query_get_result_binding_by_name` | `rasqal_query_results_get_binding_value_by_name`
`rasqal_query_get_bindings_count` | `rasqal_query_results_get_bindings_count`

A new `rasqal_free_query_results` destructor was created to delete the query results. (There is no public constructor).

Other minor bugs were fixed such as multiple constraints now being ANDed and not ORed, and adding defensive code for when queries fail and results methods are invoked.

## Rasqal 0.9.0 Changes

It is all new.

Copyright (C) 2004-2006 Dave Beckett
Copyright (C) 2003-2005 University of Bristol