Log Message:
Update pure to 0.51.

Changes from previous:
----------------------
2011-12-21  Albert Graef  <Dr.Graef@t-online.de>

	* 0.51 release.

	* interpreter.cc: Bugfixes in macro substitution involving 'when'
	expressions (fallout from changes in when_codegen 2011-11-25).

2011-12-20  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc, runtime.cc/h: Add a new faust_load() runtime
	function which makes it possible to load a Faust dsp directly,
	without using eval (which isn't available in batch-compiled
	programs). Also fixed a bug in the Faust bitcode loader which
	would make it segfault in case of an existing but invalid Faust
	bitcode file.

2011-12-18  Albert Graef  <Dr.Graef@t-online.de>

	* 0.50 release.

	* interpreter.cc (compiler): Add a --main option to the batch
	compiler which allows to set the name of the main entry point of
	the compiled module. This allows different batch-compiled modules
	to coexist in the same program.

2011-12-16  Albert Graef  <Dr.Graef@t-online.de>

	* examples/bitcode/myinterp.pure: New example which illustrates
	how to create and use a secondary interpreter instance in Pure.

2011-12-15  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc (inline_code): Add FAUST_OPT environment variable
	to allow optimization of inline Faust code. This is to be set to
	something like '| opt -O3'. Also add the -cn option with the Faust
	module name as argument to the Faust command of the inline compiler.

2011-12-13  Albert Graef  <Dr.Graef@t-online.de>

	* runtime.cc, lib/faustui.pure: Add support for metadata in Faust
	control groups.

2011-12-07  Albert Graef  <Dr.Graef@t-online.de>

	* runtime.cc, lib/faustui.pure: Add support for controller
	metadata in Faust dsps. To these ends, controls are now
	represented in the form 'f ref meta initargs', where the
	additional 'meta' argument is a list of key=>val string pairs.

	* interpreter.cc (bctype_name): Make gsl_matrix type detection
	work with dragonegg.

	* interpreter.cc, runtime.cc/h: Add support for retrieving the
	global metadata of Faust dsp classes.

2011-12-06  Albert Graef  <Dr.Graef@t-online.de>

	* lexer.ll, interpreter.cc/hh: New conditional --ifdef and
	--ifndef pragmas. Also change the way that compilation options are
	initialized using PURE_OPTION environment variables.

2011-12-05  Albert Graef  <Dr.Graef@t-online.de>

	* runtime.cc, interpreter.cc: Add custom hashing of tagged
	pointers. Reported by Peter Summerland.
	(hash): Added missing matrix cases. Reported by Peter Summerland.

2011-12-04  Albert Graef  <Dr.Graef@t-online.de>

	* runtime.cc (pure_force): Plugged a memleak in recursive
	pure_force() calls. Reported by Stephan Rudlof.

2011-12-02  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc (LoadFaustDSP): Proper cleanup for all globals in
	Faust modules when a module gets reloaded.

2011-11-30  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc (compile_interface): Optimize away superflous
	candidate patterns which are subsumed by other interface patterns.

	* interpreter.cc (LoadFaustDSP, compiler): Bugfixes in the bitcode
	linker. Make sure that external function declarations and internal
	Faust functions are never stripped from batch-compiled code. Also
	make sure that old code for internal Faust functions gets cleaned
	before reloading a Faust module.

2011-11-25  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc (when_codegen): Optimization of non-binding
	'when' clauses. This eliminates superflous environments and
	function calls for clauses of the form 'when x end' where x is
	just an expression. These now just compute x, then throw it away
	immediately, just like the $$ operator.

	* etc/pure-mode.el.in: Have #! (shebang) treated as preprocessor
	lines rather than comments, so that they aren't skipped by the
	movement and pure-send-line commands. Also, make pure-send-line
	skip over multi-line comments (if you really want to send such a
	comment to the interpreter, you can use pure-send-defun for that
	now; this will send the entire comment at once).

	* interpreter.cc/hh, runtime.cc/h, lib/primitives.pure: Add
	get_interface_typedef() operation.

2011-11-24  Albert Graef  <Dr.Graef@t-online.de>

	* lexer.ll: Add --rewarn, --rewarn2 pragmas which reset the
	corresponding warning options to their defaults.

2011-11-23  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc/hh, expr.cc/hh, parser.yy: Lots of cosmetic
	changes and bugfixes in the interfaces implementation. Also
	improved the diagnostics (-w).

2011-11-22  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc/hh, runtime.cc/h, lib/primitives.pure: Add meta
	operations for managing interfaces from Pure.

	* etc/*: Add new 'interface' keyword to the language modes.

	* pure.cc, lexer.ll: Add new 'interface' keyword to the keyword
	table. Add type symbols to the completion table.

	* lexer.ll: Add 'show interface' command.

	* expr.cc/hh, interpreter.cc/hh, lexer.ll, parser.yy: Add basic
	implementation of interface types (experimental).

2011-11-18  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc: Resolve type aliases at compile time as far as
	possible, so that the best possible matching code can be
	generated.

	* interpreter.cc: New read-only interactive and debugging options
	for conditional compilation.

2011-11-17  Albert Graef  <Dr.Graef@t-online.de>

	* configure.ac: Bump version.

	* lib/primitives.pure: The rlist type can now be defined in a
	straightforward way.

	* interpreter.cc (try_rules): Implement tail call elimination on
	simple recursive type definitions.

2011-11-16  Albert Graef  <Dr.Graef@t-online.de>

	* 0.49 release.

2011-11-15  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc/hh: Integrate code generation options (--checks
	et al) with the new conditional compilation pragmas, so that they
	can be set with --enable, --disable and queried with --if,
	--ifnot.

2011-11-14  Albert Graef  <Dr.Graef@t-online.de>

	* lib/prelude.pure, lib/matrices.pure: Add some conditional
	pragmas so that various kinds of optimization rules in the prelude
	can be disabled if the user wants to do that.

	* pure.cc, pure_norl.cc, runtime.cc: Add --enable and --disable
	command line options.

	* interpreter.cc/hh, lexer.ll: Add conditional compilation pragmas
	--enable, --disable, --if, --ifnot, --else, --endif.

	* lib/matrices.pure: Add some experimental optimization rules for
	vector et al, which make them use vectorseq et al to create
	vectors of int and double values from arithmetic seqences in an
	efficient way. (This is similar to the slices optimization in that
	it prevents the construction of an intermediate list value, which
	saves memory and speeds up things considerably for large vectors.)

2011-11-13  Albert Graef  <Dr.Graef@t-online.de>

	* lib/prelude.pure, lib/strings.pure, lib/matrices.pure: Add some
	experimental optimization rules for slices with contiguous int
	ranges, so that we don't actually construct the index list any
	more. This speeds up slices considerably and can also save
	substantial amounts of memory, especially in the matrix case.

2011-11-11  Albert Graef  <Dr.Graef@t-online.de>

	* lib/avltrees.pure, lib/dict.pure, lib/set.pure: Some bugfixes
	and optimizations in the comparison operations. Also, as discussed
	on the mailing list, we now fall back to syntactic equality of
	values in dictionary operations if semantic equality isn't
	defined.

2011-10-27  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc/hh, runtime.cc/h: Add interpreter-local storage,
	exposed by means of the pure_interp_key(), pure_interp_set() and
	pure_interp_get() functions in the runtime. This allows
	applications to keep track of static data which depends on the
	particular interpreter instance, such as symbols and Pure
	expression data. The interface is similar to the POSIX
	thread-local storage functions (pthread_key_create and friends).

2011-10-25  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.hh, runtime.cc/h: Add a pointer equality callback,
	so that tagged pointer types can hook into same() and the null
	check for pointers.

2011-10-23  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc, symtable.cc/hh: Add a new built-in __list__
	macro. This expands a tuple to a list, preserving embedded tuples
	in the same way that list values are parsed. This is provided for
	the benefit of custom aggregate notations (usually outfix
	operators) which are supposed to be parsed like the built-in list
	and matrix brackets. Note that there's no way to actually define
	this macro in Pure, so it is provided as a builtin instead.

	* configure.ac: Bump version number.

2011-10-21  Albert Graef  <Dr.Graef@t-online.de>

	* INSTALL: Slight reorganization of the installation manual, to
	make it easier to link to various subsections from the wiki and
	elsewhere. Also added a note about ready-made packages now being
	available on FreeBSD.

2011-10-18  Albert Graef  <Dr.Graef@t-online.de>

	* 0.48 release.

	* interpreter.cc (inline_code): Add experimental DragonEgg
	support.

2011-10-17  Albert Graef  <Dr.Graef@t-online.de>

	* configure.ac, interpreter.cc/hh, runtime.cc: LLVM 3.0
	compatibility fixes.

2011-10-15  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc, runtime.cc/h, lib/primitives.pure: Add a
	function lasterrpos to give more detailed error information about
	a failed val, eval or evalcmd operation. Per request by Peter
	Summerland.

2011-10-14  Albert Graef  <Dr.Graef@t-online.de>

	* lexer.ll: As suggested by John Cowan, add a --bigint pragma
	which, if enabled, causes all integer literals in the source to be
	interpreted as bigint values. This feature is still somewhat
	broken and thus not enabled by default. If you want to try it
	anyway, define USE_BIGINT_PRAGMA in lexer.ll at build time.

2011-10-13  Albert Graef  <Dr.Graef@t-online.de>

	* lexer.ll: Make the --eager, --required and --(no)defined pragmas
	accept any kind of symbol (not just an identifier), so that they
	can be applied to special operator symbols. No checking is done on
	the syntax, and a following line comment (// ...) must be set off
	from the symbol with whitespace. Note that any of these options
	implicitly declare the symbol if necessary, so if the symbol is to
	be declared using special properties such as fixity, that
	declaration must come *before* any pragma involving the symbol.

	* lexer.ll, interpreter.cc: Implemented --defined and --nodefined
	pragmas, as discussed on the mailing list. These take a global
	function symbol as parameter and mark or unmark it as a "defined"
	symbol, respectively. If a symbol that is marked as "defined" is
	defined as a function in the Pure program, then the compiler
	generates special code which ensures that each application of the
	function actually reduces to something else. Otherwise, instead of
	returning a normal form, a 'failed_match' exception will be raised.
	The --defined status of a function can be changed at any time,
	causing the function to be recompiled on the fly. The --nodefined
	pragma restores the default behaviour of returning a normal form
	upon failure.

2011-10-12  Albert Graef  <Dr.Graef@t-online.de>

	* lexer.ll: Add a special case rule so that double constants like
	1e100 are properly recognized.

	* lib/regex.pure: Move regex support into a separate module which
	can be loaded independently of the system module.

	* lib/system.pure: Improved printf/scanf implementation which
	supports GMP/MPFR (%Zd, %Rg) conversions.

2011-10-11  Albert Graef  <Dr.Graef@t-online.de>

	* Makefile.in: Bump runtime library version.

	* configure.ac: Add MPFR checks.

	* runtime.cc/h: Add GMP/MPFR printf/scanf support to the runtime.

2011-10-08  Albert Graef  <Dr.Graef@t-online.de>

	* lib/pointers.pure: Moved pointer arithmetic into separate
	module, as suggested by Max Wolf.

2011-10-05  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.hh, runtime.cc/h, printer.cc: Add light-weight
	support for pretty printing of tagged pointer values. This adds
	another way to hook into the expression pretty-printer in order to
	define custom unparsing of opaque C/C++ data structures from C/C++
	code.

2011-10-04  Albert Graef  <Dr.Graef@t-online.de>

	* lexer.ll: Add support for --warn/--nowarn pragmas, as suggested
	by Peter Summerland.

2011-09-11  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc/hh: Implement __locals__ as a built-in macro (rather
	than subsituting it away at code generation time) so that proper
	lambda lifting is performed on the local function references.

2011-09-06  Albert Graef  <Dr.Graef@t-online.de>

	* etc/pure-mode.el.in: Changed the keybindings for the block
	traversal commands to use the Meta prefix. (This used to be
	Ctrl+Shift, but this interferes with the standard binding for the
	shifted word movement commands for selecting ranges of text in cua
	mode.)

	Also, pure-mark-defun (C-M-h) and pure-send-defun (C-c C-f) now
	allow you to mark or send an inline code section (%< ... %>), if
	point is at or inside such a section.

2011-06-05  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc (macspecial): Add a __namespace__ macro which
	expands to the current namespace at the point of the call, as a
	string.

2011-05-27  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc (LoadFaustDSP): Add dsp::samplingFreq interface
	routine to retrieve the sampling rate of a Faust dsp.

	* runtime.cc (faust_method): Add primitive to retrieve the
	interface operations of a Faust dsp. This is also available under
	the name dsp_fun in lib/faustui.pure.

2011-05-13  Albert Graef  <Dr.Graef@t-online.de>

	* configure.ac: Bump version number.

	* runtime.cc (clear_lasterr): Add a routine to have lasterr()
	cleared.

	* interpreter.cc/hh (interpreter::logging), runtime.cc/h
	(pure_start_logging, pure_stop_logging): Add a logging facility
	for error messages and warnings from the compiler.

	This is still experimental and not exposed in the Pure library
	right now. It is intended to be used by modules compiling Pure
	source, so that they can have messages logged and later retrieved
	with lasterr(), in order to display the messages to the user in
	any desired way.

2011-04-17  Albert Graef  <Dr.Graef@t-online.de>

	* interpreter.cc: Experimental __func__ builtin which yields the
	lexically enclosing function (named closure or lambda). As
	suggested by Saptarshi Guha on the mailing list.

2011-04-01  Albert Graef  <Dr.Graef@t-online.de>

	* configure.ac, interpreter.cc/hh: LLVM 3.0(svn) compatibility
	fixes.