path: root/ChangeLog

2011-11-01  Kaz Kylheku  <kaz@kylheku.com>

	* txr.vim: Added installation instructions.

2011-11-01  Kaz Kylheku  <kaz@kylheku.com>

	Syntax highlighting for Vim.

	* txr.vim: New file.

2011-10-30  Kaz Kylheku  <kaz@kylheku.com>

	Version 041

	Bugfixes:

	Runaway recursion in @(block) directive, introduced in 040.

	Fixed bug in matching list variable against text, at the same
	time clarifying semantics to longest-match.

	Fixed potential excessive memory use caused by refactoring in 040.

	Features:

	New :append keyword in @(output) to append instead of overwriting.

	Variable contents can be treated as input sources using :string
	and :list keywords in @(next). Variables can be treated as output
	destinations using :into keyword in @(output).

	New @(set) directive for destructive assignment to a variable.

	New filters: :upcase and :downcase.

	@(bind) can now compare left and right objects through filters.

	Filters can now be chained into compound filters.

	Pattern matching functions can be used as filters.

	Shorthand notation in @(deffilter) when multiple strings map to the
	same replacement string.

	@(cat) directive changes syntax.

	Error handling improvements in parser: no more reams and reams of
	errors.

	* txr.c (version): Bumped.

	* txr.1: Bumped version and set date.

	* configure (txr_ver): Bumped.

2011-10-30  Kaz Kylheku  <kaz@kylheku.com>

	We don't include headers in headers in this project.

	* parser.h: Do not include <stdio.h>

	* regex.c: Include <limits.h>

	* regex.h: Do not include <limits.h>

2011-10-30  Kaz Kylheku  <kaz@kylheku.com>

	Bug #34691

	Changing the parameter passing convention for vertical directives.
	They take one parameter which is a pointer, rather than a copy
	of the structure. They do not have to perform a structure
	assignment when returning next_spec_k.

	* match.c (v_match_func): Typedef updated to new function
	signature.
	(v_skip, v_trailer, v_freeform, v_block, v_accept, v_accept, v_next,
	v_parallel, v_collect, v_flatten, v_forget, v_forget, v_merge, v_bind,
	v_set, v_cat, v_output, v_define, v_try, v_defex, v_throw, v_deffilter,
	v_filter, v_eof, v_fun): Refactored.
	(match_files): Updated dispatch logic to new style calls.
	(match_funcall): Updated to new way of calling v_fun.

2011-10-29  Kaz Kylheku  <kaz@kylheku.com>

	* HACKING: Grammar fixes. Expanded on lazy strings a little bit.
	Added something about mem_t *, and a few extra words here and there,
	including a blurb about a Valgrind debugging caveat.

2011-10-27  Kaz Kylheku  <kaz@kylheku.com>

	Bug #34657

	* txr.1: Added explanations about the differences between
	empty streams and empty lines, and to watch out when passing
	empty strings to @(next :string ...).

2011-10-26  Kaz Kylheku  <kaz@kylheku.com>

	Bugfix: prepared_error_message variable needs to be gc-protected.

	* parser.h (parse_init): Declared.

	* parser.l (parse_init): New function.

	* txr.c (main): Call parse_init.
	(txr_main): No need to gc-protect yyin_stream since parse_init does it.

2011-10-26  Kaz Kylheku  <kaz@kylheku.com>

	Parse error handling improvements.

	* parser.l (prepared_error_message): New static variable.
	(yyerror): Emit and clear prepared error message.
	(yyerrprepf): New static function.
	(yybadtoken): Function moved into parser.y.
	(grammar): For irrecoverable lexical errors, stash error message
	with yyerrprepf and return the special error token ERRTOK to generate a
	syntax error. I could find no other interface to the parser to make it
	cleanly exit.

	* parser.y (ERRTOK): New terminal symbol, does not appear anywhere
	in the grammar.
	(spec): Bail after 8 errors, recover to nearest newline, and
	use yyerrok to clear error situation.
	(YYEOF): Provided by Bison, conditionally defined for other yacc-s.
	(yybadtoken): Function moved from parser.l.  Checks for the next
	token being YYEMPTY or YYEOF, and also handles ERRTOK.

	* stream.c (vformat_to_string): New function.
	(format): If stream is nil, format to string and return it.

	* stream.h (vformat_to_string): Declared.

2011-10-26  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (v_cat): Bugfix: unterminated variable argument list.

	* tests/001/query-3.txr: Updated to new cat syntax.

2011-10-26  Kaz Kylheku  <kaz@kylheku.com>

	Fixed lame @(cat) directive, without obsolescence phase.

	* match.c (v_cat): Rewritten.

	* txr.1: Documented.

2011-10-25  Kaz Kylheku  <kaz@kylheku.com>

	* configure: put in set -u to trap unbound variables, 
	and fixed resulting errors that were found.

2011-10-25  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (filter_s): New symbol variable.
	(v_filter): New function.
	(syms_init): New symbol variable initialized.
	(dir_tables_init): New function entered into table.

	* txr.1: Documented new filter directive.

2011-10-25  Kaz Kylheku  <kaz@kylheku.com>

	dep.mk: Regenerated.

2011-10-25  Kaz Kylheku  <kaz@kylheku.com>

	Shorthand for filters which map multiple texts to a common
	replacement text.

	* filter.c (build_filter_from_list): Allow tuples to denote
	multiple keys mapping to the same value.

	* lib.c (do_curry_123_2, do_curry_123_1): New static functions.
	(curry_123_2, curry_123_1): New functions.

	* lib.h (curry_123_2, curry_123_1): New functions declared.

	* match.c (v_deffilter): Allow tuples of strings rather than
	just pairs.

	* txr.1: Updated.

2011-10-25  Kaz Kylheku  <kaz@kylheku.com>

	* parser.y: Remove mention of nonexistent terminal \\ 
	from %right associativity clause.

2011-10-25  Kaz Kylheku  <kaz@kylheku.com>

	* filter.c (fun_k): New keyword variable.
	(function_filter): Use :fun keyword symbol instead of fun.
	(filter_init): New keyword variable initialized.

	* filter.h (upcase_k, downcase_k, fun_k): Declared.

	* txr.1: Updated.

2011-10-25  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (v_bind): Use sem_error to throw errors with line number
	info.

2011-10-24  Kaz Kylheku  <kaz@kylheku.com>

	Bugs #34641, #34629.

	* lib.c (search_str_tree): If multiple strings from the needle tree
	matching within within the haystack string, then take the leftmost
	match. If there are multiple matches at the same leftmost position,
	take the longest one.

2011-10-24  Kaz Kylheku  <kaz@kylheku.com>

	* filter.c (function_filter): New function.
	(get_filter): Handle (fun ...) syntax.

	* match.c (v_bind): Establish dynamic environment frame around
	dest_bind, and stash the bindings there so filters can have access 
	to the bindings.
	(v_output): Likewise, around do_output calls.
	(v_fun): New function.
	(match_files): Function handling broken out into v_fun.
	(match_funcall): New function.

	* match.h (match_funcall): Declared.

	* unwind.c (uw_push_env): Initialize match_context.
	(uw_get_match_context, uw_set_match_context): New functions.

	* unwind.h (struct uw_dynamic_env): New member, match_context.
	(uw_get_match_context, uw_set_match_context): Declared.

	* txr.1: Documented function filters.

2011-10-24  Kaz Kylheku  <kaz@kylheku.com>

	Turning attention to some plumbing.

	* unwind.c (uw_env_stack): New static variable.
	(uw_unwind_to_exit_point): Maintain correct uw_env_stack
	during unwinding.
	(uw_find_env): Just retrieve the env stack pointer; no search.
	(uw_push_env): Store a pointer to the previous
	environmental frame and just initialize the bindings to nil.
	No need to cons up a copy of the bindings from the previous frame.
	(uw_get_func): Perform a search through the environment stack.

	* unwind.h (struct uw_dynamic_env): New member, up_env.

2011-10-23  Kaz Kylheku  <kaz@kylheku.com>

	* tests/007/except-1.txr: Use next :list instead
	of piping from echo command. As a result, this test case should run on
	MingW.

2011-10-23  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (list_k, string_k): New keyword symbol variables.
	(v_next): Implement :list and :string keywords.
	(syms_init): New keyword variables initialized.
	NOTE: the :var keyword is deprecated.

	* txr.1: Documented :list and :string.

2011-10-23  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (h_skip): Bugfix: bad agument list in debugf call.

2011-10-22  Kaz Kylheku  <kaz@kylheku.com>

	Task #11474

	* filter.c (filter_equal): Takes two filters instead of one.
	(lfilt_k, rfilt_k): New keyword variables.
	(filter_init): New keyword variables initialized.

	* filter.h (filter_equal): Declaration updated.
	(lfilt_k, rfilt_k): Declared.

	* lib.c (funcall4): New function.
	(do_curry_1234_34): New static function.
	(curry_1234_34): New function.
	(do_swap_12_21): New static function.
	(swap_12_21): New function.

	* lib.h (funcall4, curry_1234_34, swap_12_21): Declared.

	* match.c (dest_bind): Swap use the function argument swapping
	combinator when calling tree find such that the value
	being searched is on the left and pattern material is on the right.
	(v_bind): Implemented :lfilt and :rfilt.

	* txr.1: Documented :lfilt and :rfilt.

2011-10-22  Kaz Kylheku  <kaz@kylheku.com>

	* filter.c (get_filter_trie): Function renamed to get_filter. A filter
	is not necessarily a trie.
	(string_filter, compound_filter): New functions.
	(get_filter): Recognize a compound filters and return a function
	which implements it.

	* filter.h (get_filter_trie): Declaration renamed.

	* match.c (format_field, v_bind, v_output): Follow get_filter_trie
	rename. Error message text updated.

	* txr.1: Describe compound filters.

2011-10-22  Kaz Kylheku  <kaz@kylheku.com>

	Task #11474

	* filter.c (filter_equal): New function.
	(upcase_k, downcase_k): New keyword variables.
	(filter_init): New keyword variables initialized,
	and new upcase and downcase filters registered.

	* filter.h (filter_equal): Declared.

	* lib.c (tree_find): Takes new argument, the equality test function.
	(upcase_str, downcase_str): New functions.
	(do_curry_123_23): New static function.
	(curry_123_23): New function.

	* lib.h (tree_find): Declaration updated.
	(upcase_str, downcase_str, curry_123_23): Declared.

	* match.c (dest_bind): Updated to take equality function.
	Uses it and passes it down to tree_find.
	(v_bind): Filter feature implemented.
	(h_var, v_try): Add equal_f to dest_bind argument list.

	* txr.1: Updated to describe new filters and bind arguments.

2011-10-21  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (v_collect, v_coll): Establish empty list bindings
	for all :vars in the event that the collect turns up nothing.

	* txr.1: Document behavior.

2011-10-21  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (v_collect): Regression bugfix. Make it work like the comment
	says: until/last clause has visibility to uncollated bindings from
	collect.

2011-10-21  Kaz Kylheku  <kaz@kylheku.com>

	Implementing @(set) directive for assigning to variables
	destructively.

	* match.c (dest_set, v_set): New static functions.
	(dir_tables_init): Add v_set to vertical directives hash table.

	* txr.1: Documented.

2011-10-21  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (v_output): When appending output to a variable,
	flatten the previous contents so we can append to a single
	string, or to deeply nested list, etc.

	* txr.1: Documented these new extensions to next and output.

2011-10-21  Kaz Kylheku  <kaz@kylheku.com>

	New features. Strling list output streams in stream
	library, allow output to be captured as a list of strings
	representing lines (in contrast to string streams which capture
	a single string).

	The output directive can output to a variable,
	and next can scan over a variable.

	* lib.c (span_str, compl_span_str, break_str): New functions.

	* lib.h (span_str, compl_span_str, break_str): New functions declared.

	* match.c (into_k, var_k): New keyword variables.
	(mf_file_data): New static function.
	(v_next): Refactored argument handling. Added support for :var
	keyword.
	(v_output): Added support for :into keyword.

	* stream.c (strlist_mark, strlist_out_put_string,
	strlist_out_put_char): New static functions.
	(strlist_out_ops): New static struct.
	(make_strlist_output_stream, get_list_from_stream): New functions.

	* stream.h (make_strlist_output_stream, get_list_from_stream): New
	functions declared.

2011-10-21  Kaz Kylheku  <kaz@kylheku.com>

	* lib.c (proper_plist_to_alist, improper_plist_to_alist): New
	functions.

	* lib.h (proper_plist_to_alist, improper_plist_to_alist): New
	functions declared.

	* match.c (append_k): New keyword symbol variable.
	(complex_open): New append argument.
	(v_output): Streamlined parsing of keywords.
	Support :append keyword.

	* txr.1: Output directive's keyword documentation revised.

2011-10-20  Kaz Kylheku  <kaz@kylheku.com>

	Bug #34609

	* match.c (v_block): Regression induced by rabid refactoring. Block
	must apply remaining directives to data, excluding itself, otherwise
	runaway recursion takes the place of correct behavior.

2011-10-19  Kaz Kylheku  <kaz@kylheku.com>

	Version 040

	Single unescaped space  behaves like @/ +/ regex.

	Ported to native Windows via MinGW.

	Bugfixes for Cygwin and more robust handling of
	errors arising from Windows not having proper
	Unicode support (16 bit wide characters only).

	Nasty GC bug fixed for all platforms, exposed by gcc 4.5.2, x86_64. 

	[Internal] The huge functions match_line and match_files have been
	broken up into functions dispatched by hash table lookup on directive
	symbols.

	[Internal] Hashing of some objects improved.

	* txr.c (version): Bumped.

	* txr.1: Bumped version and set date.

	* configure (txr_ver): Bumped.

2011-10-19  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425

	* match.c (repeat_spec_k): New symbol variable
	(h_match_func): New typedef.
	(elem_bind): New macro.
	(h_var, h_skip, h_coll, h_parallel, h_trailer, h_eol): New functions.
	(match_line): Remaining directives moved to functions.
	(syms_init): New symbol variable initialized.
	(dir_tables_init): New functions entered into hash table.

2011-10-19  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425

	Refactoring match_files to make it easier to break up into
	subfunctions, similarly to what was done with match_files.

	* match.c (match_line_ctx): New struct type.
	(ml_all, ml_specline, ml_bindings_specline): New functions.
	(LOG_MISMATCH, LOG_MATCH): Macros moved outside of function,
	updated to refer to structure members rather than local
	variables.
	(match_line): Takes only one argument now.
	All recursive calls updated.
	(v_freeform): Call to match_line updated.
	(match_files): Likewise.

2011-10-19  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425

	* match.c (v_accept_fail, v_next, v_parallel, v_collect,
	v_flatten, v_forget_local, v_merge, v_bind, v_cat, v_output,
	v_try, v_define, v_defex, v_throw, v_deffilter, v_eof):
	New functions.
	(match_files): Remaining directives moved to functions.
	(dir_tables_init): New functions entered into hash table.

2011-10-19  Kaz Kylheku  <kaz@kylheku.com>

	* hash.c (ll_hash): Hashing of pointers should take into
	account alignment, otherwise only values divisible by the
	alignment occur. This patch takes into considerations that
	val values are pointers to object descriptors in a heap which
	are four words wide, and so most likely aligned to 16 byte
	boundaries (32 bit systems) or 32 byte boundaries (64 bit).
	We need to shift.

2011-10-18  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425

	* match.c (v_block): New function.
	(match_files): Block directive moved to function.
	(dir_tables_init): v_block entered into table.

2011-10-18  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425

	* match.c (spec_bind): New macro.
	(v_freeform): New function.
	(match_files): Freeform logic moved to function.
	(dir_tables_init): v_freeform entered into table.

2011-10-18  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425

	* match.c (same_data_k): Symbol variable renamed to next_spec_k.
	(v_skip): Restructured not to return next_spec_k when there
	are no more specs, but rather thread directly to what match_file
	will do anyway, namely return the bindings and data position.
	(v_trailer): New functions.
	(match_files): Trailer logic moved to function.
	(syms_init): Follows renaming of variable.
	(dir_tables_init): GC bugfix: did not protect global hash
	tables again, like in filter.c previously.

2011-10-17  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425

	Vertical skip directive moved into function dispatched
	via hash table. Test suite passes.

	* lib.c (cptr_s): New symbol variable.
	(cptr_equal_op): New static function.
	(cptr_equal_op, cptr, cptr_get): New functions.
	(cptr_ops): New static structure.
	(obj_init): New variable initialized.

	* lib.h (cptr_s, cptr, cptr_get): Declared.

	* match.c (decline_k, same_data_k): New symbol variables.
	(v_match_func): New typedef.
	(v_skip): New function.
	(match_files): Check symbol in v_directive_table and dispatch
	the associated function if an entry exists.
	Skip directive handling moved to v_skip function.
	(syms_init): Initialize new symbol variables.
	(dir_tables_init): Enter v_skip into v_directive_table under
	skip_s symbol.

2011-10-16  Kaz Kylheku  <kaz@kylheku.com>

	Quick and dirty port to MinGW.

	* configure: Test for presence of <sys/wait.h> added.
	Conditionally generates HAVE_SYS_WAIT variable in config.h.

	* stream.c: Include <sys/wait.h> conditionally.
	(pipe_close): Do not test ermination status with WIFEXITED, etc.
	if there is no <sys/wait.h> header.

2011-10-16  Kaz Kylheku  <kaz@kylheku.com>

	* configure: reduced post-configure advice to just point
	to the INSTALL guide.

	* INSTALL: New file.

2011-10-16  Kaz Kylheku  <kaz@kylheku.com>

	* filter.c (trie_filter_string): Fix warning about uninitialized
	variable (not a bug, but compiler cannot prove that).

2011-10-15  Kaz Kylheku  <kaz@kylheku.com>

	Task #11425. Refactoring match_files to make it easier to
	break up into subfunctions. Arguments are packaged into a structure,
	so that subfunctions won't have to all have big argument lists.

	* match.c (h_directive_table, v_directive_table): New variables.
	(match_files_ctx): New structure.
	(mf_all, mf_args, mf_data, mf_spec, mf_spec_bindings): New functions.
	(match_files): Takes only one argument now, the context
	structure. data_lineno variable is a dynamic number.
	Recursive calls to match_files are handled by creating contexts
	as appropriate with the helper functions.
	The old local variable data is now part of the context.
	(syms_init, dir_tables_init): New functions.
	(match_init): Just calls syms_init and dir_tables_init.

2011-10-15  Kaz Kylheku  <kaz@kylheku.com>

	Fixed broken GC on x86_64 (Ubuntu 11, gcc 4.5.2). 
	The issues is that due to the aggressive function inlining
	in the gc module, the mark_mem_region function is not real
	subroutine. The address of its local variable &gc_stack_top
	ended up excluding the machine context saved by setjmp in
	the parent function. I.e. the buffer was not between the
	computed stack top and bottom. Thus registers were not being
	scanned for references to values. I added a little abstraction
	to the machine context in the process of fixing this.

	* gc.c (struct mach_context, mach_context_t): New type.
	(save_context): New macro.
	(mark): Takes two new arguments, pointer to the stack top and
	machine context. It scans the machine context explicitly rather
	than relying it to be on the stack, between the top and bottom.
	This context is in fact only object within the garbage collector part
	of the activation chain that we need to scan.
	(gc): Use new abstraction to save machine context. Local variable
	is used to derive the stack top here. The stack top is the top
	of the stack above the activation frames in the garbage collector
	itself. The gc has nothing on its stack that should be scanned,
	except for the machine context, which is now handled explicitly.

2011-10-15  Kaz Kylheku  <kaz@kylheku.com>

	* configure: POSIX Portability. Use = instead of ==
	in test expressions.  This was revealed by ubuntu's dash.

2011-10-13  Kaz Kylheku  <kaz@kylheku.com>

	* parser.y (elem): Amending previous change. A single space
	should only denote multiple spaces, not mixtures of spaces and
	tabs. WE have to be careful with tabs because they can be
	semantically different from spaces (e.g. file with tab delimited
	fields which can be blank, empty or have leading or trailing spaces.)

	* txr.1: Updated.

2011-10-13  Kaz Kylheku  <kaz@kylheku.com>

	* Makefile (%.ok: %.txr): Use unified diff for showing
	differences between expected and actual test output.

	* parser.l (yybadtoken): Handle new terminal symbol, SPACE.
	New rule for producing SPACE token out of an extent of
	tabs and spaces.

	* parser.y (SPACE): New terminal symbol.
	(o_var): New nonterminal.  I noticed that the var rule was
	being used for output elements, and the var rule refers to
	elem rather than o_elem. A new o_var rule is a simplified
	duplicate of var.
	(elem): Handle SPACE token. Transform to regex if it is
	a single space, otherwise to literal text.
	(o_elem): Handle SPACE token in output.

	* tests/001/query-2.txr: This query depends on matching
	single spaces and so needs to use escapes.

	* tests/001/query-4.txr, test/001/query-4.expected: New test
	case, based on query-2.txr.  It produces the same output,
	but is simpler thanks to the new semantics of space.

	* txr.1: Documented.

2011-10-12  Kaz Kylheku  <kaz@kylheku.com>

	Bug #34538

	* lib.h (wli): This macro now does the pointer displacement by 1.
	(auto_str, static_str): #if/#else/#endif gone. These functions just
	add the type tag. The + 1 logic was incorrect; it should have
	been + sizeof(wchar_t). But even that was not right because other
	code expects a wchli_t * to point to the first character,
	such as the string_out_put_char function.

2011-10-10  Kaz Kylheku  <kaz@kylheku.com>

	Improved support for broken unicode.
	Regex support for extra-large character sets not compiled in
	if wchar_t is not wide enough for it.
	The utf-8 properly throws exceptions when encountering characters
	that it cannot represent, instead of silently ignoring the
	situation and continuing with incorrectly computed data.

	* regex.c (FULL_UNICODE): New macro.
	(CHAR_SET_L3, CHAR_SET_L2_LO, CHAR_SET_L2_HI): Only defined
	if full unicde is available.
	(CHSET_XLARGE, cset_L3_t, struct xlarge_char_set,
	L2_full, L3_fill_range, L3_contains): Ditto.
	(unon char_set): Member x1 present only under FULL_UNICODE.
	(char_set_destroy, char_set_add, char_set_add_range,
	char_set_contains): CHSET_XLARGE cases only available on
	FULL_UNICODE.
	(char_set_compile): Default cst variable to CHSET_LARGE.

	* utf8.c (FULL_UNICODE): New macro.
	(conversion_error): New function.
	(utf8_from_uc): Throw error if not FULL_UNICODE and character is
	outside the BMP.
	(utf8_decode): Likewise.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	* HACKING: Documented portability hacks for narrow wchar_t.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	Version 039

	Ported to Cygwin.

	Horizontal modes for @(trailer), @(skip).

	New :greedy keyword in skip which can be given instead of max
	distance to give it longest match semantics.

	@(collect) and @(coll) support a new clause, @(last).

	The :times keyword in @(collect) and @(coll) introduced in the
	previous release has a different meaning. The keywords :mintimes
	and :maxtimes are added, and :maxtimes behaves like :times
	did previously.

	There is a :vars keyword in @(collect) and @(coll) to have
	some control over what bindings are collected, as well
	as error checking for missing bindings and defaulting behavior.

	New @(eol) directive for explicitly matching the end of
	the input or end of a line.

	New lexical syntax: @(...) and @abc is allowed within expressions.
	This produces a special structural syntax with no assigned meaning yet.

	Awful bug fixed in function calling: if a function was called with
	multiple unbound variables, and bindings were produced for them,
	only one variable was being propagated to the calling environment.

	Bugfixes to binding environment handling in the face of
	@(local)/@(forget) directive.

	Fix for the issue of unbound variables being silently ignored
	in some contexts, like quasiliterals. An exception is now thrown.

	Bugfix for an issue with consecutive variables in output.

	Bugfix for an issue with horizontal @(cases) not collecting
	bindings.

	Bugfix for an issue with @(until) inside @(coll) not seeing
	bindings from main clause.

	* txr.c (version): Bumped.

	* txr.1: Bumped version and set date.

	* configure (txr_ver): Bumped.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	One more swing at this with the axe.

	* lib.h (wini, wref): New macros.

	* stream.c (string_out_put_char): Rewritten with macros to eliminate
	preprocessor #if test.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	* lib.h (wli, lit_noex): We need null characters on both ends
	so that this hack is correct for null strings. When recovering
	the wchar_t pointer from a null literal object, we wil increment
	unconditionally, since it always points to a null character.
	We end up skipping past null terminator #1, but safely landing on #2.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	Following up to previous commit's TODO.

	* filter.c (struct filter_par): wchar_t becomes wchli_t.

	* lib.h (wchli_t): New type: an incomplete structure type,
	so that a pointer to this type is incompatible with anything else.
	(wli): Macro produces const wchli_t * pointer instead of
	const wchar_t *.
	(auto_str, static_str): Accept a const wchli_t * instead
	of const wchar_t *, making it impossible to misuse these
	functions by passing in a literal.

	* stream.c (string_out_put_char): These type changes showed
	this hack to have a bug. Confronted with the need to cast
	from const wchar_t * to const wchli_t *, it's obvious that
	the conversion has to be done properly with the + 1 in the
	one platform case, but not the other.

	* txr.c (version): Type changed to const wchli_t.

	* txr.h (version): Declaration updated.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	Ported to Cygwin.

	TODO: there should be some type safety with the new wli macro
	so that if it is forgotten, there will be a diagnostic.

	* configure (lit_align): New configuration variable
	and configuration test. Generates LIT_ALIGN in config.h.
	Fixed the integer-holds-pointer test for the different output
	from the nm program on Cygwin. The arrays become common symbols
	marked C which do not show an offset attribute, only size:
	one less column.

	* filter.c (to_html_table, from_html_table): wrap wide string
	literals with the wli macro. This must be done from now on for
	all literals and initializes of arrays that are going to be
	directly converted to type tagged val-s.

	* lib.h (wli): New macro.
	(auto_str, static_str, litptr, lit_noex): Handle wide literals on
	platforms where they are aligned to only two bytes, such that we don't
	have two bits in the pointer. We can still add our 11 bit type tag, but
	then when recovering the pointer to the data, we have may have
	to fix up the pointer. 

	* parser.l: Another portability issue here. Flex generates a scanner
	which has #include <unistd.h> in the middle, after the source file's
	own #includes which can introduce macros. On Cygwin, there is some
	hygiene problem whereby our "noreturn" macro causes the <unistd.h>
	header to generate bad syntax and fail to compile. Stupid Cygwin
	and even stupider flex! The workaround is to include <unistd.h>
	at the top in the flex source.

	* stream.c (string_out_put_char): This is one more place where
	the string literal handling hack spreads.

	* txr.c (version): Wrap string in wli.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	* dep.mk: Regenerated. Too easy to neglect this file.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (vars_to_bindings): Regression fix: recent commit
	caused test failure. An empty list not treated as a valid collect
	variable list.

2011-10-09  Kaz Kylheku  <kaz@kylheku.com>

	* configure: Fixed indentation.

2011-10-08  Kaz Kylheku  <kaz@kylheku.com>

	* txr.1: Removed references to obsolete @(next) variant.

2011-10-08  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (vars_to_bindings): New function.
	(match_line): keyword argument :vars implemented for coll.

	* txr.1: Documented :vars.

2011-10-08  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (vars_k): New symbol variable.
	(match_files): Implemented :vars in collect.
	(match_init): New symbol variable initialized.

2011-10-08  Kaz Kylheku  <kaz@kylheku.com>

	* txr.1: Augment example of @/.*/ being used to skip to the
	end of the line with @(skip) which is now better style,
	since it avoids reaching for regexes.

2011-10-08  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_line): Skip directive bugfix. If skip is the
	last item on the line, it must match the whole line by returning
	success.

2011-10-08  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (mintimes_k, maxtimes_k): New keyword variables.
	(match_line): Implemented :mintimes and :maxtimes, changing
	the semantics of :times.
	(match_files): Likewise.
	(match_init): New keyword variables initialized.

	* txr.1: Updated.

2011-10-08  Kaz Kylheku  <kaz@kylheku.com>

	* HACKING: Formatting.

2011-10-07  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_files): Fixed spectacular bug in function calling,
	dating back to before October 2009 when txr was put into git.
	Basically, unbound variables were not handled right after
	the function return, due to the increment step being wrongly
	written as ``piter = cdr(aiter)'' in the for loop that processes the
	ub_p_a_pairs. Evil cut and paste!

2011-10-07  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (greedy_k): New keyword symbol variable.
	(match_line): Greedy skip implemented.
	(match_files): Likewise.
	(match_init): New keyword symbol variable initialized.

	* txr.1: Updated.

2011-10-07  Kaz Kylheku  <kaz@kylheku.com>

	* lib.c (eol_s): New symbol variable.
	(obj_init): New variable initialized.

	* lib.h (eol_s): Declared.

	* match.c (match_line): Implemented horizontal skip as and
	new eol directive.
	(match_lines): Vertical skip defers to horizontal skip if
	there is trailing material.

	* txr.1: Updated.

2011-10-07  Kaz Kylheku  <kaz@kylheku.com>

	* lib.c (flatten_helper): Function removed.
	(flatten): Recurse directly, using func_n1.

2011-10-07  Kaz Kylheku  <kaz@kylheku.com>

	* txr.1: fxed wrong word.

2011-10-06  Kaz Kylheku  <kaz@kylheku.com>

	Extending syntax to allow for @VAR and @(...) forms inside
	nested lists. This is in anticipation of future features.

	* lib.c (expr_s): New symbol variable.
	(obj_init): expr_s initialized.

	* lib.h (expr_s): Declared.

	* match.c (dest_bind): Now takes linenum. Tests for the meta-syntax
	denoted by the system symbols var_s and expr_s, and throws an
	error.
	(eval_form): Similar error checks added. Also, hack: do not add
	file and line number to an exception which begins with a '('
	character; just re-throw it. This suppresses duplicate line
	number addition when this throw occurs across some nestings.
	(match_files): Updated calls to dest_bind.

	* parser.l (yybadtoken): Handle new token kind, METAVAR and METAPAR.
	(grammar): Refactoring among patterns: TOK broken into
	SYM and NUM, NTOK introduced, unused NUM_END removed.
	Rule for @( producing METAPAR in nested state.

	* parser.y (METAVAR, METAPAR): New tokens.
	(meta_expr): New nonterminal.
	(expr): meta_expr and META_VAR productions handled.

2011-10-06  Kaz Kylheku  <kaz@kylheku.com>

	Renaming the currying combinators according to new scheme.

	* lib.c (bind2): Function renamed to curry_12_2.
	(bind2other): Function renamed to curry_12_1.
	(do_bind_2, do_bind2other): Helpers renamed likewise.
	(tree_find): Follows rename of bind2.

	* match.c (match_files): deffilter code follows bind2 rename
	to curry_12_2.

2011-10-06  Kaz Kylheku  <kaz@kylheku.com>

	* lib.c (funcall3, curry_123_2): New functions.
	(do_curry_123_2): New static function.

	* lib.h (funcall3, curry_123_2): Declared.

	* match.c (subst_vars): Bugfix: throw error on unbound variable instead
	of ignoring the situation. This bug caused unbound variables in
	quasiliterals to be silently ignored.
	(eval_form): Function changed to three argument form, so that
	it takes a line number for reporting errors. Restructured to catch
	the new unbound variable exception from subst_vars, and re-throw
	it with a line number. Also, throws exception now instead of returning
	nil if itself it detets an unbound variable. Uses of eval_form
	no longer have to test the return value for nil, but just assume
	it worked.
	(match_lines): Currying calls to eval form updated to use
	curry_123_2. Test of eval return value eliminated. In function
	calls, eval isn't used for reducing symbol arguments to values,
	because it now throws in the unbound case, and it's not worth
	setting up a catch for this. Instead, assoc is used directly.

2011-10-05  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_files): In function calls, the deletion of
	the unbound variable from the argument list can be done
	with a destructive operation since that list is a copy.

2011-10-04  Kaz Kylheku  <kaz@kylheku.com>

	* LICENSE, Makefile, configure, filter.c, filter.h, gc.c, gc.h, hash.c,
	hash.h, lib.c, lib.h, match.c, match.h, parser.h, parser.l, parser.y,
	regex.c, regex.h, stream.c, stream.h, txr.1, txr.c, txr.h, unwind.c,
	unwind.h, utf8.c, utf8.h: Updated e-mail address.

2011-10-04  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_line, match_files): Another correction to how bindings
	are handled in collect/coll. New bindings from the main clause and
	last clause must override old bindings. This is done by some
	additional set difference operations based on symbol identity.
	Otherwise it is possible to end up with multiple bindings for the
	same symbol, which is untidy. If the collect clause scrubs a variable
	with forget and re-binds it, then combining that environment 
	with the previous bindings will create a duplicate.
	Also, fixed a serious bug with the bindings from the last clause;
	the append was wrongly put into the loop that processes the collected
	lists.

2011-10-04  Kaz Kylheku  <kaz@kylheku.com>

	* lib.c (acons): New function.
	(set_diff): Optimize common case: list1 and list2
	are the same, or list2 is substructure of list1.
	Situations in which this won't be the case for variable bindings are
	rare.

	* lib.h (acons): Declared.

	* match.c (match_line): Use acons rather than acons_new, when binding
	variables that we know are new (the symbol is unbound). 
	When computing the set difference over bindings, use cons cell
	equality, rather than symbol equality. Symbol equality is wrong
	because a binding can be removed, and then a new binding can be
	introduced using the same symbol. This must be treated as
	a different binding.

2011-10-04  Kaz Kylheku  <kaz@kylheku.com>

	Bugfixes to the semantics of binding environments, which
	were broken in the face of deletions (local, forget).
	For some stupid reason, I had written a destructive routine for
	removing elements from an association list, and used it
	as the basis for the local and forget directives.

	* lib.c (eq_f, car_f): New variables.
	(identity_tramp, equal_tramp): Obsolete functions removed.
	(apply): Broken function disabled at run time.
	(funcall, funcall1, funcall2): Throw meaningful error instead
	of aborting.
	(alist_remove_test): New static function.
	(alist_remove, alist_remove1): Rewritten to be functional
	rather than destructive.
	(alist_nremove, alist_nremove1): Destructive functions,
	using previous implementations of alist and alist_nremove.
	(do_sort): Recurses directly rather than via sort. That was
	probably why this helper was introduced!
	(find, set_diff): New functions.
	(obj_init): gc-protect new variables eq_f and car_f, and initialize
	them. Initializations for equal_f and identity_f changed to
	use equal and identity directly, without the obsolete wrappers.

	* lib.h (eq_f, car_f, alist_nremove, alist_nremove1,
	find, set_diff): Declared.

	* match.c (match_line): Use set_diff to determine what bindings
	are new, rather than ldiff and ldiff-like logic which break when
	the new bindings do not share structure with the old.
	(match_files): Likewise.

2011-10-03  Kaz Kylheku  <kaz@kylheku.com>

	* txr.1: Starte dodcumenting the forgotten merge directive.

2011-10-03  Kaz Kylheku  <kaz@kylheku.com>

	Implemented new last clause for collect and coll.
	Bugfix in cases inside coll: was not collecting bindings.
	Bugfix for until inside coll: was not seeing bindings
	from main clause.

	* lib.c (ldiff): New function.

	* lib.h (ldiff): Declared.

	* match.c (match_line): Implemented last clause. Fixed cases
	handling by moving misplaced termination check.
	(match_files): Implemented last clause.

	* parser.y (until_last): New nonterminal symbol.
	(collect_clause): Refactored syntax to support until and last.
	(elem): Likewise.

	* txr.1: Updated.

2011-10-02  Kaz Kylheku  <kaz@kylheku.com>

	* parser.y (rep_elem): Bugfix: forgotten o_elems_transform on
	syntax tree of o_elems constituent, leading to problems with
	consecutive variables in a @(rep).

2011-10-02  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_line): Handle trailer_s directive.
	(match_files): Remove check against trailer_s not having trailing
	material. If it doesn't, it's a vertical directive processed here,
	otherwise leave it alone so match_line processed it.

2011-10-02  Kaz Kylheku  <kaz@kylheku.com>

	Compiles as C++ again.

	* lib.h (cons_set): New macro.

	* match.c (match_line, match_files): In collect clause handlers,
	move variable declarations above goto, and initialize with
	cons_set, instead of declaring and initializing with cons_bind.
	This eliminates the stupid C++ error that goto skips a variable
	initialization (which happens even when it can be trivially
	proven that the has no next use at the goto site!)

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	Version 038

	New eof directive.

	Fixes in skip directive to work very well with eof.

	Consecutive variable matching semantics improved; concept of double
	variable match introduced for unbound variable followed by
	regex variable.

	Directives collect and coll have keyword arguments for more control
	over their behavior.

	Parallel directives (all, some, none, ...) are available in
	horizontal mode.

	New choose directive for selecting one of numerous alternatives

	GC bugfix in new filtering code.

	The code has an issue compling with GNU C++ instead of C,
	which is something that is supported by this project.
	Not a release-blocking issue. Not easy to fix without
	restructuring some code.

	* txr.c (version): Bumped.

	* txr.1: Bumped version and set date.

	* configure (txr_ver): Bumped.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	Maintaining C++ compiling (except for two issues that will
	need another commit).

	* filter.c: Include "gc.h" for prototype of protect.
	(struct filter_pair): Use const wchar_t *, so we can assign
	literals.
	(html_hex_continue): Ditto.

	* lib.c (and): Function renamed to andf, since and is a C++
	operator.

	* lib.h (and): Declaration renamed.

	* match.c (match_files): Use of and updated to andf.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	HACKING: Clarified that --vg-debug is also needed to turn on on
	the Valgrind support at run-time, in addition to building it in.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	New test case, covering some filtering from HTML/XML.

	* Makefile: Defined TXR_ARGS for new test case.

	* tests/008/students.expected: New file.
	* tests/008/students.txr: New file.
	* tests/008/students.xml: New file.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	* filter.c (filters, filter_init): Serious gc bug fixed: neglected to
	inform the garbage collector about the filters global variable.
	Ouch!

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	New test case under tests/008.

	* Makefile: Made previous TXR_ARGS for 008 specific
	to tokenizing test case, and introduced separate TXR_ARGS
	for this test case.

	* tests/008/configfile: New file.

	* tests/008/configfile.expected: New file.

	* tests/008/configfile.txr: New file.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	Tokenizing test case, exercising for @(coll :gap 0)
	and horizontal @(choose :shortest ...).

	* Makefile: Defined TXR_ARGS for tests/008 directory.

	* tests/008/data: New file.
	* tests/008/tokenize.expected: New file.
	* tests/008/tokenize.txr: New file.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	New test case, covering exception handling across nested
	function invocations.

	* Makefile (TEST): Test targets marked as .PHONY, because they are.

	* tests/007/except-1.expected: New file.
	* tests/007/except-1.txr: New file.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	* parser.y (all_clause, some_clause, none_clause, maybe_clause,
	cases_clause, choose_clause, elem): Regression bug fix: bad list calls
	in parser, lacking nao terminator.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	Regression bug fix: longest match variables broken by
	2011-09-28 commit which introduced the double var match.

	* match.c (match_line): Handle case where modifier is t.

	* parser.y (var_op): Produce modifir as (t) rather than t.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	* txr.1: Documented choose and horizontal mode for paralle
	constructs.

2011-10-01  Kaz Kylheku  <kaz@kylheku.com>

	New directive: choose.

	* match.c (choose_s, longest_k, shortest_k): New variables.
	(match_line, match_files): Introduced choose directive.
	(match_init): Initialize new variables.

	* match.h (choose_s): Declared.

	* parser.l (yybadtoken): Handle CHOOSE.
	(CHOOSE): Clause added for returning this token.

	* parser.y: Added #include "match.h".
	(CHOOSE): New token symbol.
	(choose_clause): New nonterminal symbol.
	(clause): choose_clause added.
	(all_clause, some_clause, none_clause,  maybe_clause,
	cases_clause): Abstract syntax tree tweaked.
	(choose_clause): New syntax.
	(elem): Abstract syntax trees tweaked for many clauses.
	New CHOOSE clauses.
	(out_clause): New error case for choose_clause.

2011-09-30  Kaz Kylheku  <kaz@kylheku.com>

	* HACKING: Updated with debugging hints.

2011-09-29  Kaz Kylheku  <kaz@kylheku.com>

	* txr.1: Clarified consecutive variables and documented double
	variable match.

2011-09-29  Kaz Kylheku  <kaz@kylheku.com>

	* parser.l: Implemented backslash continuations in SPECIAL
	state, regexes and string literals.

	* txr.1: Documented.

2011-09-29  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_line): Implemented horizontal all, some,
	none, maybe and cases directives.
	(match_files): Recognize horizontal version of these directives
	by the presence of the extra symbol t and do not process.
	Also, bugfix in the all directive: not resetting the
	all_match flag when short circuiting out.
	* parser.y (clause_parts_h, additional_parts_h): New nonterminals.
	(elem): New clauses added.

2011-09-29  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (chars_k): New variable.
	(match_line): Keyword arguments in coll implemented.
	(match_init): chars_k variable initialized.

	* parser.l (COLL): Lexical syntax changed to allow for
	argument material.

	* parser.y (elem): Coll syntax rewritten for arguments.

	* txr.1: Updated.

2011-09-28  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (mingap_k, maxgap_k, gap_k, times_k, lines_k): New
	symbol variables.
	(match_lines): Keyword arguments in collect implemented.
	(match_init): New function.

	* match.h (match_init): Declared.

	* parser.l (COLLECT): Lexical syntax changed for COLLECT to
	allow for argument material.

	* parser.y (%union): obj renamed to val.
	(exprs_opt): New nonterminal.
	(collect_clause): Rewritten for arguments.

	* txr.c (main): Call to match_init introduced.

2011-09-28  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_line): Bugfix in double var. Do not
	prepend the next_pat to the specline if it is nil.

2011-09-28  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_line): Logic restructured to allow for
	regex variables which also have nested variables.
	Previously this code was assuming that the cases were
	mutually exclusive, and the parser happened to work that way.
	Also, added support for a "double var" match which occurs
	when an unbound variable is followed by a regex variable.
	This case should be allowed because it makes sense.
	It's similar to a variable followed by a regex, except
	that the regex is also a variable binding.

	* parser.y (o_elems_transform): New function.
	(o_elems_opt, o_elems_opt2, quasilit): Transform o_elems with new
	function. This is needed because subst_vars doesn't
	deal with the nested var syntax for consecutive variables.
	(var): New syntax case '{' IDENT exprs '}' elem. This
	allows consecutive variables to be nested in all cases.

2011-09-27  Kaz Kylheku  <kaz@kylheku.com>

	* parser.y ('{', '}'): Nope, still not right.
	These must have exactly the same precedence as
	IDENT for this to work right, of course.

2011-09-27  Kaz Kylheku  <kaz@kylheku.com>

	* parser.y ('{', '}'): Bugfix: precedence of these
	terminals was causing @foo@foo to be parsed differently
	from @foo@{foo}. We need consecutive variables to be
	specially folded in the syntax under a single var_s
	node.

2011-09-27  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_files): One more fix to this, argh.
	The test for !data should be done after matching,
	before incrementing to the next line. Then it is a true
	bottom of the loop test. This commit allows
	@(skip)
	@first_line
	@(skip nil 3)
	@(eof)
	to correctly match the first line of the input, not
	the fourth one from the bottom, since the
	second skip has an unbounded range.

2011-09-27  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_files): Another bugfix to skip.
	If a hard skip tries to go beyond EOF, then the query
	must fail. However, a skip to exactly EOF is fine.
	I.e. data can hit nil at the same time as the right
	number of skip iterations is performed.

2011-09-27  Kaz Kylheku  <kaz@kylheku.com>

	* match.c (match_files): Bugfix in skip directive.
	We should try the match at least once even if there is no data
	after a hard skip, so that the query has an opportunity
	to do an explicit match for no data, as with @(endp).
	This commit makes possible queries like:
	@fourth_line_from_bottom
	@(skip 1 3)
	@(eof)
	This query depends on @(skip 1 3) not failing when
	it runs out of data, because @(eof) checks for htis.

2011-09-27  Kaz Kylheku  <kaz@kylheku.com>

	* lib.c (eof_s): New symbol variable.
	(obj_init): New variable initialized.

	* lib.h (eof_s): Declared.

	* match.c (match_files): New @(eof) directive explicitly
	matches end of data.

	* txr.1: Updated.

2011-09-26  Kaz Kylheku  <kaz@kylheku.com>

	Version 037

	Short-circuiting behavior for @(all) and @(none).

	Obsolete forms of @(next) and @(output) syntax are gone.

	New filtering feature for substitutions in output.  Filtering to and
	from HTML built in, plus user-defined filtering with deffilter.

	Bugfixes: wrong error message in throw; lack of support for escaping
	backslashes in literals and regexes.

	* txr.c (version): Bumped to 037.

	* txr.1: Set version to 037 and bumped date.

	* configure: Bumped txr_ver to 037.

2011-09-26  Kaz Kylheku  <kaz@kylheku.com>

	Support &#NNNN; decimal escapes also.

	* filter.c (html_hex_continue): Bail with nil if no digits
	are collected. The &#x; syntax is not translated to anything.
	(html_dec_continue): New function.
	(html_hex_handler): Function renamed to html_numeric_handler.
	(filter_init): Change function-based trie node over to
	html_numeric_handler.

2011-09-26  Kaz Kylheku  <kaz@kylheku.com>

	Support &#xNNNN; hex escapes in html.  Bugfix in field formatting.
	chr function inlined.

	* filter.c (trie_value_at, trie_lookup_feed_char): Handle function
	case.
	(build_filter): New parameter, compress_p.
	(html_hex_continue, html_hex_handler): New functions.
	(filter_init): Add a function-based node to the from_html trie.

	* lib.c (chr): Function removed.
	(functionp) New function.

	* lib.h (chr): Declaration replaced with inline function.
	(functionp): Declared.

	* match.c (format_field): Bugfix: failed to apply filter
	that came in as an argument.

2011-09-26  Kaz Kylheku  <kaz@kylheku.com>

	Bugfixes: Consistent escaping in various literals. Double
	backslash codes for single backslash. Output clause can be empty.

	* parser.l (char_esc): Backslash handled.
	Use internal_error rather than abort.
	(REGCHAR, LITCHAR): Backslash added to lexical syntax.

	* parser.y (output_clause): Allow empty output clause.

2011-09-26  Kaz Kylheku  <kaz@kylheku.com>

	New feature: @(deffilter)

	Bugfix in @(throw) when non-symbol is thrown: exception message
	referred to the symbol throw rather than the erroneous object.

	* filter.c (build_filter_from_list, register_filter): New functions.

	* filter.h (register_filter): New function declared.

	* lib.c (deffilter_s): New variable defined.
	(chain): Function changed from single list argument to variable
	argument list to reduce the complexity of use.
	(do_and, and): New functions.
	(obj_init): deffilter_s initializatio added.

	* lib.h (deffilter_s, and): New declarations.
	(chain): Declaration updated to new function signature.
	(eq): Changed from macro to inline function.

	* match.c (do_output_line): Simplified expression involving chain.
	(do_output): Likewise.
	(match_files): Bugfix in error handling of throw.
	Implementation of deffilter.

	* txr.1: Documented deffilter.

2011-09-26  Kaz Kylheku  <kaz@kylheku.com>

	Trie compression. Hash table iteration.
	Bugfix in typeof.

	* filter.c (trie_compress): New function.
	(trie_value_at, trie_lookup_feed_char, filter_string): Handle cons cell
	nodes in trie.
	(build_filter): Call trie_compress.

	* gc.c (cobj_destroy_op): Function renamed to cobj_destroy_stub_op
	since it doesn't do anything.
	(cobj_destroy_free_op): New function.
	* hash.c (struct hash_iter): New type.
	(hash_destroy): Function removed.
	(hash_ops): Reference to hash_destroy replaced with
	cobj_destroy_free_op.
	(hash_count, hash_iter_mark, hash_begin, hash_next): New functions.
	(hash_iter_ops): New static structure.
	* hash.h (hash_count, hash_begin, hash_next): New functions declared.
	* lib.c (hash_iter_s): New symbol variable.
	(typeof): Bugfix: TAG_LIT type tag not handled.
	(vecref): New function.
	(obj_init): Initialize hash_iter_s.
	* lib.h (cobj_destroy_op): Declaration renamed.
	(cobj_destroy_free_op, vecref): New functions declared.
	(hash_iter_s): New variable declared.
	* stream.c (string_in_ops, byte_in_ops): cobj_destroy_op
	renamed to cobj_destroy_stub_op.

2011-09-25  Kaz Kylheku  <kaz@kylheku.com>

	Filtering from HTML implemented.

	* filter.c (from_html_k): New variable.
	(to_html_table): New static array.
	(filter_init): Intern new symbol. Instantiate new filter
	and store in filters hash.

2011-09-25  Kaz Kylheku  <kaz@kylheku.com>

	Filtering feature for variable substitution in output.

	* filter.c, filter.h: New files.

	* Makefile (OBJS): filter.o added.

	* gc.c (mark_obj): Mark new alloc field of string objets.

	* hash.c (struct hash): New member, userdata.
	(hash_mark): Mark new userdata member of hash.
	(make_hash): Initialize userdata.
	(get_hash_userdata, set_hash_userdata, hashp): New functions.

	* hash.h (get_hash_userdata, set_hash_userdata, hashp): New functions
	declared.

	* lib.c (getplist, string_extend, cobjp): New functions.
	(string_own, string, string_utf8): Initialize new alloc field to nil.
	(mkstring, mkustring): Initialize new alloc field to actual size.
	(length_str): When length is computed and cached, also compute
	and cache alloc.
	(init): Call filter_init.

	* lib.h (string string): New member, alloc.
	(num_fast): Macro converted to inline function.
	(getplist, string_extend, cobjp): New functions declared.

	* match.c (match_line): Follows change of modifier s-exp syntax.
	(format_field): New parameter, filter.
	New modifier syntax parsed. Filter retrieved, and applied.
	(subst_vars): New parameter, filter. Filter is either applied
	in this function or passed to format_field, as needed.
	(eval_form): Pass nil to new parameter of subst_vars.
	(do_output_line): New parameter, filter. Passed down to subst_vars.
	(do_output): New parameter, filter. Passed down to do_output_line.
	(match_files): Pass nil filter to subst_vars in cat directive.
	Output directive refactored to parse keywords, extract the
	filter and pass down to do_output.

	* parser.y (regex): Generate (sys:regex regex syntax ...)
	instead of (regex syntax ...).
	(elem, expr): Updated w.r.t. regex syntax change.
	(var): Cases '{' IDENT regex '}' and '{' IDENT NUMBER '}'
	are removed. new syntax '{' IDENT exprs '}' to handle these
	more generally and allow for keywords.

	* txr.1: Updated.

2011-09-23  Kaz Kylheku  <kaz@kylheku.com>

	Numeric constants become real constants.

	Vector code cleanup.

	* lib.h (zero, one, two, negone, maxint, minint): Extern declarations
	removed, macros introduced for these identifiers.

	* lib.c (zero, one, two, negone, maxint, minint): File scope
	definitions removed.
	(vector): Use vec_alloc and vec_fill enums instead of constants.
	(obj_init): Remove references to removed definitions.

2011-09-23  Kaz Kylheku  <kaz@kylheku.com>

	* LICENSE, Makefile, configure, gc.c, gc.h, hash.c, hash.h, lib.c,
	lib.h, match.c, match.h, parser.h, parser.l, parser.y, regex.c,
	regex.h, stream.c, stream.h, txr.1, txr.c, txr.h, unwind.c, unwind.h,
	utf8.c, utf8.h: Updated copyright year.

2011-09-23  Kaz Kylheku  <kaz@kylheku.com>

	* match.c, parser.y: Support for old output syntax removed.
	Leading :nothrow with trailing material is an error now.