inform7/notes/release/6-1.md

Release notes for Inform v6.1 (build 5T18)

This release was made on 30 April 2008, before Inform was open-sourced. At that time versions of Inform were identified by build codes in the form NLNN.

This is part of the historical archive of release notes.

Overview

This build is founded on a major reform of the infrastructure supporting Inform. It contains miscellaneous new features to complete the work of implementing the less speculative proposals planned in the January 2007 consultation document. (A second consultation document will be published later this year to lay out future plans.) The interface application contains a new Source view for OS X which should handle large projects much better: it will follow on other platforms in subsequent builds. The first steps are made towards an official system for translating I7 into languages of play other than English, something which has previously been done but only with great difficulty. Certain run-time algorithms have been optimised for speed, and all 162 bug reports received up to 26 April 2008 have been closed out.

Language

If, Repeat, While

• The preferred syntax for "if", "repeat" and "while" phrases has been changed to a Python-style format using colons ":" and indentation to mark that lines in the definition of a phrase or rule are being grouped together. This implements most of proposal (6.22) from the January 2007 consultation document. For instance, what was previously written thus:

  	...
  	if the actor is holding a player's holdall (called the sack)
  	begin;
  		let the transferred item be nothing;
  		repeat with the possible item running through things carried by
  		the actor begin;
  			if the possible item is not lit and the possible item is not
  			the sack, let the transferred item be the possible item;
  		end repeat;
  		...
  	end if;
  

  can now be written thus:

  	...
  	if the actor is holding a player's holdall (called the sack):
  		let the transferred item be nothing;
  		repeat with the possible item running through things carried by
  		the actor:
  			if the possible item is not lit and the possible item is not
  			the sack, let the transferred item be the possible item;
  		...
  

  We believe this is more consistent with the shape of definitions as a whole, which also take the form "preamble: item 1; item 2; ..." It also seems much closer to how books or newspapers represent lists of instructions or recipes, for instance.
• The new syntax is now used in Inform's documentation and examples. We think it's clearer and more logical, though groups of the kind shown above are surprisingly uncommon in I7 source text, because so much which would need a loop in another programming language is done implicitly in I7. (There are fewer than 600 grouped phrases in the entire Inform documentation, an average of only 1.5 per example.) But the new syntax is not compulsory. Each individual phrase or rule can be written to use either the old syntax or the new syntax (but not both in the course of the same definition). Thus, there is no need to change any existing source text - it will all compile exactly as before. Going over to the new syntax is entirely optional, and there is no intention at present to withdraw the old one.
• A few notes about the arrangements:
  • A rule or phrase using "new" syntax is required to start each phrase of the definition on a new line. (But phrases are allowed to be longer than a single line, and can wrap in any way the author wants: see the "repeat with..." phrase above for an example.)
  • Indentation must be made with a sequence of tab characters; spaces are ignored (as they already are with table columns).
  • Indentation must begin on tab stop 1, i.e., one tab stop in from the left margin, and must advance by a single tab stop for each block which begins after an "if", "repeat" or "while".
  • Indentation must not exceed 9 tab stops.
  • An "otherwise" or "otherwise if ..." clause in an "if" should be given the same indentation as the "if" it belongs to. For instance,

  		if the yellow door is open:
  			now the duckling is happy;
  		otherwise if the red door is open:
  			now the duckling is sad;
  		otherwise:
  			now the duckling is ambivalent.
  

• A new form of "if" provides a form of switch statement: this is only allowed in the "new" syntax above. For example:

  		if N is:
  		-- 1: say "1.";
  		-- 2: say "2.";
  		-- otherwise: say "Else.";
  	if the dangerous item is:
  		-- the electric hairbrush:
  			say "Mind your head.";
  		-- the silver spoon:
  			say "Steer clear of the cutlery drawer."
  

  This implements proposal (6.22c) from the January 2007 consultation document, though with slightly different punctuation syntax.
• Finally on "if": in every form except that last one, "unless" can now be used in place of "if" and with the same effect except that the sense of the condition is reversed. For instance:

  	unless N is 3, say "N is not 3.";
  	unless the yellow door is open:
  		now the duckling is happy;
  	otherwise unless the red door is locked:
  		now the duckling is sad;
  	otherwise:
  		say "The yellow door is closed and the red one unlocked.";
  

  If written in old-style syntax, "unless" should be ended with "end unless", not "end if". This implements proposal (6.24) from the January 2007 consultation document.
• Inside "repeat" and "while" loops, the new phrases "next" and "break" can be used to go directly to the next iteration, and to exit the loop immediately, respectively. ("Next" is called "continue" in a fair number of programming languages, and Inform issues a specific problem message to help people who forget this.) Thus:

  	repeat with X running from 1 to 10:
  		if X is 4, next;
  		say "[X] ";
  		if X is 7, break;
  

  prints the text "1 2 3 5 6 7". This implements proposal (6.23) from the January 2007 consultation document.
• The text substitution "[unless ...]" means the same as "[if ...]" but with the sense reversed, paralleling the use of "unless" and "if" as phrases.
• The text substitutions "[otherwise]" and "[otherwise if...]", for use within "[if]...[end if]", can now be written "[else]" and "[else if...]": this is to be consistent, since "otherwise" can be written "else" in regular code too.

Understanding

• When an item or room is created, Inform automatically makes its name something the player can type to refer to it. For instance,

  	The Wabe is a room. The blue peacock and the sundial are in the Wabe.
  

  means that the player can type EXAMINE BLUE PEACOCK or PUSH SUNDIAL or SHOWME WABE, and so on. This is almost always a good thing, but a nuisance if something's true identity is not known to the player. So:

  	The secret document is a privately-named thing in the drawer.
  	The printed name of the secret document is "[if the secret document is
  		handled]secret document[otherwise]dusty paper".
  	Understand "dusty" and "paper" as the secret document.
  	Understand "secret" and "document" as the secret document when the
  		secret document is handled.
  	After taking the secret document for the first time: say "Heavens! It
  		is the secret document!"
  

  ...uses the new property "privately-named" to make the secret document something whose name is only what Understand... explicitly says: the name it happens to have in the source text is ignored. (Privately-named is a property which affects how Inform creates the object, and it can't be given or taken away during play.)
• When a kind is created, and the source text constructs multiple duplicate items of that kind, Inform generates a plural of the kind's name in order to understand commands referring to these multiples. For instance, given...

  	The Lake is a room. A duck is a kind of animal. Four ducks are in
  	the Lake.
  

  ...the player can type TAKE DUCKS to try to pick up all four. It is now also possible to teach Inform new plural forms of name. For instance:

  	Understand "birds" and "ruddy ducks" as the plural of duck.
  

  Now TAKE BIRDS and TAKE DUCKS are equivalent. Plurals can even, strange as it may seem, be given for single things:

  	The magpie is in the Lake. Understand "birds" as the plural of the
  	magpie.
  

  Now TAKE BIRDS tries to take all four ducks and the magpie too. This implements proposal (6.49) from the January 2007 consultation document.
• When Inform receives a command like TAKE ALL, it forms up a list of the eligible objects and then generates actions for each in turn. This can now be inspected and changed. For instance,

  	let L be the multiple object list;
  

  sets L to this list. (If there is no multiple object, say if the command was TAKE PEAR, the list will be empty: it won't be a list of size 1.) Correspondingly, we can set it:

  	alter the multiple object list to L;
  

  Of course if Inform is already working through the actions, it is too late cleanly to change this list, but the following...

  	The magic rule is listed before the generate action rule in the turn
  	sequence rules.
  	A thing has a number called dramatic potential.
  	This is the magic rule:
  		let L be the multiple object list;
  		if the number of entries in L is greater than 1:
  			sort L in dramatic potential order;
  			alter the multiple object list to L.
  

  ...does a little rearrangement after the parser has finished but before actions have started to be generated.
• The meaning of the phrase

  	place X in scope
  

  used to depend on whether X was a room or not: for rooms, only the contents would be put in scope, and not X itself. This meant there was no way to put the actual names of rooms in scope, and was in any case an unnecessary complication. As from this build, the following possibilities:

  	place X in scope
  	place X in scope, but not its contents
  	place the contents of X in scope
  

  do what they appear to suggest, whether X is a room or not. (If X is a room, the new "place the contents of X in scope" does exactly what the old "place X in scope" did, so it should be easy to correct existing source text if necessary - but e.g. in the Inform examples we didn't need to make any corrections at all.)
• The "printing a parser error" activity can now override a further parser error, like so:

  	Rule for printing a parser error when parser error is noun did not
  		make sense in that context: 
  		say "If you must use 'any thing', you deserve all you get." instead.
  

  This error message appears only when an "[any ...]" token failing is the most interesting error the parser can generate, and several users have noticed that up to now there's been no way to rephrase it.

Tables

• Tables can now have amendments as well as continuations. That is, just as one can already write

  	Table of Semi-Precious Minerals (continued)
  

  to add extra rows to an existing table, one can now also write:

  	Table of Semi-Precious Minerals (amended)
  

  to change those rows. The amended table must have exactly the columns of the original and in the same order. Moreover, each row in the amended table must match exactly one row in the original. For instance:

  	Table of Plans
  	moment		outcome
  	10 AM		"takeover of Mars"
  	11:30 AM	"canals reflooded"
  	11:45 AM	"chocolate bar production doubled"
  
  	Table of Plans (amended)
  	moment		outcome
  	11:45 AM	"volcanic cave production doubled"
  

  creates a three-row Table of Plans, with reference to the chocolate bars struck out. Amendment rows may be given in any order. The process of matching a row begins at the left-most column: Inform tries to see if any single row in the original table has a matching entry. If none do, a Problem is issued. If more than one do, Inform then looks at the second column, and so on. Thus:

  	Enthusiasm is a kind of value. The enthusiasms are pumped, wired and languid.
  
  	Table of Mental States
  	feeling	extent	consequence
  	pumped	1		"you feel able to run for your life"
  	pumped	2		"you feel able to run for President"
  	wired	1		"you feel able to run"
  	languid	1		"you feel"
  
  	Table of Mental States (amended)
  	feeling	extent	consequence
  	pumped	2		"you feel able to run for the Nebraska State Legislature"
  

  ...the amendment here is made to the second row of the original table. For the present, at least, the columns used for matching may only contain: numbers, times, objects, action names, activities, figure names, sound names, truth states and any new kinds of value or units which have been declared.

Fast Route-Finding

• The ability to find routes through the map, and other relations, makes it possible to write quite sophisticated conditions concisely: but these sometimes run slowly, because they call for large amounts of computation. Two especially bad cases are provided by having dozens of characters constantly route-finding through the map in order to meander about; and having dozens of articles of clothing all partially revealing each other, overlying and underlying, so that it becomes a complicated matter to establish what can be worn on top of what else.
• For finding routes in the map, there are now two use options:

  	Use fast route-finding.
  	Use slow route-finding.
  

  This chooses between two algorithms, neither of which is best in all cases. If neither is specified, "fast" is used on the Glulx VM, and "slow" on the Z-machine. In general, "fast" is very much faster if there is a large map in which frequent route-finding goes on; but it comes at a sufficient memory cost that, for a large map, it won't be able to fit into the Z-machine, which is very short of memory. On Glulx projects, memory is only an issue if we mind that the story file and saved games will be a little larger, which could just possibly matter for very small mobile devices. "Slow" is the same algorithm used in previous builds of Inform, and it has very low memory overheads: for many maps, especially fairly small ones, and where route-finding is only an occasional need, it is not detectably slower than "fast". (For those interested, "slow" is a variation on Prim's minimal spanning tree algorithm, while "fast" is a form of the Floyd-Warshall algorithm.)
• For finding routes through relations, the same two options are available, but because we tend to create many relations which never use route-finding the default is always "slow". To make route-finding for a given relation "fast", we have to declare it that way:

  	Overlying relates various garments to various garments with
  	fast route-finding.
  	Overlapping relates various garments to each other with fast
  	route-finding.
  

  (For instance, changing the "overlying" and "underlying" relations in the example "What Not To Wear" to "fast" enormously improves performance when there are large wardrobes to choose from.) The "with fast route-finding" note can only be added to various-to-various relations: although route-finding through various-to-one and one-to-various relations is fully supported, it exploits the relative simplicity of these problems to use a more efficient algorithm than either the "fast" or "slow" ones described above.

Extensions

• Up to now, extensions have had filenames without a dot "." followed by trailing text identifying their file type (i.e., without a "filename extension", to use a completely different meaning of the word). There are some merits to this, but the demerits have won out. Inform now recognises the suffix ".i7x" (read: "I7 extension") for these filenames, and we will gradually move to this form for files downloaded from the website.
• Headings can now provide source text to be used if a given extension is included in the current run; or alternatively, if it isn't. For instance:

  	Chapter 2a (for use with Locksmith by Emily Short)
  

  specifies that everything under this heading (and its subheadings, if any) will be ignored unless the extension Locksmith by Emily Short is included. Conversely,

  	Chapter 2b (for use without Locksmith by Emily Short)
  

  will be ignored unless it isn't included. This allows extension writers to give variant implementations depending on what other extensions are in use.
• Headings can also replace portions of extensions which have been included. For instance:

  	Section 6 - Hacked locking (in place of Section 1 - Regular locking in
  		Locksmith by Emily Short)
  

  places the source text under the new heading in the place of the old (which is thrown away). If there should be two or more headings of the same name in the given extension, the first is the one replaced; if two or more headings attempt to replace the same heading in the given extension, the final attempt in source text order is the one which succeeds; and finally, heading dependencies like the above are scanned in a top-down way. Thus, if we have

  	Chapter 2a (for use with Locksmith by Emily Short)
  	...
  	Section 1 - Hacked marbles (in place of Section 4 in Marbles by Peter Wong)
  	...
  

  and we don't include Locksmith, then the replacement of Section 4 of Marbles is not made, because Section 1 - Hacked marbles is subordinate to the Chapter 2a heading which we've told Inform to ignore.
• The extensions machinery has been made more robust, fixing a number of obscure bugs not actually experienced in practice by any users, and changing existing conventions as follows:
• It is now possible for an extension to contain accented characters in author name and title: thus,

  	Include Étude Pour La Fênetre by Françoise Gauß.
  

  should work. (Accents are removed for console output; the file of the extension must have the actual name it claims, as with any other extension.)
• The word "and" is permitted in the title of an extension.
• The maximum lengths of extension title and author name, previously 31 characters each, have been raised to 50 characters each: but these are now more rigorously checked. (Previously, an extension breaking these limits would work on some platforms but not others: it would produce installation error messages on the Extensions documentation page, but these were easy to overlook by accident. An extension with overlong title or author name will now produce a Problem message when included.)
• It is now possible to give an optional line of additional credits for an extension, so that collaborators or earlier versions can get a name-check. For instance:

  	Version 1 of Banana and Mango Peeling by Jesse McGrew begins here.
  
  	"Allows banana splits."
  
  	"based on War and Peace by Leo Tolstoy, translated by Donald Rumsfeld"
  

  This last paragraph is the optional extra, which we suggest can be used in cases where, for instance, old I6 code has been wrapped up in new form - this is where to say who wrote the original.
• Installation errors are now more prominently displayed on the Extensions documentation page.
• Problem messages added and improved for checking that 'begins here' and 'ends here' sentences for extensions being used are correct. (Checking of 'ends here' sentences, in particular, was very lax previously because of a bug in the extension manager: apologies for this, because it means there are now a few extensions in circulation which have improperly written 'ends here' sentences, but which are otherwise correct, and will now be rejected. But the corrections needed will be very simple.)

Minor New Features

• It is now possible to define two different versions of the same text substitution, one in which the first letter is capitalised, the other in which it is lower case: these then have different meanings. (Inform already did this where the first word was The, A or An, and used this so that "[the noun]" had a different effect from "[The noun]": what is new is that the same rule now applies to any first word.)
• When lists of objects are printed with the text substitution "[list of ...]" (for instance, "[list of open containers]") such lists are now always grouped and printed using plurals. (In previous builds, they would be if the objects involved were all inside or on top of a given parent object, but not otherwise. It's arguable that this is a bug fix rather than a new feature.)
• The substitution "[A list of ...]" now capitalises the first indefinite article in the list, just as "[The list of ...]" does for the first definite one. (This was something we forgot to implement, and the fact that it wasn't there was reported as a bug, but properly speaking it was a missing feature before and is a new one now.)
• A backdrop can now be dynamically moved to any set of rooms. For instance, suppose rooms have the either/or property "wet", and that "stream" is a backdrop. Then -

  	When play begins:
  		move the stream backdrop to all wet rooms.
  

  sets the stream to be present in any wet room, and of course absent in any dry one. The form of words:

  		move the ... backdrop to all ...
  

  is deliberately meant to look unlike the simpler ways to move things, to emphasise that this is possible only for backdrops. The stream's position is ordinarily checked only after movements, for efficiency's sake. So if the player is in a room which suddenly changes from dry to wet, the stream will not magically appear (though it will be there if the player goes out and comes in again). If this is not good enough, the phrase "update backdrop positions" can be used to ensure the accuracy of all backdrop locations after a dramatic change -

  	Instead of pulling the lever:
  		now the Cave is wet;
  		remove the lever from play;
  		update backdrop positions;
  		say "The old rusty lever pulls away, and the thin cave wall goes
  			with it, so that a stream bursts into the cave."
  

  This implements proposal (6.54) from the January 2007 consultation document.
• When creating new verbs or prepositions, the word "reversed" can be used to reverse the sense of a relation. For instance,

  	The verb to be embedded in implies the reverse incorporation relation.
  

• The word "nothing" can now, in simple ways at least, be used in conditions to mean the non-existence of something. For instance -

  	if nothing is in the box, say "Nothing is in the box.";
  	if the box contains nothing, say "Nothing is in the box.";
  

  An exception is made for "is" alone, that is, for testing equality: otherwise

  	if X is nothing, ...
  

  would mean "if there is no thing that is equal to X"
• The verb "to incorporate" has been added to the built-in stock; that is, the following is now part of the Standard Rules:

  	The verb to incorporate (he incorporates, they incorporate, he
  	incorporated, it is incorporated, he is incorporating) implies the
  	incorporation relation.
  

  Thus X incorporates Y if and only if Y is a part of X. It was slightly anomalous that no such built-in verb existed already (analogous to "to contain" and "to support"), and several extension-writers have found it a useful linguistic device and had to define it themselves.
• A new activity "printing the announcement of light" has been added, in parallel with "printing the announcement of darkness".
• The assertion-maker has been slightly improved, so that relative clauses like the one in the third sentence here work (rather than producing problem messages):

  	A person can be asleep or awake. The Spinning Tower is a room.
  	Sleeping Beauty is a woman who is asleep in the Spinning Tower.
  

• Test scripts (for TEST) can now contain exotic characters, and follow the same apostrophe conventions as other text: thus ' becomes " except where used as a contraction, but ['] forces a genuine single quote.
• On Glulx works only, the "emphasised" type style now has the style hints weight 0 and oblique 1 set automatically when Glulx starts up: the point of this is that I7 uses this style to implement the text substitution "[italic type]".
• The new activity "printing a number of" activity allows customisation of the entries in lists which give a number of duplicate objects. For instance,

  	Rule for printing a number of blocks when the listing group size is 3:
  		say "all three blocks".
  

  In both this activity and also the existing "grouping together" activity, the number variable "listing group size" contains what it says. This implements proposal (6.44) from the January 2007 consultation document.
• It has always been possible to test the (most recent) outcome of a scene, if it's a scene which has named possible endings, as here:

  	Hindenburg Ride is a scene. Hindenburg Ride begins when play begins.
  	Hindenburg Ride ends disastrously when a random chance of 1 in 7 succeeds.
  

  We can test what happened thus:

  	if Hindenburg Ride ended disastrously, ...
  

  We can now also test what didn't happen:

  	if Hindenburg Ride did not end disastrously, ...
  

  Note that this is true only when the scene has ended, but ended differently.
• In the definition of a phrase which has options, the name of an option can be used as a condition: now, "not" followed by the name of an option can also be used as a condition, testing the obvious thing. Thus:

  	To hunt the wumpus, fiendishly:
  		if fiendishly, say "Hunting fiendishly.";
  		if not fiendishly, say "Hunting normally."
  

  ...prints one of these two texts, according to whether the "fiendishly" option is set, i.e., according to which of these is used:

  	hunt the wumpus;
  	hunt the wumpus, fiendishly;
  

• The (+ ... +) construction for using I7 source text within an I7 inclusion (or within a template file - see below) now allows an adjective name to be given, and translates it to the name of the I6 routine testing that adjective.
• A new feature so minor that with any luck nobody will notice or make use of it. I7 has a global variable called "the container in question", used in reaching inside and reaching outside rules to mean the barrier being reached through. A much nicer way to do this is:

  	Rule for reaching inside a container (called the barrier): ...
  

  where one then calls it "barrier". The only reason that "the container in question" exists is because reaching rules go back to the very early days of I7, before the "called" mechanism exists. Well: the new feature is that a parallel "supporter in question" now also exists, because it's illogical to have the one without the other, and its absence was reported as a bug. But please don't use either.

Internal Reforms

• The Standard Rules have been revised throughout: they are now more logically constructed, easier to read and better presented (for instance, in the Phrasebook index, which has a slightly new look). They advance formally to version 2.
• While much altered internally, they are almost exactly the same from the user's point of view, except that:
  • The property "inventory listing" for things has been withdrawn. (A fossil from the days of Inform 6: in I7's more rule-oriented way of looking at things, gadgets like this one are more an obstruction than a help, and it was striking that not one of the hundreds of examples ever used this property. And users often found it misleading that the property didn't play well with the activity "printing the name of something".)
  • The either/or property "transparent/opaque" is now a property only of containers, not of all things. (It only ever had any effect for containers anyway, and for some things it makes no good sense - a transparent animal is perhaps a jellyfish, but a transparent man, in the non-metaphorical sense?)
  • The either/or property "enterable" is now a property only of containers and supporters. (Again, it did nothing for any other things before.)
  • An action which fails because the player is in darkness, and it needs light, is now deemed to fail the "basic visibility rule", not the "can't act in the dark rule". (This brings it into line with the "basic accessibility rule", which is given as the reason for failure when the actor cannot touch something which is required to be in reach.)
  • The somewhat vaguely named "non-player character action rule" is now called the "requested actions require persuasion rule".
  • Implicit taking has been reformed: in past builds, the implementation of the taking action looked as if implicit takes were unlike ordinary actions, but this wasn't really so. The action variable "thing implicitly taken" has been abolished, and so have the following three rules:

  	standard set taking variables rule
  	avoid unnecessary implicit taking rule
  	don't report successful implicit takes rule
  

• Four obscure variant syntaxes, intended primarily for use by the Standard Rules, have been combined into one. The following examples show the change:

  	Open translates into Inform as open.
  	--> The open property translates into I6 as "open".
  	The I6 library object name of yourself is "selfobj".
  	--> The yourself object translates into I6 as "selfobj".
  	The adjust light rule corresponds to routine ADJUST_LIGHT_R.
  	--> The adjust light rule translates into I6 as "ADJUST_LIGHT_R".
  	Quitting the game is an action corresponding to Quit, out of world
  	and applying to nothing.
  	--> Quitting the game is an action, out of world and applying to nothing.
  	The quitting the game action translates into I6 as "Quit".
  

  In addition, one can now write:

  	The whatever variable translates into I6 as "whtvr".
  

  which was not previously possible to specify.
• Problem messages have been added to defend this combination verb better against malformed requests, though it is still intended only for low-level extensions. (As a result, "to correspond" is no longer reserved and people can define this as a verb of their own now; "to translate", of course, is still reserved. The "I6 library object name" property has been abolished. Old-style tabular action definitions, in terms of lists of I6 routine names, have also been withdrawn.)
• I7 projects no longer use the old I6 library: for fifteen years now, every story file made by Inform has included "Parser.h", "VerbLib.h" and "Grammar.h", but no longer. This is not as momentous as it sounds. I7 began by using library 6/9, then adapted to 6/10 and 6/11, but it always required minor modifications, indicated the suffix "N": thus, the latest releases of I7 have used library 6/11N. This was intended for dual use by I6 and I7 projects, but I7's use of the library had become increasingly strained. In 5J39, library 6/11N contained around 400 conditional compilations causing it to produce different code when used by I6 and I7: in some cases, drastically different. Almost half of the lines in 6/11N were ignored by I7, as were many of the concepts and features familiar to I6 users. It seemed to the authors that 6/11N was living a lie: it wasn't really the same library when used by both systems, and the continuing pretence was only making the code more and more baroque. Its form was only holding back further development. In this new build, the material from 6/11N which was still in use has been moved into the "template layer", where it joins the other I6 code used by I7. This somewhat simplifies the I7 architecture. Library 6/11N is still included in the current build, for the benefit of anyone using it with purely I6 projects in the Inform 7 user interface.
• In any case much of the significant code in the I6 library lives on, almost unmodified, in a new home. "Parser.i6t" in the new template, for instance, is more or less the supposedly abandoned "parserm.h" from Library 6/11N.
• The template layer consists of a set of about 35 mainly short files, or "segments", with the extension ".i6t". Each segment has a name and is divided up into one or more named parts. This has enabled the Include (- ... -) syntax for inserting raw I6 code to be considerably strengthened. For instance -

  	Include (- ... -) before "Flowers.i6t".
  	Include (- ... -) instead of "Flowers.i6t".
  	Include (- ... -) after "Rhizomes" in "Flowers.i6t".
  

  With these new forms of Include, the given I6 code can be placed before, instead of, or after any named segment or named part of a segment.
  • Multiple such inclusions can be made for the same segment or part, and if so, all will take effect;
  • Inclusions requested before, or after, a segment or part which has been replaced with "instead of" will take effect and appear before or after the code which appears instead of it.
  • The existing but deprecated syntax

  	Include (- ... -) before the library. 
  

  has been withdrawn; the new syntax

  	Include (- ... -) after "Definitions.i6t".
  

  should have the same effect.
  • The existing (and still fine!) syntax

  	Include (- ... -). 
  

  is, for what it's worth, equivalent to

  	Include (- ... -) after "I6 Inclusions" in "Output.i6t".
  

  • Template code can now use the same (+ ... +) notation to evaluate I7 expressions that inline definitions can; they also have access to a wide range of internal-use-only commands which shouldn't be used except in the built-in template files, but one command is safe to use:

  	{-segment:NAME}
  

  places the whole of the template file NAME in this position. The file should be named as something like "MyStuff.i6t" -- it's a leafname, not a pathname -- and Inform looks for template files first in the subfolder "I6T" of a project's "Materials" folder, if that exists, and only then in its built-in stock. This means that - (a) you can if you wish replace the built-in templates with your own, putting those in Materials/I6T, and - (b) you can if you wish include chunks of I6 code generated by external utilities - Perl scripts, lex and yacc, etc. - by compiling those to suitable template files in Materials/I6T and then using an inclusion like Include (- {-segment:MyStuff.i6t} -).
• All this allows for fine control in modifying the template, though we hope that users won't go in for template modification much or often. The template layer is gradually being tidied up: an annotated version, explaining what each part does, will be published later this year. In the mean time, those who do hack the template are warned that they may need to alter their code to keep it working with future builds.
• One application of template layer hacking might be to provide extensions which translate the language of play. At present, I7 is not configurable enough to translate the language of writing, but as from this build it should be much more viable to translate the language of the story file. To demonstrate this, a new extension, "English by David Fisher", is built in. This extension implements English, and there's no need for anyone to include it in their story files since English is already the language of play by default: but it serves as a model which translators can imitate. It should be fairly straightforward to convert existing I6 language definition files into extensions following this model. The authors suggest that these could be named in the style "Language by Translator's Name" - say, "Latin by Adam Thornton".

Optimisation

• We would like to thank Jesse McGrew for writing a profiling version of the Z-machine interpreter dumb-frotz: a great help. (It appears, incidentally, that if dumb-frotz has a 3GHz Xeon CPU core to itself, it can interpret at around 13.5 MHz; a just-in-time compiler can manage 19.7 MHz, probably the world speed record for the Z-machine. Realistically, when interpreting the Z-machine over the next couple of years, we can expect about 10 MHz, but we should divide by about five to get likely speeds on portable devices such as the iPhone, with CPUs at about 600 MHz.)
• The running time of large rulebooks (with 16 or more rules) has been improved. The recent discussion on RAIF about before, instead or after rules being inefficient in large numbers - because these rulebooks become large - led us to investigate how large an effect this really was. The answer was that it wasn't as dramatic as some people had feared, but was well worth addressing: this shaved about 24% off the running time of "Bronze" played right through to a solution. (The representation of rulebooks is now such that there is very little or no possible speed advantage to moving a before/instead/after rule into the check/carry out/report rulebooks, so this shouldn't be a factor in deciding where to put rules in future.)
• As of this build, activity rulebooks are "processed" rather than "followed". This means that they do not run the procedural rules individually as fresh contexts for rules in their own right: instead, they remain subject to procedural rules applying to whatever larger thing is going on -- i.e., in almost all cases, the current action. This change made no difference to the behaviour of any test in the test suite, and removed a further 16% from the running time of "Bronze". (The change will not so significantly affect projects which don't use procedural rules, of course.)
• Miscellaneous other adjustments, such as replacing heavily-used veneer routines with hand-coded assembly language versions better aimed at likely I7 rather than I6 use cases, should save about 10% of running time on most projects.
• At the end of this period of optimisation, "Bronze" ran about 2.5 times faster than at the start, but this was an extreme case: most examples saw more modest improvements.

Maintenance

• Inform has been made more sensitive to the casing of prepositions. So, for instance,

  	if the location is In Hallway, ...
  

  will now check to see if "location" is the room "In Hallway", rather than taking "is in" to be a reference to containment, because the capital I is suspicious.
• The "map region" property now exists for every room, even when there are no regions. (Its value is "nothing" if a room isn't in a region.) The point of this is to allow extensions which provide extra features for region-using works to compile. So, not quite a new feature, not quite a bug fix.
• The ancient I6 library reply:

  	> PUSH SUNDIAL EAST
  	Is that the best you can think of?
  

  has been reworded:

  	> PUSH SUNDIAL EAST
  	The sundial cannot be pushed from place to place.
  

  (The original message has too much of a narrative tone, particularly for modern IF, and most authors prefer a more neutral message.)

Documentation, examples and extensions

Recipe Book

• "Varying What Is Read" revised to account for many more types of parsing issue.
• Three new sections, "Designing New Commands", "Writing New Commands", and "Modifying Existing Commands" added at the beginning of the Commands chapter. These are meant to help people find technical features scattered throughout Writing with Inform, and also to offer some design guidance. "Modifying Existing Commands" tries to avoid overlap with the guidelines in the Advanced Action chapter and instead exists to point readers to the resources there and also in the Activities and Rulebooks chapters.
• "Looking" substantially revised to reflect new behavior.
• "Actions on Multiple Objects" added to the Commands chapter.
• "The Flow of Conversation" added to the Other Characters chapter to offer some general guidance about drafting conversation.

Examples

• Added "Escape from the Seraglio" to demonstrate a way to vary printing of text such as "grapes: ..." when acting on multiple items at once.
• Added "The Left Hand of Autumn" to demonstrate printing more sophisticated descriptions of multiple objects when all are examined at once.
• Added "Noisemaking" to demonstrate adding a new stage to action processing, during which other characters can observe and react to what the player has done.
• Added "Delicious, Delicious Rocks" to demonstrate adding a new stage to action processing, during which the player's action is sanity-checked before any implicit takes, etc., are generated.""
• Added "Provenance Unknown" to demonstrate how PUSH TELEVISION WEST might be converted to pushing the cart on which the television rests.
• Added "Low Light" to demonstrate an object that is visible and manipulable only when a bright light source is on.
• Added "Kiwi" to demonstrate a kind of shelf whose contents can only be seen if the player is standing on something.
• Added "Jamaica 1688" to demonstrate how to modify the final question of the game.
• Added "Trieste" added as a simple test and demonstration of table amendments.
• Added "Formicidae" added to demonstrate changing the order of the multiple object list.
• Added "WXPQ" added to demonstrate replacing the "That noun doesn't make sense in this context." parser error.
• Added "Copper River" added to demonstrate the idea of "interesting" and "dull" objects: the game determines which items are currently important to the puzzles or narrative and mentions those in the room description, while suppressing everything else.
• Added "Priority Lab" added to offer a sandbox for trying out priority ordering in room descriptions, and some debugging tools.
• Added "Casino Banal" added to demonstrate more advanced uses of priority ordering.
• Added "Zorb" to demonstrate making some changes to the circumstances in which the player can push objects between rooms.
• Added "Vouvray" to demonstrate plural names at the beginning of the Kinds chapter.
• Added "Prolegomena" to demonstrate the printing a number... activity.
• Added "Quiz Show" to demonstrate asking open-ended questions of the player, which can be answered only on the subsequent turn.
• Added "Orange Cones" to demonstrate moving backdrops to conditionally-specified rooms.
• Changes to "Alias", "Air Conditioning is Standard", "A Haughty Spirit", and "Dinner is Served" to reflect new strictness about properties such as enterable and transparent. (These were all effectively minor bugs that had previously gone unnoticed.)
• Changes to "What Not To Wear", to reflect new strictness and to make some running speed improvements. More speed improvements are necessary.
• Change to "Pink and Blue" so that it works under Glulx as well as on the Z-machine.
• "Second Oldest" corrected for a typo in the middle initial of Dennis Jerz.
• "Frizz" adjusted so that instead of laboriously putting the wet and dry glove rules into various rulebooks, it now more elegantly creates a "post-check" rulebook between the check and carry out phases, and relies on that.
• "Equipment List" modified to remove a bug in the divided-wide style of inventory listing.
• "Switch" modified to demonstrate an actual switch statement now that one is available (but still to show how the same thing can be accomplished with otherwise if... or with a table of alternates)
• Updated "Instant EXAMINE and LOOK" into a playable example, now called "Timeless", with modifications reflecting the new action sequence rules.
• "Patient Zero" revised to remove several bugs to do with exit descriptions and nondescript item listing.
• "DIAGNOSE command" converted to a complete, runnable example (now called "Red Cross").
• "Responding to questions starting with WHO, WHAT, etc." converted to a complete, runnable example (now called "Query")
• "Examining everything at once" converted to a complete, runnable example (now called "Beekeeper's Apprentice").
• "Hotel Stechelberg" converted to a complete, runnable example.
• "Replacing standard action report rules" converted to a complete, runnable example (now called "We").
• "Laura" slightly updated to mention the privately-named feature and to mention some of the more advanced parsing features that can be found in the Understanding chapter.
• "Puff of Orange Smoke" updated to use the privately-named feature.
• "Verbosity" edited to mention the syntax for checking current verbosity levels during play.
• "First Name Basis" adjusted to demonstrate plural names for a kind.
• Adjustments made to "Money for Nothing", "Bic", "Chronic Hinting Syndrome", "Dubai", "Patient Zero", "Bribery", "Search and Seizure", "Lakeside Living", "Lemonade", "Modern Conveniences", "Trying Taking Manhattan", "Rock Garden", "Otranto", "Savannah", "Stately Gardens", "Tilt 2", "Tilt 3", "Thirst 2", and "Noisy Cricket" to clean up code using "unless".

Extensions

• "Standard Rules" advanced to version 2: see below.
• "Locksmith" edited to make it easier to change the output text; version number advanced to 6.
• "Plurality" advanced to version 6, and a bug fixed whereby is-are did not print the correct output in the case where the object was the player.

Problem messages

• Problem message added, in place of a disastrous compiler hang (apologies), for the incorrect syntax

  	if one person (called the dude - a person) is in Home, ...
  

  where the user thinks he has to give the kind of value for "dude" - which he doesn't and indeed can't, since it's necessarily the kind of value of the person in question.
• Problem message added to pick up mistakes when people type sentences like

  	Jumping when the actor is on the trampoline is high-jumping.
  

  which don't do what they expect (the only legal reading of this asks to put an object called "jumping when the actor" on top of another one called "trampoline is high-jumping", and it seems unlikely that this is what the writer intended).
• Problem message added to catch maps which have more than two rooms connecting to a two-sided door. (There was already a problem to catch a door connecting to more than two rooms.)
• Problem message added (in place of I6 error) for use of "otherwise if..." after the "otherwise" clause in an "if".
• Problem message added to catch "if ..., repeat ... begin;" where the "begin" is ambiguous as to which of "if" and "repeat" it belongs to.
• Problem message added (in place of I6 error) for too many 'Understand "verb ..." as...' sentences for the same "verb".
• Problem message added to catch attempts to create "topics that vary", a form of global variable that isn't allowed.
• Problem message added (in place of internal error) for writing "[a topic]" as a grammar token, in I6 style, instead of "[text]", the I7 way to do the same thing; and similarly for "[an object]" instead of "[thing]".
• Problem message added (in place of internal error) to catch certain complicated and completely wrong ways to define relations.
• Problem message added (in place of internal error) for writing a rule based on an action applying to a value, where the name of the kind of value is written instead of a specific value.
• Problem message added to catch attempts to make impossibly unspecific requests using cardinality quantifiers with now: "now almost all of the doors are open", "now six things are edible", and so on.
• Problem message added for creating a property name consisting only of the word "presence" (since this causes ambiguities with "...in the presence of...").
• Problem message added for using "if V is a C listed in T", where V is a value, C is a column in a table T, and unfortunately V is of a kind incompatible with the contents of C - for instance, a number when C holds only text.
• Problem message added for creating constant lists of values where the lists aren't recognised because one or more of the entries doesn't make sense.
• Problem message added to catch contradictory declarations like:

  	Eleven is a 10 that varies.
  

• Problem message added to catch attempts to use punctuation characters in Understand ... sentences which can't be matched by the parser anyway, so that the sentences appear to the user to be being ignored.
• Problem message added to catch bizarre sentences like

  	5 is an activity.
  

  (Or rather, to give them one problem message and not a cascade.)

Bug fixes

• Bug fixed whereby "if X can see Y" did not properly work if the player were in darkness. (Fixing this slightly changes the way we report a situation where the player is in an opaque container, without a light source, and asks someone outside the container to close it: we can now only witness that the container closes, and we don't actually see who closes it.)
• Bug fixed whereby if two phrase definitions have identical wordings, it would be the earlier whose definition was applied, not the later. (It ought to be the later, firstly because the documentation says so, and secondly because this enables definitions in the Standard Rules to be overridden more easily - because the SR are always read earlier than anything else.)
• Bug fixed whereby the rules [A] and [B] in the following would be regarded wrongly as being only equally specific:

  	A flowerpot is a kind of thing. A flowerpot can be unbroken or broken.
  	A Ming Vase is a kind of flowerpot. [Yes, I know, it isn't. Never mind.]
  	Instead of attacking an unbroken flowerpot: ... [A]
  	Instead of attacking an unbroken Ming Vase: ... [B]
  

  In fact, [B] is more specific and should therefore have priority over [A], because all Ming Vases are flowerpots but not vice versa, and this is now fixed.
• Bug fixed whereby a skipped line for a paragraph break would in some circumstances be omitted between subsequent paragraphs in a room description.
• Bug fixed whereby excessive skipped lines (two or three superfluous ones) would sometimes appear after out-of-world actions have reported.
• Bug fixed whereby action, activity and rulebook variables could not be used as text substitutions when supplied to phrases with indexed text arguments.
• Bug fixed whereby phrases with indexed text arguments would be unable to compile if they also required run-time disambiguation for other arguments, and would produce I6 errors instead.
• Bug fixed whereby use of indexed text which used text substitutions, but didn't print on screen, would sometimes nevertheless cause incorrect paragraph spacing in what was printed next.
• Bug fixed whereby constructing indexed text from other text, in a way which required use of text substitution, which itself needed to construct some indexed text, would produce garbled results.
• Bug fixed whereby using "exactly matches the text" would behave the same as "matches the text", that is, would not check the "exactly" part: this worked for regular expression matching, but not for plain text matching, because we forgot to implement this case. (Sorry. Of course, "exactly matches the text" means the same as "is", so people probably weren't convenienced too much.)
• Bug fixed whereby constant lists occurring in code, in works which otherwise contain no indexed texts, lists or stored actions, would fail to compile through I6.
• Bug fixed whereby abstract use of "...is listed in..." in source text which contains no actual lists would fail to compile through I6.
• Bug fixed whereby constant lists used in expressions other than assignments would not always have the correct contents.
• Bug fixed whereby constant lists used to initialise a "list of objects" would fail if the objects in question had a specific kind made explicit by other assertions.
• Bug fixed whereby constant lists of texts, when assigned to global variables, properties or table entries whose kind of value is "list of indexed text" rather than "list of text", would be incorrect.
• Bug fixed whereby constant lists of lists of numbers, where some of the numbers were negative, would have garbled contents.
• Bugs fixed whereby constant lists of text which included at least one text substitution in one of the texts would sometimes fail to compiled through I6, or else would produce odd results at run-time.
• Run time problem added for attempts to use "entry N of L", where L is a list and N is an index out of range.
• Bug fixed whereby changing a list to the empty list explicitly like so -

  	now L is {};
  

  ...would result in forgetting the kind of value stored in L if it were subsequently to be filled again, so that saying the contents might produce cryptic numbers instead of the proper values.
• Bug fixed whereby

  	if X is listed in {1, 2, 3}, say "Hello.";
  

  would be misparsed because the commas inside the braces would be confused with the one outside.
• Bug fixed whereby a phrase to decide a list (or indexed text), but which depended on arguments requiring run-time type checking, would either fail to compile through I6 or (more rarely) produce bogus results.
• Bug fixed whereby use of lists, indexed text, stored actions, "(called ...)", or certain other unusual constructions, would fail to compile through I6 if they were made within "Definition:"s of adjectives or "when" conditions of relations or of "Understand ..." lines.
• Bug fixed whereby variables could not be declared to have kind "list of K that varies", where K is a either a kind of object (e.g. "list of rooms") or a new kind of value.
• Bug fixed whereby creating a kind called "link" would cause I6 errors.
• Bug fixed whereby type-checking would incorrectly allow

  	The secret word is a text which varies. The secret word is "xyzzy".
  	Before consulting the book about the secret word: say "Magic!"
  

  ...which should not be allowed because matching against variable text like this has to be done using indexed text, and can't be done by direct methods. (Type-checking did correctly allow this for constant text.)
• Bug fixed whereby type-checking would fail to find the correct interpretation of a "try ..." action, where the action applied to a value and the value was in turn calculated arithmetically, e.g.

  	try hanging around until the time of day plus 6 minutes;
  

  where "hanging around until" is an action applying to a time.
• Bug fixed whereby type-checking would not properly be applied to relative clauses incorrectly applied to descriptions, so that

  	repeat with X running through members of D who are male:
  

  would apparently work if D is a description that varies - but only because Inform is misreading "D who are male" as itself a description, which it isn't, because only a person can be male: a description can't.
• Bug fixed whereby type-checking would not correctly interpret, e.g.,

  	let the irrelevant fact be whether or not 1 is 3;
  

  as a new variable "irrelevant fact", and would instead overlay it on an existing one, the result being mayhem.
• Bug fixed whereby a "your former self" person would sometimes be picked up by, for instance, repeats through all people or lists of people in cases where the source text specifies a particular person as the player-character, so that no "yourself" object ought to exist.
• Bug fixed whereby the list-writer would not group together similar items into a numbered collection if they were people who were carrying things. Thus:

  	A thug is a kind of person. A knife is a kind of thing.
  	Every thug carries a knife. Five thugs are in the Alley.
  

  would report "You can see a thug, a thug, a thug, a thug and a thug here."
• Bug fixed whereby the text substitution "[the player's command]" would have too few words to it during an "after reading a command" rule taking place after the parser has asked a question like "Which do you mean, ...?"; and similarly where it would hold the word "again" or "g" rather than the command being repeated if the player had typed AGAIN or G.
• Bug fixed whereby matching the player's command against a topic would sometimes give wrong answers at the start of play, or after a very short command in the previous turn.
• Bug fixed whereby the parser will no longer say "You can only do that to something animate" if the supposedly animate object's name as typed wasn't recognised at all: it now says "You can't see any such thing." in the usual way. (This seems to have been a curiosity in I6 going back at least ten years.)
• Bug fixed whereby an implicit take (by someone else) generated by a requested action would fail to be recognised as another form of request.
• Bug fixed whereby an "instead" or sometimes also a "before" rule like this:

  	Instead of an actor jumping: say "[The actor] prepares to leap."
  

  ...would sometimes be applied before the persuasion rules had decided whether or not the actor in question would even try.
• Bug fixed whereby a relation between two kinds of value which aren't objects would sometimes have its second term wrongly interpreted as an object just the same - for instance,

  	Divisibility relates a number (called N) to a number (called M)
  	when the remainder after dividing M by N is 0.
  

  did not work because M was wrongly thought an object. It works now.
• Bug fixed whereby conditions containing fairly elaborate double-negatives would sometimes fail to compile, producing I6 errors: for instance,

  	if no hat is not enclosed by a person, ...
  

• Bug fixed whereby run-time type checking was not properly defending relations between specific kinds of object, so that a condition would sometimes be misapplied to objects not of the that kind, resulting in spurious run-time problems (albeit only if the relation were being tested for objects to which it really doesn't apply).
• Run-time problems added for attempts to remove the player from play (a logical impossibility) or to remove doors from play (which would make a mess of the map), and for attempts to change the player to someone who has been removed from play.
• Bug fixed whereby, on Glulx, an attempt to expand the heap by dynamic memory allocation might fail if the current heap were completely full (i.e., with not even the smallest block of memory free): in some cases, a run-time hang would result.
• Bug fixed whereby the count of how many turns over which a category of actions has been happening would sometimes be wrong if the action qualified only when a certain condition held, which did not hold at the start of the action but did hold at the end. For instance, suppose we have:

  	A thing can be examined or unexamined.
  	Carry out examining something: now the noun is examined.
  	After examining an examined thing for the third turn: say "Not again!"
  

  If the player types EXAMINE BOX, never having done so before, then this does not qualify as "examining an examined thing": but previous builds would have counted it towards the three turns needed for the rule to fire because, at the very end of the action, the description "examining an examined thing" would indeed match, the box by then having acquired the "examined" property.
• Bug fixed whereby the count of turns is not fooled by multiple actions in a single turn: suppose we have the rule

  	Before taking for the third turn: say "Not again!"
  

  and suppose the player types TAKE ALL, picking up a dozen items. In previous builds, the rule would treat these as different turns, but now they are treated as the same turn.
• Bug fixed whereby "when" clauses in the preambles of rules for actions were not always allowed to see the action variables for the actions they belonged to: e.g.,

  	Check going when the room gone to is dark: ...
  

  would not compile even though "room gone to" is a variable belonging to the action "going", which owns the "check going" rulebook. A "when" clause for a rule can now see exactly the variables which the rule's definition can see.
• Bug fixed whereby "asking ... to ..." actions would not work in rules which counted them: for instance,

  	Instead of asking Daphne to take the snack for the second time: ...
  

  would never fire. It now does; note that the count is of the number of times the action has been requested. If Daphne first takes the snack on her own initiative, and then the player asks her, that doesn't fire the rule.
• The count has further been reformed by ensuring that silent actions can never count towards the number of turns in such a rule; silent actions are never the main point of what is happening in a turn.
• Bug fixed whereby "[one of]...[or]...[in random order]" would fail on the Z-machine if there were 13 or more alternatives, and could cause spurious programming errors on Glulx.
• Bug fixed whereby making something a part of a door would in some cases cause a bogus problem message claiming to find two apparently unrelated sentences contradictory.
• Bug fixed (or, arguably, specification clarified) so that when one thing makes another, and the new item derives its name from the old, then a "printed name" for the original is transferred to the new. For instance:

  	An oak tree is a kind of thing. Some leaves are a kind of thing.
  	Some leaves are part of every oak tree.
  	The printed name of an oak tree is usually "a mighty oak".
  	Oak1 is an oak tree in Stage. 	
  

  ...now results in leaves called "a mighty oak's leaves", not "Oak1's leaves", because the printed name "a mighty oak" transfers from Oak1.
• Bug fixed whereby if a character were asked to do something with multiple objects (say with the command HELEN, GET ALL) then it would be assumed that agreement to perform the action with the first item would extend to the rest of the list, too. Persuasion rules are now properly checked for each item in the list in turn.
• Bug fixed whereby rules predicated on a list of two or more actions, where an action name before the last could be read as both a complete action name and also an abbreviation for a different one, would have both interpretations applied instead of only the complete one: for example, if actions called "franking" and "franking it with" both existed, then "Instead of franking or taking" would be misread as applying to any of the "franking", "franking it with" or "taking" actions - whereas "Instead of franking" and "Instead of taking or franking" would not be misread in this way.
• Bug fixed whereby the "in" would be misinterpreted if it occurred in the name of a rule being explicitly placed in a rulebook, as here:

  	The new can't travel in what's not a vehicle rule is listed instead
  	of the can't travel in what's not a vehicle rule in the check
  	going rules.
  

• Bug fixed whereby some extension namespace clashes would fail to be reported correctly on the dictionary page where three or more different extensions all defined the same term.
• Bugs fixed whereby names with exotic ingredients such as ~, ^, @ would either be misprinted or misparsed, or both.
• Bug fixed whereby a "Definition:" would fail with an internal error if applied to just an "object" rather than a named kind such as "thing". For instance -

  	Definition: An object is weaponlike if it is the knife.
  

• Bug fixed whereby "now X is P of Y", where X is a variable and P is a property whose kind is a unit with the same name, would sometimes wrongly try to set P for X as well even when X is a variable of kind P rather than an object having P as a property. On the Z-machine this produced a spurious programming error; on Glulx, it sometimes crashed.
• Bug fixed whereby asserting that a property is set to its own kind of value, rather than a specific value, would cause an internal error rather than produce a sensible problem message.
• Bug fixed whereby the use of a specific named object combined with adjectives, in a context where only the object is expected, might cause an internal error rather than issue a problem message.
• Bug fixed whereby paragraph breaks in the middle of phrase definitions would sometimes incorrectly be allowed, if the material just before the paragraph break ended in a semicolon.
• Bug fixed whereby the "does the player mean" rules did not properly work for requests made by the player for other people to do things.
• Bug fixed whereby making an assertion about a form of named construction (a type which is not a kind of value) would cause an internal error. For instance,

  	A condition is usually true.
  

• Bug fixed whereby a "when" condition in a relation which makes a calling so as to refer to an earlier result to decide a later one, would produce I6 errors and fail to compile.
• Bugs fixed, or really, syntax clarified as to when qualifiers such as "always" and "usually" can be used in assertions: these are allowed on either side of the verb in most assertions, but not on both (for which a problem message has been added), and not in assertions admitting no doubt (such as "Looking is an action applying to nothing"). Previously Inform would silently allow, though ignore, some such usages.
• Similarly, "worn", "carried" and "here" can now only be used in assertions using the verb "to be".
• Similarly, "of", "from" and "and" now lose their grammatical meanings as introducers of clauses in assertions if they are unexpectedly written with an upper-case O, F or A, respectively. Thus On the shelf is Of Mice And Men and The Girl From Ipanema. places two objects on the shelf, with the obvious names, and doesn't get sidetracked into thinking the shelf contains (for instance) an item called "Of Mice" together with some "men".
• Bug fixed whereby optional clauses matched against action variables would sometimes not work for actions which apply to nothing. For instance,

  	The jumping action has an object called the situation (matched as "at").
  	Instead of jumping at the Place, ...
  

  was not being recognised.
• Bug fixed whereby a rule like Check taking: say "You can't, because [if Fred is visible]Fred might

  	see.[otherwise]I say so." instead.
  

  ...might only halt the action, as the "instead" implies, if the "otherwise" branch is taken through the text.
• Bug fixed - well, anyway, sensitivity improved - so that when a kind of value is defined with a table, the names of the possible values in column 1 are no longer so likely to cause namespace clashes with things or rooms defined elsewhere.
• Bug fixed whereby when a table is used to define a kind of value or a set of objects, a bracketed kind of value declaration in a table column name would not be recognised. (For instance, if a table column is headed "alpha (number)" then the name is "alpha" and the values have to be numbers.)
• Bug fixed whereby properties which are defined by column names in tables used to define objects (or values), for which the entry in row 1 happens to be text which has substitutions, would then only allow other texts with substitutions as values - not plain text.
• Bug fixed whereby giving a value as "object" in a table used to define objects would result in peculiar problem messages at best, and an internal error at worst.
• Bug fixed to do with writing tables containing numbers to files in projects using Glulx.
• Bug fixed whereby conditions based on actions would sometimes fail to compile with I6 errors if the actions involved items or people which were specified by local ("let" or "called") or global variables rather than named explicitly.
• Bug fixed whereby declared plurals (with "The plural of ... is ...") would only sometimes be used by room descriptions.
• Bug fixed whereby, contrary to the claim in Inform's problem messages, a Table could not be created which was named with a number alone ("Table 6").
• Bug fixed whereby, if a room or thing existed whose name included a number (say, "Room 101"), then

  	now X is a random number between 1 and 101;
  

  would sometimes be rejected as a compound condition for "now", because the "and" had been misinterpreted.
• Bug fixed whereby extension documentation would sometimes mis-space braces "{" and "}".
• Story files running on Glulx interpreters now properly check the "unicode" gestalt before trying to use Unicode character printing: such checks will only fail on old and now deprecated interpreters.
• Bug fixed whereby the Phrasebook index would be garbled if words in the lexicon includes the characters "<" or ">".
• Bug fixed whereby names containing "from" would sometimes have their original articles taken as part of the name itself: for instance,

  	The telegram from Klaxor is in the Breakfast Nook.
  

  would produce a proper noun, "The telegram from Klaxor", rather than parsing it as "the" (definite article) + "telegram from Klaxor". (That this bug was not more widely felt is chiefly because another mechanism in Inform tended to compensate for it.)
• Bug fixed whereby "called" names were sometimes unable to contain the words "with" or "having": for instance, this failed -

  	The golf ball is in a container called the flask and cap with flange.
  

• Bug fixed whereby consecutive articles would on rare occasions be allowed in noun phrases ("a the tree", say).
• Bug fixed whereby RESTORE would not always work as a reply to the final question ("Would you like to RESTART, RESTORE a saved game or QUIT?").
• Last and thoroughly least, but in response to a genuine bug report form, code added to protect NI from the "Year 2038" bug. This is the point at which 32-bit integer representations of time in non-leap-seconds since January 1 1970 begin to overflow. NI itself handles time correctly, but it uses C library calls on all its platforms which follow Unix conventions (including on Windows), which means they behave incorrectly on computers whose system clock is set to later than 2038. Work progresses but there is as yet no agreed solution to the Year 2038 bug. When there is, we will recompile NI against the improved C libraries then existing. In the mean time, users are advised to avoid time travel beyond 18 January 2038.

Mac OS X app

• The Source panel is now divided into two side-by-side views: Contents and Source. These are alongside each other, but only one is visible at a time, and each slides out of the way to make room for the other as needed. The Contents view shows a contents page for the source text, automatically generated from its headings. A slider can be used to control how much detail is shown. Clicking any heading slides back into the contents view, but showing only the material under that heading (and its subheadings, if any). This makes very large source texts much more manageable, and also provides a useful overview of an entire project.

Windows app

• The Contents view has also been partially implemented on Windows. On selecting this pane from the source tab, a window slides in from the left showing some or all of the headings in the source, depending on the slider at the bottom of the window. Clicking on a heading causes the contents pane to slide back and the source tab to jump to the chosen heading.
• A spell checker has been added, using the "hunspell" project from OpenOffice.org. Only words that will appear as text in the game are checked. Currently this is accessed through the new "Check Spelling" Edit menu item: checking spelling as the user types will be implemented later.
• Copying tables from the documentation to the source tab via the clipboard or through drag and drop should now work correctly: the table will be pasted with tabs rather than spaces between columns.
• If the registry DWORD value "HKCU\Software\David Kinder\Inform\Window\Watch File Changes" exists and is set to zero, then the application will not notify the user if the "source.ni" file is changed by another program.

Linux app

• The long-awaited Skein tab has been added to the GNOME application; all features that are relevant without an accompanying Transcript tab are fully-functional.
• The Game tab now runs Glulxe 0.4.3.
• GtkSourceView 2.0 adopted, which means several fixes for the syntax highlighting. Thanks to Zachary Amsden for submitting a patch which did much of the work.
  • Most importantly, nested comments are now highlighted correctly.
  • Inform 6 code is highlighted as in the OS X application.
  • Words like "if" and "otherwise" are no longer highlighted burgundy.
  • Syntax highlighting in general should be somewhat faster.
• Fixed various, minor bugs, some of which were tracked down and patched by Alan De Smet and Jonathan Liu.
• Jonathan Liu has contributed a package for Arch Linux i686.