inform7/resources/Changes/Change Logs/4F59.txt

4F59 (21 December 2006)
The main purpose of this build is to publish a redesigned system for
phrase and rule declarations, fixing a number of miscellaneous bugs,
removing some exceptions and clarifying ambiguities in the existing design.
Chapter 18 of the documentation is substantially rewritten as a result, and
the Rules page of the index has been redesigned. We believe that the new
design is much less ambiguous and, as a result, more fully explained than
the old, but the removal of some of these ambiguities does mean that minor
changes to some existing source text will be needed. If you have a work in
progress nearing its completion, you may need to test that the new rules
system does not change its behaviour.

Phrases can be defined by "To ...:" (declaring a new phrase to be used in
	the definitions of other phrases), by "Definition:" (defining adjectives),
	by "At ...:" (declaring events to happen at given times) or as rules
	to go into rulebooks (for instance, "Instead of taking:" goes into the
	"instead" rulebook). In order to make it easier to tell immediately
	which of these four forms is intended:
		(i) Rulebook names are now forbidden to begin with the words
			"To", "At" or "Definition". (So far as we are aware, nobody
			has ever done this, so this should not cause inconvenience.)
		(ii) Events happening at a fixed time are written "At 3:02 AM:" or
			similar: events happening at some time not yet determined are
			now written "At the time when the clock chimes:" rather than,
			as in previous builds, just "When the clock chimes:". This
			removes the confusing ambiguity with scene start/end rules
			(e.g. "When Scene IV begins:") and with "When play begins:", etc.
When Inform adds rules to rulebooks, it sorts them so that more specifically
	applicable rules (say, "instead of taking the fish") come before vaguer
	ones ("instead of taking or dropping something"). The method of sorting
	used was largely unchanged from 3K27 to 4B91, but has now sharpened
	in the following ways:
		(i) being "in" a room is considered more specific than in a region,
		(ii) and in a subregion more specific than in a super-region,
		(iii) "during..." clauses are now taken account of,
		(iv) "in the presence of..." clauses are now taken account of,
		(v) rules attached to a wider range of actions ("taking or dropping")
			are less specific than rules attached to a narrower range
			("taking"),
		(vi) rules with longer or more complicated "when" conditions are
			considered more specific than those with shorter,
		(vii) rules applying in a limited range of turns or for a limited
			number of times are considered more specific than other such
			rules if the number of turns in which the rule could apply
			is smaller.
	Though these changes may change the effect of some complicated source
	texts now standing, they should only really affect cases where rules
	were previously considered equally applicable.
When the Index shows the contents of a rulebook, it now uses a graphical
	notation to show which rules are considered more specific than which
	others. Hovering the mouse over one of the icons used in this notation
	causes a "tool tip" to be displayed which explains on what basis the
	decision was taken.
The special verb "to be listed", used to specify how named rules are listed
	in rulebooks, is now more flexible. The existing syntax remains:
		The summer breeze rule is listed in the every turn rules.
		The summer breeze rule is listed after the chirping magpie rule
			in the every turn rules.
		The summer breeze rule is listed before the chirping magpie rule
			in the every turn rules.
	And the following possibilities are added:
		The summer breeze rule is listed first in the every turn rules.
		The summer breeze rule is listed last in the every turn rules.
		The can't eat unless edible rule is not listed in the check eating rules.
		The can't eat unless edible rule is not listed in any rulebook.
		The refined palate rule is listed instead of the can't eat unless
			edible rule in the check eating rules.
	The last three possibilities allow rules to be abolished for the whole
	game without the need for procedural rules. (A rule abolished in this way
	still exists, it merely isn't found in rulebooks at the start of play.)
	This will make extensions which carry out large-scale library changes
	more efficient.
A "when/while" clause can now be attached to a rule in an object-based
	rulebook not derived from an activity. (These used to be the only
	rulebooks whose rules were not allowed a "when" clause, so the change
	removes an unnecessary exception.)
The synonym "final" for "last", in the context of rulebook placements, has
	been withdrawn - it was an unnecessary complication. Thus "The last
	chirping magpie rule:" still works, but "The final chirping magpie rule:"
	does not.
The new text substitution "[otherwise if ...]" has been added: this can be
	used in text, between "[if ...]" and "[end if]" substitutions, in just
	the same way that the phrase "otherwise if ..." can be used between
	"if ..." and "end if" phrases.
A new rulebook, "does the player mean", has been added to give the parser
	clues on how to disambiguate commands. (This offers facilities analogous
	to those provided by ChooseObjects in Inform 6, but applying to whole
	actions and not to nouns alone.) See the new section 16.16 in the
	documentation.
Changes to the examples are as follows:
	Masochism Deli added to demonstrate "does the player mean..." rules.
	Flotation added to demonstrate an object-based rulebook and named outcomes.
	Being Peter added to demonstrate an action-based rulebook with named
		outcomes.
	Bronze, 3 AM, MRE, Mr Spruce's Non-Modal Question, Chronic Hinting
		Syndrome, Fifty Times Fifty Ways, Happy Hour, Lakeside Living,
		Lemonade, Noisy Cricket, Patient Zero, Y Ask Y modified to show
		"otherwise if" better.
	Barter Barter, Bribery, Bruneseau's Journey, The Dark Ages Revisited,
		Emma, Fragment of a Greek Tragedy, Mimicry, Minimal Movement,
		Nickel and Dimed, Stately Gardens, Under Contract, Waning Moon
		modified to get rid of now-unnecessary procedural rules and use
		"is not listed..." instead.
	Aftershock, Crusoe, Get Axe, The Hang of Thursdays, Panache, Swigmore U,
		Uptempo, Zqlran Era 8 modified to get rid of now-unnecessary
		procedural rules and use "is listed instead of..." instead.
	Instant Examine and Look modified to get rid of procedural rule in favor
		of a first rule in the turn sequence rules. Commentary added to
		explain how the procedural rule might be used and why the first-rule
		method might be preferable.
	No Place Like Home reassigned to the Awarding Points section, as being
		more relevant there.
	Strictly Ballroom corrected for a missing word.
	Up and Up modified to use after going rather than before, as this is more
		reliable.
	Beneath the Surface improved to make the chair a supporter.
	Witnessed 1 expanded to include new "does the player mean..." rules,
		improving parsing behavior of the example.
	The Night Before added to demonstrate "does the player mean..." rules to
		lower the parsing significance of body parts belonging to the player
		compared to those of other people;
	Hudsucker Industries substantially updated to simplify logic, provide
		better parsing behavior using "does the player mean..." rules, and
		allow the player to refer to sorted letters by property.
	Costa Rican Ornithology given slightly more explanation of the topic
		column, since this appears before the format has been fully introduced.
	We, and the two gas diffusion examples, moved to a new location.
	We given slightly more commentary to point users at extensions for
		changing library messages if they want to do so wholesale.
	No Relation edited to discuss how Instead of going by... applies to
		vehicles and other objects.
	Morning After edited for a typo in the commentary.
	Uptown Girls edited for a typo in the source text.
File extension for blorbed Glulx-format releases changed from ".zblorb"
	to ".gblorb". (Apologies: an oversight.)
The horizontal compass directions can no longer automatically be referred to
	by the word "wall", so that "examine the north wall" no longer generates
	the action of examining north. This was an old Infocom convention, carried
	over into Inform 6 for some years, but which causes problems more often
	than it confers benefits.
Bug fixed by which (on Windows only) accented letters sometimes caused
	confusion with digits.
Bug fixed by which a rule which applied e.g. "for the third to eighth time"
	(an explicit range of iterations) would generate code which failed to
	compile in I6.
Bug fixed in which rules "listed after" or "listed before" might give
	spurious problems if the rulebook named had a name including the
	word "with".
Bug fixed whereby the Glulx interpreter was not checked to see if it could
	provide pictures before being instructed so to do, which produced
	problems with some text-only Glulx interpreters.