# Inform Release Notes

### Inform Compiler 6.30 to 6.36

## Introduction

This is a maintenance release of the Inform system for creating adventure games, intended to address issues that have arisen since the 6.21 compiler and 6/10 library files were released in 1999, and subsequently since the 6.30 compiler was released in 2004. The focus is primarily on fixing problems, but a small number of enhancements are included.

Although just about all known bugs are fixed, the approach to enhancing Inform is more conservative. The selection of suggestions to implement has been governed by three factors:

- avoidance of changes which might cause existing games to misbehave;

- minimisation of features which would require updates to the Inform Designer’s Manual;

- essential simplicity. With Graham Nelson’s permission, this release has been produced by a volunteer taskforce, whose enthusiasm has been tempered by a certain lack of familiarity with the internals of Inform. Thus, we have concentrated on ‘safe’ changes; the implementation of some good ideas has been postponed until we are more confident that we know what we’re doing.

Having said that, this release does incorporate one major advance. It is based on Andrew Plotkin’s bi-platform — Z-machine and Glulx — compiler and library files, which were in turn derived from the the 6.21 compiler and 6/10 library. The result is that the two Virtual Machine (VM) strands have merged into a single compiler and library which, although continuing by default to produce Z-code, can alternatively generate code for the Glulx VM if you supply the `-G` compiler switch. There’s more on this topic in Support for Glulx. Before that, though, we’ll summarise the changes to the compiler and to the library files.

If you’ve translated the Inform library into another language, you may find Information for translators helpful.

Since the first release of the Inform 6.3 compiler, the Inform 6 library has been split into a separate project, maintained at https://gitlab.com/DavidGriffith/inform6lib.

## Acknowledgements

Far too many people contributed towards this release — reporting and resolving bugs, making helpful suggestions, providing support and facilities, testing, and so on — for their names to be individually listed. So instead, this is a general thank-you to everybody who has made this release happen, and specific ones to Graham for permitting it in the first place, and to Andrew for his pioneering work on Glulx.

## Compiler 6.36

These are the changes delivered in version 6.36 of the Inform compiler.

### Features added

- The algorithm used to apply abbreviations for Z-code has been replaced with a more efficient dynamic programming algorithm, based on the paper by R.A. Wagner "Common phrases and minimum-space text storage", Communications of the ACM, 16 (3) (1973).

- Inform has been refactored to use dynamic memory allocation rather than fixed size buffers. As a result, the following settings are now removed: if the available space is filled, Inform will allocate more memory without requiring user intervention.

  - ALLOC_CHUNK_SIZE
  - SYMBOLS_CHUNK_SIZE
  - MAX_ABBREVS (removed only for Glulx)
  - MAX_ACTIONS
  - MAX_ADJECTIVES
  - MAX_ARRAYS
  - MAX_CLASSES
  - MAX_DICT_ENTRIES
  - MAX_EXPRESSION_NODES
  - MAX_GLOBAL_VARIABLES
  - MAX_INCLUSION_DEPTH
  - MAX_INDIV_PROP_TABLE_SIZE
  - MAX_LABELS
  - MAX_LINESPACE
  - MAX_LINK_DATA_SIZE
  - MAX_LOCAL_VARIABLES (now a constant)
  - MAX_LOW_STRINGS
  - MAX_NUM_STATIC_STRINGS
  - MAX_OBJ_PROP_COUNT
  - MAX_OBJ_PROP_TABLE_SIZE
  - MAX_OBJECTS
  - MAX_PROP_TABLE_SIZE
  - MAX_QTEXT_SIZE
  - MAX_SOURCE_FILES
  - MAX_STATIC_DATA
  - MAX_STATIC_STRINGS
  - MAX_SYMBOLS
  - MAX_TRANSCRIPT_SIZE
  - MAX_UNICODE_CHARS
  - MAX_VERBS
  - MAX_VERBSPACE
  - MAX_ZCODE_SIZE
  As a result of this, the memory size command line arguments (`$SMALL`, `$LARGE` and `$HUGE`) are now redundant, and have been removed.

- It is now possible to declare an individual property with the `Property` directive:

        Property individual propname;

- A new setting `$ZCODE_LESS_DICT_DATA` has been introduced. When set to a non-zero value, this tells the compiler to omit the last byte of Z-code dictionary entries (which can be referred as `#dict_par3`), as this is commonly unused.

- There are now warnings if the compiler detects that the type used in certain expressions is not correct. This only checks expressions that contain defined symbols, and does not change the generated code. The checks are:

  - `remove O`: O is an object
  - `move O to P`: O is an object; P is an object or a class
  - `give O A`: O is an object; A is an attribute
  - `O has/hasnt A`: O is an object; A is an attribute
  - `O in/notin P`: O is an object; P is an object or a class
  - `X ofclass C`: C is a class
  - `X provides P`: P is a property
  - `X.P`, `X.P()`, `X.&P`, `X.#P`: P is a property

- Assembly output (`-a` mode) now shows symbolic information for each assembly operand, if possible.

- The `-u` switch now generates `$MAX_ABBREVS` possible abbreviations.

- The `Trace verbs` directive now prints out the entire grammar table.

- Using the `-D` switch when the game or library does not support `debug_flag` now produces an explanatory warning:

        DEBUG mode is on, but this story or library does not appear to support it

- Expressions of the form `(x <= y or z)` or `(x >= y or z)` now produce a warning message: while their effect is documented, well defined, and is not being changed, it is not necessarily what a user might expect.

- The check for whether an abbreviation actually reduces the size of the Z-code output file has been made more accurate, and the message if an abbreviation does not reduce the size is now a warning, rather than an error.

### Bugs fixed

- For Glulx, stub functions (and the veneer function `Symb__Tab()`) are now always compiled as local-argument functions (with a type byte of 0xC1). Previously, they were in some cases compiled as stack-argument functions (with a type byte of 0xC0).

- Counts of properties in errors and in the statistics report (output with the `-s` switch) are now consistent, and reflect how many properties the user can define.

- The check that there are not too many common properties defined now correctly excludes individual and alias properties.

- Inform will now report an error if the "class" line of a class definition mentions the class being defined.

- A crash when compiling a malformed array declaration has been fixed.

## Compiler 6.35

These are the changes delivered in version 6.35 of the Inform compiler.

### Features added

- Some Unix-style command line options are now supported, primarily to avoid the use of $ in command lines (although the old syntax is still supported). The new syntax for these options is:

        --help
        --path PATH=dir
        --addpath PATH=dir
        --list
        --size huge, --size large, --size small
        --helpopt SETTING
        --opt SETTING=number
        --config filename

- Numeric constants can be declared as command line options, either like a setting:

        $#SYMBOL
        $#SYMBOL=NUM

  Or as a new Unix-style command line option:

        --define SYMBOL
        --define SYMBOL=NUM

  This defines SYMBOL as a constant, just like the `Constant` directive. Like that directive, if no value is supplied, it defaults to zero.

- The settings `$MAX_ABBREVS` and `MAX_DYNAMIC_STRINGS` control the number of abbreviations and the number of dynamic strings, respectively. When compiling to Z-code these settings are linked, as they both use the same 96 Z-code abbreviations that are available.

- The setting `$TRANSCRIPT_FORMAT` controls the output format of the `-r` option. The default is still the same format as before, (and can be explicitly selected with `$TRANSCRIPT_FORMAT=0`), but `$TRANSCRIPT_FORMAT=1` enables the new, more informative and machine-readable format.

- The `Origsource` directive, added in version 6.34, is now used in error reporting, regardless of the error format selected. (Previously it only appeared with the default error message format, E0.)

- If an attempt is made to redefine an existing symbol, there is now a clearer error message, explaining what the error is and where the symbol was previously defined.

- `-g3` is now a valid option: it enables tracing for all routines, including the veneer. This functionality was added back in Inform 6.21, but the code to check the actual option was omitted.

- Using the option `-k` (which turns on the generation of debugging information) no longer implies `-D` (which turns on debug mode).

### Bugs fixed

- Only the following directives are now allowed in a function or object definition: all others give an error:

        #ifv3
        #ifv5
        #ifdef
        #ifndef
        #iftrue
        #iffalse
        #ifnot
        #endif
        #message
        #origsource
        #trace

- An `#ifdef` statement at the start of a `switch` block now compiles correctly, and no longer gives a spurious error.

- The following, incorrect forms of array declaration now generate an error:

        Array foo --> 'dictword';
        Array foo --> FunctionName;
        Array foo --> [];

- If a common property array overflows when compiling to Z-code version 3, the object is no longer corrupted.

- The incorrect code

        Object foo with name 'x';

  now correctly causes the warning

        'name' property should only contain dictionary words

  when compiled to either Glulx or Z-code: previously the warning only appeared when compiling to Z-code.

- The compiler now correctly handles `#If` directives around `if` and `else` clauses.

- Forward declared properties (that is, properties that are used before they are defined in the game source code) now work correctly.

- Where directives allow a constant to be used (`Release`, `Version`, `Dictionary`, `Iftrue` and `Iffalse`), the compiler now reports an error if the constant is not defined.

- When compiling to Z-code version 3, dictionary words are now correctly truncated at 6 Z-characters (instead of 9).

- When compiling to Z-code version 3, two dictionary words that differed only in Z-characters 7-9 would lead to two identical dictionary entries: now there will only be one entry.

## Compiler 6.34

These are the changes delivered in version 6.34 of the Inform compiler.

### Features added

- The following system constants are now supported for Glulx: `#highest_class_number`, `#highest_object_number`, `#lowest_attribute_number`, `#lowest_action_number`, `#lowest_routine_number`, `#lowest_array_number`, `#lowest_constant_number`, `#lowest_class_number`, `#lowest_object_number`, and `#lowest_property_number`.

- Unicode characters can now be included in Glulx word arrays as literals, e.g.

        Array text1 table "A @{1c4} A";
        Array text2 --> "A @oef A";

- For Glulx, high-plane Unicode characters in the range $100000 to $10FFFF are supported in UTF-8 source code, and in `@{...}` sequences, which can now contain up to six hex digits.

- The new command line switch `-V` simply prints the version and date of the compiler and then exits.

- The new setting `$SERIAL` sets the six digit serial number written into the header of the game, e.g.

        $SERIAL=160305

- It has always been possible to replace the paths used by the compiler with a command line option of the form `+include_path=foo`. It is now possible to add to an existing path without replacing it by using an additional '+' character, like so: `++include_path=foo`.

- The `Replace` directive can now be applied to routines in any file, whether it has the `System_file` directive or not. `Replace` also now works on recursive functions, which it previously did not. Its behavior can now be described this way:

        Replace Func;
        Replace Func OriginalFunc;

  Multiple definitions of `Func()` may follow this directive. `Func` will refer to the last-defined version, except that definitions in normal files are preferred over definitions in `System_file` files or the veneer. With the two-symbol form (introduced in 6.33), the latter symbol will refer to the first-defined version of the function.

- A new `Origsource` directive has been added to allow a record of the location of the relevant in a higher-level language that has been converted to Inform 6. (In practice, this will very likely be the location in an Inform 7 source.) The syntax is

        Origsource <file>
        Origsource <file> <line>
        Origsource <file> <line> <char>
        Origsource

  The first three forms declare that all following lines are derived from the named Inform 7 source file (with an optional line number and character number). This will be reported in error messages and in debug output. The declaration holds through the next `Origsource` directive (but does not apply to included files). The fourth form, with no arguments, clears the declaration. Unlike the `Include` directive, `Origsource` does not open the named file or even verify that it exists. The filename is treated as an opaque string.

- The constant `$INDIV_PROP_START` is now a setting that can be changed for Glulx.

- Arrays that are never modified can be declared as "static": in Z-code, this places the array at the end of readable memory (after the dictionary and before the beginning of code storage); in Glulx, it places the array at the end of ROM (after string storage). The syntax is

        Array arrayname static --> 1 3 5 7 9 11 13 15;

### Bugs fixed

- It is no longer possible to cause values to be pushed onto the stack but not then pulled by evaluating a logical expression but not assigning or using the result of that expression.

- Replacing a recursive function now works correctly.

- The output for the `$list` command line argument now includes the value of the `$MAX_ARRAYS` setting.

- Memory settings can no longer overflow if set to very large values. These values are limited to a maximum of 999999999: setting them higher just results in a warning.

- The debugging output file now contains the correct function addresses even when the compiler has been told to omit unused functions.

- Invalid statements with empty parentheses (like `return ();`) now generate a sensible error.

- Crashes caused by over-long identifiers have been fixed. Note that as a result, the previously allowed (although undocumented) use of strings or dictionary words in an action-based (implicit) switch statement now causes an error.

- The object table is now always generated at an even Z-Machine address, as the logic in the veneer routine `RA__Pr()` requires this.

- The F and u options are now explicitly disallowed with the `Switches` directive.

- Assigning values to system functions now leads to an error message, rather than a crash.

- Crashes due to over-long abbreviations have been fixed.

- Representing the at symbol '@' by `@{0040}` now works when compiling to Glulx.

- The `USE_TEMPORARY_FILES` option no longer has a bug that led to files being closed more than once.

- The platform-specific definitions in `header.h` for Unix have been cleaned up: "UNIX64" has been removed, since it was identical to "UNIX"; and "UNIX" no longer implies "USE_TEMPORARY_FILES".

- The platform-specific definitions in `header.h` for the Macintosh have been cleaned up: "MACINTOSH" is now "MAC_CLASSIC"; "OSX" is now "MACOS", and "MACOS" now uses "HUGE_SIZE" for the default array sizes.

- The maximum length of a verb is now limited to 120 (which can be changed in the source code). Previously very long verbs would crash the compiler.

- Compiling to Z-code version 3 has shown a number of regressions since Inform 6.15:

  - Diverted actions, of the form `<<ACTION>>`, are fixed.
  - The veneer routine `RA__Pr()` can be used.

## Compiler 6.33

These are the changes delivered in version 6.33 of the Inform compiler.

### Features added

- Unused routines can now be detected and omitted from the compiled game, through two new settings. If `$WARN_UNUSED_ROUTINES` is set to 1, unused routines (other than those in the Inform library) are reported during compilation; if it is set to 2, unused routines anywhere, even in the library, are reported. If `$OMIT_UNUSED_ROUTINES` is set to 1, unused routines are omitted.

- A new command line switch `-Cu` can be used to specify that the source file character set is UTF-8, allowing source files to contain Unicode characters beyond those defined in ISO 8859-1 to 8859-9.

- A new `#Undef` directive will cause a previously defined constant to become undefined.

- `#Ifdef` directives are now allowed within an object declaration.

- Action statements can have an optional extra ‘actor’ argument, allowing action statements of the form

        <Take pie, orc>; ! simple form
        <<Look, floyd>>; ! auto-returning form

  Note that this also requires a library change to be useful.

- A previously declared routine can be renamed with a new form of the `Replace` directive. For example, if a source file contained

        Replace Banner OriginalBanner;

  It could then (after including the library) contain this definion of a function:

        [ Banner;
          OriginalBanner();
          print "Extra version info!^";
        ];

  The library's banner code would then be in `OriginalBanner()`.

- The previously deprecated `Dictionary` directive can now have the following forms:

        Dictionary 'word';
        Dictionary 'word' val1;
        Dictionary 'word' val1 val3;

  The first of these forms just adds the word to the dictionary, with all flags set to zero, if it is not already in the dictionary. The second form also sets the `dict_par1` flag to the given value, or bitwise-or’s the value in if the word already exists. The third form also sets the `dict_par3` in the same way as for `dict_par1`.

  The values can be numeric literals or constants. They can be 0-255 for Z-code, or 0-65535 for Glulx.

- The “`font on`” and “`font off`” statements now call the `@set_font` opcode for Z-code V5 and higher.

- The Glulx version of the `Unsigned__Compare()` veneer routine has been changed to a more efficient implementation, using Glulx’s unsigned comparison opcodes.

- The debugging output file, generated when the `-k` is used, has been changed to a new, XML-based format.

- Two new Z-code settings have been added to support the extra words in the header extension table specified in section 11.1.7 of the Z-Machine Standards Document version 1.1. `$ZCODE_HEADER_EXT_WORDS` specifies how many extra words to add (so for all three words defined in the 1.1 standard, this would be set to 3). `$ZCODE_HEADER_FLAGS_3` specifies the value to put in the first of these three words, which is the "flags3" field.

- A new Glulx setting `$GLULX_OBJECT_EXT_BYTES` has been added, which specifies an amount of additional space to add to each object record. The default is 0.

### Bugs fixed

- Function calls of the form `f(g)(h)` (that is, where `f()` returns the address of a function that is called with `h` as its argument) are now compiled correctly: previously, such calls were compiled as if the code was `f(g(h))`.

- The bounds checking related to internal arrays that are are sized from various compiler settings has been improved, so that it should not be possible to crash the compiler if these settings are too small. In addition, a start has been made on allowing the compiler to grow its internal buffers, rather than relying on these settings to specify sufficient buffer sizes.

- The error message shown when too many global variables are declared now tells the user to increase the `$MAX_GLOBAL_VARIABLES` setting.

- The setting `$MAX_CLASS_TABLE_SIZE`, which was not used anywhere, has been removed.

- The compiler no longer crashes if run with the `-k` switch and passed a source file containing no routines at all.

- Floating-point constants in “`#Ifdef TARGET_GLULX;`” sections do not now cause an error when compiling to Z-code.

- The error message produced if an action routine is not found for an action name has been improved to include the action name, and a sensible line number.

- The compiler is now better at not producing spurious additional errors after it has encountered a directive that contains an error.

- The compiler no longer crashes when reporting errors after line 65,535 in long Inform 6 source files.

- The compiler now reports a meaningful text compression rate when outputting statistics for Glulx with the `-Gs` switches.

- An error is now reported if a source file ends with an unterminated object definition.

- The three argument form of the `read` statement no longer assumes that the routine passed as the third argument to the statement will not change the global variable that the statement uses internally.

- The 'Abbreviate' statement now works with words containing non-English characters.

- Attempting to use `@pop` opcode for V5 or higher no longer results in a crash.

- The Glulx setting `$NUM_ATTR_BYTES`, which determines the number of bytes in an object set aside for attribute flags, now works correctly. Note that this has required a change to the veneer routines that conflicts with the definition of `FUNC_2_CP__Tab()` in the ‘Accelerated Functions’ section of the Glulx 3.1.2 specification. If you change this setting, you should take great care if you also use the Glulx accelerated functions feature (as Inform 7 does by default).

- The syntax of declaring a function so that it prints its name and arguments:

        [ Whatever * x y;
          ! Whatever function logic ...
        ];

  is now supported for Glulx.

- The statistics produced by the `-s` compiler switch are now correct for Glulx.

## Compiler 6.32

These are the changes delivered in version 6.32 of the Inform compiler.

### Features added

Items of the form [C63NNN] quote the feature’s reference number in the ‘Compiler’ section of the Inform Patch List.

- The Z-machine opcodes for pushing and pulling values from the stack are `@push` and `@pull`, used like this:

        @push x;
        @pull x;

  However for Glulx the opcode syntax is different: instead the `@copy` opcode is used:

        @copy x sp;
        @copy sp x;

  The compiler now supports the `@push` and `@pull` syntax under Glulx as an alias for `@copy`, allowing the same code to be used for both the Z-machine and Glulx. [C63104]

- Custom Glulx opcodes (such as opcodes that post-date the compiler) can now be specified with the custom opcode syntax. The format of this syntax is

        @"FlagsCount:Code"

  `Flags` (which are optional) can include “S” for store, “SS” for two stores, “B” for branch format, or “R” if execution never continues after the opcode. `Count` is the number of arguments (currently limited to 0-9), and `Code` is a decimal integer representing the opcode number.

  For example, `@"S3:123"` is the syntax for a three-argument opcode (load, load, store) whose opcode number in decimal is 123, and `@"2:234"` is the syntax for a two-argument opcode (load, load) whose number is 234. [C63107]

- When compiling to Glulx, the Glulx format version number of the resulting story file is usually determined by which Glulx opcodes are used in the source code. This version number can now be over-ridden by providing a `-v` command line argument after the `-G` switch to select Glulx mode. For example, the arguments `-G -v3.1.0` set the Glulx version number to “3.1.0”. [C63108]

- The Unicode related opcode added to the Glulx 3.0.0 specification, `@streamunichar`, is now supported.

- When compiling to Glulx, characters outside of the ISO 8859-1 range can now be used in strings. The maximum number of such characters allowed is determined by a new memory setting, `$MAX_UNICODE_CHARS`.

- When compiling to Glulx, the syntax

        print (char) value;

  now works for values greater than 255, printing the appropriate Unicode character. (For such values `@streamunichar` is used; for those less than or equal to 255, `@streamchar` is used as before.)

- The memory heap related opcodes added to the Glulx 3.1.0 specification (that is, `@mzero`, `@mcopy`, `@malloc` and `@mfree`) are now supported.

- The acceleration related opcodes added to the Glulx 3.1.1 specification (that is, `@accelfunc` and `@accelparam`) are now supported. There is also a new syntax to get the address of a global variable `var`, with the expression “`#g$var`”: this is provided so that such addresses can be provided to the `@accelparam` opcode.

- The floating point related opcodes added to the Glulx 3.1.2 specification (that is, `@numtof`, `@ftonumz`, `@ftonumn`, `@ceil`, `@floor`, `@fadd`, `@fsub`, `@fmul`, `@fdiv`, `@fmod`, `@sqrt`, `@exp`, `@log`, `@pow`, `@sin`, `@cos`, `@tan`, `@asin`, `@acos`, `@atan`, `@atan2`, `@jfeq`, `@jfne`, `@jflt`, `@jfle`, `@jfgt`, `@jfge`, `@jisnan` and `@jisinf`) are now supported.

- Floating point constants can be used in the Inform source code. Thes constants are expressed in the form “$+1.0e+1”: that is, a dollar sign, followed by a plus or minus sign, followed by a floating point number, and then optionally a positive or negative integer exponent. Inform does not attempt anything other than converting these constants to their 32-bit integer representation: there is no constant folding as there is with integers, so the expression “`$+1.0 + $+1.0`” is not meaningful, and does not produce the floating point value “2.0”.

  As an example of the use of these constants, the following adds together 100 and 123.45:

        @fadd $+100 $+1.2345e+2 result;

  The compiler also defines the constants “`FLOAT_INFINITY`”, “`FLOAT_NINFINITY`” and “`FLOAT_NAN`” for positive infinity, negative infinity and “not a number”, respectively.

- Glulx has a simple memory extension feature, where the game’s header declares the memory space to be larger than the game file. The extra space is filled out with zeroes when the game starts. This is now supported by a new option `$MEMORY_MAP_EXTENSION`. This defaults to 0: if it is redefined to a larger value then the size of the game’s memory space is extended by that amount.

- The number of verbs allowed by the compiler when compiling to Glulx is no longer limited to fewer than 256. As part of producing the game file, the compiler creates a dictionary table that contains verb numbers. However, despite in Glulx there being space for a verb number between 0 and 65535 in this table, only one byte of it (that is, values between 0 and 255) was used. This has been fixed.

  However, this also requires library changes to be useful, as the library makes use of this dictionary table. The library used by Inform 7 has been adjusted to take advantage of this, but the Inform 6 library has not.

- The dictionary of Glulx games can now contain characters outside of ISO 8859-1. There is a new memory setting, `$DICT_CHAR_SIZE`: by default this is 1, but setting it to 4 causes the compiler to create a dictionary containing 32-bit Unicode characters.

  However, this also requires library changes to be useful, as the library makes use of this dictionary table.

### Bugs fixed

Items of the form [C63NNN] quote the bug’s reference number in the ‘Compiler’ section of the Inform Patch List.

- Strict mode is no longer enabled by default when generating V3 and V4 Z-code files, as strict mode makes use of opcodes that are V5+ only. [C63007]

- The base unit of Inform’s internal memory allocation for various structures (for example the buffer used to hold the generated code) is no longer fixed: it is now controlled by a setting `$ALLOC_CHUNK_SIZE`. This allows, for example, the maximum Glulx code size to be greater than 640Kb. [C63102]

- When compiling to Glulx, the stack size of the resulting story file is no longer fixed at 4096: it can be changed by the setting `$MAX_STACK_SIZE`. [C63108]

- The compiler could crash if the size of the grammar table exceeded the size of the Z-machine readable memory: this is now fixed. [C63110]

- Creating a Z-code game file with precisely 64Kb of readable memory produced an invalid file. This is now prevented, so that the largest readable memory size is 64Kb minus 2 bytes. [C63112]

- Previously, under Glulx the `print_to_array()` function could be called with either two arguments, specifying both the array to print to and its length, or just one argument, the later matching what is allowed when compiling to Z-code. This one argument form has now been withdrawn under Glulx as a security hole, and a source to problems with writing beyond the end of the array: now the array length must be specified. (See also Features available only in Glulx.)

- Veneer routines are no longer excluded from Inform’s assembly output (which is accessed with the `-a` command line switch).

- For Linux and other Unix variants the default memory settings have been increased, which should remove the need to change the compiler settings when building large projects on these platforms.

- For Mac OS X, the maximum length of a file path is now 8192 characters, which should prevent any further problems with long paths on this platform.

## Compiler 6.31

These are the changes delivered in version 6.31 of the Inform compiler.

### Bugs fixed

Items of the form [C63NNN] quote the bug’s reference number in the ‘Compiler’ section of the Inform Patch List.

- When individual properties are read (successfully), there is no longer a futile attempt to look up the property index in the common property table. [C63016]

- Complex `if` statements, of the form `if (x == 1 or 3 or 5 ... or 99),` now don’t crash the compiler. [C63013]

- The compiler is better at handling lengthy path names. [C63009]

- Backpatching and other strange errors no longer occur if the code size of a V8 game exceeds 256K. [C63005]

- An Object or Class definition with more than 32 common property values now doesn’t cause an internal compiler error. [C63001]

## Compiler 6.30

These are the changes delivered in version 6.30 of the Inform compiler.

### Features added

- The compiler automatically defines a `WORDSIZE` constant, whose value is 2 when compiling for the Z-machine, and 4 when the target is Glulx. The constant specifies the number of bytes in a VM word, and we recommend that you use it in the small number of circumstances where this value is significant. The compiler also defines a constant `TARGET_GLULX` if you supply the `-G` switch, or `TARGET_ZCODE` otherwise; in both cases the constant value is 0. For more information on the use of these constants, see Support for Glulx.

- The `Switches` directive, which enables certain compiler switches to be set from within the source file rather than on the compiler command line, has been superseded by a more powerful mechanism. The special comment characters “!%”, occurring on the very first line or lines of the source file, enable you to specify Inform Command Language (ICL) commands to control the compilation. For example:

        !% -E1G                                    ! Glulx, 'Microsoft' errors
        !% -~S                                     ! disable Strict mode
        !% +include_path=./test,./,../lib/contrib  ! look in 'test' library
        !% $MAX_STATIC_MEMORY=20000
        Constant STORY "RUINS";
        ...

  ICL is described in §39 of the Inform Designer’s Manual. In brief: each line specifies a single command, starting with “-” to define one or more switches, “+” to define a path variable, or “$” to define a memory setting. Comments are introduced by “$”. The ICL command “`compile`” is not permitted at the head of a source file.

- Two new ICL memory settings are available; both of these could previously be changed only by rebuilding the compiler. `$MAX_SOURCE_FILES` has a default of 256, and `$MAX_INCLUSION_DEPTH` has a default value of 5.

- A new directive, similar to `Array ... string` and `Array ... table`, is provided:

        Array array buffer N;
        Array array buffer expr1 expr2 ... exprN;
        Array array buffer "string";

  This creates a hybrid array of the form used by `string.print_to_array()` and the new library routine `PrintToBuffer()`, in which the first word `array-->0` contains `N` and the following `N` bytes `array->WORDSIZE`, `array->(WORDSIZE+1)` ... `array->(WORDSIZE+N-1)` contain the specified expression values or string characters.

- A new `(A)` print rule — similar to the existing `(The)` — prints an object’s indirect article with its first letter capitalised. The printed article is “A” or “An” by default, or else taken from the object’s article property.

- The minimum size of the Z-code header extension table can be set using the command line switch `-Wn`. For example, `-W6` makes the table at least six words long.

- Source code in character sets other than ISO 8859-1 to 8859-9 is now supported, provided that the character set can be mapped onto one of the ISO 8859 sets.

  A mapping file is used to define how the source code is to be processed. This file consists of a directive indicating the ISO 8859 set to be mapped to, followed by 256 numbers giving the mapping. As an example, under Microsoft Windows, Russian text is encoded with the character set defined as Microsoft code page 1251. The following text defines a mapping to the ISO 8859-5 set:

        ! Windows Cyrillic (code page 1251) to ISO 8859-5
        C5
          0, 63, 63, 63, 63, 63, 63, 63, 63, 32, 10, 63, 10, 10, 63, 63
         63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63
         32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47
         48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63
         64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79
         80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95
         96, 97, 98, 99,100,101,102,103,104,105,106,107,108,109,110,111
        112,113,114,115,116,117,118,119,120,121,122,123,124,125,126, 63
        162,163, 44,243, 34, 46, 63, 63, 63, 63,169, 60,170,172,171,175
        242, 39, 39, 34, 34, 46, 45, 45,152, 84,249, 62,250,252,251,255
         32,174,254,168, 36, 63,124,253,161, 67,164, 60, 63, 45, 82,167
         63, 63,166,246, 63, 63, 63, 46,241,240,244, 62,248,165,245,247
        176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191
        192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207
        208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223
        224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239

  Lines starting with “!” are treated as comments. The next line, beginning with “C”, defines the ISO set to map to in the same way as the `-Cn` command line switch.

  To use the mapping, Inform treats each character in the source file as a number between 0 and 255, and uses that number as an index into the mapping table. For example, suppose that the character read in from a Russian Windows text file is the Cyrillic small letter “ya”.This character is represented in the Russian Windows character set by the number 255. Inform takes the 255th entry in the mapping, which is 239. Therefore the character is regarded as being 239 in ISO 8859-5.

  The name of the mapping file is specified by a new compiler path variable `+charset_map`. If the above mapping is held in a text file `win1251.map`, a Russian game could be compiled with a command line of the form:

        inform +charset_map=win1251.map +language_name=Russian mygame.inf

- The `@check_unicode` and `@print_unicode` opcodes, introduced in the Z-Machine Standards Document version 1.0, can now be called by name rather than by using the clumsier generic syntax `@"EXT:11S"` and `@"EXT:12S"`. For example:

        @print_unicode $0401; ! Cyrillic capital letter IO

- Strict mode (which compiles run-time integrity checks into your game) has been decoupled from Debug mode (which defines debugging verbs like TRACE and SHOWOBJ). This means that it’s no longer necessary to turn off Strict checking (in order to disable the Debug verbs) before releasing a game, though of course you can do so if you wish to save space and increase performance. By default, Strict mode is enabled (turn it off with `-~S`) and Debug mode is disabled (turn it on with `-D`).

- The compiler now issues a warning if you use `array->n` on an array of words, or `array-->n` on an array of bytes. Use the new `Array ... buffer` directive to create a hybrid array which can be accessed without these warnings.

- The compiler also issues a warning if you refer to an unqualified property name within a routine, for example by typing `(number==0)` when you intended `(self.number==0)`.

- Another new warning appears if you include something other than a dictionary word in an object’s `name` property. This is most commonly triggered if you try to add a single-letter word by typing `name 'g' 'string'` when you intended `name 'g//' 'string'`.

### Bugs fixed

Items of the form [C62NNN] quote the bug’s reference number in the ‘Compiler’ section of the Inform Patch List.

- A problem with multiple assignment involving pointer arithmetic in Strict mode giving the wrong answer has been fixed. [C62127]

- After using `Extend only` to separate off an element of an existing Verb definition, new synonyms for the separated verb now work correctly; previously they were applied to the residue of the original definition. [C62126]

- Strict mode now tests for the use of `@put_prop` or `@get_prop` opcodes when a common property is longer than two bytes — the Z-Machine Standards Document says that this is illegal, and that the result is unspecified. The error message is of the form “[** Programming error: obj (object number N) has a property prop, but it is longer than 2 bytes so you cannot use "." to read **]”. This means that you have used the `obj.prop` construct in the situation where `prop` is a common property containing two or more values; typically `prop` is being explicitly used as an array, or it’s an additive property and both `obj` and its parent class have defined values for it. The problem does not occur if `prop` is an individual property. [C62125]

- Handling of European quotes is (finally) correct: the “«” symbol is produced by any of `@<<`, `@@163` and `@{00AB}`, while any of `@>>`, `@@162` and `@{00BB}` produce the matching “»”. Note, however, that this problem originated in an error in the previous version of the Z-Machine Standards Document, and therefore older interpreters written to that specification, or more recent ones adjusted to work with the incorrect fix introduced at Inform 6.12, may still not give the correct results. [C62124]

- The “no such constant” compilation error message now quotes the number of the appropriate source line. [C62123]

- The `metaclass()` and `ZRoutine()` routines no longer report large unsigned values — above the game’s Static memory area — as of type String. More usefully, the constant `NULL` (-1) is not reported as a String. [C62122]

- Complex expressions combining a routine call and the `ofclass` and `or` operators no longer generate incorrect code. [C62121]

- Negative constants in assembly operations — for example, `@set_colour 4 (-1);` — no longer cause the compiler to report an unexpected expression. [C62119]

- Various problems with handling ISO 8859 characters in the range 128-255, and also in the use of @@ escape sequences, have been resolved. [C62117, C62115, C6211, C62003]

- An `Abbreviate` directive containing a substring of “<unknown attribute>” may crash the compiler; hopefully, no more. [C62116]

- The 320Kb size limit placed by Inform on v6 and v7 games has been raised to 512Kb. [C62114]

- Following a `Zcharacter` directive replacing the entire alphabet table, dictionary entries are no longer corrupted. [C62113]

- The compiler now generates conditional branches spanning up to 63 bytes, lifting the previous unnecessary limit of a 31-byte span and leading to slightly shorter code. [C62112]

- Putting an object in itself doesn’t now loop indefinitely. [C62110]

- Various problems with the `@store`, `@inc_chk`, `@dec_chk`, `@not` and `@je` opcodes have been resolved. [C62109, C62108, C62105]

- Problems with nested conditional compilation directives `#Ifndef...#Ifnot...#Endif` have been resolved. [C62107]

- A long dictionary word — such as `'elephants//p'` — now correctly sets the plural bit. [C62103]

- Problems with constant folding — that is, having the expression evaluated at compile-time — partly addressed in the previous bi-platform compiler, have been fixed. [C62102]

- When compiling for Glulx, the compiler uses the `@callf`, `@callfi`, `@callfii` or `@callfiii` opcodes where applicable for generated calls instead of always pushing arguments onto the stack and using `@call`.

- The presence of a `Switches G;` directive no longer causes the compiler to crash.

- An unexpected limit of 1024 labels per routine in the Z-machine assembly language generated by the compiler has been raised to 32768. The most likely way to encounter this limit is by creating a `switch` statement with an extremely large number of cases.

- A problem with the `read` statement generating the wrong opcode in a version 4 game has been corrected.

- A dynamic class declaration such as `Class Pebble(NUM_PEBBLES) ... ;` no longer creates a mysteriously large number of instances if `NUM_PEBBLES` isn’t defined.

## Library 6/11

At the same time as the Inform 6.30 release, a new version of the Inform library was made. These are the changes delivered in version 6/11 of the Inform library.

### Features added

- The library automatically defines four constants: `LIBRARY_PARSER` at the end of Parser.h, `LIBRARY_VERBLIB` at the end of VerbLib.h, `LIBRARY_GRAMMAR` at the end of Grammar.h, and `LIBRARY_ENGLISH` at the end of English.h. Contributed library extensions can use these constants to check that they have been Included in the correct location. A fifth constant `LIBRARY_VERSION`, currently defined as the number 611, can be checked by extensions which require this particular version of the library.

- The word “wall” has been removed from the `CompassDirection` objects defined in English.h, whose names are now simply “north”, “south”, etc.

- The verbs LOOK [TO THE] NORTH, LOOK DOWN, LOOK OUT[SIDE] etc — but not LOOK IN[SIDE], which is already available — have been added. By default, the response is of the form “You see nothing unexpected ...”, but you can change this for individual directions in individual rooms by providing a compass_look property:

        Room   study "Your study"
          with description "There is a doorway to the east of this austere room.",
               compass_look [ obj;
                   if (obj == e_obj) "You see a doorway.";
                   if (obj == n_obj or s_obj or w_obj) "You see the wall.";
               ],
               e_to hallway;

  This enhancement uses the mechanism described in this topic in the Inform 6 FAQ (except that the `compass_look` property was previously named `compasslook`), and means that you no longer need to make the library changes described there.

- The verbs `ASK npc TO command` and `TELL npc TO command` — both synomymous with `npc,command` — are provided. The new grammar is:

        Verb 'ask'
            ...
            * creature 'to' topic -> AskTo
            ...

  in which the `creature` token matches the `npc` and the `topic` token represents the `command`. `AskTo` isn’t an action in the usual sense: it’s trapped by the parser and converted to the original `npc,command` format. The `npc` can intercept the `command` by providing an `orders` property in the usual way — see §18 of the Inform Designer’s Manual.

  This enhancement means that you may no longer require Irene Callaci’s `AskTellOrder.h` library extension.

- The verbs RECORDING [ON|OFF] and REPLAY are now always available, irrespective of the DEBUG state. This may cause compilation errors if you have already defined these verbs yourself.

- The verbs PRY, PRISE, PRIZE and LEVER have been added. This may cause compilation errors if you have already defined these verbs yourself.

- The parser treats input lines beginning with “*” as a comment, without attempting any further parsing. The character used to introduce comments can be changed by defining `COMMENT_CHARACTER` before you `Include Parser`. For example:

        Constant COMMENT_CHARACTER '!';

  Since comments are used primarily when capturing a transcript — either of a complete game (SCRIPT ON) or of input commands only (RECORDING ON) — the parser responds “[Comment recorded]” or “[Comment NOT recorded]” as appropriate.

- The `selfobj` object now includes an empty `add_to_scope` property, which you can over-ride with your own routine, typically to equip the player with body parts. For a single object:

        selfobj.add_to_scope = nose;

  or for multiple objects:

        [ IncludeBodyParts; PlaceInScope(nose); PlaceInScope(hands); ];
        selfobj.add_to_scope = IncludeBodyParts;

- The task-based scoring system (§22 of the Inform Designer’s Manual) uses a byte array, which precludes the awarding of large or negative scores. To get round this, you can `Replace` the `TaskScore()` library routine as follows, and then define `task_scores` as a word array:

        Replace TaskScore;
        Array task_scores --> 100 200 300 400 (-50) 600;
        [ TaskScore i; return task_scores-->i; ];

- The scoring system is completely disabled if you define a constant `NO_SCORE` near the start of your game.

        Constant NO_SCORE;

- A new `before_implicit` property is available; at the moment this is used only by the parser, when it is about to perform an implicit TAKE (for example, EAT APPLE when you’re not holding the apple). You can give this property to an object if you wish to control the parser’s behaviour. The property’s value should be a constant or a routine which returns: 0 to report “(first taking the...)” and then attempt to do so (this is what currently happens); 1 to attempt the TAKE without first issuing the message, 2 to proceed with the requested action without attempting the TAKE, or 3 to object that “You aren’t holding that!”. The object can test `action_to_be` to determine which action has triggered the TAKE:

        before_implicit [;
          Take: if (action_to_be == ##Eat) return 2;
        ],

- A new system variable `sys_statusline_flag` is set to 1 initially if you have used the `statusline time;` directive in your program to show a clock, and to 0 otherwise. It can be changed by the program.

- An object’s `invent` property — if it has one — is now invoked both when displaying the player’s inventory and when including the object in a room description. `invent` is invoked in the usual way (with `inventory_stage` first set to 1, and then set to 2) both when mentioning the object in a room description, and when listing it in the player’s inventory. By default you’ll get the same output each time. If you need to distinguish between the two occasions, you can test `(c_style&PARTINV_BIT)` — true during a room description — or `(c_style&FULLINV_BIT)` — true during an inventory. Here’s an example:

        Object  -> "sack"
          with  name 'sack',
                invent [;
                    ! When listing objects in the player's inventory
                    if (c_style&FULLINV_BIT) rfalse;

                    ! When listing objects at the end of a room description
                    if (inventory_stage == 1) switch (children(self)) {
                        0: print "an empty sack";
                        1: print "a sack containing ", (a) child(self);
                        default: print "an assortment of objects in a sack";
                        }
                    rtrue;
                    ],
          has   container open;

  This enhancement uses the mechanism described in this topic in the Inform 6 FAQ and means that you no longer need to `Include WriteList`.

- The `turns` counter is now initialised to 0, not 1. You can change this if you define a constant `START_MOVE` near the start of your game.

        Constant START_MOVE 1;

- A new `LibraryExtensions` object is defined, whose function is to act as a parent to initialisation objects created by library extensions. These objects may provide `ext_initialise` and/or `ext_messages` property routines, whose role is to help integrate the extension into a game. This is best explained by example.

  Consider the `SmartCantGo.h` extension, which replaces “You can’t go that way” messages by the more informative “You can go only north, south and east”, and can be integrated into a game by adding a `ChangeDefault(cant_go, SmartCantGo)` statement to your `Initialise()` routine. Instead of requiring the author to make this addition, the extension could now cause it to happen automatically by defining an initialisation object as a child of `LibraryExtensions`, like this:

        Object  "(SmartCantGo)" LibraryExtensions
          with  ext_initialise [; ChangeDefault(cant_go, SmartCantGo); ];

  Just before calling the game’s `Initialise()` routine, the library loops through the children — if any — of `LibraryExtensions`, and executes those `ext_initialise` properties that it finds there. The property routines can perform any appropriate setup processing that would otherwise have to be inserted into the `Initialise()` routine itself; for example, starting a daemon running.

  A similar process takes place when displaying library messages. The library first checks whether the author has provided a `LibraryMessages` object to intercept the message which it is about to display. If not, it now loops through the children of `LibraryExtensions`, and executes `ext_messages` properties that it finds there. If none of those routines returns true to signal that the message has been dealt with, the standard library text is then printed in the usual way. For example, here’s how an extension might automatically intercept Inventory messages (unless the game has already handled them via `LibraryMessages`):

        Object  "(someInventoryExtension)" LibraryExtensions
          with  ext_messages [;
                    Inv: switch(lm_n) {
                      1: "You are empty-handed.";
                      2: "Your possessions include";
                    }
                ];

  Note that this is an experimental feature, and may be modified or extended in the light of experience.

### Library routines

Several new library routines are provided to harmonise commonly-encountered differences between the Z-machine and Glulx VMs (see also Library routines available only in Glulx).

`KeyCharPrimitive()`

> waits for a single key, and returns the character from 1-255 (or, for Glulx, one of the Glk special key codes.). For Glulx only, an extended form is available — see Library routines available only in Glulx.

`KeyDelay(time)`

> waits `time` tenths of a second for a single key. If no key is pressed within that period it returns zero; otherwise it returns the character from 1-255.

`ClearScreen()
ClearScreen(selector)`

> `ClearScreen()` clears both the status line and the main window. The cursor moves to the top of the screen. The routine should be followed by a call to `MoveCursor()` or `MainWindow()`. Alternatively, using `ClearScreen(selector)`: if `selector` is 0, both are cleared; if `selector` is 1 only the status line is cleared; if `selector` is 2 only the main window is cleared.

`MoveCursor()
MoveCursor(line, column)`

> `MoveCursor()` selects the status line for output. `MoveCursor(line, column)` selects the status line for output and moves the cursor to the given `line` and `column` within the status area, where line 1 is the top line and column 1 is the far left. (This is necessary because the Glk convention is to number both lines and columns from 0 rather than 1.)

`MainWindow()`

> selects the main (buffered) text window for output.

`StatusLineHeight(lines)`

> sets the height of the status line in lines. The standard `DrawStatusLine()` calls this every turn, which isn’t a bad thing, since `StatusLineHeight()` is smart. If you replace `DrawStatusLine()`, maintain this convention. (The library menu routines fiddle with the status line, and it’s up to `DrawStatusLine()` to reset it after the menus are over.)

> A new library variable `gg_statuswin_cursize` holds the current setting (in both VMs).

`ScreenWidth()`

> returns the number of characters that can be printed in a monospaced font between the left and right borders of the currently selected window. For Glulx only, the extended form `ScreenWidth(win)` works on a specified window id; note that the results are unreliable if the normal style for that window uses a proportional font.

`ScreenHeight()`

> returns the height in lines of the main window.

`SetColour(fg, bg)
SetColour(fg, bg, selector)`

> `SetColour(fg, bg)` sets the current foreground and background text colours, using the same codes as the `@set_colour` opcode in the Z-machine (1=default, 2=black, 3=red, 4=green etc.). Using `SetColour(fg, bg, selector)`, colours can be set separately in each window: if `selector` is 0, both are set (the top window will have inverted colours for the Z-machine); if `selector` is 1 only the status line is affected; if `selector` is 2 only the main window is affected.

> All colour functions are effective only if the library variable `clr_on` is set to non-zero.

> The advantage over `@set_colour` is that when the player restores a saved game or types UNDO, the colours will be correct for that state of the game.

> For Glulx, the routine produces an appropriate effect if style hints are enabled by the interpreter; it also clears the screen. For the Z-machine, a separate call to `ClearScreen()` is required.

> These associated constants are now provided for use with `SetColour()`; the final three are useful also with `ClearScreen()`:

>       Constant CLR_DEFAULT 1;
>       Constant CLR_BLACK 2;
>       Constant CLR_RED 3;
>       Constant CLR_GREEN 4;
>       Constant CLR_YELLOW 5;
>       Constant CLR_BLUE 6;
>       Constant CLR_MAGENTA 7;
>       Constant CLR_CYAN 8;
>       Constant CLR_WHITE 9;
>       Constant CLR_PURPLE 7;
>       Constant CLR_AZURE 8;
>       Constant WIN_ALL 0;
>       Constant WIN_STATUS 1;
>       Constant WIN_MAIN 2;

`DecimalNumber(num)`

> prints `num` as a decimal number (it is in fact identical to `print num;`). It may be useful in conjunction with...

`PrintToBuffer(array, arraylen, string)
PrintToBuffer(array, arraylen, obj)
PrintToBuffer(array, arraylen, obj, prop)
PrintToBuffer(array, arraylen, routine, arg1, arg2)`

> prints its arguments — a string, an object’s name, the value of an object’s property, or a routine with up to two arguments — to the buffer `array`. The number of characters written to the buffer is a word at `array-->0` (and is the value returned by the routine); the actual characters start at `array->WORDSIZE`. The maximum number of characters is specified in `arraylen`; for the Z-machine, an overrun caused by printing more than this value will produce an error message that you have corrupted the contents of memory beyond the array (for Glulx, the output is automatically truncated at the specified `arraylen`).

> For Glulx, see also `PrintAnyToArray()` in Library routines available only in Glulx, which has slightly extended capabilities, and which returns the number of characters written rather than writing them at `array-->0`.

`Length(string)
Length(obj, prop)`

> returns the number of characters in the string. Note that this prints to one of the parser arrays, and therefore it is your responsibility to ensure that the length cannot be greater that 160 characters.

`UpperCase(char)
LowerCase(char)`

> return `char` in upper or lower case (if it was alphabetic), or unchanged (otherwise). Changes affecting A-Z and a-z are always reliable; changes to accented characters will not work if you have supplied a compiler switch `-C2` through `-C9`, or used a `Zcharacter` directive to adjust the standard ZSCII character set.

`PrintCapitalised(obj, prop, flag, nocaps)`

> is based upon `PrintOrRun(obj, prop, flag)`. `PrintOrRun()` tests `obj.prop`, and either runs it (if a Routine), or prints it (if a String). In the latter case, a newline is then output unless `flag` is `true`. `PrintCapitalised()` does all that; the difference is that the first letter of any output is in upper case unless `nocaps` is `true`.

`Cap(string, nocaps)`

> prints the `string` with the first letter in upper case, unless `nocaps` is true. Can also be used as a print rule:

>       print ..., (Cap) myString, ...;

`Centre(string)
Centre(obj, prop)`

> prints a single-line `string` approximately centrally between the left and right borders of the screen by preceding it with an appropriate number of spaces. The routine works only for monospaced fonts (that is, after `font off;`), and is only likely to work well in the main Glulx window if the normal style for TextBuffer uses a non-proportional font. It is however useful for centring information in the status line. Can also be used as a print rule:

>       print ..., (Centre) myString, ...;

`PrintOrRunVal(value, flag)`

> if `value` refers to to an object, prints that object’s name; if `value` refers to a routine, runs that routine; if `value` refers to a string, prints that string (with a terminating newline unless `flag` is true).

### Bugs fixed

Items of the form [L610NN] quote the bug’s reference number in the ‘Library’ section of the Inform Patch List.

- A command like EMPTY ME no longer replies “yourself can't contain things”. [L61036]

- The commands TAKE ALL FROM X and REMOVE ALL FROM X, where X is a closed or empty container, now produce sensible messages rather than “You can’t see any such thing” and “You can’t use multiple objects with that verb” respectively. [L61035]

- A problem with the misbehaviour of `name` properties on rooms, in conjunction with THE, has been corrected. [L61034]

- The command PUT X INTO X now correctly produces “You can’t put something inside itself”, rather than “You can’t see any such thing”. [L61033]

- Run-time errors resulting from `IndirectlyContains()` attempting to find the parent of a Class which supports dynamic creation of objects have been resolved. [L61032]

- Code in `Parser__parse()` which deals with looking ahead to the indirect object in cases like PUT ALL INTO BAG (a MULTIEXCEPT token) and TAKE ALL FROM BAG (a MULTIINSIDE token) now correctly sets the `advance_warning` global (to BAG). [L61031, L61023]

- The Inform Designer’s Manual (p. 98) states that SHOWOBJ should accept an object number; now it does. [L61030]

- The `YesOrNo()` routine now re-prompts correctly after garbage input. [L61029]

- The parse buffer is no longer declared and initialised incorrectly (albeit harmlessly). [L61028, L60708]

- The Inform Designer’s Manual (p. 93) defines the calling order of routines and properties for the ‘Before’ stage as follows:

  1. `GamePreRoutine()`
  2. `orders` of the player
  3. `react_before` of every object in scope
  4. `before` of the current room
  5. `before` of the first noun, if specified

  In the library, however, steps 3 and 4 are executed in reverse order. They are now as documented. [L61027]

- A `found_in` floating object which the player is able to take (probably due to a coding error) is no longer silently dropped when the player returns to one of the listed rooms. [L61026]

- A small problem with inherited `describe` properties has been corrected. [L61025]

- Standard screen-handling is now implemented in v6 games. [L61022]

- The handling of “You can’t go that way” messages is made consistent. Also, the statement `ChangeDefault(cant_go,myRoutine);` now works. [L61020]

- Attempting to place an object in/on an object where it is already now results in “It’s already there”, rather than “You need to be holding it before you can put it into something else”. [L61019]

- A problem with misleading inventory listing has been clarified. [L61018]

- The command LEAVE X now correctly produces “But you aren’t in/on the X”, if appropriate. [L61017]

- The response to READ was inappropriate when an object is misspelled or out of scope. [L61016]

- A small bug in the choice of library messages for PUSH and TURN, which wasn’t noticeable unless you overrode the messages to be different from PULL, has been corrected. [L61015]

- If you are in a dark room, you cannot examine what you are holding. Yet if you open a container you brought in from a lit room, the standard message “You open the box, revealing a...” was not being suppressed. [L61014]

- The `ScoreMatchL()` routine in Parserm.h incorrectly decided which objects meet descriptors. As a result, some objects that didn’t meet descriptors were not properly removed from the match list when the library is deciding which objects best match a player’s input. [L61013]

- The Infix problem parsing commands containing commas and periods has been fixed. [L61010]

- A problem when describing what’s visible after opening a container has been corrected. [L61009]

- An inappropriate message after GO NORTH CIRCULAR has been corrected. [L61008]

- Modified foreground and background colours are now correct after RESTORE and UNDO. [L61007]

- The `grammar` property now works with a large game whose dictionary lies above $8000. [L61006]

- A buffer conflict with disambiguation and UNDO has been resolved. [L61004]

- If a player is inside a closed, non-transparent container, the library prints an extra blank line between the header “The container” and the first `inside_description` line it prints. No more. [L61002]

- The list writing routines do not handle plural containers correctly. If you have two empty boxes, it might list “two boxes (which is closed)”. Not only should it say “are closed”, but it will lump empty containers together even if some are open and others aren’t. Now resolved. [L61001]

- A conflict between `DrawStatusLine()` and `DisplayStatus()` on how to determine whether to display turns or time is settled in favour of checking a header flag. [L60709]

## Support for Glulx

One of the limitations of the Z-machine is the size of the largest game that it supports: 256Kb if you compile a version 5 game, or 512Kb if you compile for version 8. If you find yourself up against this limit and you’ve tried all the standard tricks to save a few bytes here and there, then it’s time to switch to Glulx. That’s easy to do: you just supply the `-G` compiler switch, the compiler generates Glulx code, and any Glulx interpreter will be able to run it.

Actually, it isn’t always quite that simple...

### Knowing which is which

As mentioned earlier, the compiler automatically defines a couple of useful constants. If you’re compiling for the Z-machine then `TARGET_ZCODE` is defined; if you’re compiling for Glulx then you’re given `TARGET_GLULX` instead. You can use these with the `Ifdef` directive, like this:

      #Ifdef TARGET_ZCODE;
      ! Z-machine code here
      #Endif;
      #Ifdef TARGET_GLULX;
      ! Equivalent Glulx code here
      #Endif;

or more commonly like this:

      #Ifdef TARGET_ZCODE;
      ! Z-machine code here
      #Ifnot;
      ! Equivalent Glulx code here
      #Endif;

You’ll find a lot of this if you look in the library files, but it’s less frequently needed in a source file.

### Glulx differences

The two VMs are not identical, and you need to be aware of their differences.

#### Word size

The most basic difference between Glulx and the Z-machine is that words are four bytes long instead of two. All Glulx variables are 32-bit values, the stack contains 32-bit values, property entries are 32-bit values, and so on.

In most Inform programming, you don’t need to worry about this change at all. For example, if you have an array

      Array mylist --> 10;

...then Z-code Inform allocates ten words — that is, twenty bytes — and you can access these values as `mylist-->0` through `mylist-->9`. If you compile the same code under Glulx Inform, the compiler again allocates ten words — now forty bytes — and you can still access them as `mylist-->0` through `mylist-->9`. Everything works the same, except that the array can contain values greater than the Z-machine’s limit of 65535.

`Table` arrays also refer to two- or four-byte word values, and the first word is the length of the array. `String` and `->` arrays, and the `->` notation, still refer to single bytes. You should not have to modify your code here, either.

There are two important cases where you will have to modify your code. First is the `.#` operator. The expression `obj.#prop` returns the length of the property in bytes. Since properties almost always contain words rather than bytes, it is very common to have Z-machine code like:

      len = (obj.#prop) / 2;
      for (i=0 : i<len : i++)
          print (string) (obj.&prop)-->i;

In Glulx Inform programs, it is necessary to divide by 4 instead of by 2, so you should replace the above code with:

      len = (obj.#prop) / WORDSIZE;
      for (i=0 : i<len : i++)
       print (string) (obj.&prop)-->i;

This will compile and run correctly in both VMs.

The other circumstance where your code may need modifying in this manner is when using the ‘print to array’ feature. Code like this:

      Array mybuf buffer 100; ! must be big enough for largest string you'll print
      mystr = "hello";
      mystr.print_to_array(mybuf);

results in the first word of `mybuf` containing 5 (the number of characters in `mystr`), and the following five bytes containing ‘h’, ‘e’, ‘l’, ‘l’ and ‘o’. In the Z-machine, you could then output the characters from the array with either of these code fragments:

      len = 2 + mybuf-->0
      for (i=2 : i<len : i++)
       print (char) mybuf->i;

      len = mybuf-->0
      for (i=0 : i<len : i++)
       print (char) mybuf->(i+2);

Again, you can make the code safe for both VMs if you change “`2`” to “`WORDSIZE`”:

      len = WORDSIZE + mybuf-->0
      for (i=WORDSIZE : i<len : i++)
       print (char) mybuf->i;

      len = mybuf-->0
      for (i=0 : i<len : i++)
       print (char) mybuf->(i+WORDSIZE);

See also Features available only in Glulx for details of `print_to_array` under Glulx.

#### Directives

Glulx handles the majority of Inform directives, with two exceptions:

- The `Zcharacter` directive causes a compilation error, since Glulx does not use the ZSCII character set. Your best approach is to bypass the directive when compiling for Glulx:

        #Ifdef TARGET_ZCODE;
        Zcharacter ... ;
        #Endif;

- The (obsolete) `Lowstring` directive causes a run-time error when used like this:

        Lowstring mystr "hello";

        string 0 mystr;
        print "@00 and goodbye.";

  This simpler form, avoiding the use of `Lowstring`, works successfully:

        string 0 "hello";
        print "@00 and goodbye.";

  See also Features available only in Glulx for additional printing variable support.

#### Statements

Glulx handles the majority of Inform statements, with a few exceptions. If you try to use any of these statements in Glulx, you will cause a compilation error:

- `save, restore`: These are more complicated procedures in Glulx than in Z-code, and cannot be implemented without involving library variables and routines. If you want to do this sort of thing, modify or copy the library `SaveSub()` and `RestoreSub()` routines.

- `read`: Similarly, reading a line of text in Glulx involves the library; the compiler cannot generate stand-alone code to do it. See instead the library `KeyboardPrimitive()` routine.

- `@opcode`: The Z-machine assembly language is completely different from that of Glulx. If you have used any assembly instructions, you will need to conceal them when compiling for Glulx, as described in Knowing which is which. See also Features available only in Glulx for details of the `glk()` function call.

Glulx now supports the Inform `style` statement, mapping the Z-machine forms onto Glk styles:

> Inform statement | Equivalent Glk style
> `style roman;` | `style_Normal`
> `style reverse;` | `style_Alert`
> `style bold;` | `style_Subheader`
> `style underline;` | `style_Emphasized`
> `style fixed;` | `style_Preformatted`

However, it is important to remember that, with Glulx, the appearance of a game is under the player’s control — Glulx interpreters enable the font parameters associated with each style to be specified at run-time. Therefore, you should use styles with caution, and if necessary alert the player to the settings which your game expects.

#### Character handling

Unlike the Z-machine, which internally uses the ZSCII character set (see the Inform Designer’s Manual Table 2 on p. 519), Glulx uses strings consisting of either 8-bit characters in the ISO 8859-1 (Latin-1) encoding (which is the same as ZSCII for character values 0-127, but different for character values 128-255), or 32-bit Unicode characters. In general you don't need to worry about which string representation is used: the compiler will figure it out for you. The impact is as follows:

- `@escape_sequence`: Escape sequences such as `@:a` and `@LL` (for “ä” and “£” respectively) are accepted identically by both VMs.

- `@@decnum`: The number is the character’s internal decimal value, so `@@65` is “A” in both VMs, but `@@165` is “ï” in the Z-machine and “¥” in Glulx.

- `@{hexnum}`: The number is the character’s Unicode value, so `@{41}` is “A” and `@{EF}` is “ï” in both VMs. However, `@{A5}` is “¥” in Glulx, but causes a Z-machine compilation error because “¥” isn’t a ZSCII character.

- `-Cn`: The compiler switches `-C1` through `-C9` specify that the source file uses the character set defined by ISO 8859-1 through 8859-9 respectively. In the Z-machine, the switch also initialises the higher ZSCII character set to appropriate values; this later feature is irrelevant when compiling for Glulx.

- Dictionaries in Glulx Inform 6 games have to consist of only ISO 8859-1 characters at present. This is being worked on, and the necessary compiler changes have been made, but further library work is still needed.

#### Compiler switches

We’ve already mentioned the `-G` command line switch, which causes the compiler to output code for Glulx rather than for the Z-machine. There are a few other changes in this area (see the Inform Designer’s Manual Table 3 on p. 521).

> Switch | To | Meaning
> `-k` | off/on | incompatible with `-G` (output debugging information)
> `-v*` | 3 to 8 | incompatible with `-G` (set Z-machine Version)
> `-G` | off/on | compile for Glulx VM
> `-H` | off/on | use Huffman compression on Glulx strings (on by default)
> `-X` | off/on | incompatible with `-G` (include Infix debugger)

### Glulx additions

Glulx offers some additional capabilities above those of the Z-machine:

#### Features available only in Glulx

- For Glulx, `print_to_array` function requires two arguments, the first being the array to print to, and the second the length of that array:

        len = mystr.print_to_array(mybuf, 80);

  This example writes no more than 76 characters into the array. If `mybuf` is an 80-byte array, you can be sure it will not be overrun. (Do not try this with the second argument less than 4.)

  The value written into `mybuf-->0`, and the value returned, are not limited to the number of characters written; they represent the number of characters in the complete string. This means that:

        len = mystr.print_to_array(mybuf, 4);

  is an ugly but perfectly legal way to find the length of a string. (And in this case, `mybuf` need only be four bytes long.)

- Z-code Inform supports 32 printing variables, `@00` to `@31`, which you can include in strings and then set with the statement:

        string num "value";

  In Glulx, this limit is raised to 64. Furthermore, in Glulx you can set these variables to a stand-alone routine as well as a string:

        [ routine; print "value"; ];

        string num routine;

  In this case, the routine is called with no arguments and the result discarded; you should print your desired output inside the routine.

  In Glulx, unlike Z-code, a printing variable string can itself contain `@..` codes, allowing recursion. You can nest this as deeply as you want. However, it is obviously a bad idea to cause an infinite recursion. For example, this will certainly crash the interpreter:

        string 3 "This is a @03!";
        print "What is @03?";

- Many of the things that used to be Z-code assembly are now handled by Glk function calls. Making a Glk function call from Inform is slightly awkward, but not difficult.

  All of Glk is handled by the built-in Inform function `glk()`, which takes one or more arguments. The first argument is an integer; this tells which Glk call in being invoked. The remaining arguments are just the arguments to the Glk call, in order.

  Say, for example, that you want to set the text style to “preformatted”. The Inform code to accomplish this is:

        glk($0086, 2);

  The hex value $0086 means `glk_set_style`; the value “2” means `Preformatted`.

  The table of Glk calls, and the integers that refer to them, is given in Section 12.1.6 of the Glk specification (remember that the values given there are hexadecimal).

  Since calls based on numeric codes are not very easy to read, we recommend that you download John Cater’s `infglk.h` library header, which defines wrapper functions and constants. For example, you could achieve the same effect with this call:

        glk_set_style(style_Preformatted);

  When you read the Glk specification, bear in mind that the `NULL` value it talks about is the C language `NULL` (0), not the Inform Library `NULL` (-1). `infglk.h` defines a constant `GLK_NULL` (equal to 0) which you can use where appropriate.

- By default, arguments to routines work the same in Glulx as they do in Z-code. When you call a routine, the arguments that you pass are written into the routine’s local variables, in order. If you pass too many arguments, the extras are discarded; too few, and the unused local variables are filled with zeroes.

  However, the Glulx VM supports a second style of routine. You can define a routine of this type by naming the first argument `_vararg_count`. For example:

        [ StackFunc _vararg_count ix pos len;
            !   Glulx code here
        ];

  If you do this, the routine arguments are not written into the local variables. Instead, they are pushed onto the stack, and you must use Glulx assembly to pull them off. All the local variables are initialized to zero, except for `_vararg_count`, which (as you might expect) contains the number of arguments that were passed in.

  Note that `_vararg_count` is a normal local variable, aside from its useful initial value. You can assign to it, increment or decrement it, use it in expressions, and so on.

  Stack-argument routines are most useful if you want a routine with variable arguments, or if you want to write a wrapper that passes its arguments on to another routine.

#### Library routines available only in Glulx

`KeyCharPrimitive(win, nostat);`

> If `win` is nonzero, the character input request goes to that Glk window (instead of `gg_mainwin`, the default.) If `nostat` is nonzero, any window rearrangement event is returned immediately as value 80000000 (instead of the default behavior, which is to call `DrawStatusLine()` and keep waiting.)

`PrintAnything(thingie, ...);`

> In the Z-machine, strings and routines are “packed” addresses, dictionary words are normal addresses, and game objects are represented as sequential numbers from 1 to `#top_object`. These ranges overlap; a string, a dictionary word, and an object could conceivably all be represented by the same numeric value.

> In Glulx, all those things are represented by normal addresses, so different items will always have different values. Furthermore, the first byte found at the address is an identifier value, which specifies what kind of item the address contains.

> `PrintAnything()` prints any thingie — string, routine (with optional arguments), object, object property (with optional arguments), or dictionary word — known to the library.

> > Calling | Is equivalent to
> > `PrintAnything()` | (nothing printed)
> > `PrintAnything(0)` | (nothing printed)
> > `PrintAnything(string)` | `print (string) "string";`
> > `PrintAnything(dictionaryword)` | `print (address) 'dictionaryword';`
> > `PrintAnything(obj)` | `print (name) obj;`
> > `PrintAnything(obj, prop)` | `obj.prop();`
> > `PrintAnything(obj, prop, args...)` | `obj.prop(args...);`
> > `PrintAnything(routine)` | `routine();`
> > `PrintAnything(routine, args...)` | `routine(args...);`

> Extra arguments after a `string` or dictionary `word` are safely ignored. The (first) argument you pass in is always interpreted as a thingie reference, not as an integer. This is why none of the forms shown above print out an integer. However, you can get the same effect by calling

>       PrintAnything(DecimalNumber, num);

> ...which is where the `DecimalNumber()` routine comes in handy. You can also, of course, use other library routines, and do tricks like

>       PrintAnything(EnglishNumber, num);
>       PrintAnything(DefArt, obj);

> None of this may seem very useful; after all, there are already ways to print all those things. But `PrintAnything()` is vital in implementing the following routine:

`PrintAnyToArray(array, arraylen, thingie, ...);`

> This works the same way, except that instead of printing to the screen, the output is diverted to the given array.

> The first two arguments must be the array address and its maximum length. Up to that many characters will be written into the array; any extras will be silently discarded. This means that you do not have to worry about array overruns.

> The `PrintAnyToArray()` routine returns the number of characters generated. (This may be greater than the length of the array. It represents the entire text that was output, not the limited number written into the array.)

> It is safe to nest `PrintAnyToArray()` calls. That is, you can call `PrintAnyToArray(routine)`, where `routine()` itself calls `PrintAnyToArray()`. (However, if they try to write to the same array, chaos will ensue.)

> It is legal for `arraylen` to be zero (in which case `array` is ignored, and may be zero as well.) This discards all of the output, and simply returns the number of characters generated. You can use this to find the length of anything — even a function call.

#### Entry points available only in Glulx

An entry point is a routine which you can provide in your code, or leave out; the library will call it if it’s present, ignore it if not — see §21 of the Inform Designer’s Manual.

The library has some entry points which aid in writing more complicated interfaces — games with sound, graphics, extra windows, and other fancy Glk tricks. If you’re just writing a standard Infocom-style game, you can ignore this section.

`HandleGlkEvent(ev, context, abortres)`

> This entry point is called every time a Glk event occurs. The event could indicate nearly anything: a line of input from the player, a window resize or redraw event, a clock tick, a mouse click, or so on.

> The library handles all the events necessary for a normal Infocom-style game. You need to supply a `HandleGlkEvent()` routine only if you want to add extra functionality. The `ev` argument is a four-word array which describes the event. `ev-->0` is the type of the event; `ev-->1` is the window involved (if relevant); and `ev-->2` and `ev-->3` are extra information. The `context` argument is 0 if the event occurred during line input (normal commands, `YesOrNo()`, or some other use of the `KeyboardPrimitive()` library routine); 1 indicates that the event occurred during character input (any use of the `KeyCharPrimitive()` library routine). The `abortres` argument is used only if you want to cancel player input and force a particular result; see below.

> If you return 2 from `HandleGlkEvent()`, player input will immediately be aborted. Some additional code is also required:

> - If this was character input `(context==1)`, you must call the Glk `cancel_char_event` function, and then set `abortres-->0` to the character you want returned. Then return 2; `KeyCharPrimitive()` will end and return the character, as if the player had hit it.

> - If this was line input `(context==0)`, you must call the Glk `cancel_line_event function`. (You can pass an array argument to see what the player had typed so far.) Then, fill in the length of the input to be returned in `abortres-->0`. If this is nonzero, write the input characters sequentially into the array starting at `abortres-->WORDSIZE`, up to (but not including) `abortres-->(WORDSIZE+len)`. Do not exceed 256 characters. Then return 2; `KeyboardPrimitive()` will end and return the line.

> If you return -1 from `HandleGlkEvent()`, player input will continue even after a keystroke (for character input) or after the enter key (for line input). You must re-request input by calling `request_char_input` or `request_line_input`. Any other return value from `HandleGlkEvent()` (a normal return, `rfalse`, or `rtrue`) will not affect the course of player input.

`InitGlkWindow(winrock)`

> This entry point is called by the library when it sets up the standard windows: the story window, the status window, and (if you use quote boxes) the quote box window. The story and status windows are created when the game starts (before `Initialise()`). The quote window is created and destroyed as necessary.

> `InitGlkWindow()` is called in five phases:

> 1. The library calls `InitGlkWindow(0)`. This occurs at the very beginning of execution, even before `Initialise()`. You can set up any situation you want. (However, remember that the story and status windows might already exist — for example, if the player has just typed RESTART.) This is a good time to set `gg_statuswin_size` to a value other than 1. Return 0 to proceed with the standard library window setup, or 1 if you’ve created all the windows yourself.

> 2. The library calls `InitGlkWindow(GG_MAINWIN_ROCK)`, before creating the story window. This is a good time to set up style hints for the story window. Return 0 to let the library create the window; return 1 if you have yourself created a window and stored it in `gg_mainwin`.

> 3. The library calls `InitGlkWindow(GG_STATUSWIN_ROCK)`, before creating the status window. Again, return 0 to let the library do it; return 1 if you have created a window and stored it in `gg_statuswin`.

> 4. The library calls `InitGlkWindow(1)`. This is the end of window setup; you can take this opportunity to open other windows. (Or you can do that in your `Initialise()` routine. It doesn’t matter much.)

> 5. The library calls `InitGlkWindow(GG_QUOTEWIN_ROCK)`, before creating the quote box window. This does not occur during game initialization; the quote box window is created during the game, whenever you print a quote, and destroyed one turn later. As usual, return 1 to indicate that you’ve created a window in `gg_quotewin`. (The desired number of lines for the window can be found in `gg_arguments-->0`.)

> However you handle window initialization, remember that the library requires a `gg_mainwin`. If you don’t create one, and don’t allow the library to do so, the game will shut down. Contrariwise, the status window and quote windows are optional; the library can get along without them.

`IdentifyGlkObject(phase, type, ref, rock)`

> This entry point is called by the library to let you know what Glk objects exist. You must supply this routine if you create any windows, filerefs, file streams, or sound channels beyond the standard library ones. (This is necessary because after a RESTORE, RESTART, or UNDO command, your global variables containing Glk objects will be wrong.)

> `IdentifyGlkObject()` is called in three phases:

> 1. The library calls `IdentifyGlkObject()` with `phase==0`. You should set all your Glk object references to zero.

> 2. The library calls `IdentifyGlkObject()` with `phase==1`. This occurs once for each window, stream, and fileref that the library doesn’t recognize. (The library handles the two standard windows, and the files and streams that have to do with saving, transcripts, and command records. You only have to deal with objects that you create.) You should set whatever reference is appropriate to the object. For each object: `type` will be 0, 1, 2 for windows, streams, filerefs respectively; `ref` will be the object reference; and `rock` will be the object’s rock, by which you can recognize it.

> 3. The library calls `IdentifyGlkObject()` with `phase==2`. This occurs once, after all the other calls, and gives you a chance to recognize objects that aren’t windows, streams, or filerefs. If you don’t create any such objects, you can ignore that bit. But you should also take the opportunity to update all your Glk objects to the game state that was just started or restored. (For example, redraw graphics, or set the right background sounds playing.)

### Information for translators

The library is designed to be easily translatable, and there are currently versions available in French, German and several other languages. If you maintain one of these translations, the following information may be useful to you.

#### English.h

This is the “language definition file”, and in translation is replaced by `French.h`, `German.h`, etc. The following changes have been made:

- Class `CompassDirection` and its objects have been extensively revised.

- Routine `LanguageVerb()` has been reworked.

- Routines `LanguageVerbIsDebugging()`, `LanguageVerbLikesAdverb()` and `LanguageVerbMayBeName()` have been added to isolate language-specific tests previously embedded in `parserm.h`.

- Constants `YOU__TX` and `COMMA__TX` have been added.

- Routine `LanguageLM()` has been sorted alphabetically.

- In that routine, `CommandsOff`, `CommandsOn` and `CommandsRead` have been added.

- Also in that routine, `Exit`, `Inv`, `Look`, `Miscellany`, `Places`, `Pronouns` and `Score` have been extended, and `Go` has been modified.

- Constant `LIBRARY_ENGLISH` has been added. We suggest that translated versions instead define `LIBRARY_DUTCH`, `LIBRARY_FRENCH`, `LIBRARY_GERMAN`, `LIBRARY_ITALIAN`, `LIBRARY_SPANISH`, `LIBRARY_SWEDISH` etc, in case it becomes useful at some time to determine which language is in force.

#### Grammar.h

This file contains grammars for English verbs like TAKE and DROP, and in translation is replaced by `FrenchG.h`, `GermanG.h`, etc. The following changes have been made:

- The grammars have been sorted alphabetically.

- Verb definitions `'recording'` and `'replay'` are no longer conditional on DEBUG.

- Verb definitions `'showobj'`, `'ask'`, `'exit'`, `'look'` and `'tell'` have been extended.

- Verb definition `'pry'` `'prise'` etc has been added.

- Constant `LIBRARY_GRAMMAR` has been added.