-*-Help-*-

AEGizmos Help

                                            version: 1.3.3
                                            created: 06/13/1994 {02:17:40 pm}
                                        last update: 03/06/2006 {08:40:30 PM}


Alpha has very extensive support for scripting and inter-application 
communication. 

    1) Alpha is completely scriptable in Tcl, which is far better suited for 
       internal scripting than AppleScript.
       
    2) Alpha accepts the required apple events, plus 'dosc', which is used 
       to tell Alpha to execute a Tcl script.
       
    3) Alpha has a command, AEBuild, which allows arbitrarily complicated 
       apple events to be built and sent. 
       
    4) Queue'd replies of messages sent by AEBuild are AEPrint'd and passed 
       to the tcl proc: handleReply (in "appleEvents.tcl").
       
    5) Alpha has several internal handlers to support interaction with 
       Think, but basically the entire interface is done in Tcl using 
       AEBuild. Compiler errors are parsed and passed to the procedure
       proc: handleThinkReply.


	----------------------------------------------------------------------


The following is a text version of the AEBuild/AEPrint docs.

	  	Apple Events    The ® Builder/Printer

Version 1.3.3

Jens Peter Alfke
11 October 1993
AppleScript Team
© Apple Computer, Inc. 1991Ð1993

	  	Introduction


OK, What Is It?

Even with the helpful Object Support Library routines that assemble common
Apple event object descriptors, building descriptors and events is still a
pain.  IÕve written a library of two functions that make it quick and easy
to build or display Apple event descriptors and the Apple events
themselves.

The AEBuild function takes a format string Ñ a description in a very simple
language of an Apple event descriptor Ñ and generates a real descriptor
(which could be a record or list or event) out of it.  The AEPrint function
does the reverse: given an Apple event descriptor, list or record, it
prettyprints it to a string.  (The resulting string, if sent to AEBuild,
would reproduce the original AEDesc structure.)

AEBuild can plug variable parameters into the structures it generates Ñ as
with printf, all you do is put marker characters in the format string and
supply the parameter values as extra function arguments.

The benefits of using this library are fourfold:

¥ ItÕs easier for you to write the code to build Apple event structures. 
  You only have to remember one function call and a few simple syntax rules. 
  Your resulting code is also easier to understand.

¥ As of version 1.2, your code is even faster: AEBuild is three to four
  times as fast as the regular Apple Event Manager routines at constructing
  complex structures.  (Your mileage may vary.)

¥ Your code is smaller: the code for AEBuild and the AEStream library is
  about 6k in size, and the overhead for each call is minimal.  (Most of the
  descriptor string consists of the same four-letter codes youÕd be using in
  your program code anyway, and the strings can even be stored in resources
  for more code savings.)
        
¥ AEPrint helps in debugging programs, by turning mysterious AEDesc
  structures into human-readable text.


        WhatÕs New?
 

In version 1.3:

¥ A new function, AEPrintSize, computes how long the string built by
  AEPrint would be, without actually creating it.  This is useful if you want
  to allocate storage for the string dynamically.

¥ AEPrint no longer truncates hex dumps (of unknown descriptors) after 32
  bytes.

And in version 1.3.2:

¥ AEPrint no longer uses the stdio library.  This should help reduce code
  size (and eliminate some problems in code resources) but to do it I had to
  cripple floating-point display.  Floating-point descriptors now print as
  the integer part followed by Ò.XXXXÓ.
    
And in version 1.3.3:

¥ After a brilliant suggestion by Rob Dye, AEPrint now uses the built in
  float- to-text coercion to display floating-point descriptors.

¥ Fixed a possible problem with AEBuild input strings containing Return
  characters, in the MPW version of the library.


	  	How To Call the Functions


These are all C functions.  They all take variable numbers of arguments, so
theyÕd be difficult or impossible to call from Pascal, anyway.  (And
remember, kids: there are no Pascal compilers for the PowerPC chipÉ)

	  	 	AEBuild

	OSErr
	AEBuild(  AEDesc *desc, const char *descriptorStr, ... ),
	vAEBuild( AEDesc *desc, const char *descriptorStr, void *args );

AEBuild reads a null-terminated descriptor string (usually a constant,
although it could come from anywhere), parses it and builds a corresponding
AEDesc structure.  (DonÕt worry, IÕll describe the syntax of the descriptor
string in the next section.)  If the descriptor string contains magic
parameter-substitution characters (Ò@Ó) then corresponding values of the
correct type must be supplied as function arguments, just as with printf.

(vAEBuild is analogous to vprintf: Instead of passing the parameters along
with the function, you supply a va_list, as defined in <stdarg.h>, that
points to the parameter list.  ItÕs otherwise identical.)

AEBuild returns an OSErr.  Any errors returned by Apple Event Manager
routines while building the descriptor will be sent back to you.  The most
likely results are memFullErr and errAECoercionFail.  Also likely is
aeBuildSyntaxErr, resulting from an incorrect descriptor string.  (Make
sure to debug your descriptor strings, perhaps using the demo application,
before you put them in programs!)  The basic version of AEBuild just
reports that a syntax error occurred, without giving any additional
information.  If you want to know more (perhaps the string came from a
user, to whom youÕd like to report a helpful error message) you can use the
other version of the library.  This version includes a wee bit of extra
code, and two global variables that will contain useful information after a
syntax error:

	extern AEBuild_SyntaxErrType
	AEBuild_ErrCode;
	extern long


	  	 	AEBuild_ErrPos;


AEBuild_ErrCode is an enumerated value that will contain a specific error
code.  The error codes are defined in AEBuild.h. AEBuild_ErrPos will contain
the index into the descriptor string at which the error occurred: usually one
character past the end of the offending token.  AEBuildParameters

	  	 	AEBuildParameters

	OSErr	AEBuildParameters(  AppleEvent *event, 
								const char *descriptorStr, ... );

AEBuildParameters adds parameters and/or attributes to an existing Apple
event.  descriptorStr specifies the parameters (required and optional) and
attributes.  Its syntax is described below (see especially the Apple Event
Descriptor Strings subsection); itÕs almost the same as the syntax for
AEBuild, with a few additions and modifications.

(vAEBuildParameters is analogous to vprintf: Instead of passing the
parameters along with the function, you supply a va_list, as defined in
<stdarg.h>, that points to the parameter list.  ItÕs otherwise identical.)

	  	 	AEBuildAppleEvent

	AEBuildAppleEvent(  AEEventClass theClass, AEEventID theID,
	                    DescType addressType, void *addressData, 
						long addressLength, short returnID, long transactionID,
	                    AppleEvent *event, const char *descriptorStr, ... );

AEBuildAppleEvent is like AEBuild but builds an Apple event, including
parameters and attributes.  Or, you could say that itÕs like
AEBuildParameters but creates the event from scratch.

Most of the parameters are just like the parameters to AECreateAppleEvent,
although you pass the target address data directly, instead of via a
pre-built descriptor.  The resulting Apple event will appear in the event
parameter.  descriptorStr specifies the parameters (required and optional)
and attributes.  The syntax is described below (see especially the Apple
Event Descriptor Strings subsection); itÕs almost the same as the syntax for
AEBuild, with a few additions and modifications.

(vAEBuildAppleEvent is analogous to vprintf: Instead of passing the
parameters along with the function, you supply a va_list, as defined in
<stdarg.h>, that points to the parameter list.  ItÕs otherwise identical.)

	  	 	AEPrint

	OSErr AEPrint( AEDesc *desc, char *bufStr, long bufSize );

AEPrint reads the Apple event descriptor desc and writes a corresponding
descriptor string into the string pointed to by bufStr.  It will write no
more than bufSize characters, including the trailing null character.  Any
errors returned by Apple Event Manager routines will be returned to the
caller; this isnÕt very likely unless the AEDesc structure is somehow
corrupt.

The descriptor string produced, if sent to AEBuild, will build a descriptor
identical to the original one.  AEPrint tries to detect AERecords that have
been coerced to other types and print them as coerced records.  Structures of
unknown type that canÕt be coerced to AERecords are dumped as hex data.

AEPrint can also print complete Apple events as well as regular descriptors. 
The syntax of the resulting string for an event is like that used by
AEBuildParameters and AEBuildAppleEvent, except that:

¥   The string begins with the event class and ID separated by a backslash.
¥   the parameter list is surrounded by curly braces.
¥   Attributes are also displayed; they look like parameters but are preceded by 
    Ò&Ós.

The builder functions do not accept this event syntax yet.ÊÊ


	  	 	AEPrintSize

	OSErr AEPrintSize( AEDesc *desc, long *bufSizeNeeded );

AEPrintSize computes the buffer size that AEPrint would require if given the
same descriptor.  (The size is equal to the string length, plus 1 byte for
the trailing null.)  This is handy for pre-flighting AEPrint, if you want to
allocate the buffer dynamically instead of relying on one of fixed size .


	----------------------------------------------------------------------


	  	Descriptor-String Syntax


The real meat of all this, of course, is the syntax of the descriptor
strings.  ItÕs pretty simple: basic data types like numbers and strings can
be described directly, and then built up into lists and records.  IÕve even
provided a pseudo- BNF grammar (next section) for those of you who actually
enjoy reading those things.

Basic Types

The fundamental data types are:

Type            Examples        Type-code       Description
----            --------        ---------       -----------
Integer         1234            'long' or       A sequence of decimal digits,
                -5678           'shor'          optionally preceded by a minus
                                                sign.

Enum/Type       whos            'enum'          A magic four-letter code. Will be
Code            longint         (Use coercion   truncated or padded with spaces
                'long'          to change to    to exactly four characters. If you
                <=              'type')         put straight or curly single-
                '8-)'                           quotes around it, it can contain
                ÔZQ 5Õ                          any characters. If not, it canÕt
                m                               contain any of: @Ô'ÒÓ:-,([{}])
                                                and canÕt begin with a digit.

String      ÒA String.Ó         'TEXT'          Any sequence of characters
            ÒMultiple lines                     within open and close curly
            are okay.Ó                          quotes. WonÕt be null-terminated.

Hex Data    Ç4170706C65È        ??              An even number of hex digits
            Ç0102 03ff          (Must be        between French quotes (Option-
             e b 6 cÈ           coerced to      \, Option-Shift-\). Whitespace is
                                some type)      ignored.

Yes, you have to use the actual four-letter codes for enums, type codes,
keywords and object types, instead of the mnemonic constants.  Luckily the
codes are semi-mnemonic anyway.  I did it this way to avoid the massive
overhead, both in code size and execution speed, of a symbol table.  You can
find the definitions of the constants in the text file ÒAEObjects.pÓ, which
is part of the Apple Events Object Support Library.ÊÊ


	  	Coercion


Any basic element (except a hex string) by itself is a descriptor, whose
descriptorType is as given in the table.  You can coerce a basic element to a
different type by putting it in parentheses with a type-code placed before
it.  Here are some examples:

	sing(1234)
	type(line)
	long(CODE)
	hexd(ÒA StringÓ)
	'blob'(Ç4170706C65È)

Coercions of numeric values are effected by calling AECoerceDesc; if the
coercion fails, youÕll get an errAECoercionFail error returned to you. 
Coercions of other types just replace the descriptorType field of the
AEDesc.ÊÊ

Hex strings must be coerced to something, since they have no intrinsic type.ÊÊ

You can also coerce nothing, to get a descriptor with zero-length data:

	emty()

Even the type can be omitted, leaving just (), in which case the type is 'null'.


	  	Lists


To make an AEDescList, just enclose a comma-separated list of descriptors in
square brackets.  For example:

	[123, -456, Òet ceteraÓ]
	[sing(1234), long(CODE),
	 [ÒwheelsÓ, Òwithin wheelsÓ]]
	[]

The elements of a list can be of different types, and a list can contain
other lists or records (see below) as elements.

Lists cannot be coerced to other types; the type of a list is always 'list'.


	  	Records


An AERecord is indicated by a comma-separated list of elements enclosed in
curly braces.  Each element of a record consists of a keyword (a type-code,
as described under Basic Types) followed by a Ò:Ó, followed by a value, which
can be any descriptor: a basic type, a list or another record.  For example:

	{x:100, y:-100}
	{'origin': {x:100, y:-100}, extent: {x:500, y:500},
	 cont: [1, 5, 25]}
	{}

The default type of a record is 'reco'.  Many of the Apple Events Object
Model structures are AERecords that have been coerced to some other data
type, like 'indx' or 'whos'.  You can coerce a record structure to any type
by preceding it with a type code.  For example:

	rang{ star: 5, stop: 6}

Warning Coercing to an existing type, such as 'bool' or 'TEXT', is a bad
idea.  Anyone parsing the descriptor (including AEPrint) will recognize the
type and assume that the data has the normal interpretation, which in this
case it wouldnÕt.  Bad to awful things would happen.  DonÕt do it.


	  	Apple Events


The syntax of the formatting string for an entire Apple event (as passed to
AEBuildAppleEvent) is almost identical to that of a record.  Each keyed
element specified in the string becomes a parameter or attribute of the
event.  The differences are:

¥   There are no curly-braces at the beginning and end of the string.
¥   The character Ò~Ó before a parameter keyword makes it optional.

HereÕs an example of how to construct an Open Selection event for the Finder:

	AliasHandle parent, itemToOpen;
	const OSType finderSignature = 'MACS';
	AppleEvent event;
	OSErr err;
	
	// Construct the aliases here (not shown)
	
	err= AEBuildEppleEvent(
			'FNDR', 'SOPE',
			typeApplSignature, @finderSignature, sizeof(finderSignature),
			kAutoGenerateReturnID, kAnyTransactionID,
			&event,										// Event to be created
			"----: alis(@@), fsel: [alis(@@)]",			// Format string
				parent,									// param for 1st @@
				itemToOpen								// param for 2nd @@
	);
	

	  	Substituting Parameters


To plug your own values into the midst of a descriptor, use the magic Ò@Ó
character.  You can use Ò@Ó anywhere you can put a basic element like an
integer.  Each Ò@Ó is replaced by a value taken from the parameter list sent
to the AEBuild function.  The type of value created depends on the context in
which the Ò@Ó is used: in particular, how itÕs coerced.

Type Coerced to:	Type of fn parameter read:			Comments:
----------------	--------------------------			---------
No coercion			AEDesc*								A plain Ò@Ó will be replaced with a
														descriptor parameter.
														
Numeric 			(bool, shor,
					long, sing, doub, exte)	short, short, long, float,
					short double, double				Remember that THINK CÕs double
														corresponds to type 'exte'!
														
TEXT				char*								Pointer to a null-terminated C string.

Any other type		long followed by void*				Expects a length parameter followed by
														a pointer to the descriptor data.

Important: Note particularly: that TEXT parameters must be null-terminated 
strings, although the resulting descriptor data will not be null-
terminated; and that the general case expects two parameters: the 
dataÕs size and location.

In addition, you can substitute data from a handle by using two @ signs.  An
Ò@@Ó parameter will read a single handle from the parameter list and use the
data pointed to by that handle as the value of the descriptor.  The Ò@@Ó must
be coerced so that AEBuild will know what type to make the descriptor;
however, the type coerced to can be anything (the table above is ignored.)

This mechanism is still a bit limited, and may well be improved in the future.


	  	Descriptor-String Grammar


Since no language, however small, can be taken seriously unless it comes
fully equipped with a formidable-looking BNF grammar specification, I here
present one.  No attempt has been made to prevent Messrs.  Backus and/or Naur
from rolling over in their respective graves.

Character Classification:

whitespace	Ô Õ, Ô\rÕ, Ô\nÕ, Ô\tÕ
digit	0 É 9
paren, bracket,
braces	(, ), [, ], {, }
single-quote	'
double quotes	Ò, Ó
hex quotes	Ç, È
colon	:
comma	,
at-sign	@
identchar	any other printable character

Tokens:

ident ::=	identchar (identchar | digit)*	ÑPadded/truncated
	' character* '	to exactly 4 chars
integer ::=	[ - ] digit+	ÑJust as in C
string ::=	Ò (character)* Ó
hexstring ::=	Ç (hexdigit | whitespace)* È	ÑEven no. of digits, please

Grammar Rules for AEBuild:

formatstring ::=	obj	ÑThis is the top level of syntax
obj ::=	data	ÑSingle AEDesc; shortcut for (data)
	structure	ÑUn-coerced structure
	ident structure	ÑCoerced to some other type
structure ::=	( data )	ÑSingle AEDesc
	[ objectlist ]	ÑAEList type
	{ keywordlist }	ÑAERecord type
objectlist ::=	ÇblankÈ	ÑComma-separated list of things
	obj [ , obj ]*
keywordpair ::=	ident : obj	ÑKeyword/value pair
keywordlist ::=	ÇblankÈ	ÑList of said pairs
	keywordpair [ , keywordpair ]*
data ::=	@	ÑGets appropriate data from fn param
	integer	Ñ'shor' or 'long' unless coerced
	ident	ÑA 4-char type code ('type') unless coerced
	string	ÑUnterminated text; 'TEXT' type unless coerced
	hexstring	ÑRaw hex data; must be coerced to some type!
	
Grammar Rules for AEBuildAppleEvent:

eventstring ::=	evtkeywordlist	ÑTop level syntax for AEBuildAppleEvent
evtkeywordpair ::=	[~] ident : obj	ÑKeyword/value pair
evtkeywordlist ::=	ÇblankÈ	ÑList of said pairs
	evtkeywordpair [ , evtkeywordpair ]*
	
There. Now itÕs all crystal-clear, right?


	  	An Example & Timing Comparison


As an example, IÕll take a C function to generate an object descriptor (taken
from a Pascal example in the Object Model ERS, fleshed out and with gobs of
error checking added) and turn it into a call to AEBuild.  The object
descriptor we want to generate is:

First line of document 'Spinnaker' whose first word is 'April' and whose
second word is 'is'

Then IÕll execute both functions and compare their execution times.

C Code Using Object-Packing Library

OSErr
BuildByHand( AEDesc *dDocument, AEDesc *theResultObj )
{

    OSErr err;
    AEDesc dObjectExamined, dNum, dWord1, dWord2, dAprilText, dIsText,
           dComparison1, dComparison2, dLogicalTerms, dTheTest, dLineOne, dTestedLines;
    
    dObjectExamined.dataHandle =    /* Zero things to start out with so we can safely */
        dNum.dataHandle =               /* execute our fail code if things don't work out */
        dWord1.dataHandle =
        dWord2.dataHandle =
        dAprilText.dataHandle =
        dIsText.dataHandle =
        dComparison1.dataHandle =
        dComparison2.dataHandle =
        dLogicalTerms.dataHandle =
        dTheTest.dataHandle =
        dLineOne.dataHandle =
        dTestedLines.dataHandle =
            NIL;
    
    if( err= AECreateDesc( 'exmn', NIL, 0, &dObjectExamined ) )
        goto fail;
    
    if( err= MakeIndexDescriptor(1,&dNum) )
        goto fail;
    if( err= MakeObjDescriptor( 'word', &dObjectExamined, formIndex, &dNum,
                    false, &dWord1) )
        goto fail;
    if( err= AECreateDesc( 'TEXT', "April", 5, &dAprilText ) )
        goto fail;
    
    AEDisposeDesc(&dNum);
    if( err= MakeIndexDescriptor(2,&dNum) )
        goto fail;
    if( err= MakeObjDescriptor( 'word', &dObjectExamined, formIndex, &dNum,
                    true, &dWord2) )
        goto fail;
    if( err= AECreateDesc( 'TEXT', "is", 2, &dIsText ) )
        goto fail;
    
    if( err= MakeCompDescriptor( '=   ', &dAprilText, &dWord1, true, &dComparison1 ) )
        goto fail;
    if( err= MakeCompDescriptor( '=   ', &dIsText,    &dWord2, true, &dComparison2 ) )
        goto fail;
    
    if( err= AECreateList( NIL, 0, false, &dLogicalTerms ) )
        goto fail;
    if( err= AEPutDesc( dLogicalTerms, 1, dComparison1 ) )
        goto fail;
    if( err= AEPutDesc( dLogicalTerms, 2, dComparison2 ) )
        goto fail;
    
    AEDisposeDesc(&dComparison1);
    AEDisposeDesc(&dComparison2);
    
    if( err= MakeLogicalDescriptor( &dLogicalTerms, 'AND ', true, &dTheTest) )
        goto fail;
    
    if( err= MakeObjDescriptor(classLine,&dDocument,formTest,&dTheTest,true,
                                    &dTestedLines) )
        goto fail;
    
    if( err= MakeIndexDescriptor(1,&dLineOne) )
        goto fail;
    if( err= MakeObjDescriptor( classLine, &dTestedLines, formIndex, &dLineOne,
            true, theResultObj ) )
        goto fail;
    return noErr;
    
    fail:                           /* Clean up in case we couldn't build it */
    AEDisposeDesc(theResultObj);
    AEDisposeDesc(&dObjectExamined);
    AEDisposeDesc(&dNum);
    AEDisposeDesc(&dWord1);
    AEDisposeDesc(&dWord2);
    AEDisposeDesc(&dAprilText);
    AEDisposeDesc(&dIsText);
    AEDisposeDesc(&dComparison1);
    AEDisposeDesc(&dComparison2);
    AEDisposeDesc(&dLogicalTerms);
    AEDisposeDesc(&dTheTest);
    AEDisposeDesc(&dLineOne);
    AEDisposeDesc(&dTestedLines);
    
    return err;
}

MPW 3.2b5 C compiled this into 816 bytes of object code.

I found that the average time to execute this function was 0.0188 seconds
(Quadra 700) or 0.0113 seconds (IIfx).  Use this figure for comparison only;
your times may vary.  The timing is especially dependent on the number of
blocks in the heap, since so many block allocations and disposals are
happening.


	  	AppleScript


First line of document 'Spinnaker' whose first word is 'April' and whose
second word is 'is'

Descriptor String

obj{ want:type('line'),
     from: obj{ want: type('line'), from: @, form: 'test',
                seld: logi{
                           term: [comp{ relo:=, obj1:ÒAprilÓ,
                                        obj2:obj{ want:type('word'), from:exmn(), 
                                                  form:indx, seld:1 }
                                      },
                                  comp{ relo:=, obj1:ÒisÓ,
                                        obj2:obj{ want:type('word'), from:exmn(),
                                                  form:indx, seld:2 }
                                      }
                                 ],
                           logc:AND
                         }
              },
     form: 'indx',
     seld: 1
}

AEBuild Call

char descriptor[] =				/* Same descriptor string as above. Note clever */
"obj{ want:type('line'),"		/* method used to break string across lines. */
    "from: obj{ want: type('line'), from: @, form: 'test',"		/* Note parameter here */
               "seld: logi{"
                          "term: [comp{ relo:=, obj1:ÒAprilÓ,"
                                       "obj2:"
                             "obj{ want:type('word'), from:exmn(), form:indx, seld:1 }},"
                                 "comp{ relo:=, obj1:ÒisÓ,"
                                       "obj2:"
                             "obj{ want:type('word'), from:exmn(), form:indx, seld:2 }}"
                                "],"
                          "logc:AND"
                        "}"
             "},"
    "form: 'indx',"
    "seld: 1"
"}";

void PackWordDesc( AEDesc *dDocumentObject )	/* ÒSpinnakerÓ descriptor is a parameter */
{
	err = AEBuild(&theResultObj,
					descriptorString,
					dDocumentObject);					/* AEDesc* parameter for "@" */
}

MPW 3.2b5 C compiled this into 42 bytes of object code, plus 310 bytes of data 
storage for the string.

I found that the average time to execute this function was 0.0049 seconds 
(Quadra 700) or 0.0070 seconds (IIfx). Use this figure for comparison only; your 
times may vary. The timing is dependent on the number of blocks in the heap, 
since heap blocks are being allocated and resized.


	  	Timing Conclusions


With previous versions of this library, there was a 70% increase in
execution time when using the AEBuild routine.  After delivering the bad
news, I wrote: However, if speed does become an issue, there is always the
option of turbocharging AEBuild by having it directly build descriptors
without going through the Apple Event Manager functions at all.  This would
save an incredible number of Memory Manager calls and probably increase
performance severalfold.  Anyone using AEBuild will get all these
improvements for free.  This is exactly what I did in version 1.1.  In
fact, I wrote a library (AEStream) to do it, so you can do it too.  ItÕs
easy.

AEBuild is now 1.5 to 4 times as fast (depending on CPU) as the using the
Apple Event Manager and/or Object Packing Library routines.  (This means
that AEStream was responsible for a threefold speed-up in AEBuild.  Not
bad, when you take into account other overhead like parsing the format
string!)  Needless to say, if you were already using AEBuild you get this
speed increase absolutely free.  Enjoy!


	  	The Demo Program


IÕve included a demonstration program in the distribution.  This is a
program I used to debug the library.  It reads a line of input, uses
AEBuild to translate it into an AEDesc, uses AEPrint to translate the
AEDesc back into a string, and prints each resulting string.  Error codes
are reported, including syntax-error messages.  The source code is provided
in case you want to see how the functions are called.  s Warning The demo
tool does not handle parameter substitution (the Ò@Ó character).  If you
try to substitute parameters, messy and unpleasant things may happen.  Use
some numeric value in place of parameters, and then replace it with Ò@Ós
after you paste the string into your program.


	  	The Header Files


Here for your convenience are printouts of the header files as of 21 July 1992.

AEBuild.h

#define aeBuild_SyntaxErr	12345			/* Let's get an Official OSErr code someday */

typedef enum{								/* Syntax Error Codes: */
	aeBuildSyntaxNoErr = 0,						/* (No error) */
	aeBuildSyntaxBadToken,						/* Illegal character */
	aeBuildSyntaxBadEOF,							/* Unexpected end of format string */
	aeBuildSyntaxNoEOF,							/* Unexpected extra stuff past end */
	aeBuildSyntaxBadNegative,					/* "-" not followed by digits */
	aeBuildSyntaxMissingQuote,					/* Missing close "'" */
	aeBuildSyntaxBadHex,							/* Non-digit in hex string */
	aeBuildSyntaxOddHex,							/* Odd # of hex digits */
	aeBuildSyntaxNoCloseHex,						/* Missing "È" */
	aeBuildSyntaxUncoercedHex,					/* Hex string must be coerced to a type */
	aeBuildSyntaxNoCloseString,					/* Missing "Ó" */
	aeBuildSyntaxBadDesc,						/* Illegal descriptor */
	aeBuildSyntaxBadData,						/* Bad data value inside (É) */
	aeBuildSyntaxNoCloseParen,					/* Missing ")" after data value */
	aeBuildSyntaxNoCloseBracket,				/* Expected "," or "]" */
	aeBuildSyntaxNoCloseBrace,					/* Expected "," or "}" */
	aeBuildSyntaxNoKey,							/* Missing keyword in record */
	aeBuildSyntaxNoColon,						/* Missing ":" after keyword in record */
	aeBuildSyntaxCoercedList,					/* Cannot coerce a list */
	aeBuildSyntaxUncoercedDoubleAt				/* "@@" substitution must be coerced */
} AEBuild_SyntaxErrType;

// In all the "v..." functions, the "args" parameter is really a va_list.
// It's listed as void* here to avoid having to #include stdarg.h.

// Building a descriptor:

OSErr
	AEBuild(  AEDesc *dst, const char *src, ... ),
	vAEBuild( AEDesc *dst, const char *src, const void *args );

// Adding a parameter to an Apple event:

OSErr
	AEBuildParameters( AppleEvent *event, const char *format, ... ),
	vAEBuildParameters( AppleEvent *event, const char *format, const void *args );

// Building an entire Apple event:

OSErr
	AEBuildAppleEvent( AEEventClass theClass, AEEventID theID,
						DescType addressType, const void *addressData, long addressLength,
						short returnID, long transactionID, AppleEvent *result,
						const char *paramsFmt, ... ),
	vAEBuildAppleEvent( AEEventClass theClass, AEEventID theID,
						DescType addressType, const void *addressData, long addressLength,
						short returnID, long transactionID, AppleEvent *resultEvt,
						const char *paramsFmt, const void *args );
AEBuildGlobals.h
/*
 *	AEBuildGlobals.h							Copyright ©1991 Apple Computer, Inc.
 */


extern AEBuild_SyntaxErrType
	AEBuild_ErrCode;					/* Examine after AEBuild returns a syntax error */
extern long
	AEBuild_ErrPos;					/* Index of error in format string */
AEPrint.h
/*
 *	AEPrint.h										Copyright ©1991 Apple Computer, Inc.
 */

OSErr AEPrint( AEDesc *desc, char *bufStr, long bufSize );


  Yes, it really took half again as long on a Quadra!  I think that cache
flushing during the PACK call is responsible.  (It barely slows down at all
when you disable the caches.)


	----------------------------------------------------------------------


Author: Jens Peter Alfke

AEGizmos file updated by Craig Barton Upright

E-mail: <cupright@alumni.princeton.edu>
   www: <http://www.purl.org/net/cbu>

