#error entering fi_util.t...

#endif

#if !defined( FINCH_UTILITY_LIBRARY )

#include "tads.h"

#include "t3.h"

#include "lookup.h"

modify TadsObject

    _name = nil

    _init_TadsObject() {}

    construct() {

        _init_();

    }

    _init_( [args] ) {

        if (self == TadsObject) return;

        local obj = (args.length > 0 ? args[1] : self);

        local lst = getSuperclassList();

        foreach (local c in lst)

            c._init_( obj );

        callDefinedMethod( obj, '_init_' + self._name );

    }

;

/**

 *  Permits the Finch utilities by saving the global symbol hashtable

 *  before it gets garbage-collected after preinit.

 */

FinchUtility: PreinitObject

    globalSymbols = nil

    storeGlobalSymbols = true

    execute() {

        globalSymbols = t3GetGlobalSymbols();

        t3DebugTrace( T3DebugBreak );

        globalSymbols.forEach(

            { tok, obj :

                dataType( obj ) == TypeObject &&

                obj.ofKind( TadsObject )

                    ? obj._name = tok

                    : nil

            }

        );

        for (local o = firstObj(); o; o = nextObj( o )) {

            if (o.ofKind( TadsObject)) {

                o._init_();

            }

        }

    }

;

/**

 *  Retrieves the global symbol hashtable, saved by the FinchUtility

 *  PreinitObject.

 */

getGlobalSymbols() {

    return FinchUtility.globalSymbols;

}

/**

 *  Calls the given method-name on the given object using the given

 *  argument list.

 *

 *  @param  obj     an object reference

 *  @param  meth    a string containing a valid property name

 *  @param  params  all following parameters will be passed sequentially

 *                  to the method

 *  @return         whatever the method returned

 *  @exception  NoSuchSymbolException if the method name can't be found in

 *                  the global symbol table

 *  @exception  NoSuchMethodException if the associated entry in the

 *                  global symbol table isn't a property

 *  @exception  InvocationTargetException if the method itself threw an

 *                  exception.

 */

callMethod( obj, meth, [params] ) {

    //  get the actual method reference from the symbol table

    local prop = (getGlobalSymbols())[ meth ];

    //  if the symbol doesn't exist, throw an exception

    if (prop == nil)

        throw new NoSuchSymbolException( meth );

    //  if the symbol isn't a property, throw an exception

    else if (dataType( prop ) != TypeProp)

        throw new NoSuchMethodException( meth );

    else {

        try {

            return obj.(prop)( params... );

        }

        catch (Exception e) {

            throw new InvocationTargetException( obj, meth, e );

        }

    }

}

/**

 *  Calls the given method-name on the given object using the given

 *  argument list.  If the method does not exist, or exists but isn't

 *  defined on this object, ignore it (instead of, say, trying to call

 *  a method that we know won't ever be valid, since code can never be

 *  assigned to a method in the current implementation of the VM).

 *

 *  @param  obj     an object reference

 *  @param  meth    a string containing a valid property name

 *  @param  params  all following parameters will be passed sequentially

 *                  to the method

 *  @return         whatever the method returned

 *  @exception  NoSuchMethodException if the associated entry in the

 *                  global symbol table isn't a property

 *  @exception  InvocationTargetException if the method itself threw an

 *                  exception.

 */

callDefinedMethod( obj, meth, [params] ) {

    // get the actual method reference from the symbol table

    local prop = (getGlobalSymbols())[ meth ];

    // if the symbol doesn't exist, abort.

    if (prop == nil) return nil;

    // if the property isn't defined by this object, abort.

    if (!obj.propDefined( prop )) return nil;

    // if the symbol isn't a property, throw an exception

    else if (dataType( prop ) != TypeProp)

        throw new NoSuchMethodException( meth );

    else {

        try {

            return obj.(prop)( params... );

        }

        catch (Exception e) {

            throw new InvocationTargetException( obj, meth, e );

        }

    }

}

/**

 *  Creates a new property, updating the global symbol table.

 *

 *  @param  str     a string to correspond to the new property

 *  @return         the new property

 */

createGlobalProperty( str ) {

    // allocate a new property id

    local prop = t3AllocProp();

    // assign it to the given string

    (getGlobalSymbols())[ str ] = prop;

    // return the new property

    return prop;

}

/**

 *  A nearly meta-exception thrown when reflectively invoked code

 *  throws an exception.

 */

class InvocationTargetException: Exception

    location = nil

    position = nil

    datum = nil

    construct( obj, meth, e ) {

        location = obj;

        position = meth;

        datum = e;

    }

    getMessage() {

        "InvocationTargetException: the method << position >>

        on the object << location._name >> threw the following

        exception: << datum.getMessage() >>. ";

    }

;

/**

 *  An exception thrown when a reflectively invoked method

 *  does't actually exist.

 */

class NoSuchMethodException: Exception

    position = nil

    construct( meth ) {

        position = meth;

    }

    getMessage() {

        "NoSuchMethodException: the symbol << position >>

        does not correspond to a property address.";

    }

;

/**

 *  An exception thrown when a reflectively requested symbol

 *  does't actually exist.

 */

class NoSuchSymbolException: Exception

    position = nil

    construct( sym ) {

        position = sym;

    }

    getMessage() {

        "NoSuchSymbolException: the symbol << position >>

        does not exist in the global symbols table.";

    }

;

#endif