VMS Help PASCAL, Predeclared Routines, Dyn Alloc  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Compaq Pascal  provides  dynamic  allocation  routines  for  the
  creation  and  use  of pointer variables.  Use pointer variables
  and  dynamic  allocation  routines   to   create   linked   data
  structures.

1 - ADDRESS

  The ADDRESS function returns a pointer value that is the address
  of the parameter.

  Syntax:

     ADDRESS( x )

  The parameter 'x' can  be  a  variable  of  any  type  except  a
  component  of  a packed structured type.  A compile-time warning
  results if 'x' is a formal  VAR  parameter,  a  component  of  a
  formal  VAR  parameter,  or  a  variable  that does not have the
  READONLY or VOLATILE attribute.

  A pointer can only refer to a VOLATILE variable  or  a  variable
  allocated by the NEW procedure.

2 - DISPOSE

  The DISPOSE procedure deallocates memory for a dynamic variable.

  Syntax:

     DISPOSE( p )

  The parameter 'p' is a pointer variable.  The 't' parameters are
  constant  expressions that match the corresponding 't' parameter
  used in the call to the NEW procedure that allocated the memory.
  If you use 't' parameters in a call to NEW, you must specify the
  same 't' parameters in the call to DISPOSE.   If  you  allocated
  memory  using d parameters, just specify the pointer variable to
  the corresponding DISPOSE call.

  The DISPOSE  procedure  deallocates  the  object  to  which  the
  pointer variable points.  You cannot call DISPOSE more than once
  for the same dynamic variable.

3 - IADDRESS

  The IADDRESS function  returns  an  INTEGER_ADDRESS  value  that
  refers  to  a  the  address  of either a VOLATILE parameter or a
  routine, and does not generate compile-time  warnings  (as  does
  the  ADDRESS  function).  The IADDRESS function is commonly used
  for constructing  arguments  for  system  services  of  the  VMS
  operating system.

  Syntax:

     IADDRESS( x )

  The parameter 'x' can be of any type except  a  component  of  a
  packed structured type or a routine name.  The parameter 'x' can
  be a variable, parameter, routine, or constant-expression.  When
  IADDRESS  is  used on constant-expressions, the returned address
  is valid for  the  remainder  of  the  program.   Two  calls  to
  IADDRESS with the same constant may not return the same address.

  Note that the Compaq Pascal compiler automatically assumes  that
  all  pointers refer either to dynamic variables allocated by the
  NEW procedure or to variables that have the VOLATILE  attribute;
  therefore, you should use utmost caution when using the IADDRESS
  function.   This  function  does   not   generate   compile-time
  warnings.

4 - NEW

  The NEW procedure allocates memory for the dynamic  variable  to
  which  a  pointer  variable  refers.   The  value  of  the newly
  allocated variable is set to the initial value of the base  type
  if defined; otherwise, the value of the variable is undefined.

  Syntax:

     NEW( p [[, {t1,...,tn | d1,...,dn} ]] )

  The parameter 'p' is a pointer variable.

  The  parameters  't1,...,tn'  are  constant  expressions  of  an
  ordinal  type that represent nested tag-field values, where 't1'
  is the outermost variant.

  If the object of the pointer is a non-schema  record  type  with
  variants,  then  you have two ways of allocating memory.  If you
  do not specify 't' parameters, Compaq  Pascal  allocates  enough
  memory  to  hold  any  of the variants of the record.  If you do
  specify 't' parameters,  then  Compaq  Pascal  allocates  enough
  memory to hold only the variant or variants that you specify.

  Since the 't' parameters cause Compaq Pascal to allocate  memory
  for  the  variant alone and not for the whole record, you cannot
  assign or evaluate the record as a whole;  you  can  assign  and
  evaluate  only  the individual fields.  Also, a call to NEW does
  not set the tag fields of a variant record.

  The paramters 'd1,...,dn' are compile-time or  run-time  ordinal
  values that must be the same type as the formal discriminants of
  the object.

  If the object of the pointer is  of  an  undiscriminated  schema
  type,  you  must  specify a 'd' parameter for each of the formal
  discriminants  of  the  schema   type.    The   'd'   parameters
  discriminate  the  schema  type  in  much the same way as actual
  discriminants in a discriminated schema.   Compaq  Pascal  bases
  the size of the allocation on the value of the 'd' parameters.

  If the object is a schema record type, then  you  must  use  'd'
  parameters;  you  cannot  use 't' parameters or a combination of
  the syntaxes.  If the schema  record  type  contains  a  variant
  (which  depends on one of the formal discriminants) then the 'd'
  parameter discriminates the schema, determines the variant,  and
  allows  Compaq  Pascal  to  compute  the  necessary  size of the
  allocation.

  Note that if you specify 't' parameters to  the  NEW  procedure,
  you  must  specify  the  same  't'  parameters  to  the  DISPOSE
  procedure  that  deallocates  memory   for   the   corresponding
  variable.