EXPAND		dynamic-clause		[GIVING operand5]
		array-clause

This document covers the following topics:

• Function

• Syntax Description

For explanations of the symbols used in the syntax diagram, see Syntax Symbols.

Related statements: REDUCE | RESIZE

Belongs to Function Group: Memory Management Control for Dynamic Variables or X-Arrays

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Function

The EXPAND statement is used to expand:

• the allocated length of a dynamic variable (dynamic-clause), or

• the number of occurrences of X-arrays (array-clause).

For further information, see the following sections in the Programming Guide:

• Using Dynamic Variables

• Allocating/Freeing Memory Space for a Dynamic Variable

• X-Arrays

• Storage Management of X-Group Arrays

Syntax Description

Operand Definition Table:

Operand	Possible Structure						Possible Formats													Referencing Permitted	Dynamic Definition
operand1		S	A				A	U					B							no	no
operand2	C	S									I									no	no
operand3			A		G		A	U	N	P	I	F	B	D	T	L	C	G	O	yes	no
operand4	C	S							N	P	I									no	no
operand5		S									I4									no	yes

Syntax Element Description:

Syntax Element	Description
dynamic-clause	Dynamic Clause: The EXPAND DYNAMIC VARIABLE statement expands the allocated length of a dynamic variable (operand1) to the value specified with operand2. For more information, see Dynamic Clause below.
operand1	Dynamic Variable: operand1 is the dynamic variable for which the size is to be expanded.
operand2	Target Length of Dynamic Variable: operand2 is used to specify the length to which the dynamic variable is to be expanded. The value specified must be a non-negative integer constant or a variable of type integer.
array-clause	Array Clause: The EXPAND ARRAY statement increases the number of occurrences of the X-array (operand3) to the upper and lower bound specified with (dim[,dim[,dim]]). For more information, see Array Clause below.
operand3	X-Array: operand3 is the X-array for which the number of occurrences may be increased. The index notation of the array is optional. As index notation only the complete range notation * is allowed for each dimension.
dim operand4	Dimension: The lower and upper bound notation (operand4 or asterisk) to which the X-array should be expanded is specified here. If the current value of the upper or lower bound should be used, an asterisk (*) may be specified in place of operand4. For more information, see Dimension below.
GIVING operand5	GIVING Clause: If the GIVING clause is not specified, Natural runtime error processing is triggered if an error occurs. If the GIVING clause is specified, operand5 contains the Natural message number if an error occurred, or zero upon success.

Dynamic Clause

[SIZE OF] DYNAMIC [VARIABLE] operand1 TO operand2

The EXPAND DYNAMIC VARIABLE statement expands the allocated size of a dynamic variable (operand1) to the value specified with operand2.

If operand2 is less than the currently allocated length of operand1, the statement will be ignored for this dynamic variable. The currently allocated length (*LENGTH) of the dynamic variable is not modified.

Array Clause

[AND RESET] [OCCURRENCES OF] ARRAY operand3 TO (dim[,dim [,dim]])

The EXPAND ARRAY statement increases the number of occurrences of the X-array (operand3) to the upper and lower bound specified with TO (dim [,dim[,dim]]).

The RESET option resets all occurrences of the expanded X-array to its default zero value. By default (no RESET option), the actual values are kept and the expanded (new) occurrences are reset.

When using the EXPAND statement, it is only possible to increase the number of occurrences. If the requested number is smaller than the currently allocated number of occurrences, it will simply be ignored.

An upper or lower bound used in an EXPAND statement must be exactly the same as the corresponding upper or lower bound defined for the array.

Example:

DEFINE DATA LOCAL
1 #a(I4/1:*)
1 #g(1:*)
  2 #ga(I4/1:*)

1 #i(i4)
END-DEFINE
...
/* allocating #a(1:10)
EXPAND ARRAY #a TO (1:10)       /* #a is allocated 10
EXPAND ARRAY #a TO (*:10)       /* occurrences.


/* allocating #ga(1:10,1:20)
EXPAND ARRAY #g TO (1:10)       /* 1st dimension is set to (1:10)
EXPAND ARRAY #ga TO (*:*,1:20)  /* 1st dimension is dependent and 
                                /* therefore kept with (*:*)
                                /* 2nd dimension is set to (1:20)
 
EXPAND ARRAY #a TO (5:10)       /* This is rejected because the lower index
                                /* must be 1 or *
EXPAND ARRAY #a TO (#i:10)      /* This is rejected because the lower index
                                /* must be 1 or *

EXPAND ARRAY #ga TO (1:10,1:20) /* (1:10) for the 1st dimension is rejected
                                /* because the dimension is dependent and 
                                /* must be specified with (*:*).

For further information, see the following topics in the Programming Guide:

• Storage Management of X-Arrays

• Storage Management of X-Group Arrays

Dimension

Each of the dimensions (dim) specified in the Array Clause is defined using the following syntax:

	*
		* operand4		:		* operand4

The lower and upper bound notation (operand4 or asterisk) to which the X-array should be expanded is specified here. If the current value of the upper or lower bound should be used, an asterisk (*) may be specified in place of operand4. Instead of *:*, you may also specify a single asterisk.

The number of dimensions (dim) must exactly match the defined number of dimensions of the X-array (1, 2 or 3).

If the number of occurrences for a specified dimension is less than the number of the currently allocated occurrences, the number of occurrences is not changed for the corresponding dimension.