String_Hash_Tables

Versatile implementation of hash tables.
• Generic to allow all kinds of content.
• Variable size (always prime).

		type Item_Type
	Generic type of the items to be stored.

		type Hash_Table_Access
	Import inner implementation of hash tables.

Construction

		function Create
	Create a new hash table with the given table size.
	Param  Type  Description return  Hash_Table_Access  The new table.

Storing and retrieving data

		procedure Put
	Check for available space in the table, grow if necessary, then insert the key item pair into the table. Raises Key_Exists if the key is already in use.
	Param  Type  Description in out This  Hash_Table_Access  Add pair to this hash table. in Key  String  Create this key. in Item  Item_Type  Associate this item.

		procedure Get
	Retrieve an item from the table. Output parameter Found is True if and only if the key was found.
	Param  Type  Description access This  Hash_Table  Get value from this hash table. in Key  String  Look up this key. out Item  Item_Type  The item that was found. out Found  Boolean  True if the item was found.

		function Get
	Retrieve an item from the table. Raises Key_Not_Found if the key is not in the table.
	Param  Type  Description access This  Hash_Table  Get value from this hash table. in Key  String  Look up this key. return  Item_Type  The item that was found.

Indexed access

		procedure Get_Index
	Get the index of a given key.
	Param  Type  Description access This  Hash_Table  Get key from this hash table. in Key  String  Iteration pointer to the current field. out Index  Positive  The index of the requested key. out Found  Boolean  True if the key was found.

		function Get_Index
	Get the index of a given key.
	Param  Type  Description access This  Hash_Table  Get key from this hash table. in Key  String  Iteration pointer to the current field. return  Positive  The index of the requested key.

		function Get_Key
	Get the key at a given index position.
	Param  Type  Description access This  Hash_Table  Get key from this hash table. in Index  Positive  Iteration pointer to the current field. return  String  The requested key.

		function Get_Item
	Get the item at a given index position.
	Param  Type  Description access This  Hash_Table  Get item from this hash table. in Index  Positive  Iteration pointer to the current field. return  Item_Type  The requested item.

Iterating

		procedure Next
	Iterate over the items in the table. You should start with an Index of 0 and stop iterating as soon as Index is 0 again.
	Param  Type  Description access This  Hash_Table  Iterate through this hash table. in out Index  Natural  Iteration pointer to the current field.

Performance debugging

		procedure Print_Usage
	Print a visual representation of the hash table's usage. Empty fields are represented by a '-' character, used fields by '#'.
	Param  Type  Description access This  Hash_Table  Print usage of this hash table.