C Packages

Listing 1 Ada Symbol Table Package

package SYM_UTIL is
                         -- Global debug switch.
    SYM_UTIL_DEBUG: BOOLEAN := FALSE ;
                         -- Add symbol to table.
    procedure SYM_ADD (NAME: STRING, VALUE: INTEGER)
                      -- Delete symbol from table.
    procedure SYM_DELETE (NAME: STRING) ;
                          -- Lookup a symbol.
    function SYM_LOOKUP (NAME: STRING) return INTEGER ;
 end SYM_UTIL ;
 
 package body SYM_UTIL is
                          -- Internal variables.
    type SYMBOL NODE is record
       ...
    end record ;
    SYMBOL_LIST: access SYMBOL_NODE := null ;
                          -- Public functions.
    procedure SYM_ADD (NAME: STRING, VALUE: INTEGER) is
    begin
       ... adds NAME/VALUE pair to the symbol table ...
    end SYM_ADD ;

    procedure SYM_DELETE (NAME: STRING) is
    begin
       ... deletes NAME from the symbol table ...
    end SYM_DELETE ;

    function SYM_LOOKUP (NAME: STRING) return INTEGER is
    begin
       ... returns NAME's value from the symbol table ...
    end SYM_LOOKUP ;
                       -- Internal function called
                        -- by the other functions.
    function SYM_LOCATE (NAME: STRING)
       return access SYMBOL_NODE is
    begin
       ... locates NAME's node in the symbol list ...
    end SYM_LOCATE ;

 end SYM_UTIL ;
/* End of File */