----------------------------------------------------------------
  Simple 16bit Non-Pipeline Processor (SN/X) V1.3 Compiler

  (C)Copyright by Naohiko Shimizu, 2001-2011
  All rights are reserved.

  Contact information: Dr. Naohiko Shimizu
    IP Architecture Laboratory
    Email: nshimizu@ip-arch.jp
    URL: http://www.ip-arch.jp/
  
  Update informations:
    27-Mar-2013: Interrupt support, SHMZ
    11-Sep-2011: hexdecimal/logical operators, SHMZ
    12-Sep-2005: local variable added, SHMZ
    10-Sep-2005: Language specification extended, SHMZ
    04-Aug-2002: modified for PARTHENON lecture
----------------------------------------------------------------

Every variables and value of functions are 16bit integer.

Variables:

 special: [a-z] are located at memory address of 1 to 26.
          mem[adder] is supported as absolute address array.

 global: [_a-zA-Z][_0-9a-zA-Z]* will be located on 27 or higher.
         newly available identifiers are treated as global.
 array:
	int any_var_name [ num_of_elements ]; defines an array in global area.

 special and global variables can be base of an array.
 ex. z[0] is located on 26, z[1] is on 27, ...

Function declaration:

  void fname(a1,a2,...) def_local statement
  int  fname(a1,a2,...) def_local statement
  interrupt  fname() def_local statement

The number of arguments is arbitrary.

Arguments of functions:

 [_a-zA-Z][_0-9a-zA-Z]* will be located on stack and treated as local.

control statement syntax:

 if(conditon) taken_statement
 if(conditon) taken_statement else not_taken_statement
 while(conditon) statement
 for(setup; condition; continue) statement
 return expression ;
 break;
 
def_local:
 int vname, vname, .... ;

operators:
 +,-,*,&,|,~,<,>,<=,>=,++,--,>>,<<, (&&, || not debugged)
pointers:
 &VARIABLE, *VARIABLE can be used.
 ,foo  "," is a function pointer operator for interrupt call back

directives:

#include "filename"
	it cannot execute nesting includes