//---------------------------------------------------------------
//		RANGE CHECKING EXAMPLE
//--------------------------------------------------------------
// Set the compiler directives "subrange_check" and "subscript_check"
// at the top of the module to specify either or both
// types of run time range checking code be generated when
// the "X_Range_Error" is armed.
//
// The compiler directives "subrange_check" and "subscript_check"
// are defaulted to false when compiler is envoked.
//
// The "subscript_check" may be the most useful for programs
// where space is limited because array subscript violations
// are probably the most usual cause of crashing codes.
// "Subrange_check" generates a LOT of code.
//



%set subrange_check = false
%set subscript_check = true

main module testarm

    use	TEXTIO
    declare
	I : static 16 bit integer range 1..4 initially 1
	A : static array [1..4] of 16 bit integer
    enddeclare

guard

    I *= +2
    A [i] := 2
    procedure JOIE ()
	ARM X_RANGE_ERROR		// Range checking code only generated
					// in scopes where it is armed.    
					// And, it applies over the entire
					// scope so it doesnt matter where
					// in the scope the statement is.
    	I := I + 1
    	A [i] := 2			// It is illegal to both arm and
				// disarm within the same scope.
    endprocedure

    procedure SAM ()
    	DISARM X_RANGE_ERROR
    	I := I + 2
    	procedure PETE ()
	    ARM X_RANGE_ERROR
	    A [i] := 2		// THIS STATEMENT CAUSE X_RANGE ERROR
	    I := 2
    	endprocedure
    
	A [i] := 1
    	PETE ()
    endprocedure

    JOIE ()
    SAM ()

  catch 
    case X_RANGE_ERROR:
	out_line (TTY, "Caught you you bugger")
endguard
endmodule