dds.hin

1984-1993模糊 C 源代码竞赛.zip 非常的好,不过这是DOS格式,要用UE去打开.

Best Language Tool: <[e-mail]> Diomidis Spinellis

	Diomidis Spinellis
	Imperial College, University of London
	Myrsinis 1
	GR-145 62 Kifissia
	Greece


Judges' comments:

    Compile and run.  Give the following lines as input:
    
	OLD LANDER.BAS
	RUN

    Be sure not to run out of fuel!


Selected notes from the author:

    This is the DDS-BASIC Interpreter (Version 1.00). 

    Immediate commands:

	RUN	LIST	NEW	OLD filename
	BYE	SAVE filename

    Program commands:

	variable names a to z		variables initialized to 0 on RUN
	FOR var = exp TO exp		NEXT variable
	GOSUB exp			RETURN
	GOTO exp			IF exp THEN exp
	INPUT variable			PRINT string
	PRINT exp			var = exp
	REM any text			END

    Expressions (ranked by precedence):

	Bracketed expressions
	number (leading 0 for octal, 0x for hex, else decimal), variable
	Unary -
	* / 
	+ - 
	= <> 
	> < 
	<= >=
	(* and + are also used for boolean AND and boolean OR)
	Boolean expressions evaluate to 0 for false and 1 for true

    Editing:

	- Line editor using line re-entry.
	- A line number with nothing following it, deletes the line.

    Input format:

	- Free format positioning of tokens on the line.
	- No space is allowed before the line number.
	- Exactly one space is needed between the OLD or SAVE command and 
	  the filename.
	- ALL INPUT MUST BE UPPERCASE.

    Limits:

	Line numbers		1-10000
	Line length		999 characters
	FOR nesting		26
	GOSUB			999 levels
	Program			Dynamically allocated
	Expressions		-32768 - 32767 for 16 bit machines, 
				-2147483648 - 2147483647 for 32 bit machines

    Error checking / error reports:

	No error checking is performed.
	The message `core dumped' signifies a syntax or semantic error.

    Hosting Environment:

	ANSI C, traditional K&R C or OSF ANDF
	ASCII or EBCIDIC character set
	48K bytes memory

    The Speed of DDS-BASIC Interpreter (Version 1.00). relative to
    Microsoft Advanced BASIC 3.31 is Approximately 60%.

    The code size could be further reduced by doing ugly things like
    not declaring the return type of functions, not freeing memory,
    #defining define, and joining lines.  In its present 1536 character
    form the program is reasonably portable (it may fail to run in a
    tagged object architecture) and nicely formatted (it fits in an
    80*25 screen).