maybe_compiler

trying to implement compiler in Lazarus according to 'dragon book'

Current status of project

• prints parse tree of the 'program' provided in text window or from file
• prints syntax tree of the 'program' provided in text window or from file
• prints postfix translation of expressions provided in text window or from file
• error messages, syntax tree and postfix translation are currently output to console only

How to run it

Open project file 'compiler.lpi' in Lazarus and run it

Syntax

Grammar is described in head comment of 'parser.pas'. Here is summary:

• program must be enclosed in curly brackets { }
• block inside program must be enclosed in curly brackets
• statements must be finished with ';'
• indentation does not matter
• variables used inside program or block must be declared before use. Possible types 'num' and 'bool'.
• numerical expressions can use operators =. +. -. *, / and parens ( )
• boolean expressions can use operators ||, && and parens (). For values
• integer and decimal numbers are accepted
• bool values are case sensitive 'true' and 'false'

Program example

	{
    num x;
    num y;
    bool z;
    	{
        x = 34/5 - (2*8);
        }
    y = 3 * x;
    z = true || (false && true);
}