I have been reading some articles about parsing/compiling programs and I decided to try my hand at writing an interpreter of my own. I made a little calculator similar to some lex/yacc examples out there, but without the lex/yacc, just as a learning experience. If anyone cares to read through the source and point out glaring errors I would be quite thankful. I plan to eventually write a toy language without the aid of lex/yacc so I need to understand this stuff. source