MathInterpreter

Final Project for class:

Formal Languages and Compilers

Instructor:

Dr inż. Maciej Gierdziewicz

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The user input is analyzed in two sections of code called the lexer and parser, before finally being interpreted by the interpreter.

Lexer:

• The lexer groups the input characters into small segments called tokens and identifies the type of each token.
• The characters in the input for ex. 12 + 24 are grouped into the tokens: ‘NUMBER:12’, ‘PLUS’, and ‘NUMBER:24’.
• Whitespace is ignored by the lexer.
• The tokens are then passed on to the parser.

Parser:

• The parser analyzes the sequence of tokens to determine what is intended to happen and in what order.
• When the parser sees NUMBER, followed by PLUS, followed by NUMBER, it passes on that the two numbers should be added together In the case of a multiply operation added into the mix, the parser determines that the two numbers next to the multiply operator should be multiplied first before the addition takes place.
• The represented as a tree, the result is then passed on to the interpreter.

Interpreter:

-The interpreter simply does what's intended according to the parser's results, and contains the code for all the different math operations. -It keeps calculating according to priority and keeps updating the result until there is no more operation and finally prints out the result.