Logical parser

Question

how can i parse and calculate an expression like
" !((a | b) | b & c & !(d) & ((a | !(a) & b)|b) & e) " ?
a,b,c,d...... is boolean.
Sorry for my English.
i need your help!
Thank you..

Answer 1

I take it, that your experience with parsers is small, and you want to do it yourself (there are grammar based parsers around). That is at least laudable.
Write a recursive descent grammar; I find that the easiest way.
Every parse function accepts some grammatical construct: operator, variable.
If it accepts a grammatical construct, it advances the position.
The result can be a syntax tree.
abstract class Node {
    public boolean evaluate();
class BinaryOp extends Node {
    public BinaryOp(Node lhs, Node rhs) {
class AndOp extends BinaryOp ....The parsing should be done on an token input stream (reading entire words),
that again is done on a normal java.io.InputStream.
Finally if you've done all that, it is time to do nice things:
canonical forms, no binary nodes, but &(x, y, z, ...).