grammar udo.test.Test hidden(WS)

import "http://www.eclipse.org/emf/2002/Ecore" as ecore
generate test...

Test:
    a=E ';';

E returns ex:
    A ({ex.left=current} '|'? right=A)*;

A returns ex:
    P ({ex.left=current} '+' right=P)*;

P returns ex:
    O ({ex.left=current} right=P) | T;

T returns ex:
    '(' right=E ')' | c='X';

O returns ex:
    o=('+' | '-');

terminal WS:
    ' ';