Calc: remove default epsilon in + allow for scientific notation

examples/calc/AST.cpp

@@ -23,7 +23,7 @@ namespace {
             if (args.size() != 3)
                 return 0;
             double test = args[0]->eval(vars, funs);
-            if (std::fabs(test) < 1e-8)
+            if (test == 0)
                 return args[2]->eval(vars, funs);
             else
                 return args[1]->eval(vars, funs);

examples/calc/calcLexer.lxs

@@ -11,6 +11,6 @@ DIVIDE = /
 EXPONENT = ^
 LT = <
 ASSIGN = =
-NUM = (0|[1-9][0-9]*)(\.[0-9]+)?
+NUM = (0|[1-9][0-9]*)(\.[0-9]+)?([eE]-?[0-9]+)?
 IDENT = [a-zA-Z_][a-zA-Z0-9_]*
 ignore = \n|\r| |\t