Hi! Currently sub routines cannot access the outer (main routine/block) variables, parameters and cursors - #4769.
There is some details to make that happen safely. Currently a variable cannot have its value changed while its being used. var = var + <expression> No expression can reset var. As soon we let sub routines change outer variables, that will be possible. Currently VariableNode just returns a descriptor pointing to the variable's impure_value present in the variable declaration. To make outer access safe, variables accessed in outer scope would be flagged and its VariableNode (even in the main routine/block) should copy the value to its own impure_value. It will be a bit slower, but I don't see a problem. What worried me more is how to represent things in BLR. A simple approach would be to have blr_outer_variable. But it is not only variables. There is also parameters, fields, dbkeys, cursor statements. What seems for me the way to go is to implement single blr_outer_map that maps main routine's things to sub routines in they own number space. blr_outer_map, blr_outer_map_variable, 0,0, 3,0 It maps main's variable 0,0 to this sub routine's 3,0, so it can access with blr_variable, 3,0. blr_outer_map, blr_outer_map_cursor, 1,0, 2,0 Maps main's cursor 1,0 to this sub routine's 2,0, so it can access with blr_cursor_stmt, 2,0. Comments? Adriano Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
