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| -rw-r--r-- | Changes | 16 |
1 files changed, 10 insertions, 6 deletions
@@ -1,13 +1,17 @@ Language features: -- Introduction of a new kind of data types: the virtual data types. - Virtual types are intended to modelize non free algebraic types that +- Introduction of a new kind of data types: the concrete data types + with private constructors or labels, private types for short. + Private types are intended to modelize non free algebraic types that must verify semantic relations that were not enforceable in previously available Caml data types. - Values from virtual types can be freely used in pattern matching but - the creation of values is reserved to special purpose functions - provided in the type definition module. + Values from private types can be freely used in pattern matching but + the creation of values for private types is reserved to special + purpose functions provided in the module implementation where the + private type definition occurs. That way, the construction functions can enforce any required invariant for - the datatype. + the datatype. Private types are semi-concrete (since they allow + pattern matching as concrete types do) and semi-abstract (since they + forbid direct construction of values as abstract types do). - Added integer literals of types int32, nativeint, int64 (written with an 'l', 'n' or 'L' suffix respectively). |