| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Increase eligibility requirements for implicit conversions,
such that T => U is ineligible if
T <: Null <or> AnyRef <: U
This has the salutary effect of allowing us to ditch 16
ridiculous implicits from Predef, since they existed solely
to work around the absence of this restriction.
There was one tiny impact on actual source code (one line
in one file) shown here, necessitated because the literal null
is not eligible to be implicitly converted to A via <:<.
def f[A](implicit ev: Null <:< A): A = null // before
def f[A](implicit ev: Null <:< A): A = ev(null) // after
As impositions go it's on the tame side.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
*** Important note for busy commit log skimmers ***
Symbol method "fullName" has been trying to serve the dual role of "how
to print a symbol" and "how to find a class file." It cannot serve both
these roles simultaneously, primarily because of package objects but
other little things as well. Since in the majority of situations we want
the one which corresponds to the idealized scala world, not the grubby
bytecode, I went with that for fullName. When you require the path to a
class (e.g. you are calling Class.forName) you should use javaClassName.
package foo { package object bar { class Bippy } }
If sym is Bippy's symbol, then
sym.fullName == foo.bar.Bippy
sym.javaClassName == foo.bar.package.Bippy
*** End important note ***
There are many situations where we (until now) forewent revealing
everything we knew about a type mismatch. For instance, this isn't very
helpful of scalac (at least in those more common cases where you didn't
define type X on the previous repl line.)
scala> type X = Int
defined type alias X
scala> def f(x: X): Byte = x
<console>:8: error: type mismatch;
found : X
required: Byte
def f(x: X): Byte = x
^
Now it says:
found : X
(which expands to) Int
required: Byte
def f(x: X): Byte = x
^
In addition I rearchitected a number of methods involving:
- finding a symbol's owner
- calculating a symbol's name
- determining whether to print a prefix
No review.
|
