The support is gated by a frontend option,
-enable-operator-designated-protocols.
This means that in an operator declaration we can declare a protocol
which has one or more requirements specifying this operator. The
operators from that designated protocol will be the first ones we try
when type checking an expression. If we successfully typecheck using
the operators specified in that protocol, we do not attempt any other
overloads of the same operator.
This makes it possible to dramatically speed up successful
typechecking.
wasn't being detected while parsing operator decls, and so declarations of
invalid operators would be accepted without error and then later couldn't
be used.
Now errors correctly and new tests added.
And improve the error message for non-empty braces; if we're going to
ignore the contents, we should at least point you in the right
direction for Swift 3.
rdar://problem/27576922
What I've implemented here deviates from the current proposal text
in the following ways:
- I had to introduce a FunctionArrowPrecedence to capture the parsing
of -> in expression contexts.
- I found it convenient to continue to model the assignment property
explicitly.
- The comparison and casting operators have historically been
non-associative; I have chosen to preserve that, since I don't
think this proposal intended to change it.
- This uses the precedence group names and higherThan/lowerThan
as agreed in discussion.
Rename 'assignment' attribute of infix operators to 'mutating'. Add
'has_assignment' attribute, which results in an implicit declaration of
the assignment version of the same operator. Parse "func =foo"
declaration and "foo.=bar" expression. Validate some basic properties of
in-place methods.
Not yet implemented: automatic generation of wrapper for =foo() if foo()
is implemented, or vice versa; likewise for operators.
Swift SVN r26508
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
modifiers and with the func implementations of the operators. This resolves the rest of:
<rdar://problem/17527000> change operator declarations from "operator prefix" to "prefix operator" & make operator a keyword
Swift SVN r19931
At the top level, if 'operator' is followed by 'infix', 'prefix', or 'postfix', consider it a contextual keyword, and parse an operator decl following it that looks like:
operator {infix|postfix|prefix} <+> {
attributes…
}
Prefix and postfix operator decls currently admit no attributes. Infix operators have 'associativity {left|right|none}' and 'precedence <int>' attributes.
This patch implements parsing for operator declarations but does not yet attach the declared attributes to func decls for the operators.
Swift SVN r4596
