This commit implements closure syntax that places the (optional)
parameter list in pipes within the curly braces of a closure. This
syntax "slides" well from very simple closures with anonymous
arguments, e.g.,
sort(array, {$1 > $0})
to naming the arguments
sort(array, {|x, y| x > y})
to adding a return type and/or parameter types
sort(array, {|x : String, y : String| -> Bool x > y})
and with multiple statements in the body:
sort(array, {|x, y|
print("Comparing \(x) and \(y)\n")
return x > y
})
When the body contains only a single expression, that expression
participates in type inference with its enclosing expression, which
allows one to type-check, e.g.,
map(strings, {|x| x.toUpper()})
without context. If one has multiple statements, however, one will
need to provide additional type information either with context
strings = map(strings, {
return $0.toUpper()
})
or via annotations
map(strings, {|x| -> String
return x.toUpper()
}
because we don't perform inter-statement type inference.
The new closure expressions are only available with the new type
checker, where they completely displace the existing { $0 + $1 }
anonymous closures. 'func' expressions remain unchanged.
The tiny test changes (in SIL output and the constraint-checker test)
are due to the PipeClosureExpr AST storing anonymous closure arguments
($0, $1, etc.) within a pattern in the AST. It's far cleaner to
implement this way.
The testing here is still fairly light. In particular, we need better
testing of parser recovery, name lookup for closures with local types,
more deduction scenarios, and multi-statement closures (which don't
get exercised beyond the unit tests).
Swift SVN r5169
This simple refactor makes pattern-tuple-element available for re-use
in closure expressions. As a drive-by, diagnose non-final ellipses via
diagnose() rather than via assert(), the latter being considered
rather unfriendly. Also, take pains to restore AST invariants after
such an error.
Swift SVN r5163
One can now attach an initializer to a member variable. That value
will used as the default initialization for the member variable(s) it
initializes. Fixes <rdar://problem/12597404>.
Swift SVN r4989
We use three tag bits on Expr*, Stmt*, Decl*, TypeBase* and SILTypeInfo*, and four on DeclContext*, so set the alignment of the pointed-to types formally with alignas(N) instead of relying on operator new passing down the right alignment to the allocator. Get rid of the informal T::Alignment members of these classes and pass alignof(T) to their allocators. Fix the 'operator new' of DeclContext subclasses so that we can actually use the four tag bits PointerLikeTypeTraits<DeclContext*> claims are available.
Swift SVN r4587
rdar://12315571
Allow a function to be defined with this syntax:
func doThing(a:Thing) withItem(b:Item) -> Result { ... }
This allows the keyword names in the function type (in this case
`(_:Thing, withItem:Item) -> Result`) to differ from the names bound in the
function body (in this case `(a:Thing, b:Item) -> Result`, which allows
for Cocoa-style `verbingNoun` keyword idioms to be used without requiring
those keywords to also be used as awkward variable names. In addition
to modifying the parser, this patch extends the FuncExpr type by replacing
the former `getParamPatterns` accessor with separate `getArgParamPatterns`
and `getBodyParamPatterns`, which retrieve the argument name patterns and
body parameter binding patterns respectively.
Swift SVN r3098
analysis for patterns.
Major changes:
1. We no longer try to compute the types of functions in the parser.
2. The type of a function always matches the type of the argument patterns.
3. Every FuncDecl now has a corresponding FuncExpr; that FuncExpr might not
have a body, though.
4. We now use a new class "ExprHandle" so that both a pattern and a type
can hold a reference to the same expression.
Hopefully this will be a more reasonable foundation for further changes to
how we compute the types of FuncDecls in generics and for the implementation
of type location information.
Swift SVN r2370
not have reference semantics. Deciding whether the container
type has reference semantics requires us to perform
some amount of limited name-binding and type-checking first,
which introduces a few complexities.
Also, fix a bug in uncurried call emission.
Methods work now.
Swift SVN r1112
A function argument clause is now one or more patterns (which
must be parenthesized and explicitly type all positions) not
separated by arrows; the first arrow then separates off the
return type.
Revisions to language reference forthcoming.
Swift SVN r1099
