Sema knows better how to call getLogicValue to get an i1 from a conditional than SILGen does. Fake up a placeholder variable we can slot into a 'expr ~= var' expression, and have the type-checker run on the entire apply expr to generate getLogicValue() conversions on the applied result.
Swift SVN r5995
Create a scope for each case block to contain bindings from its patterns, and invoke addVarsToScope after parsing case label patterns to introduce vars into that scope. Refactor addVarsToScope to use an ASTWalker so it finds pattern vars embedded in expr patterns.
Swift SVN r5899
Because of '~=' lookahead and precedence parsing, we need to be able to parse pattern productions in expression position and validate them after name binding. Add an unresolved Expr node that can hold a subpattern for this purpose.
Swift SVN r5825
We decided to go with 'var' as a distributive pattern introducer which applies to bare identifiers within the subpattern. For example, 'var (a, b)' and '(var a, var b)' would be equivalent patterns. To model this, give 'var' its own AST node with a subpattern and remove the introducer loc from NamedPattern.
Swift SVN r5824
I talked to John about parsing patterns today, and because of the magnitude of name-lookup-dependent ambiguities between patterns and expressions, we agreed that at least for a first-pass implementation it makes sense to parse patterns as extensions of the expr grammar and charge name binding with distinguishing patterns from expressions. This gets us out of needing the concept of an "unresolved pattern", at least in the short term.
Swift SVN r5808
A single case block can have one or more 'case ...:' labels. 'case' labels contain patterns instead of exprs. 'default:' is a funny spelling for 'case _:'. Change the CaseStmt representation and rip out all the parsing, type-checking, and SILGen built off the old representation.
Swift SVN r5795
Introduce Pattern subclasses for the 'is T', 'T(<pattern>)', and '<expr>' pattern syntaxes we'll be introducing for pattern-matching "switch" statements. Also add an 'UnresolvedCalLPattern' to act as an intermediate for name lookup to resolve to a nominal type, oneof element, or function call expression pattern. Since we'll need to be able to rewrite patterns like we do expressions, add setters to AST nodes that contain references to subpatterns. Implement some basic walking logic in places we search patterns for var decls, but punt on any more complex type-checking or SILGen derived from these nodes until we actually use them.
Swift SVN r5780
Sub-patterns are now considered part of the enclosing pattern, so if the
parent pattern pointer is const, the child pointer will be too.
I changed the minimal number of files to make this work, but future code
should use "const Pattern *" when intended, and "Pattern *" only if they
intend to modify the pattern.
Swift SVN r5743
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
