We parse 'try' as if it were a unary operator allowed on an
arbitrary element of an expr-sequence, but sequence-folding
constrains it to never appear on the RHS of most operators.
We do allow it on the RHS of an assignment or conditional
operator, but not if there's anything to the right which
was not parsed within the RHS.
We do this for assignments so that
var x = try whatever
and
x = try whatever
both work as you might expect.
We do this for conditionals because it feels natural to
allow 'try' in the center operand, and then disallowing it
in the right operand feels very strange.
In both case, this works largely because these operators are
assumed to be very low-precedence; there are no standard
operators which would parse outside the RHS. But if you
create one and use 'try' before it, we'll diagnose it.
Swift SVN r26052
a let/var pattern. Now any identifier in one of these is a variable binding,
not sometimes a value references (depending on contextual syntax).
This isn't expected to have a widespread effect on existing real world code:
- No impact on the stdlib.
- It does fix two validation crash tests, but possibly because the original issue is hidden by a different diagnostic path in the compiler.
- This needed two tests to be tweaked to undistribute "let".
On the positive side, this means that "case let x?:" now works properly, woo.
Swift SVN r26000
Corrected several places where compiler generated AST nodes were not properly
marked as implicit.
For interpolated strings also fixed string segment locations and made sure
the first and last segments are preserved in AST even if they are empty.
Swift SVN r25983
This introduces a new pattern, spelled "x?" which is sugar for
matching ".Some(x)". It also changes the parser slightly so that
_ (the discard expr) is parsed as a unary expr instead of as an
expr. This allows it to have postfix ? after it, which is important
in pattern contexts to support "case _?:".
Swift SVN r25907
The previous commit enabled this; now it's just about removing the
restriction in the parser and tightening up code completion.
Using 'super' in a closure where 'self' is captured weak or unowned still
doesn't work; the reference to 'self' within the closure is treated as
strong regardless of how it's declared. Fixing this requires a cascade of
effort, so instead I just cloned rdar://problem/19755221.
rdar://problem/14883824
Swift SVN r25065
- Closures that are comprised of only a single return statement are now considered to be "single expression" closures. (rdar://problem/17550847)
- Unannotated single expression closures with non-void return types can now be used in void contexts. (rdar://problem/17228969)
- Situations where a multi-statement closure's type could not be inferred because of the lack of a return-type annotation are now properly diagnosed. (rdar://problem/17212107)
I also encountered a number of crashers along the way, which should now be fixed.
Swift SVN r24817
Previously the "as" keyword could either represent coercion or or forced
downcasting. This change separates the two notions. "as" now only means
type conversion, while the new "as!" operator is used to perform forced
downcasting. If a program uses "as" where "as!" is called for, we emit a
diagnostic and fixit.
Internally, this change removes the UnresolvedCheckedCastExpr class, in
favor of directly instantiating CoerceExpr when parsing the "as"
operator, and ForcedCheckedCastExpr when parsing the "as!" operator.
Swift SVN r24253
a capture list hung off the CaptureExpr it was associated with. This made
sense lexically (since a capture list is nested inside of the closure) but
not semantically. Semantically, the capture list initializers are evaluated
outside the closure, the variables are bound to those values, then the closure
captures the newly bound values.
To directly represent this, represent captures with a new CaptureListExpr node,
which contains the ClosureExpr inside of it. This correctly models the semantic
relationship, and makes sure that AST walkers all process the initializers of the
capture list as being *outside* of the closure.
This fixes rdar://19146761 and probably others.
Swift SVN r23756
Provides consistency in behavior, particularly in enum raw values, where we reject non-literals. Factor out a common NumberLiteralExpr base for integer and float literals that handles the common sign and representation stuff. Fixes rdar://problem/16504472.
Swift SVN r23390
The issue is reproducible in erroneous code scenario when a string literal
has invalid stuff inside interpolation segment, like: “... \( abc } ) ...”.
In this case we used to do some magic for switching context inside the string
and parse the interior of \(...) as regular expression list, but expected that
the parsing finishes at closing “)” which does not necessarily true in case
the code has errors.
The assertion was replaced with an error diagnostics.
Swift SVN r23296
This patch extends the AST and parsing of #os(...) queries to permit queries for
multiple platforms, e.g., #os(OSX >= 10.10, iOS >= 8.0). It also improves
parsing error recovery.
Swift SVN r22154
This patch adds a new 'pound_os' token, a new case for it in parseExprPostfix, and parsing of platform version constraints, e.g., OSX >= 10.10.
It also adds enough type checking and SILGen to get the parsing tests to run without triggering "Unimplemented" assertions.
Swift SVN r21865
it indirectly through another pointer from Decl, just embed DeclAttributes
directly into Decl and get rid of the "getMutableAttrs" nonsense.
Swift SVN r20216
Completely disable the AST transformation for single-expression closures. When
this transformation picks up an incomplete expression, the resulting AST is
almost guaranteed to have type mismatches, and the type checker just marks
everything with error types.
rdar://17193319 rdar://17086137
Swift SVN r20153
Introduce the new BooleanLiteralConvertible protocol for Boolean
literals. Take "true" and "false" as real keywords (which is most of the
reason for the testsuite churn). Make Bool BooleanLiteralConvertible
and the default Boolean literal type, and ObjCBool
BooleanLiteralConvertible. Fixes <rdar://problem/17405310> and the
recent regression that made ObjCBool not work with true/false.
Swift SVN r19728
- Change the parser to accept "objc" without an @ sign as a contextual
keyword, including the dance to handle the general parenthesized case.
- Update all comments to refer to "objc" instead of "@objc".
- Update all diagnostics accordingly.
- Update all tests that fail due to the diagnostics change.
- Switch the stdlib to use the new syntax.
This does not switch all tests to use the new syntax, nor does it warn about
the old syntax yet. That will be forthcoming. Also, this needs a bit of
refactoring, which will be coming up.
Swift SVN r19555
We were working around this in several different places, which was
error-prone (see <rdar://problem/17479771>). This way, we always have
usable left/right delimiter locations.
Swift SVN r19292
This is all goodness, and eliminates a major source of implicit conversions.
One thing this regresses on though, is that we now reject "x == nil" where
x is an option type and the element of the optional is not Equtatable. If
this is important, there are ways to enable this, but directly testing it as
a logic value is more straight-forward.
This does not include support for pattern matching against nil, that will be
a follow on patch.
Swift SVN r18918
Do this by only warning on self-referential uses of a variable when there's
not another binding found in the local scope. This probably still restricts
some reasonable edge cases, but it at least allows shadowing the variable
with a local name.
<rdar://problem/17087232>
Swift SVN r18771
There's a bit of a reshuffle of the ExplicitCastExpr subclasses:
- The existing ConditionalCheckedCastExpr expression node now represents
"as?".
- A new ForcedCheckedCastExpr node represents "as" when it is a
downcast.
- CoerceExpr represents "as" when it is a coercion.
- A new UnresolvedCheckedCastExpr node describes "as" before it has
been type-checked down to ForcedCheckedCastExpr or CoerceExpr. This
wasn't a strictly necessary change, but it helps us detangle what's
going on.
There are a few new diagnostics to help users avoid getting bitten by
as/as? mistakes:
- Custom errors when a forced downcast (as) is used as the operand
of postfix '!' or '?', with Fix-Its to remove the '!' or make the
downcast conditional (with as?), respectively.
- A warning when a forced downcast is injected into an optional,
with a suggestion to use a conditional downcast.
- A new error when the postfix '!' is used for a contextual
downcast, with a Fix-It to replace it with "as T" with the
contextual type T.
Lots of test updates, none of which felt like regressions. The new
tests are in test/expr/cast/optionals.swift.
Addresses <rdar://problem/17000058>
Swift SVN r18556
This preserves more of source info (e.g. API name location) and simplifies things since
we don't have to construct ParamDecls for the unnamed parameters later on.
Swift SVN r17828
