mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
4cc616f2be
this type is only going to cover dependent types for which there is absolutely no structure. Still no functionality change. Swift SVN r1292
286 lines
8.6 KiB
C++
286 lines
8.6 KiB
C++
//===--- ParsePattern.cpp - Swift Language Parser for Patterns ------------===//
|
|
//
|
|
// This source file is part of the Swift.org open source project
|
|
//
|
|
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
|
|
// Licensed under Apache License v2.0 with Runtime Library Exception
|
|
//
|
|
// See http://swift.org/LICENSE.txt for license information
|
|
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Pattern Parsing and AST Building
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "Parser.h"
|
|
using namespace swift;
|
|
|
|
/// Check that the given type is fully-typed.
|
|
/// FIXME: this is *terrible* for source locations.
|
|
static bool checkFullyTyped(Parser &P, Type type) {
|
|
switch (type->getKind()) {
|
|
// Any sort of non-structural type can be ignored here.
|
|
// Many of these are not actually possible to encounter in the
|
|
// parser, but it's okay.
|
|
case TypeKind::Error:
|
|
case TypeKind::BuiltinInteger:
|
|
case TypeKind::BuiltinFloat:
|
|
case TypeKind::BuiltinObjectPointer:
|
|
case TypeKind::NameAlias: // FIXME: underlying type could be non-fully-typed!
|
|
case TypeKind::Identifier:
|
|
case TypeKind::Protocol:
|
|
case TypeKind::OneOf:
|
|
case TypeKind::MetaType:
|
|
case TypeKind::Module:
|
|
case TypeKind::UnstructuredDependent:
|
|
return false;
|
|
|
|
case TypeKind::Paren:
|
|
return checkFullyTyped(P, cast<ParenType>(type)->getUnderlyingType());
|
|
|
|
case TypeKind::LValue:
|
|
return checkFullyTyped(P, cast<LValueType>(type)->getObjectType());
|
|
|
|
case TypeKind::Array:
|
|
return checkFullyTyped(P, cast<ArrayType>(type)->getBaseType());
|
|
|
|
case TypeKind::Function: {
|
|
FunctionType *fn = cast<FunctionType>(type);
|
|
return checkFullyTyped(P, fn->getInput())
|
|
| checkFullyTyped(P, fn->getResult());
|
|
}
|
|
|
|
case TypeKind::Tuple: {
|
|
TupleType *tuple = cast<TupleType>(type);
|
|
bool isInvalid = false;
|
|
for (auto &elt : tuple->getFields()) {
|
|
if (elt.getType().isNull()) {
|
|
assert(elt.hasInit());
|
|
P.diagnose(elt.getInit()->getLoc(),
|
|
diag::untyped_tuple_elt_in_function_signature)
|
|
<< elt.getInit()->getSourceRange();
|
|
isInvalid = true;
|
|
} else {
|
|
isInvalid |= checkFullyTyped(P, elt.getType());
|
|
}
|
|
}
|
|
return isInvalid;
|
|
}
|
|
}
|
|
llvm_unreachable("bad type kind");
|
|
}
|
|
|
|
/// Check that the given pattern is fully-typed.
|
|
static bool checkFullyTyped(Parser &P, Pattern *pattern) {
|
|
switch (pattern->getKind()) {
|
|
// Any type with an explicit annotation is okay, as long as the
|
|
// annotation is fully-typed.
|
|
case PatternKind::Typed:
|
|
return checkFullyTyped(P, pattern->getType());
|
|
|
|
// Paren types depend on their parenthesized pattern.
|
|
case PatternKind::Paren: {
|
|
Pattern *sub = cast<ParenPattern>(pattern)->getSubPattern();
|
|
if (checkFullyTyped(P, sub)) return true;
|
|
pattern->setType(sub->getType());
|
|
return false;
|
|
}
|
|
|
|
// Tuple types can be built up from their components.
|
|
case PatternKind::Tuple: {
|
|
TuplePattern *tuple = cast<TuplePattern>(pattern);
|
|
SmallVector<TupleTypeElt, 8> typeElts;
|
|
typeElts.reserve(tuple->getNumFields());
|
|
for (const TuplePatternElt &elt : tuple->getFields()) {
|
|
Pattern *subpattern = elt.getPattern();
|
|
if (checkFullyTyped(P, subpattern))
|
|
return true;
|
|
typeElts.push_back(TupleTypeElt(subpattern->getType(),
|
|
subpattern->getBoundName(),
|
|
elt.getInit()));
|
|
}
|
|
tuple->setType(TupleType::get(typeElts, P.Context));
|
|
return false;
|
|
}
|
|
|
|
// Everything else is uninferrable.
|
|
case PatternKind::Named:
|
|
case PatternKind::Any:
|
|
P.diagnose(pattern->getLoc(), diag::untyped_pattern_in_function_signature)
|
|
<< pattern->getSourceRange();
|
|
return true;
|
|
}
|
|
llvm_unreachable("bad pattern kind");
|
|
}
|
|
|
|
/// parseFunctionSignature - Parse a function definition signature.
|
|
/// func-signature:
|
|
/// pattern-tuple+ func-signature-result?
|
|
/// func-signature-result:
|
|
/// '->' type
|
|
bool Parser::parseFunctionSignature(SmallVectorImpl<Pattern*> ¶ms,
|
|
Type &type) {
|
|
// Parse curried function argument clauses as long as we can.
|
|
bool hasSemaError = false;
|
|
do {
|
|
ParseResult<Pattern> pattern = parsePatternTuple();
|
|
if (pattern.isParseError()) {
|
|
return true;
|
|
} else if (pattern.isSemaError()) {
|
|
hasSemaError = true;
|
|
} else {
|
|
params.push_back(pattern.get());
|
|
}
|
|
} while (Tok.is(tok::l_paren) || Tok.is(tok::l_paren_space));
|
|
|
|
// If there's a trailing arrow, parse the rest as the result type.
|
|
if (consumeIf(tok::arrow)) {
|
|
if (parseType(type))
|
|
return true;
|
|
|
|
checkFullyTyped(*this, type);
|
|
|
|
// Otherwise, we implicitly return ().
|
|
} else {
|
|
type = TupleType::getEmpty(Context);
|
|
}
|
|
|
|
// Now build up the function type. We require all function
|
|
// signatures to be fully-typed: that is, all top-down paths to a
|
|
// leaf pattern must pass through a TypedPattern.
|
|
for (unsigned i = params.size(); i != 0; --i) {
|
|
Pattern *param = params[i - 1];
|
|
|
|
Type paramType;
|
|
if (checkFullyTyped(*this, param)) {
|
|
// Recover by ignoring everything.
|
|
paramType = TupleType::getEmpty(Context);
|
|
} else {
|
|
paramType = param->getType();
|
|
}
|
|
type = FunctionType::get(paramType, type, Context);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/// Parse a pattern.
|
|
/// pattern ::= pattern-atom
|
|
/// pattern ::= pattern-atom ':' type-annotation
|
|
ParseResult<Pattern> Parser::parsePattern() {
|
|
// First, parse the pattern atom.
|
|
ParseResult<Pattern> pattern = parsePatternAtom();
|
|
if (pattern.isParseError()) return true;
|
|
|
|
// Now parse an optional type annotation.
|
|
if (consumeIf(tok::colon)) {
|
|
Type type;
|
|
if (parseTypeAnnotation(type))
|
|
return true;
|
|
|
|
if (!pattern.isSemaError())
|
|
pattern = new (Context) TypedPattern(pattern.get(), type);
|
|
}
|
|
|
|
return pattern;
|
|
}
|
|
|
|
/// Parse a pattern "atom", meaning the part that precedes the
|
|
/// optional type annotation.
|
|
///
|
|
/// pattern-atom ::= identifier
|
|
/// pattern-atom ::= pattern-tuple
|
|
ParseResult<Pattern> Parser::parsePatternAtom() {
|
|
switch (Tok.getKind()) {
|
|
case tok::l_paren:
|
|
case tok::l_paren_space:
|
|
return parsePatternTuple();
|
|
|
|
case tok::identifier: {
|
|
SourceLoc loc = Tok.getLoc();
|
|
StringRef text = Tok.getText();
|
|
consumeToken(tok::identifier);
|
|
|
|
// '_' is a special case which means 'ignore this'.
|
|
if (text == "_") {
|
|
return new (Context) AnyPattern(loc);
|
|
} else {
|
|
Identifier ident = Context.getIdentifier(text);
|
|
VarDecl *var = new (Context) VarDecl(loc, ident, Type(), nullptr,
|
|
CurDeclContext);
|
|
return new (Context) NamedPattern(var);
|
|
}
|
|
}
|
|
|
|
default:
|
|
diagnose(Tok, diag::expected_pattern);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/// Parse a tuple pattern.
|
|
///
|
|
/// pattern-tuple:
|
|
//// '(' pattern-tuple-body? ')'
|
|
/// pattern-tuple-body:
|
|
/// pattern-tuple-element (',' pattern-tuple-body)*
|
|
/// pattern-tuple-element:
|
|
/// pattern ('=' expr)?
|
|
ParseResult<Pattern> Parser::parsePatternTuple() {
|
|
assert(Tok.is(tok::l_paren) || Tok.is(tok::l_paren_space));
|
|
|
|
// We're looking at the left parenthesis; consume it.
|
|
SourceLoc lp = consumeToken();
|
|
|
|
// Parse all the elements.
|
|
SmallVector<TuplePatternElt, 8> elts;
|
|
bool hasSemaError = false;
|
|
if (Tok.isNot(tok::r_paren)) {
|
|
do {
|
|
ParseResult<Pattern> pattern = parsePattern();
|
|
Expr *init = nullptr;
|
|
|
|
if (pattern.isParseError()) {
|
|
skipUntil(tok::r_paren);
|
|
return true;
|
|
} else if (consumeIf(tok::equal)) {
|
|
NullablePtr<Expr> initR = parseExpr(diag::expected_initializer_expr);
|
|
if (initR.isNull()) {
|
|
skipUntil(tok::r_paren);
|
|
return true;
|
|
}
|
|
|
|
init = initR.get();
|
|
}
|
|
|
|
if (pattern.isSemaError()) {
|
|
hasSemaError = true;
|
|
} else {
|
|
elts.push_back(TuplePatternElt(pattern.get(), init));
|
|
}
|
|
} while (consumeIf(tok::comma));
|
|
|
|
if (Tok.isNot(tok::r_paren)) {
|
|
diagnose(Tok, diag::expected_rparen_tuple_pattern_list);
|
|
skipUntil(tok::r_paren);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// Consume the right parenthesis.
|
|
SourceLoc rp = consumeToken(tok::r_paren);
|
|
|
|
if (hasSemaError)
|
|
return ParseResult<Pattern>::getSemaError();
|
|
|
|
// A pattern which wraps a single anonymous pattern is not a tuple.
|
|
if (elts.size() == 1 &&
|
|
elts[0].getInit() == nullptr &&
|
|
elts[0].getPattern()->getBoundName().empty())
|
|
return new (Context) ParenPattern(lp, elts[0].getPattern(), rp);
|
|
|
|
return TuplePattern::create(Context, lp, elts, rp);
|
|
}
|