public NamedFunctionDeclarationSyntax ParseNamedFunction(
FixedList <AttributeSyntax> attributes,
FixedList <IModiferToken> modifiers)
{
Tokens.Expect <IFunctionKeywordToken>();
var identifier = Tokens.RequiredToken <IIdentifierToken>();
var genericParameters = AcceptGenericParameters();
var name = nameContext.Qualify(identifier.Value);
var bodyParser = NestedParser(name);
var parameters = bodyParser.ParseParameters();
var lifetimeBounds = bodyParser.ParseLifetimeBounds();
ExpressionSyntax returnType = null;
if (Tokens.Accept <IRightArrowToken>())
{
returnType = ParseExpression();
}
var genericConstraints = ParseGenericConstraints();
var mayEffects = ParseMayEffects();
var noEffects = ParseNoEffects();
var(requires, ensures) = ParseFunctionContracts();
var body = bodyParser.ParseFunctionBody();
return(new NamedFunctionDeclarationSyntax(File, modifiers, name, identifier.Span,
genericParameters, parameters, lifetimeBounds, returnType, genericConstraints, mayEffects,
noEffects, requires, ensures, body));
}
private FieldDeclarationSyntax ParseField(
FixedList <AttributeSyntax> attributes,
FixedList <IModiferToken> modifiers)
{
// TODO include these in the syntax tree
var binding = Tokens.Expect <IBindingToken>();
var getterAccess = AcceptFieldGetter();
var identifier = Tokens.RequiredToken <IIdentifierToken>();
var name = nameContext.Qualify(identifier.Value);
ExpressionSyntax typeExpression = null;
if (Tokens.Accept <IColonToken>())
{
// Need to not consume the assignment that separates the type from the initializer,
// hence the min operator precedence.
typeExpression = ParseExpression(OperatorPrecedence.AboveAssignment);
}
ExpressionSyntax initializer = null;
if (Tokens.Accept <IEqualsToken>())
{
initializer = ParseExpression();
}
Tokens.Expect <ISemicolonToken>();
return(new FieldDeclarationSyntax(File, attributes, modifiers, getterAccess, name,
identifier.Span, typeExpression, initializer));
}
private ThrowEffectEntrySyntax ParseThrowEffectEntry()
{
var isParams = Tokens.Accept <IParamsKeywordToken>();
var exceptionType = ParseExpression();
return(new ThrowEffectEntrySyntax(isParams, exceptionType));
}
private ConstDeclarationSyntax ParseConst(
FixedList <AttributeSyntax> attributes,
FixedList <IModiferToken> modifiers)
{
try
{
Tokens.Expect <IConstKeywordToken>();
var identifier = Tokens.RequiredToken <IIdentifierToken>();
var name = nameContext.Qualify(identifier.Value);
ExpressionSyntax type = null;
if (Tokens.Accept <IColonToken>())
{
// Need to not consume the assignment that separates the type from the initializer,
// hence the min operator precedence.
type = ParseExpression(OperatorPrecedence.AboveAssignment);
}
ExpressionSyntax initializer = null;
if (Tokens.Accept <IEqualsToken>())
{
initializer = ParseExpression();
}
Tokens.Expect <ISemicolonToken>();
return(new ConstDeclarationSyntax(File, attributes, modifiers, name,
identifier.Span, type, initializer));
}
catch (ParseFailedException)
{
SkipToEndOfStatement();
throw;
}
}
internal FieldDeclarationSyntax ParseField(
IClassDeclarationSyntax declaringType,
bool mutableBinding,
ModifierParser modifiers)
{
var accessModifer = modifiers.ParseAccessModifier();
modifiers.ParseEndOfModifiers();
// We should only be called when there is a binding keyword
var binding = Tokens.Required <IBindingToken>();
var identifier = Tokens.RequiredToken <IIdentifierToken>();
Name name = identifier.Value;
Tokens.Expect <IColonToken>();
var type = ParseType();
IExpressionSyntax?initializer = null;
if (Tokens.Accept <IEqualsToken>())
{
initializer = ParseExpression();
}
var semicolon = Tokens.Expect <ISemicolonToken>();
var span = TextSpan.Covering(binding, semicolon);
return(new FieldDeclarationSyntax(declaringType, span, File, accessModifer, mutableBinding,
identifier.Span, name, type, initializer));
}
// Requires the binding has already been consumed
private IStatementSyntax ParseRestOfVariableDeclaration(
TextSpan binding,
bool mutableBinding)
{
var identifier = Tokens.RequiredToken <IIdentifierToken>();
var name = identifier.Value;
ITypeSyntax?type = null;
bool inferMutableType = false;
if (Tokens.Accept <IColonToken>())
{
(type, inferMutableType) = ParseVariableDeclarationType();
}
IExpressionSyntax?initializer = null;
if (Tokens.Accept <IEqualsToken>())
{
initializer = ParseExpression();
}
var semicolon = Tokens.Expect <ISemicolonToken>();
var span = TextSpan.Covering(binding, semicolon);
return(new VariableDeclarationStatementSyntax(span,
mutableBinding, name, identifier.Span, type, inferMutableType, initializer));
}
private ExpressionSyntax AcceptBaseClass()
{
if (!Tokens.Accept <IColonToken>())
{
return(null);
}
return(ParseExpression());
}
private FixedList <ExpressionSyntax> AcceptBaseTypes()
{
if (!Tokens.Accept <ILessThanColonToken>())
{
return(null);
}
return(AcceptOneOrMore <ExpressionSyntax, ICommaToken>(ParseExpression));
}
private ExpressionSyntax AcceptInvariant()
{
if (!Tokens.Accept <IInvariantKeywordToken>())
{
return(null);
}
return(ParseExpression());
}
private FixedList <EffectSyntax> ParseNoEffects()
{
if (!Tokens.Accept <INoKeywordToken>())
{
return(FixedList <EffectSyntax> .Empty);
}
return(AcceptOneOrMore <EffectSyntax, ICommaToken>(ParseEffect));
}
private (ITypeSyntax?, IReachabilityAnnotationsSyntax) ParseReturn()
{
if (Tokens.Accept <IRightArrowToken>())
{
return(ParseType(), ParseReachabilityAnnotations());
}
return(null, new ReachabilityAnnotationsSyntax(Tokens.Current.Span.AtStart(), null, null));
}
public BlockSyntax AcceptBlock()
{
var openBrace = Tokens.Current.Span;
if (!Tokens.Accept <IOpenBraceToken>())
{
return(null);
}
return(ParseRestOfBlock(openBrace));
}
public GenericConstraintSyntax AcceptGenericConstraint()
{
if (!Tokens.Accept <IWhereKeywordToken>())
{
return(null);
}
var expression = ParseExpression();
return(new GenericConstraintSyntax(expression));
}
/// <summary>
/// Skip tokens until we reach what we assume to be the end of a statement
/// </summary>
// TODO does this belong on a statement parser or something
private void SkipToEndOfStatement()
{
while (!Tokens.AtEnd <ISemicolonToken>())
{
Tokens.Next();
}
// Consume the semicolon is we aren't at the end of the file.
var _ = Tokens.Accept <ISemicolonToken>();
}
public FixedList <GenericParameterSyntax> AcceptGenericParameters()
{
if (!Tokens.Accept <IOpenBracketToken>())
{
return(null);
}
var parameters = ParseMany <GenericParameterSyntax, ICommaToken, ICloseBracketToken>(ParseGenericParameter);
Tokens.Expect <ICloseBracketToken>();
return(parameters);
}
public ExpressionSyntax ParseName()
{
ExpressionSyntax name = ParseSimpleName();
while (Tokens.Accept <IDotToken>())
{
var simpleName = ParseSimpleName();
var span = TextSpan.Covering(name.Span, simpleName.Span);
name = new MemberAccessExpressionSyntax(span, name, AccessOperator.Standard, simpleName);
}
return(name);
}
public ParameterSyntax ParseParameter()
{
switch (Tokens.Current)
{
case IRefKeywordToken _:
case IMutableKeywordToken _:
case ISelfKeywordToken _:
{
var span = Tokens.Current.Span;
var refSelf = Tokens.Accept <IRefKeywordToken>();
var mutableSelf = Tokens.Accept <IMutableKeywordToken>();
var selfSpan = Tokens.Expect <ISelfKeywordToken>();
span = TextSpan.Covering(span, selfSpan);
var name = nameContext.Qualify(SpecialName.Self);
return(new SelfParameterSyntax(span, name, refSelf, mutableSelf));
}
case IDotToken _:
{
var dot = Tokens.Expect <IDotToken>();
var identifier = Tokens.RequiredToken <IIdentifierToken>();
var equals = Tokens.AcceptToken <IEqualsToken>();
ExpressionSyntax defaultValue = null;
if (equals != null)
{
defaultValue = ParseExpression();
}
var span = TextSpan.Covering(dot, identifier.Span, defaultValue?.Span);
var name = nameContext.Qualify(SimpleName.Special("field_" + identifier.Value));
return(new FieldParameterSyntax(span, name, defaultValue));
}
default:
{
var span = Tokens.Current.Span;
var isParams = Tokens.Accept <IParamsKeywordToken>();
var mutableBinding = Tokens.Accept <IVarKeywordToken>();
var identifier = Tokens.RequiredToken <IIdentifierOrUnderscoreToken>();
var name = nameContext.Qualify(variableNumbers.VariableName(identifier.Value));
Tokens.Expect <IColonToken>();
// Need to not consume the assignment that separates the type from the default value,
// hence the min operator precedence.
var type = ParseExpression(OperatorPrecedence.AboveAssignment);
ExpressionSyntax defaultValue = null;
if (Tokens.Accept <IEqualsToken>())
{
defaultValue = ParseExpression();
}
span = TextSpan.Covering(span, type.Span, defaultValue?.Span);
return(new NamedParameterSyntax(span, isParams, mutableBinding, name, type, defaultValue));
}
}
}
private AttributeSyntax AcceptAttribute()
{
if (!Tokens.Accept <IHashHashToken>())
{
return(null);
}
var name = ParseName();
FixedList <ArgumentSyntax> arguments = null;
if (Tokens.Accept <IOpenParenToken>())
{
arguments = ParseArguments();
Tokens.Expect <ICloseParenToken>();
}
return(new AttributeSyntax(name, arguments));
}
public UsingDirectiveSyntax AcceptUsingDirective()
{
if (!Tokens.Accept <IUsingKeywordToken>())
{
return(null);
}
var identifiers = AcceptOneOrMore <IIdentifierToken, IDotToken>(
() => Tokens.AcceptToken <IIdentifierToken>());
RootName name = GlobalNamespaceName.Instance;
foreach (var identifier in identifiers)
{
name = name.Qualify(identifier.Value);
}
Tokens.Expect <ISemicolonToken>();
return(new UsingDirectiveSyntax((Name)name));
}
public GenericParameterSyntax ParseGenericParameter()
{
Name name;
var dollar = Tokens.AcceptToken <IDollarToken>();
if (dollar != null)
{
var lifetime = Tokens.RequiredToken <ILifetimeNameToken>();
var span = TextSpan.Covering(dollar.Span, lifetime.Span);
switch (lifetime)
{
case IIdentifierToken lifetimeIdentifier:
name = nameContext.Qualify(lifetimeIdentifier.Value);
break;
case IRefKeywordToken _:
name = nameContext.Qualify(SpecialName.Ref);
break;
case IOwnedKeywordToken _:
Add(ParseError.OwnedNotValidAsGenericLifetimeParameter(File, span));
// We just treat it as if they had written `$\owned`
name = nameContext.Qualify("owned");
break;
default:
throw NonExhaustiveMatchException.For(lifetime);
}
return(new GenericParameterSyntax(true, false, name, null));
}
var isParams = Tokens.Accept <IParamsKeywordToken>();
var identifier = Tokens.RequiredToken <IIdentifierToken>();
name = nameContext.Qualify(identifier.Value);
ExpressionSyntax typeExpression = null;
if (Tokens.Accept <IColonToken>())
{
typeExpression = ParseExpression();
}
return(new GenericParameterSyntax(false, isParams, name, typeExpression));
}
public INamedParameterSyntax ParseFunctionParameter()
{
var span = Tokens.Current.Span;
var mutableBinding = Tokens.Accept <IVarKeywordToken>();
var identifier = Tokens.RequiredToken <IIdentifierOrUnderscoreToken>();
var name = identifier.Value;
Tokens.Expect <IColonToken>();
var type = ParseType();
IExpressionSyntax?defaultValue = null;
if (Tokens.Accept <IEqualsToken>())
{
defaultValue = ParseExpression();
}
span = TextSpan.Covering(span, type.Span, defaultValue?.Span);
return(new NamedParameterSyntax(span, mutableBinding, name, type, defaultValue));
}
public IParameterSyntax ParseMethodParameter()
{
switch (Tokens.Current)
{
case IMutableKeywordToken _:
case ISelfKeywordToken _:
{
var span = Tokens.Current.Span;
var mutableSelf = Tokens.Accept <IMutableKeywordToken>();
var selfSpan = Tokens.Expect <ISelfKeywordToken>();
span = TextSpan.Covering(span, selfSpan);
return(new SelfParameterSyntax(span, mutableSelf));
}
default:
return(ParseFunctionParameter());
}
}
public FixedList <T> ParseMany <T, TSeparator, TTerminator>(Func <T> parseItem)
where T : class
where TSeparator : class, IToken
where TTerminator : IToken
{
var items = new List <T>();
while (!Tokens.AtEnd <TTerminator>())
{
items.Add(parseItem());
if (!Tokens.Accept <TSeparator>())
{
break;
}
}
return(items.ToFixedList());
}
public FixedList <T> AcceptSeparatedList <T, TSeparator>(Func <T> acceptItem)
where T : class
where TSeparator : class, IToken
{
var items = new List <T>();
var item = acceptItem();
while (item != null)
{
items.Add(item);
if (!Tokens.Accept <TSeparator>())
{
break;
}
item = acceptItem();
}
return(items.ToFixedList());
}
private NameSyntax ParseSimpleName()
{
var identifier = Tokens.RequiredToken <IIdentifierToken>();
var name = new SimpleName(identifier.Value);
NameSyntax syntax;
if (Tokens.Accept <IOpenBracketToken>())
{
var arguments = ParseArguments();
var closeBracket = Tokens.Expect <ICloseBracketToken>();
var span = TextSpan.Covering(identifier.Span, closeBracket);
syntax = new GenericNameSyntax(span, identifier.Value, arguments);
}
else
{
syntax = new IdentifierNameSyntax(identifier.Span, name);
}
return(syntax);
}
private (NamespaceName, TextSpan) ParseNamespaceName()
{
var firstSegment = Tokens.RequiredToken <IIdentifierToken>();
var span = firstSegment.Span;
NamespaceName name = firstSegment.Value;
while (Tokens.Accept <IDotToken>())
{
var(nameSegment, segmentSpan) = Tokens.ExpectToken <IIdentifierToken>();
// We need the span to cover a trailing dot
span = TextSpan.Covering(span, segmentSpan);
if (nameSegment is null)
{
break;
}
name = name.Qualify(nameSegment.Value);
}
return(name, span);
}
/// <summary>
/// Parse an expected item and then parse additional items as long as there is
/// a separator.
/// </summary>
public FixedList <T> ParseManySeparated <T, TSeparator>(Func <T> parseItem)
//where T : class
where TSeparator : class, IToken
{
var item = parseItem();
if (item is null)
{
throw new ParseFailedException();
}
var items = new List <T>()
{
item
};
while (Tokens.Accept <TSeparator>())
{
items.Add(parseItem());
}
return(items.ToFixedList());
}
// Requires the binding has already been consumed
private StatementSyntax ParseRestOfVariableDeclaration(bool mutableBinding)
{
var identifier = Tokens.RequiredToken <IIdentifierToken>();
var name = this.nameContext.Qualify(variableNumbers.VariableName(identifier.Value));
ExpressionSyntax type = null;
if (Tokens.Accept <IColonToken>())
{
// Need to not consume the assignment that separates the type from the initializer,
// hence the min operator precedence.
type = ParseExpression(OperatorPrecedence.LogicalOr);
}
ExpressionSyntax initializer = null;
if (Tokens.Accept <IEqualsToken>())
{
initializer = ParseExpression();
}
Tokens.Expect <ISemicolonToken>();
return(new VariableDeclarationStatementSyntax(mutableBinding, name, identifier.Span, type,
initializer));
}
public FixedList <T> AcceptOneOrMore <T, TSeparator>(Func <T> acceptItem)
where T : class
where TSeparator : class, IToken
{
var item = acceptItem();
if (item == null)
{
throw new ParseFailedException();
}
var items = new List <T>();
while (item != null)
{
items.Add(item);
if (!Tokens.Accept <TSeparator>())
{
break;
}
item = acceptItem();
}
return(items.ToFixedList());
}
public OperatorDeclarationSyntax ParseOperator(
FixedList <AttributeSyntax> attributes,
FixedList <IModiferToken> modifiers)
{
var operatorKeyword = Tokens.Expect <IOperatorKeywordToken>();
var genericParameters = AcceptGenericParameters();
// TODO correctly store these in the syntax class
OverloadableOperator oper;
TextSpan endOperatorSpan;
switch (Tokens.Current)
{
case IHashToken _:
Tokens.Expect <IHashToken>();
switch (Tokens.Current)
{
case IOpenParenToken _:
Tokens.Next();
endOperatorSpan = Tokens.Expect <ICloseParenToken>();
oper = OverloadableOperator.TupleInitializer;
break;
case IOpenBracketToken _:
Tokens.Next();
endOperatorSpan = Tokens.Expect <ICloseBracketToken>();
oper = OverloadableOperator.ListInitializer;
break;
case IOpenBraceToken _:
Tokens.Next();
endOperatorSpan = Tokens.Expect <ICloseBraceToken>();
oper = OverloadableOperator.SetInitializer;
break;
default:
throw NonExhaustiveMatchException.For(Tokens.Current);
}
break;
case IStringLiteralToken _:
endOperatorSpan = Tokens.Expect <IStringLiteralToken>();
// TODO need to check it is empty string
oper = OverloadableOperator.StringLiteral;
break;
// TODO case for user defined literals ''
default:
Tokens.UnexpectedToken();
throw new ParseFailedException();
}
var nameSpan = TextSpan.Covering(operatorKeyword, endOperatorSpan);
var name = nameContext.Qualify(SimpleName.Special("op_" + oper));
var bodyParser = NestedParser(name);
var parameters = bodyParser.ParseParameters();
var lifetimeBounds = bodyParser.ParseLifetimeBounds();
ExpressionSyntax returnType = null;
if (Tokens.Accept <IRightArrowToken>())
{
returnType = bodyParser.ParseExpression();
}
var genericConstraints = ParseGenericConstraints();
var mayEffects = ParseMayEffects();
var noEffects = ParseNoEffects();
var(requires, ensures) = ParseFunctionContracts();
var body = bodyParser.ParseBlock();
return(new OperatorDeclarationSyntax(File, modifiers, name, nameSpan, genericParameters,
parameters, lifetimeBounds, returnType, genericConstraints, mayEffects, noEffects, requires,
ensures, body));
}