/**
* Parses the rest of a v-name, and constructs an AST to represent its phrase
* structure.
*
* @param firstIdentifier
* the {@link triangle.compiler.syntax.trees.terminals.Identifier}
* that is the start of the
* {@link triangle.compiler.syntax.trees.vnames.Vname}
*
* @return a {@link triangle.compiler.syntax.trees.vnames.Vname}
*
* @throws SyntaxError
* a syntactic error
*
*/
Vname ParseRestOfVname(Identifier firstIdentifier)
{
var startLocation = firstIdentifier.Start;
Vname vname = new SimpleVname(firstIdentifier, firstIdentifier.Position);
while (_currentToken.Kind == TokenKind.Dot ||
_currentToken.Kind == TokenKind.LeftBracket)
{
if (_currentToken.Kind == TokenKind.Dot)
{
AcceptIt();
var identifier = ParseIdentifier();
var vnamePosition = new SourcePosition(startLocation, _currentToken.Finish);
vname = new DotVname(vname, identifier, vnamePosition);
}
else
{
AcceptIt();
var expression = ParseExpression();
Accept(TokenKind.RightBracket);
var vnamePosition = new SourcePosition(startLocation, _currentToken.Finish);
vname = new SubscriptVname(vname, expression, vnamePosition);
}
}
return(vname);
}
public IFetchableEntity VisitSubscriptVname(SubscriptVname ast, Frame frame)
{
var baseObject = ast.Vname.Visit(this, frame);
var elemSize = ast.Type.Visit(this, null);
if (!ast.Expression.IsLiteral)
{
// v-name is indexed by a proper expression, not a literal
if (ast.Vname.IsIndexed)
{
frame = frame.Expand(Machine.IntegerSize);
}
ast.Expression.Visit(this, frame);
if (elemSize != 1)
{
_emitter.Emit(OpCode.LOADL, elemSize);
_emitter.Emit(OpCode.CALL, Register.SB, Register.PB, Primitive.MULT);
}
if (ast.Vname.IsIndexed)
{
_emitter.Emit(OpCode.CALL, Register.SB, Register.PB, Primitive.ADD);
}
}
return(baseObject);
}
public TypeDenoter VisitSubscriptVname(SubscriptVname ast, Void arg)
{
var vnameType = ast.Vname.Visit(this);
var expressionType = ast.Expression.Visit(this);
if (vnameType != StandardEnvironment.ErrorType)
{
if (vnameType is ArrayTypeDenoter arrayType)
{
CheckAndReportError(expressionType.Equals(StandardEnvironment.IntegerType),
"Integer expression expected here", ast.Expression);
ast.Type = arrayType.Type;
}
else
{
ReportError("array expected here", ast.Vname);
}
}
return(ast.Type);
}
