internal void Accept(NodeEndL endl)
{
builder.currentLineNumber = endl.EndLine;
builder.OpEndL();
}
void ASTVisitor.Accept(NodeEndL value)
{
Accept(value);
}
private Node PrimaryExpression(bool allowPostfixInvocation = true)
{
if (!TokensRemain)
return null;
var loc = Location;
Node node;
switch (Current.type)
{
case WILDCARD:
// If we aren't in a truly anon function, we ignore this
if (CurrentFunction != null && CurrentFunction.fullAnon && CurrentFunction.paramNames.Count == 0)
CurrentFunction.paramNames.Add(null);
node = new NodeWildcard(loc);
Advance();
break;
case PARAM_INDEX:
var index = (uint)Current.intValue;
// If we aren't in a truly anon function, we ignore this
if (CurrentFunction != null && CurrentFunction.fullAnon)
while (CurrentFunction.paramNames.Count <= index)
CurrentFunction.paramNames.Add(null);
node = new NodeParamIndex(loc, index);
Advance();
break;
case IDENTIFIER:
node = new NodeIdentifier(loc, Current.image);
Advance();
break;
case SYMBOL:
node = new NodeSymbol(loc, Current.image);
Advance();
break;
case NULL:
node = new NodeNull(loc);
Advance();
break;
case TRUE:
case FALSE:
node = new NodeBool(loc, Check(TRUE));
Advance();
break;
case ENDL:
node = new NodeEndL(loc);
Advance();
break;
case THIS:
node = new NodeThis(loc);
Advance();
break;
case SELF:
node = new NodeSelf(loc);
Advance();
break;
case INT:
node = new NodeInt(loc, Current.intValue);
Advance();
break;
case FLOAT:
node = new NodeFloat(loc, Current.floatValue);
Advance();
break;
case STRING:
node = new NodeString(loc, Current.image);
Advance();
break;
case OPEN_BRACE:
Advance();
if (Check(CLOSE_BRACE))
{
// 0-length tuple:
node = new NodeTuple(loc, new List<Node>());
node.EndLine = Current.location.line;
Advance();
}
else
{
var values = CommaExpressions();
if (values.Count != 1)
{
// This is a tuple :D
node = new NodeTuple(loc, values);
Expect(CLOSE_BRACE, "Closing brace (')') expected to end tuple expression.");
node.EndLine = tokens[-1].location.line;
}
else
{
Expect(CLOSE_BRACE, "Closing brace (')') expected to surround expression.");
// Just an expression, carry on:
node = values[0];
}
}
break;
case OPEN_SQUARE_BRACE:
// This is a list :D
Advance();
node = new NodeList(loc, (TokensRemain && Current.type != CLOSE_SQUARE_BRACE) ? CommaExpressions() : new List<Node>());
Expect(CLOSE_SQUARE_BRACE, "Closing square brace (']') expected to end list expression.");
node.EndLine = tokens[-1].location.line;
break;
case OPEN_CURLY_BRACE:
// This is a code block :D
Advance();
var exprs = new List<Node>();
while (!Check(CLOSE_CURLY_BRACE))
{
if (!TokensRemain)
{
log.Error(tokens[-1].location, "Unfinished block. A closing curly brace ('}') should be used to end blocks.");
break;
}
var expr = Expression();
if (expr != null)
exprs.Add(expr);
}
Expect(CLOSE_CURLY_BRACE, "Closing curly brace ('}') expected to end block.");
node = new NodeBlock(loc, exprs);
node.EndLine = tokens[-1].location.line;
break;
case TAILREC:
Advance();
Expect(OPEN_BRACE, "Expected an open brace ('(') to begin the tailrec argument list.");
List<Node> args;
if (!Check(CLOSE_BRACE))
args = CommaExpressions();
else args = new List<Node>();
Expect(CLOSE_BRACE, "Expected a close brace (')') to end the tailrec argument list.");
node = new NodeTailRec(loc, args);
break;
// These can't be postfix'd, so we don't allow it.
case OPERATOR:
var prefix = Current.image;
Advance();
if (!TokensRemain)
log.Error(loc, "An expression is expected after prefix operator, but the end of the file was reached.");
var prefixValue = PrimaryExpression();
return new NodePrefix(loc, prefix, prefixValue);
case NOT:
Advance();
if (!TokensRemain)
log.Error(loc, "An expression is expected after the 'not' keyword, but the end of the file was reached.");
return new NodeNot(loc, Expression());
case THROW:
Advance();
if (!TokensRemain)
log.Error(loc, "An expression is expected after the 'throw' keyword, but the end of the file was reached.");
return new NodeThrow(loc, Expression());
case YIELD:
Advance();
if (!TokensRemain)
log.Error(loc, "An expression is expected after the 'yield' keyword, but the end of the file was reached.");
return new NodeYield(loc, Expression());
case RES:
Advance();
if (!TokensRemain)
log.Error(loc, "An expression is expected after the 'res' keyword, but the end of the file was reached.");
return new NodeRes(loc, Expression());
case BREAK:
Advance();
string bLabel = null;
if (Check(IDENTIFIER) && Current.location.line == loc.line)
{
bLabel = Current.image;
Advance();
}
return new NodeBreak(loc, bLabel);
case CONT:
Advance();
string cLabel = null;
if (Check(IDENTIFIER) && Current.location.line == loc.line)
{
cLabel = Current.image;
Advance();
}
return new NodeCont(loc, cLabel);
case FN: return ParseFn();
case GEN: return ParseFn(true);
case VAR: return ParseVar();
case IF: return ParseIf();
case WHILE: return ParseWhile();
case TRY: return ParseTry();
case ITER: return ParseIter();
case EACH: return ParseEach();
// And here, we don't know what they want... oops.
default:
log.Error(Location, "Unexpected token '{0}', skipping...", Current.ToString());
// We don't know what to do with this, let's skip and try to recover.
Advance();
// Error saying we couldn't understand the token:
// return a new primary expression.
return PrimaryExpression();
}
// TODO postfix
return Postfix(node, allowPostfixInvocation);
}