/// <summary>
/// Matches a <c>Primary</c> non-terminal.
/// </summary>
/// <returns><c>true</c> if the <c>Primary</c> was matched successfully; otherwise, <c>false</c>.</returns>
/// <remarks>
/// The non-terminal can start with: <c>Nil</c>, <c>False</c>, <c>True</c>, <c>Number</c>, <c>String</c>.
/// </remarks>
protected virtual bool MatchPrimary(out Expression expression) {
expression = null;
if (this.TokenIs(this.LookAheadToken, LuatTokenId.Nil)) {
if (!this.Match(LuatTokenId.Nil))
return false;
expression = new NilExpression( this.Token.TextRange );
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.False)) {
if (!this.Match(LuatTokenId.False))
return false;
expression = new BooleanExpression( false, this.Token.TextRange);
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.True)) {
if (!this.Match(LuatTokenId.True))
return false;
expression = new BooleanExpression( true, this.Token.TextRange);
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.Number)) {
if (!this.Match(LuatTokenId.Number))
return false;
expression = new NumberExpression( Convert.ToDouble(this.TokenText), this.Token.TextRange );
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.String)) {
if (!this.MatchStringExpression(out expression))
return false;
}
else
return false;
return true;
}
public override bool Install(LuatScript script)
{
if (false == base.Install(script))
{
return(false);
}
if (false == IsLocal && Values.Count == 0)
{
// Illegal assignment statement, assumes parser has already emitted error.
return(false);
}
int variableCount = Variables.Count;
for (int variableIndex = 0; variableIndex < variableCount; ++variableIndex)
{
Expression lhs = Variables[variableIndex] as Expression;
Expression rhs;
if (variableIndex < Values.Count)
{
rhs = Values[variableIndex] as Expression;
}
else
{
rhs = new NilExpression(lhs.TextRange);
rhs.Resolve(script);
this.ChildNodes.Add(rhs);
}
LuatVariable variable = lhs.Resolve(script) as LuatVariable;
bool bValid = false;
do
{
if (null == variable)
{
break;
}
if (variable.IsReadOnly)
{
this.AddError(string.Format("{0} is read-only", lhs.DisplayText));
break;
}
bValid = true;
}while (false);
if (false == bValid)
{
// Failed to resolve or create the name.
// Undo all the assignments we've done and return incomplete.
Uninstall(script);
return(false);
}
string displayText = string.Format("{0} = {1}", lhs.DisplayText, rhs.DisplayText);
LuatValue.IReference reference = new Parser.AST.Expression.Reference(script, rhs, displayText);
variable.AddAssignment(reference);
AddUninstallAction(script, delegate() { variable.RemoveAssignment(reference); });
}
return(true);
}
/// <summary>
/// Matches a <c>ExpressionNoFunctionInner</c> non-terminal.
/// </summary>
/// <returns><c>true</c> if the <c>ExpressionNoFunctionInner</c> was matched successfully; otherwise, <c>false</c>.</returns>
/// <remarks>
/// The non-terminal can start with: <c>OpenParenthesis</c>, <c>OpenCurlyBrace</c>, <c>Identifier</c>, <c>TripleDot</c>, <c>Nil</c>, <c>False</c>, <c>True</c>, <c>Number</c>, <c>Subtraction</c>, <c>Not</c>, <c>Hash</c>, <c>String</c>.
/// </remarks>
protected virtual bool MatchExpressionNoFunctionInner(out Expression expression) {
expression = null;
if (this.IsInMultiMatchSet(6, this.LookAheadToken)) {
if (!this.MatchPrimary(out expression))
return false;
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.TripleDot)) {
if (!this.Match(LuatTokenId.TripleDot))
return false;
expression = new NilExpression( this.Token.TextRange );
}
else if (((this.TokenIs(this.LookAheadToken, LuatTokenId.OpenParenthesis)) || (this.TokenIs(this.LookAheadToken, LuatTokenId.OpenCurlyBrace)) || (this.TokenIs(this.LookAheadToken, LuatTokenId.Identifier)))) {
if (this.TokenIs(this.LookAheadToken, LuatTokenId.Identifier)) {
if (!this.MatchVariable(out expression))
return false;
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.OpenCurlyBrace)) {
if (!this.MatchTableConstructor(out expression))
return false;
}
else if (this.TokenIs(this.LookAheadToken, LuatTokenId.OpenParenthesis)) {
if (!this.MatchParenthesis(out expression))
return false;
}
else
return false;
while (this.IsInMultiMatchSet(7, this.LookAheadToken)) {
if (((this.TokenIs(this.LookAheadToken, LuatTokenId.Dot)) || (this.TokenIs(this.LookAheadToken, LuatTokenId.OpenSquareBracket)))) {
if (!this.MatchIndex(ref expression))
return false;
}
else if (this.IsInMultiMatchSet(8, this.LookAheadToken)) {
if (!this.MatchCallSuffix(ref expression))
return false;
}
else
return false;
}
}
else if (((this.TokenIs(this.LookAheadToken, LuatTokenId.Subtraction)) || (this.TokenIs(this.LookAheadToken, LuatTokenId.Not)) || (this.TokenIs(this.LookAheadToken, LuatTokenId.Hash)))) {
int start = this.LookAheadToken.StartOffset;
OperatorType operatorType;
if (!this.MatchUnaryOp(out operatorType))
return false;
Expression rhs = null;
if (!this.MatchExpression(out rhs))
return false;
expression = new UnaryExpression( operatorType, rhs, new TextRange( start, this.Token.EndOffset) );
}
else
return false;
while (this.IsInMultiMatchSet(9, this.LookAheadToken)) {
OperatorType operatorType;
if (!this.MatchBinaryOp(out operatorType))
return false;
Expression rhs = null;
if (!this.MatchExpression(out rhs))
return false;
expression = new BinaryExpression( operatorType, expression, rhs );
}
return true;
}