/// <summary>
/// Parses a top level expression
/// </summary>
/// <returns>An expression syntax tree</returns>
private ExpressionSyntaxTree ParseTopLevelExpression()
{
ExpressionSyntaxTree expression = this.ParseExpression();
if (expression != null)
{
//Make an anonymous prototype
PrototypeSyntaxTree prototype = new PrototypeSyntaxTree("", new List<string>());
return new FunctionSyntaxTree(prototype, expression);
}
return null;
}
/// <summary>
/// Parses a function definition
/// </summary>
/// <returns>A function syntax tree</returns>
private FunctionSyntaxTree ParseDefinition()
{
this.NextToken(); //Consume the def
PrototypeSyntaxTree prototype = this.ParsePrototype();
if (prototype == null)
{
return null;
}
//Parse the body
ExpressionSyntaxTree bodyExpression = this.ParseExpression();
if (bodyExpression != null)
{
return new FunctionSyntaxTree(prototype, bodyExpression);
}
return null;
}
/// <summary>
/// Parses an extern
/// </summary>
/// <returns>A external function syntax tree</returns>
private ExternalFunctionSyntaxTree ParseExtern()
{
this.NextToken(); //Consume the extern
PrototypeSyntaxTree protoType = this.ParsePrototype();
CharacterToken charToken = this.currentToken as CharacterToken;
if ((charToken != null && charToken.Value != ':') || charToken == null)
{
throw new ParserException("Expected ':' after extern");
}
//Consume the :
this.NextToken();
charToken = this.currentToken as CharacterToken;
if ((charToken != null && charToken.Value != ':') || charToken == null)
{
throw new ParserException("Expected ':' after extern");
}
//Consume the :
this.NextToken();
if (this.currentToken.Type != TokenType.Identifier)
{
throw new ParserException("Expected indentifier.");
}
string funcRef = ((IdentifierToken)this.currentToken).Value;
//Consume the identifier
this.NextToken();
return new ExternalFunctionSyntaxTree(protoType, funcRef);
}
/// <summary>
/// Creates a new external function syntax tree
/// </summary>
/// <param name="name">The prototype</param>
/// <param name="funcReference">The name of the external function</param>
public ExternalFunctionSyntaxTree(PrototypeSyntaxTree prototype, string funcReference)
{
this.prototype = prototype;
this.funcReference = funcReference;
}
/// <summary>
/// Creates a new function syntax tree
/// </summary>
/// <param name="name">The prototype</param>
/// <param name="arguments">The body</param>
public FunctionSyntaxTree(PrototypeSyntaxTree prototype, ExpressionSyntaxTree body)
{
this.prototype = prototype;
this.body = body;
}
/// <summary>
/// Creates a new external function syntax tree
/// </summary>
/// <param name="name">The prototype</param>
/// <param name="funcReference">The name of the external function</param>
public ExternalFunctionSyntaxTree(PrototypeSyntaxTree prototype, string funcReference)
{
this.prototype = prototype;
this.funcReference = funcReference;
}
/// <summary>
/// Creates a new function syntax tree
/// </summary>
/// <param name="name">The prototype</param>
/// <param name="arguments">The body</param>
public FunctionSyntaxTree(PrototypeSyntaxTree prototype, ExpressionSyntaxTree body)
{
this.prototype = prototype;
this.body = body;
}
