private ASTStatementBase ParseWhile()
{
Require(TokenType.WHILE);
Require(TokenType.LEFT_PARENTHESIS);
ASTExpressionBase condition = ParseExpression();
Require(TokenType.RIGHT_PARENTHESIS);
_loopLevel++;
ASTStatementBase body = ParseStatement();
_loopLevel--;
return(new ASTWhile(condition, body));
}
private void DeclareFunction(List <ASTFunctionBase> functionDeclarations)
{
var name = Require(TokenType.IDENTIFIER).Text;
var baseClass = "";
if (Match(TokenType.DOUBLE_COLON))
{
Consume();
baseClass = Require(TokenType.IDENTIFIER).Text;
var tmp = baseClass;
baseClass = name;
name = tmp;
}
Require(TokenType.LEFT_PARENTHESIS);
List <string> arguments = new List <string>();
while (!Match(TokenType.RIGHT_PARENTHESIS))
{
arguments.Add(Require(TokenType.IDENTIFIER).Text);
if (Match(TokenType.COMMA))
{
Consume();
if (!Match(TokenType.IDENTIFIER))
{
throw new ParserException($"Argument name is expected following a comma.", _lexer.Line, _lexer.Character);
}
}
}
Require(TokenType.RIGHT_PARENTHESIS);
ASTStatementBase body = ParseBlock();
if (baseClass.Length != 0)
{
functionDeclarations.Add(new ASTMemberFunction(name, baseClass, arguments, body));
}
else
{
functionDeclarations.Add(new ASTGlobalFunction(name, arguments, body));
}
}
private ASTStatementBase ParseFor()
{
Require(TokenType.FOR);
Require(TokenType.LEFT_PARENTHESIS);
ASTExpressionBase initializer = ParseExpression();
Require(TokenType.SEMICOLON);
ASTExpressionBase condition = ParseExpression();
Require(TokenType.SEMICOLON);
ASTExpressionBase incrementer = ParseExpression();
Require(TokenType.RIGHT_PARENTHESIS);
_loopLevel++;
ASTStatementBase body = ParseStatement();
_loopLevel--;
return(new ASTFor(initializer, condition, incrementer, body));
}
private ASTStatementBase ParseIf()
{
Require(TokenType.IF);
Require(TokenType.LEFT_PARENTHESIS);
ASTExpressionBase condition = ParseExpression();
Require(TokenType.RIGHT_PARENTHESIS);
ASTStatementBase ifPart = ParseStatement();
ASTStatementBase elsePart = null;
if (Match(TokenType.ELSE))
{
Consume();
elsePart = ParseStatement();
}
if (elsePart == null)
{
return(new ASTIf(condition, ifPart));
}
return(new ASTIf(condition, ifPart, elsePart));
}
