ASTExpression ParseExpressionImpl()
{
Token first = lexer.NextToken();
switch (first.Type)
{
case TokenType.True:
return(new ASTLiteral(true));
case TokenType.False:
return(new ASTLiteral(false));
case TokenType.Number:
if (first.Source.Contains("."))
{
return(new ASTLiteral(float.Parse(first.Source)));
}
try {
int i = int.Parse(first.Source);
} catch (System.Exception e) {
Debug.LogError("Integer Invalid: " + first.Source + " len: " + first.Source.Length);
}
return(new ASTLiteral(int.Parse(first.Source)));
case TokenType.String:
return(new ASTLiteral(first.Source));
case TokenType.Identifier:
{
if (lexer.PeekNext() == TokenType.BracketOpen)
{
ASTFuncCall funcCall = new ASTFuncCall(first.Source);
lexer.NextToken(); // Eat open bracket
while (true)
{
if (lexer.PeekNext() == TokenType.BracketClose)
{
lexer.NextToken();
break;
}
ASTExpression arg = ParseExpression();
funcCall.AddArg(arg);
if (lexer.PeekNext() == TokenType.BracketClose)
{
lexer.NextToken();
break;
}
MatchNext(TokenType.Comma);
}
return(funcCall);
}
return(new ASTVariable(first.Source));
}
default:
throw new Exception("Unexpected token " + first);
}
}
ASTStatement ParseStatement()
{
if (lexer.PeekNext() == TokenType.Identifier) // Function call
{
ASTFuncCall funcCall = ParseExpression() as ASTFuncCall;
return(new ASTInlineCall(funcCall));
}
Token first = lexer.NextToken();
switch (first.Type)
{
case TokenType.Set:
{
Token varNameToken = MatchNext(TokenType.Identifier);
List <ASTExpression> indexers = new List <ASTExpression>();
while (lexer.PeekNext() == TokenType.SquareBraceOpen)
{
MatchNext(TokenType.SquareBraceOpen);
indexers.Add(ParseExpression());
MatchNext(TokenType.SquareBraceClose);
}
MatchNext(TokenType.To);
ASTExpression expression = ParseExpression();
return(new ASTSet(varNameToken.Source, expression, indexers));
}
case TokenType.If:
{
ASTExpression check = ParseExpression();
ASTStatements statements = new ASTStatements();
ASTIf ifStmnt = new ASTIf(check, statements);
MatchNext(TokenType.Do);
while (lexer.PeekNext() != TokenType.End)
{
if (lexer.PeekNext() == TokenType.Else)
{
lexer.NextToken();
statements = new ASTStatements();
ifStmnt.SetElse(statements);
MatchNext(TokenType.Do);
}
else if (lexer.PeekNext() == TokenType.Elif)
{
lexer.NextToken();
statements = new ASTStatements();
ASTIf elseifStmnt = new ASTIf(ParseExpression(), statements);
ifStmnt.SetElseIf(elseifStmnt);
MatchNext(TokenType.Do);
}
statements.AddStatement(ParseStatement());
}
lexer.NextToken();
return(ifStmnt);
}
case TokenType.While:
{
ASTExpression check = ParseExpression();
ASTStatements statements = new ASTStatements();
ASTWhile whileStmnt = new ASTWhile(check, statements);
MatchNext(TokenType.Do);
while (lexer.PeekNext() != TokenType.End)
{
statements.AddStatement(ParseStatement());
}
lexer.NextToken();
return(whileStmnt);
}
case TokenType.Return:
{
return(new ASTReturn(ParseExpression()));
}
default:
throw new Exception("Unexpected token " + first);
}
return(null);
}
public ASTInlineCall(ASTFuncCall funcCall)
{
this.funcCall = funcCall;
}