public void ParseBlock( Block block, Tokens tokens )
{
bool enclosed = false;
if ( tokens.PeekToken () == BeginBlock )
{
enclosed = true;
tokens.RemoveNextToken ( BeginBlock );
}
while ( !tokens.AtEnd () )
{
if ( enclosed && tokens.PeekToken () == EndBlock )
{
tokens.RemoveNextToken ( EndBlock );
break;
}
bool parsed = false;
foreach ( IStatementParser parser in _parsers )
{
IStatement nextStatement;
if ( parser.TryParse( tokens, block.Scope, out nextStatement ) )
{
block.Add ( nextStatement );
parsed = true;
break;
}
}
if (!parsed)
throw new Exception("Unable to parse token " + tokens.PeekToken() );
}
}
public Expression ParseArray(IScope scope, Tokens tokens)
{
var result = new ArrayExpr( _executorFactory.GetArrayExecutor() );
tokens.RemoveNextToken(BeginArray);
while (tokens.PeekToken() != EndArray)
{
result.Elements.Add(this.ParseValue(scope, tokens));
tokens.RemoveNextToken(ArraySeparator);
}
tokens.RemoveNextToken(EndArray);
return result;
}
public bool TryParse(Tokens tokens, IScope scope, out IStatement statement)
{
if ( tokens.PeekToken () == PrintTag )
{
// Print statement
tokens.RemoveNextToken ( PrintTag );
Print print = new Print( _executorFactory.GetPrintExecutor ());
print.Expr = _expressionParser.ParseExpression ( scope, tokens );
statement = print;
return true;
}
statement = null;
return false;
}
public bool TryParse(Tokens tokens, IScope scope, out IStatement statement)
{
if ( tokens.PeekToken () == IfTag )
{
tokens.RemoveNextToken ( IfTag );
If iff = new If ( _executorFactory.GetIfExecutor ());
iff.Test = _expressionParser.ParseExpression ( scope, tokens );
iff.Body = _blockParser.GetBlock ( scope, tokens );
statement = iff;
return true;
}
statement = null;
return false;
}
public bool TryParse(Tokens tokens, IScope scope, out IStatement statement)
{
// This is a block call
Variable variable = new Variable ( _executorFactory.GetVariableExecutor() );
variable.Scope = scope;
variable.Ident = tokens.PullToken ();
// Check if there is an indexer into the variable
if (tokens.PeekToken () == "[")
{
tokens.PullToken ();
variable.Indexer = _expressionParser.ParseExpression ( scope, tokens );
tokens.RemoveNextToken ("]");
}
if ( tokens.NextTokenIs("(") )
{
// Parse the parameters..
variable.Parameters = _expressionParser.ParseArray( scope, tokens ) as ArrayExpr;
}
statement = variable;
return true;
}
/// <summary>
/// Value is a constant string, number or variable name.
/// </summary>
/// <param name="tokens"></param>
/// <returns></returns>
public Expression ParseValue( IScope scope, Tokens tokens )
{
Expression value = null;
if ( tokens.NextTokenIs ( BeginBlock ) )
{
value = _blockParser.GetBlock ( scope, tokens );
}
else if ( tokens.PeekToken().StartsWith ( "'" ) && tokens.PeekToken().EndsWith ( "'" ) )
{
string literal = tokens.PullToken().Trim ( '\'' );
value = new StringLiteral
{
Value = literal
};
}
else if ( tokens.PeekToken().IsNumber () )
{
value = new NumberLiteral
{
Value = double.Parse ( tokens.PullToken() )
};
}
else if ( tokens.NextTokenIs(BeginArray) )
{
return this.ParseArray ( scope, tokens );
}
else
{
var variable = new Variable ( _executorFactory.GetVariableExecutor () );
variable.Scope = scope;
variable.Ident = tokens.PullToken();
// Check if there is an indexer into the variable
if (tokens.PeekToken () == "[")
{
tokens.PullToken ();
variable.Indexer = ParseExpression ( scope, tokens );
tokens.RemoveNextToken ("]");
}
value = variable;
}
return value;
}
