public static IAction LoadFromString(string location, string source)
{
using (var lexer = new Lexer(location, source))
return lexer.Scan();
}
public IAction Scan()
{
if (_source == null)
using (var sr = new StreamReader(FileSystem.GetFile(_location).Name))
_source = sr.ReadToEnd();
var aggregate = new Aggregate();
while (_offset < _source.Length)
{
// stops for the end of file or {
ForwardTag();
if (_offset >= _source.Length)
return aggregate;
_offset++;
var sequence = new Sequence();
LexTag();
if (_token.type == TokenType.Identifier)
sequence.Params.Add(new Constant(_token.value));
else if (_token.type == TokenType.String)
sequence.Params.Add(new Constant(_token.value));
else
{
ErrorAction("Expecting a value (variable location, string, or number)");
return null;
}
LexTag();
if (_token.type != TokenType.Separator)
{
ErrorAction("Expecting a method name (this should be something like .Assign())");
return null;
}
LexTag();
if (_token.type != TokenType.Identifier)
{
ErrorAction("An operation must be defined (this should be something like .Assign())");
return null;
}
var functionName = _token.value;
LexTag();
if (_token.type != TokenType.ArgumentOpen)
{
ErrorAction("Expecting \"(\"");
return null;
}
LexTag();
if (_token.type != TokenType.ArgumentClose)
{
Console.WriteLine("Expecting \")\"");
Console.WriteLine(PrintToken('!'));
return null;
}
LexTag();
if (_token.type == TokenType.EOF)
{
ErrorAction("Reached the end of file too soon, expecting more content");
return null;
}
if (_token.type == TokenType.Error)
{
ErrorAction(_token.value);
return null;
}
//Newline found within tag (skipping tag)
if (_token.type == TokenType.Newline)
continue;
// _token.type should always equal TokenType.TagClose at this point
if (_token.type != TokenType.TagClose)
throw new Exception("Unknown State\n" + PrintToken('!'));
if (functionName == "Import")
{
if (!File.Exists(_location))
{
ErrorAction("Import statement used and current location does not exist: " + _location);
return null;
}
if (!(sequence.Params[0] is Constant))
{
ErrorAction("Import statement requires a constant parameter");
return null;
}
// strip the filename off our path
var currentFile = new FileInfo(_location);
var pathToImport = ((Constant)sequence.Params[0]).Value.ToString();
var newPath = Path.Combine(currentFile.Directory.FullName, pathToImport);
// lex it
var lexer = new Lexer(newPath);
var result = lexer.Scan();
aggregate.Params.AddRange(result.Params);
continue;
}
var inner = ScanInner();
if (inner == null)
return null;
LexTag();
if (_token.type != TokenType.Identifier || _token.value != functionName)
{
ErrorAction("Expecting {/" + functionName + "}");
return null;
}
var func = ActionHandlers
.Where(p => p.Key.Type == ActionType.External
&& p.Key.Identifier == functionName
&& p.Key.HasParameter == false)
.Select(p => p.Value)
.FirstOrNull();
if (func == null)
{
ErrorAction("Unknown initial function");
return null;
}
var action = (IBlock)func();
action.Content = inner;
sequence.Params.Add(action);
LexTag();
if (_token.type != TokenType.TagClose)
{
ErrorAction("Expecting \"}\"");
return null;
}
aggregate.Params.Add(sequence);
}
return aggregate;
}
public static IAction LoadFromFile(string location)
{
using (var lexer = new Lexer(location))
return lexer.Scan();
}