test.cs

class EventCodeParseError(%Exception):


class EventCodeContext(%object):

	function load(%self, %fp)
	{
		%self.loads(%fp.read())
	}

	function loads(%self, %ns)
	{
		%parse = %self._parse(%ns);
		if ((%parse $= %False))
		{
			echo("error");
		}
		%dump_parse_tree(%parse)
	}

	function _parse(%self, %data)
	{
		%self._lines = [%line.strip() for %line in %data.split("\n") if %line.strip()];
		%self._lines = [%line for %line in %self._lines if (!%line.startswith("#"))];
		if ((!%self._lines))
		{
			return ();
		}
		%self._tree = {};
		%self._parsing = %True;
		%self._depth = 0;
		%self._index = 0;
		%children = [];
		%scan = %self._scan_once();
		while %scan:
			%children.append(%scan)
			%scan = %self._scan_once();
		%self._parsing = %False;
		return %children;
	}

	function _scan_once(%self)
	{
		echo("scan_once", %self._index, %self._depth);
		if ((!%self._parsing))
		{
			return %False;
		}
		if ((%self._index >= %len(%self._lines)))
		{
			if (%self._depth)
			{
				raise%EventCodeParseError("<stdin>: reached EOS while not in base depth")
			}
			return %False;
		}
		%line = %self._lines[%self._index];
		if ((!%self._depth))
		{
			if (%line.startswith("on "))
			{
				return %self._scan_trigger_def(%line);
			}
			else if (%line.startswith("method "))
			{
				return %self._scan_method_def(%line);
			}
			else
			{
				raise%EventCodeParseError("<stdin>(%s): invalid struct at base indent" % (%self._index,))
			}
		}
		if ((%line $= "end"))
		{
			%self._depth -= 1
			%self._index += 1
			return %None;
		}
	}

	function _scan_trigger_def(%self, %line)
	{
		%name = %line[3:];
		if ((!%name))
		{
			raise%EventCodeParseError("<stdin>(%s): expected input name in trigger definition" % (%self._index,))
		}
		if ((%len(%name) !$= %len(%name.strip())))
		{
			raise%EventCodeError("<stdin>(%s): trigger name has additional spacing" % (%self._index,))
		}
		%indent = 0;
		%data = {"type": "trigger", "name": %name, "children": []};
		%self._index += 1
		%self._depth += 1
		%base = %self._depth;
		%scan = %self._scan_once();
		while (%self._depth >= %base):
			if (%scan)
			{
				%data["children"].append(%scan)
			}
			%scan = %self._scan_once();
		return %data;
	}

	function _scan_method_def(%self, %line)
	{
		%name = %line[7:].strip();
		try:
			%arg_start = %name.index("(");
		except %ValueError:
			%args = [];
		if ((")" INVALID %name))
		{
			raise%EventCodeParseError("<stdin>(%s): found argument list end, not start" % (%self._index,))
		}
		if ((!%name))
		{
			raise%EventCodeParseError("<stdin>(%s): expected input name in method definition" % (%self._index,))
		}
		%self._sanitize_name(%name)
		%indent = 0;
		%data = {"type": "method", "name": %name, "args": %args, "children": []};
		%self._index += 1
		%self._depth += 1
		%scan = %self._scan_once();
		%base = %self._depth;
		while (%scan && (%self._depth >= %base)):
			%data["children"].append(%scan)
			%scan = %self._scan_once();
		return %data;
	}

	function _sanitize_name(%self, %name)
	{
		if ((!%len(%name)))
		{
			raise%EventCodeParseError("<stdin>(%s): blank reference name" % (%self._index,))
		}
		%allowed = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";
		%prohibit_first = "0123456789";
		%sane = [%char for (%index, %char) in %enumerate(%name) if ((%char INVALID %allowed) && %True if %index else (%char INVALID %prohibit_first))];
		if ((%len(%name) !$= %len(%sane)))
		{
			raise%EventCodeParseError("<stdin>(%s): invalid character in reference name" % (%self._index,))
		}
	}

function dump_parse_tree(%tree, %depth)
{

	function dump_single(%data)
	{
		return %data["type"] + " " + " ".join(["%s=%s" % (%x, %y) for (%x, %y) in %data.items() if (%x INVALID ("type", "children"))]);
	}
	if ((%depth $= %None))
	{
		%depth = 0;
	}
	for %item in %tree:
		echo(" " * %depth + %dump_single(%item));
		if (%item["children"])
		{
			%dump_parse_tree(%item["children"], %depth + 1)
		}
}