protected Parser Pascal()
{
Parser plus_minus = ((Parser)"[\\-+]")[ops()];
Parser ident = ((Parser)"[_a-zA-Z]\\w*")[ops()];
Parser u_int = ((Parser)"\\d+")[ops()];
Parser u_num = u_int > !("." > u_int) > !('e' > (!plus_minus) > u_int);
Parser pstr = ((Parser)"'([^']|'')*'")[ops()]; // Pascal uses two single-quotes to mark a single quote.
Parser u_const = u_num | ident | @"#nil\s" | pstr;
Parser p_const = u_const | (plus_minus > (ident | u_num));
Parser para_item = !((Parser)@"#var\s") > (ident % ",") > ':' > ident;
Parser para_list = !('(' > (para_item % ';') > ')');
Parser simple_type = (ident | (p_const > ".." > p_const) | ('(' > (ident % ',') > ')'));
#region types
// Mutual dependence requires a holding parser (so the object reference stays the same);
var field_list_h = new HoldingParser();
var p_type_h = new HoldingParser();
Parser pt_setof = (@"#set\s" > ((Parser)@"#of\s") > simple_type);
Parser pt_array = (@"#array\s" > ((Parser)'[') > (simple_type % ',') > ']' > ((Parser)@"#of\s") > p_type_h);
Parser pt_recrd = (@"#record\s" > field_list_h > @"#end");
Parser pt_files = (@"#file\s" > (!(@"#of\s" > p_type_h)));
Parser p_type = (simple_type | ('^' > ident) | (pt_setof | pt_array | pt_recrd | pt_files) );
//Parser p_type = (pt_setof | simple_type | ('^' > ident) );
p_type_h.HeldParser = p_type; // complete self-reference
Parser field_list = (!(((ident%',')>':'>p_type)<';'))
> (!(@"#case\s" > !(ident % ':') > ident > @"#of\s"
> (((p_const % ',') > ':' > '(' > field_list_h > ')') % ';')));
field_list_h.HeldParser = field_list; // complete mutual dependance
#endregion
#region expressions
var factor_h = new HoldingParser();
Parser compares = ((Parser)"<" | "<=" | "=" | "<>" | ">=" | ">" | (Parser)@"#in\s");
Parser operators = ((Parser)'*' | '/' | @"#div\s" | @"#mod\s" | (Parser)@"#in\s");
Parser p_term = (factor_h % operators)[act];
Parser simp_expr = -(!(plus_minus) > (p_term % @"#or\s"));
Parser p_expression = simp_expr > !(compares > simp_expr);
Parser p_variable = ident > !(-(('[' > (p_expression % '.') > ']')
| ('.' > ident)
| '^'));
Parser fact_array = Atom.Wrap((Parser)'[' > -( ((p_expression%',') > !("..">p_expression))%',' ) > ']');
Parser factor = (u_const | p_variable | (ident > !('(' > (p_expression % ',') > ')'))
| ('('>p_expression>')') | (@"#not\s">factor_h) | fact_array );
factor_h.HeldParser = factor;
#endregion
return (factor);
}
protected Parser Xml()
{
Parser text = ((Parser)"[^<>]*")[ops()];
Parser identifier = ((Parser)"[_a-zA-Z][_a-zA-Z0-9]*")[ops()];
Parser quoted_string = "\"" > identifier > "\"";
Parser attribute = identifier > "=" > quoted_string;
Parser open_tag = Atom.Wrap("<" > identifier > (!attribute) > ">");
Parser close_tag = Atom.Wrap("</" > identifier > ">");
var xml_tree = new HoldingParser();
Parser content = (open_tag > -(xml_tree | text) > close_tag);
xml_tree.HeldParser = !content;
return xml_tree;
}
