public void LoadGrammar(Stream stream)
{
var schemas = new XmlSchemaSet();
string pwd = AppDomain.CurrentDomain.BaseDirectory;
schemas.Add("http://savva.moe/compiler/grammar.xsd", Path.Combine(pwd, "Schemas", "GrammarSchema.xsd"));
var rules = XmlReader.Create(stream, new XmlReaderSettings
{
ValidationType = ValidationType.Schema,
Schemas = schemas
});
var g = new Grammar.Grammar();
while (rules.Read())
{
if (!rules.IsStartElement()) continue;
string term, product;
switch (rules.Name)
{
case "grammar":
continue;
case "start":
string start = rules.GetAttribute("rule");
if (string.IsNullOrWhiteSpace(start))
throw new XmlException("Start rule cannot be empty");
g.Start = new NonTerminal(start);
continue;
case "rule":
term = rules.GetAttribute("name");
product = rules.GetAttribute("production");
break;
default:
throw new XmlException($"Rules definition cannot contain '{rules.Name}' element");
}
if (string.IsNullOrWhiteSpace(term))
throw new ParserException("Rule's term cannot be empty");
if (string.IsNullOrWhiteSpace(product))
throw new NotImplementedException("Epsilon-rules aren't yet implemented");
var production = product
.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
.Select<string, Symbol>(t =>
{
if (t.StartsWith("$"))
return new Terminal(t.Substring(1));
return new NonTerminal(t);
})
.ToList();
g.Add(term, production);
}
Grammar = g;
}
public void LoadGrammar(Stream stream)
{
var schemas = new XmlSchemaSet();
string pwd = AppDomain.CurrentDomain.BaseDirectory;
schemas.Add("http://savva.moe/compiler/grammar.xsd", Path.Combine(pwd, "Schemas", "GrammarSchema.xsd"));
var rules = XmlReader.Create(stream, new XmlReaderSettings
{
ValidationType = ValidationType.Schema,
Schemas = schemas
});
var g = new Grammar.Grammar();
while (rules.Read())
{
if (!rules.IsStartElement())
{
continue;
}
string term, product;
switch (rules.Name)
{
case "grammar":
continue;
case "start":
string start = rules.GetAttribute("rule");
if (string.IsNullOrWhiteSpace(start))
{
throw new XmlException("Start rule cannot be empty");
}
g.Start = new NonTerminal(start);
continue;
case "rule":
term = rules.GetAttribute("name");
product = rules.GetAttribute("production");
break;
default:
throw new XmlException($"Rules definition cannot contain '{rules.Name}' element");
}
if (string.IsNullOrWhiteSpace(term))
{
throw new ParserException("Rule's term cannot be empty");
}
if (string.IsNullOrWhiteSpace(product))
{
throw new NotImplementedException("Epsilon-rules aren't yet implemented");
}
var production = product
.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
.Select <string, Symbol>(t =>
{
if (t.StartsWith("$"))
{
return(new Terminal(t.Substring(1)));
}
return(new NonTerminal(t));
})
.ToList();
g.Add(term, production);
}
Grammar = g;
}
