static string _ToRegex(XbnfDocument d, XbnfExpression e)
{
var le = e as XbnfLiteralExpression;
if (null != le)
{
return(_EscapeLiteral(XbnfNode.Escape(le.Value)));
}
var rxe = e as XbnfRegexExpression;
if (null != rxe)
{
return(string.Concat("(", rxe.Value, ")"));
}
var rfe = e as XbnfRefExpression;
if (null != rfe)
{
_ToRegex(d, d.Productions[rfe.Symbol].Expression);
}
var re = e as XbnfRepeatExpression;
if (null != re)
{
if (re.IsOptional)
{
return(string.Concat("(", _ToRegex(d, re.Expression), ")*"));
}
else
{
return(string.Concat("(", _ToRegex(d, re.Expression), ")+"));
}
}
var oe = e as XbnfOrExpression;
if (null != oe)
{
return(string.Concat("(", _ToRegex(d, oe.Left), "|", _ToRegex(d, oe.Right), ")"));
}
var oc = e as XbnfConcatExpression;
if (null != oc)
{
return(string.Concat(_ToRegex(d, oe.Left), _ToRegex(d, oe.Right)));
}
var ope = e as XbnfOptionalExpression;
if (null != ope)
{
return(string.Concat("(", _ToRegex(d, ope.Expression), ")?"));
}
return("");
}
static XbnfProduction _GetProductionForExpression(XbnfDocument d, XbnfExpression e)
{
for (int ic = d.Productions.Count, i = 0; i < ic; ++i)
{
var prod = d.Productions[i];
if (e == prod.Expression)
{
return(prod);
}
}
return(null);
}
static IList <IList <string> > _GetDysOptional(XbnfDocument d, ICollection <string> syms, IDictionary <XbnfExpression, string> tmap, IDictionary <string, XbnfAttributeList> attrs, IList <KeyValuePair <string, IList <string> > > rules, XbnfProduction p, XbnfOptionalExpression ope)
{
var l = new List <IList <string> >();
if (null != ope.Expression)
{
l.AddRange(_GetDysjunctions(d, syms, tmap, attrs, rules, p, ope.Expression));
var ll = new List <string>();
if (!l.Contains(ll, OrderedCollectionEqualityComparer <string> .Default))
{
l.Add(ll);
}
}
return(l);
}
static IList <IList <string> > _GetDysConcat(XbnfDocument d, ICollection <string> syms, IDictionary <XbnfExpression, string> tmap, IDictionary <string, XbnfAttributeList> attrs, IList <KeyValuePair <string, IList <string> > > rules, XbnfProduction p, XbnfConcatExpression ce)
{
var l = new List <IList <string> >();
if (null == ce.Right)
{
if (null == ce.Left)
{
return(l);
}
foreach (var ll in _GetDysjunctions(d, syms, tmap, attrs, rules, p, ce.Left))
{
l.Add(new List <string>(ll));
}
return(l);
}
else if (null == ce.Left)
{
foreach (var ll in _GetDysjunctions(d, syms, tmap, attrs, rules, p, ce.Right))
{
l.Add(new List <string>(ll));
}
return(l);
}
foreach (var ll in _GetDysjunctions(d, syms, tmap, attrs, rules, p, ce.Left))
{
foreach (var ll2 in _GetDysjunctions(d, syms, tmap, attrs, rules, p, ce.Right))
{
var ll3 = new List <string>();
ll3.AddRange(ll);
ll3.AddRange(ll2);
if (!l.Contains(ll3, OrderedCollectionEqualityComparer <string> .Default))
{
l.Add(ll3);
}
}
}
return(l);
}
static IList <IList <string> > _GetDysOr(XbnfDocument d, ICollection <string> syms, IDictionary <XbnfExpression, string> tmap, IDictionary <string, XbnfAttributeList> attrs, IList <KeyValuePair <string, IList <string> > > rules, XbnfProduction p, XbnfOrExpression oe)
{
var l = new List <IList <string> >();
if (null == oe.Left)
{
l.Add(new List <string>());
}
else
{
foreach (var ll in _GetDysjunctions(d, syms, tmap, attrs, rules, p, oe.Left))
{
if (!l.Contains(ll, OrderedCollectionEqualityComparer <string> .Default))
{
l.Add(ll);
}
}
}
if (null == oe.Right)
{
var ll = new List <string>();
if (!l.Contains(ll, OrderedCollectionEqualityComparer <string> .Default))
{
l.Add(ll);
}
}
else
{
foreach (var ll in _GetDysjunctions(d, syms, tmap, attrs, rules, p, oe.Right))
{
if (!l.Contains(ll, OrderedCollectionEqualityComparer <string> .Default))
{
l.Add(ll);
}
}
}
return(l);
}
static IList <IList <string> > _GetDysRepeat(XbnfDocument d, ICollection <string> syms, IDictionary <XbnfExpression, string> tmap, IDictionary <string, XbnfAttributeList> attrs, IList <KeyValuePair <string, IList <string> > > rules, XbnfProduction p, XbnfRepeatExpression re)
{
string sid = null;
var sr = re.Expression as XbnfRefExpression;
if (null != d && null != sr)
{
sid = string.Concat(sr.Symbol, "list");
}
if (string.IsNullOrEmpty(sid))
{
var cc = re.Expression as XbnfConcatExpression;
if (null != cc)
{
sr = cc.Right as XbnfRefExpression;
if (null != sr)
{
sid = string.Concat(sr.Symbol, "listtail");
}
}
}
if (string.IsNullOrEmpty(sid))
{
sid = "implicitlist";
}
var listId = sid;
var i = 2;
var ss = listId;
while (syms.Contains(ss))
{
ss = string.Concat(listId, i.ToString());
++i;
}
syms.Add(ss);
var attr = new XbnfAttribute("collapsed", true);
var attrlist = new XbnfAttributeList();
attrlist.Add(attr);
attrs.Add(listId, attrlist);
var expr =
new XbnfOrExpression(
new XbnfConcatExpression(
new XbnfRefExpression(listId), re.Expression), re.Expression);
foreach (var nt in _GetDysjunctions(d, syms, tmap, attrs, rules, p, expr))
{
var l = new List <string>();
var r = new KeyValuePair <string, IList <string> >(listId, l);
foreach (var s in nt)
{
if (1 < r.Value.Count && null == s)
{
continue;
}
r.Value.Add(s);
}
rules.Add(r);
}
if (!re.IsOptional)
{
return(new List <IList <string> >(new IList <string>[] { new List <string>(new string[] { listId }) }));
}
else
{
var res = new List <IList <string> >();
res.Add(new List <string>(new string[] { listId }));
res.Add(new List <string>());
return(res);
}
}
static IList <IList <string> > _GetDysjunctions(
XbnfDocument d,
ICollection <string> syms,
IDictionary <XbnfExpression, string> tmap,
IDictionary <string, XbnfAttributeList> attrs,
IList <KeyValuePair <string, IList <string> > > rules,
XbnfProduction p,
XbnfExpression e
)
{
var le = e as XbnfLiteralExpression;
if (null != le)
{
var res = new List <IList <string> >();
var l = new List <string>();
l.Add(tmap[le]);
res.Add(l);
return(res);
}
var rxe = e as XbnfRegexExpression;
if (null != rxe)
{
var res = new List <IList <string> >();
var l = new List <string>();
l.Add(tmap[rxe]);
res.Add(l);
return(res);
}
var rfe = e as XbnfRefExpression;
if (null != rfe)
{
var res = new List <IList <string> >();
var l = new List <string>();
l.Add(rfe.Symbol);
res.Add(l);
return(res);
}
var ce = e as XbnfConcatExpression;
if (null != ce)
{
return(_GetDysConcat(d, syms, tmap, attrs, rules, p, ce));
}
var oe = e as XbnfOrExpression;
if (null != oe)
{
return(_GetDysOr(d, syms, tmap, attrs, rules, p, oe));
}
var ope = e as XbnfOptionalExpression;
if (null != ope)
{
return(_GetDysOptional(d, syms, tmap, attrs, rules, p, ope));
}
var re = e as XbnfRepeatExpression;
if (null != re)
{
return(_GetDysRepeat(d, syms, tmap, attrs, rules, p, re));
}
throw new NotSupportedException("The specified expression type is not supported.");
}
public static void Transform(XbnfDocument document, TextWriter writer)
{
var syms = new HashSet <string>();
// gather the attributes and production names
for (int ic = document.Productions.Count, i = 0; i < ic; ++i)
{
var p = document.Productions[i];
syms.Add(p.Name);
if (0 < p.Attributes.Count)
{
writer.Write(string.Concat(p.Name, ":"));
var delim = "";
for (int jc = p.Attributes.Count, j = 0; j < jc; ++j)
{
writer.Write(string.Concat(delim, p.Attributes[j].ToString()));
delim = ", ";
}
writer.WriteLine();
}
}
// use a list dictionary to keep these in order
var tmap = new ListDictionary <XbnfExpression, string>();
var attrSets = new Dictionary <string, XbnfAttributeList>();
var rules = new List <KeyValuePair <string, IList <string> > >();
// below are scratch
var working = new HashSet <XbnfExpression>();
var done = new HashSet <XbnfExpression>();
// now get the terminals and their ids, declaring if necessary
for (int ic = document.Productions.Count, i = 0; i < ic; ++i)
{
var p = document.Productions[i];
if (p.IsTerminal)
{
tmap.Add(p.Expression, p.Name);
done.Add(p.Expression);
}
else
{
_VisitFetchTerminals(p.Expression, working);
}
}
foreach (var term in working)
{
if (!done.Contains(term))
{
var newId = _GetImplicitTermId(syms);
tmap.Add(term, newId);
}
}
var ntd = new Dictionary <string, IList <IList <string> > >();
// now we can use tmap and syms to help solve the rest of our productions
for (int ic = document.Productions.Count, i = 0; i < ic; ++i)
{
var p = document.Productions[i];
if (!p.IsTerminal)
{
var dys = _GetDysjunctions(document, syms, tmap, attrSets, rules, p, p.Expression);
ntd.Add(p.Name, dys);
}
}
// now that we've done that, write the rest of our attributes
foreach (var attrs in attrSets)
{
writer.Write(string.Concat(attrs.Key, ":"));
var delim = "";
for (int jc = attrs.Value.Count, j = 0; j < jc; ++j)
{
writer.Write(string.Concat(delim, attrs.Value[j].ToString()));
delim = ", ";
}
writer.WriteLine();
}
// now write our main rules
foreach (var nt in ntd)
{
foreach (var l in nt.Value)
{
writer.Write(string.Concat(nt.Key, "->"));
foreach (var s in l)
{
writer.Write(string.Concat(" ", s));
}
writer.WriteLine();
}
}
// write our secondary rules
foreach (var rule in rules)
{
writer.Write(string.Concat(rule.Key, "->"));
foreach (var s in rule.Value)
{
writer.Write(string.Concat(" ", s));
}
writer.WriteLine();
}
writer.WriteLine();
// write our terminals
for (int ic = tmap.Count, i = 0; i < ic; ++i)
{
var te = tmap[i];
writer.WriteLine(string.Concat(te.Value, "= \'", _ToRegex(document, te.Key), "\'"));
}
writer.Flush();
return;
}
public static void Transform(TextReader input, TextWriter output) => Transform(XbnfDocument.ReadFrom(input), output);
