public static CfgLL1ParseTable ToLL1ParseTable(this CfgDocument cfg, IProgress <CfgLL1Progress> progress = null)
{
CfgLL1ParseTable result = null;
var msgs = TryToLL1ParseTable(cfg, progress, out result);
CfgException.ThrowIfErrors(msgs);
return(result);
}
/// <summary>
/// Constructs a new instance of the parser
/// </summary>
/// <param name="parseTable">The parse table to use</param>
/// <param name="tokenizer">The tokenizer to use </param>
/// <param name="startSymbol">The start symbol</param>
public LL1DebugParser(CfgDocument cfg,
IEnumerable <Token> tokenizer)
{
_cfg = cfg;
_PopulateAttrs();
_parseTable = cfg.ToLL1ParseTable();
_stack = new Stack <string>();
_errorToken.Symbol = null;
Restart(tokenizer);
}
public static IList <CfgMessage> TryToLL1ParseTable(this CfgDocument cfg, IProgress <CfgLL1Progress> progress, out CfgLL1ParseTable parseTable)
{
// Here we populate the outer dictionary with one non-terminal for each key
// we populate each inner dictionary with the result terminals and associated
// rules of the predict tables except in the case where the predict table
// contains null. In that case, we use the follows to get the terminals and
// the rule associated with the null predict in order to compute the inner
// dictionary. The conflict resolution tables are always empty for LL(1)
if (null != progress)
{
progress.Report(new CfgLL1Progress(CfgLL1Status.ComputingPredicts, 0));
}
var predict = cfg.FillPredict();
if (null != progress)
{
progress.Report(new CfgLL1Progress(CfgLL1Status.ComputingFollows, 0));
}
var follows = cfg.FillFollows();
var result = new List <CfgMessage>();
parseTable = new CfgLL1ParseTable();
var j = 0;
foreach (var nt in cfg.EnumNonTerminals())
{
var d = new Dictionary <string, CfgLL1ParseTableEntry>();
foreach (var f in predict[nt])
{
if (null != f.Symbol)
{
CfgLL1ParseTableEntry re;
re.Rule = f.Rule;
CfgLL1ParseTableEntry or;
if (d.TryGetValue(f.Symbol, out or))
{
result.Add(new CfgMessage(CfgErrorLevel.Error, 1,
string.Format(
"first first conflict between {0} and {1} on {2}",
or.Rule,
f.Rule,
f.Symbol), f.Rule.Line, f.Rule.Column, f.Rule.Position));
}
else
{
d.Add(f.Symbol, re);
}
if (null != progress)
{
progress.Report(new CfgLL1Progress(CfgLL1Status.CreatingParseTable, j));
}
++j;
}
else
{
var ff = follows[nt];
foreach (var fe in ff)
{
CfgLL1ParseTableEntry or;
if (d.TryGetValue(fe, out or))
{
// we can override conflict handling with the followsConflict
// attribute. If specified (first/last/error - error is default) it will choose
// the first or last rule respectively.
var fc = cfg.GetAttribute(nt, "followsConflict", "error") as string;
if ("error" == fc)
{
result.Add(new CfgMessage(CfgErrorLevel.Error, -1,
string.Format(
"first follows conflict between {0} and {1} on {2}",
or.Rule,
f.Rule,
fe), f.Rule.Line, f.Rule.Column, f.Rule.Position));
}
else if ("last" == fc)
{
d[fe] = new CfgLL1ParseTableEntry(f.Rule);
}
}
else
{
d.Add(fe, new CfgLL1ParseTableEntry(f.Rule));
}
if (null != progress)
{
progress.Report(new CfgLL1Progress(CfgLL1Status.CreatingParseTable, j));
}
++j;
}
}
}
parseTable.Add(nt, d);
}
return(result);
}
public static IList <CfgMessage> TryToLL1ParseTable(this CfgDocument cfg, out CfgLL1ParseTable parseTable) => TryToLL1ParseTable(cfg, null, out parseTable);