public string TryGetSort(IConsTerm term)
{
if (term.IsCons("cf", 1))
return TryGetSort((IConsTerm)term[0]);
if (term.IsCons("lex", 1))
return TryGetSort((IConsTerm)term[0]);
if (term.IsCons("sort", 1))
return term[0].ToString();
if (term.IsCons("parameterized-sort", 2))
return GetParameterizedSortName(term);
if (term.IsCons("char-class", 1))
return null;
if (term.IsCons("alt", 2))
return GetAltSortName(term);
return null;
}
/// <summary>
/// Parses a shift action item.
/// </summary>
/// <param name="term">The term.</param>
/// <returns>The parsed action item.</returns>
/// <example>
/// The term might look like this:
/// <code>
/// shift(22)
/// </code>
/// </example>
private ActionItem ParseShift(IConsTerm term)
{
#region Contract
Contract.Requires<ArgumentNullException>(term != null);
Contract.Requires<ArgumentException>(term.IsCons("shift", 1));
Contract.Ensures(Contract.Result<ActionItem>() != null);
#endregion
var nextState = new StateRef(term[0].ToInt32());
return new ShiftActionItem(nextState);
}
/// <summary>
/// Parses a reduce action item.
/// </summary>
/// <param name="term">The term.</param>
/// <param name="labels">The labels in the parse table.</param>
/// <returns>The parsed action item.</returns>
/// <example>
/// The term might look like this (without lookahead)
/// <code>
/// reduce(0,280,0)
/// </code>
/// or this (with lookahead)
/// <code>
/// reduce(0,280,0,[follow-restriction([char-class([42,47])])])
/// </code>
/// </example>
private ActionItem ParseReduce(IConsTerm term, IReadOnlyList<Label> labels)
{
#region Contract
Contract.Requires<ArgumentNullException>(term != null);
Contract.Requires<ArgumentException>(term.IsCons("reduce", 3) || term.IsCons("reduce", 4));
Contract.Requires<ArgumentNullException>(labels != null);
Contract.Ensures(Contract.Result<ActionItem>() != null);
#endregion
int productionArity = term[0].ToInt32();
var label = new LabelRef(term[1].ToInt32() - SpoofaxParseTableFormat.LabelBase);
ProductionType status = (ProductionType)term[2].ToInt32();
bool isRecover = labels[label.Index].Production.IsRecover;
bool isCompletion = labels[label.Index].Production.IsCompletion;
var followRestriction = term.SubTerms.Count == 4 ? ParseLookaheadCharRanges((IListTerm)term[3]) : ArrayExt.Empty<IReadOnlySet<CodePoint>>();
// Redundant information. Let's check it while we're at it.
var production = labels[label.Index].Production;
Contract.Assert(production.Arity == productionArity);
Contract.Assert(production.IsCompletion == isCompletion);
Contract.Assert(production.IsRecover == isRecover);
Contract.Assert(production.Type == status);
return new ReduceActionItem(label, followRestriction);
}
/// <summary>
/// Parses an accept action item.
/// </summary>
/// <param name="term">The term.</param>
/// <returns>The parsed action item.</returns>
/// <example>
/// The term might look like this:
/// <code>
/// accept()
/// </code>
/// </example>
private ActionItem ParseAccept(IConsTerm term)
{
#region Contract
Contract.Requires<ArgumentNullException>(term != null);
Contract.Requires<ArgumentException>(term.IsCons("accept", 0));
Contract.Ensures(Contract.Result<ActionItem>() != null);
#endregion
return new AcceptActionItem();
}