/// <summary>
/// Parse given input string in the concrete grammar.
/// </summary>
/// <param name="str">Input string to be parsed.</param>
/// <param name="cat">Category (Type) to parse.</param>
/// <param name="heuristics">Heuristic (see the GF C runtime docs).</param>
/// <param name="Callback1">Callback function.</param>
/// <param name="Callback2">Callback function.</param>
/// <returns>Enumerates pairs of (abstract grammar) expressions and corresponding probability.</returns>
public IEnumerable <Tuple <Expr, float> > Parse(string str, Type cat = null, double?heuristics = null,
Action Callback1 = null, Action Callback2 = null)
{
var parse_pool = new NativeGU.NativeMemoryPool();
var exn = new NativeGU.NativeExceptionContext(parse_pool);
cat = cat ?? PGF.StartCat;
using (var nativeStr = new Native.NativeString(str))
{
var result_pool = new NativeGU.NativeMemoryPool();
var callbackMap = Native.pgf_new_callbacks_map(this.Ptr, parse_pool.Ptr);
var iterator = Native.pgf_parse_with_heuristics(this.Ptr, cat.Ptr,
nativeStr.Ptr, heuristics ?? -1, callbackMap,
exn.Ptr, parse_pool.Ptr, result_pool.Ptr);
if (iterator == IntPtr.Zero || exn.IsRaised)
{
throw new ParseError();
}
else
{
foreach (var ptr in NativeGU.IteratorToIEnumerable(iterator, parse_pool.Ptr))
{
var exprProb = (Native.PgfExprProb)Marshal.PtrToStructure(ptr, typeof(Native.PgfExprProb));
yield return(Tuple.Create(Expr.FromPtr(exprProb.expr, result_pool),
exprProb.prob));
}
}
}
}
/// <summary>
/// Get all possible linearization for an expression (see <see cref="Linearize(Expression)"/>).
/// </summary>
/// <param name="e"></param>
/// <returns></returns>
public IEnumerable <string> LinearizeAll(Expr e)
{
var tmp_pool = new NativeGU.NativeMemoryPool();
var exn = new NativeGU.NativeExceptionContext(tmp_pool);
var cts = Native.pgf_lzr_concretize(Ptr, e.Ptr, exn.Ptr, tmp_pool.Ptr);
if (exn.IsRaised || cts == IntPtr.Zero)
{
throw new PGFError("Could not linearize the abstract tree.");
}
return(NativeGU.IteratorToIEnumerable(cts, tmp_pool.Ptr).Select(LinearizeCnc));
}
/// <summary>
/// Returns an enumerable over the set of all expression in
/// the given category. The expressions are enumerated in decreasing
/// probability order.
/// </summary>
/// <param name="cat">the start category.</param>
/// <returns></returns>
public IEnumerable <Expr> GenerateAll(Type cat = null)
{
cat = cat ?? StartCat;
var tmp_pool = new NativeGU.NativeMemoryPool();
var exn = new NativeGU.NativeExceptionContext(tmp_pool);
var result_pool = new NativeGU.NativeMemoryPool();
IntPtr ptr = IntPtr.Zero;
var iterator = Native.pgf_generate_all(this._ptr, cat.Ptr, exn.Ptr, tmp_pool.Ptr, result_pool.Ptr);
return(NativeGU.IteratorToIEnumerable(iterator, tmp_pool.Ptr).Select(p =>
{
var exprProb = Marshal.PtrToStructure <Native.PgfExprProb>(ptr);
return Expr.FromPtr(exprProb.expr, result_pool);
}));
}
