/// <summary>
/// Loads next <see cref="LToken"/> from the specified <see cref="LuaTableTextReader"/>.
/// </summary>
/// <param name="reader">The reader from which to load the next <see cref="LToken"/>.</param>
/// <exception cref="ArgumentNullException"><paramref name="reader"/> is <c>null</c>.</exception>
/// <exception cref="LuaTableReaderException">There are unexpected input in the <paramref name="reader"/>.</exception>
/// <returns>The loaded Lua token.</returns>
public static LToken Load(LuaTableTextReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
if (reader.CurrentToken == LuaTableReaderToken.None)
{
reader.Read();
}
SkipComments(reader);
switch (reader.CurrentToken)
{
case LuaTableReaderToken.None:
case LuaTableReaderToken.TableStart:
return(LTable.Load(reader));
case LuaTableReaderToken.Key:
return(LField.Load(reader));
case LuaTableReaderToken.Value:
return(LValue.Load(reader));
default:
throw MakeUnexpectedTokenException(reader);
}
}
public bool RemoveByName(LValue name)
{
if (name == null || name.TokenType == LTokenType.Nil)
{
return(false);
}
if (fieldsDict.Count == 0)
{
// Positional fields only
// Fast route
if (name.TokenType == LTokenType.Integer)
{
var intName = (int)name;
if (intName <= 0 || intName > Items.Count)
{
return(false);
}
Items.RemoveAt(intName - 1);
return(true);
}
}
// Named field
if (fieldsDict.TryGetValue(name, out var field))
{
var success = Items.Remove(field);
Debug.Assert(success);
return(true);
}
// Positional field
if (name.TokenType == LTokenType.Integer)
{
var intName = (int)name;
// Sanity check
if (intName <= 0 || intName > Items.Count)
{
return(false);
}
int positionalIndex = 0;
for (int i = 0; i < Items.Count; i++)
{
if (Items[i].Name == null)
{
positionalIndex++;
if (intName == positionalIndex)
{
Items.RemoveAt(i);
return(true);
}
}
}
}
return(false);
}
/// <summary>
/// Initializes a new Lua table field with the specified name and value.
/// </summary>
/// <param name="name">Name of the field. Use <c>null</c> for positional field.</param>
/// <param name="value">Value of the field. Can be <c>null</c>, which means <see cref="LValue.Nil"/>.</param>
/// <exception cref="ArgumentException"><paramref name="name"/>.<see cref="LValue.TokenType"/> is <see cref="LTokenType.Nil"/>.</exception>
public LField(LValue name, LToken value)
{
if (name != null && name.TokenType == LTokenType.Nil)
{
throw new ArgumentException("Cannot use nil as field name.");
}
Name = name;
_Value = value ?? LValue.Nil;
}
public LField FieldFromName(LValue name, bool allowsCreation)
{
Debug.Assert(name != null && name.TokenType != LTokenType.Nil);
if (name.TokenType == LTokenType.Integer)
{
return(FieldFromName((int)name, name, allowsCreation));
}
// Named field
if (fieldsDict.TryGetValue(name, out var field))
{
return(field);
}
return(null);
}
/// <summary>
/// Inserts a field or value at the end of the table expression.
/// </summary>
/// <param name="content">The field or value of the field.</param>
public void Add(object content)
{
if (content is LField field)
{
Add(field);
}
else if (content is LToken value)
{
Add(value);
}
else
{
var tv = new LValue(content);
Add(tv);
}
}
public new static LField Load(LuaTableTextReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
if (reader.CurrentToken == LuaTableReaderToken.None)
{
reader.Read();
}
SkipComments(reader);
LValue key = null;
if (reader.CurrentToken == LuaTableReaderToken.Key)
{
key = new LValue(reader.CurrentValue);
reader.Read();
SkipComments(reader);
}
LToken value = LToken.Load(reader);
return(new LField(key, value));
}
public LField FieldFromName(int name, LValue nameRef, bool allowsCreation)
{
if (nameRef != null && fieldsDict.TryGetValue(name, out var field))
{
return(field);
}
if (fieldsDict.Count == 0)
{
// Positional fields only
// Fast route
if (name <= 0 || name > Items.Count)
{
if (!allowsCreation)
{
return(null);
}
var f = new LField(name == Items.Count ? null : new LValue(name), null);
Items.Add(f);
return(f);
}
return(Items[name - 1]);
}
// Positional field
// Sanity check
if (name <= 0 || name > Items.Count - fieldsDict.Count)
{
var nr = nameRef ?? new LValue(name);
if (fieldsDict.TryGetValue(nr, out var f))
{
return(f);
}
if (!allowsCreation)
{
return(null);
}
f = new LField(name > 0 && name - 1 == Items.Count - fieldsDict.Count ? null : nr, null);
Items.Add(f);
return(f);
}
// Get the positional field
int positionalIndex = 0;
foreach (var i in Items)
{
if (i.Name != null)
{
continue;
}
positionalIndex++;
if (name == positionalIndex)
{
return(i);
}
}
#if NETSTANDARD2_0
Debug.Fail("Should not execute to here.");
#else
Debug.Assert(false);
#endif
return(null);
}
/// <summary>
/// Inserts a field at the end of the table expression.
/// </summary>
/// <param name="name">The name of the new field to be appended.</param>
/// <param name="value">The value of the new field to be appended. <c>null</c> will be treated the same as <see cref="LValue.Nil"/>.</param>
public void Add(LValue name, LToken value)
{
store.Add(new LField(name, value));
}
/// <summary>
/// Tries to get the field instance with the specified field name.
/// </summary>
/// <param name="name">The field name.</param>
/// <returns>The field instance, or <c>null</c> if no matching field exists.</returns>
public LField Field(LValue name)
{
return(store.FieldFromName(name, false));
}
/// <summary>
/// Gets/sets the field value associated with the specified field key.
/// </summary>
/// <param name="name">The key of the field to set or get.</param>
/// <returns>The value of the specified field, or <c>null</c> if the field does not exist.</returns>
public override LToken this[LValue name]
{
get { return(store.FieldFromName(name, false)?.Value); }
set { store.FieldFromName(name, true).Value = value; }
}
/// <summary>
/// Removes a field from table by its field name.
/// </summary>
/// <param name="name">Field name.</param>
/// <returns>Whether a matching item has been removed.</returns>
/// <remarks>To remvoe a positional field, pass a numeric value to the <paramref name="name"/> parameter.</remarks>
public bool Remove(LValue name)
{
return(store.RemoveByName(name));
}
