/** Parses a \c guard definition, which makes a \c value accessible through the a getter and/or a setter.
*
* guard Foo is io .foo:
* get:
* return .foo
* set:
* .foo := 2 * value
*/
private GuardStatement ParseGuardStatement()
{
Token start = _matcher.Match(TokenKind.Keyword_Guard);
_matcher.Match(TokenKind.Space);
SymbolDefinition name = ParseSymbolDefinition(SymbolKind.Guard);
#if false
Token @base = null;
if (_matcher.This.Kind == TokenKind.Dot)
{
_matcher.Match(TokenKind.Dot);
@base = name;
@name = _matcher.Match(TokenKind.Name);
}
#endif
_matcher.Match(TokenKind.Space);
_matcher.Match(TokenKind.Keyword_Is);
_matcher.Match(TokenKind.Space);
DirectionKind direction = ParseDirection();
_matcher.Match(TokenKind.Space);
#if DONE
Expression member = ParseInstanceExpression();
#else
_matcher.Match(TokenKind.Dot);
Token token = _matcher.Match(TokenKind.Name);
SymbolReference reference = new SymbolReference(token.Cursor, PathKind.Instance, token.Text);
Type type = new NamedType(token.Cursor, reference);
#endif
Statement getter = null;
Statement setter = null;
if (_matcher.This.Kind == TokenKind.Colon)
{
_matcher.Match(TokenKind.Colon);
_matcher.Match(TokenKind.EndOfLine);
token = _matcher.Match(TokenKind.Indent); // NOTE: Update 'token'!
switch (direction)
{
case DirectionKind.Out:
getter = ParseGetRoutine((Type) type.Clone());
break;
case DirectionKind.In:
setter = ParseSetRoutine((Type) type.Clone());
break;
case DirectionKind.InOut:
if (_matcher.This.Kind == TokenKind.Keyword_Get)
getter = ParseGetRoutine((Type) type.Clone());
if (_matcher.This.Kind == TokenKind.Keyword_Set)
setter = ParseSetRoutine((Type) type.Clone());
if (getter == null && setter == null)
throw new ParserError(token.Cursor, "Getter or setter must be specified after colon");
break;
default:
throw new System.ArgumentException("direction");
}
_matcher.Match(TokenKind.Dedent);
}
if (getter == null)
{
if (direction != DirectionKind.In)
getter = CreateDefaultGetter(token.Cursor, token.Text);
else
getter = new NoneStatement(token.Cursor);
}
if (setter == null)
{
if (direction != DirectionKind.Out)
setter = CreateDefaultSetter(token.Cursor, token.Text);
else
setter = new NoneStatement(token.Cursor);
}
return new GuardStatement(start.Cursor, name, direction, type, getter, setter);
}
