public bool ImportFile(SourceStream source, out SymbolTable result)
{
result = null;
if (!source.IsValid())
{
return(false);
}
var slice = source.GetSlice();
if (!slice.MatchString(KeywordImport))
{
return(false);
}
SkipCommentsAndWhitespace(slice);
if (!slice.MatchString(TokenImportFirst))
{
throw new ParseError($"Expected '{TokenImportFirst}'.", slice);
}
int start = slice.Index();
int count = slice.FindNext(TokenImportFinal);
if (count < 0)
{
throw new ParseError($"Expected '{TokenImportFinal}'.", slice);
}
if (!slice.ReadAbsolute(start, count, out string path))
{
throw new ParseError("Unable to read inlcude path.", slice);
}
slice.MoveBy(path.Length);
if (!slice.MatchString(TokenImportFinal))
{
throw new ParseError($"Expected '{TokenImportFinal}'.", slice);
}
result = GetSymbolsFromFile(path);
source.Join(slice);
return(true);
}
static bool SkipCommentsAndWhitespace(SourceStream source)
{
if (!source.IsValid())
{
return(false);
}
var slice = source.GetSlice();
while (true)
{
slice.SkipWhitespace();
if (slice.MatchString(TokenCommentBlockFirst))
{
int index = slice.FindNext(TokenCommentBlockFinal);
if (index < 0)
{
slice.MoveBy(-TokenCommentBlockFirst.Length);
throw new ParseError($"unterminated comment, expected to find '{TokenCommentBlockFinal}'.", slice);
}
slice.MoveBy(index + TokenCommentBlockFinal.Length);
}
else if (slice.MatchString(TokenCommentLineFirst))
{
int index = slice.FindNext(TokenCommandLineFinal);
if (index < 0)
{
if (index < 0)
{
slice.MoveBy(-TokenCommentLineFirst.Length);
throw new ParseError($"unterminated comment, expected to find '\\n'.", slice);
}
}
slice.MoveBy(index + TokenCommandLineFinal.Length);
}
else
{
source.Join(slice);
return(true);
}
}
}
public bool Match(SourceStream source, out StructType result)
{
result = null;
if (!source.IsValid())
{
return(false);
}
var slice = source.GetSlice();
if (!slice.MatchString(KeywordStruct))
{
return(false);
}
SkipCommentsAndWhitespace(slice);
if (!slice.ReadWord(out string name))
{
throw new ParseError("expected struct name.", slice);
}
if (!name.IsNameLegal())
{
slice.MoveBy(-name.Length);
throw new ParseError($"'{name}' is not a legal struct name.", slice);
}
SkipCommentsAndWhitespace(slice);
if (!slice.MatchString(TokenStructFirst))
{
throw new ParseError($"expeceted '{TokenStructFirst}'.", slice);
}
var members = new TypeSet();
while (slice.IsValid())
{
SkipCommentsAndWhitespace(slice);
if (slice.MatchString(TokenStructFinal))
{
break;
}
if (!Match(slice, out MemberType member))
{
throw new ParseError("failed to parse member.", slice);
}
members.Add(member.Ordinal(), member);
}
var span = source.Join(slice);
result = new StructType(name, members, span);
return(true);
}
