public static bool EndContext(Input input, int depth = 2)
{
if (Char2.IsNewLine(input.Current()))
{
var index = 0;
while (input.HasPeek(index) && input.Peek(index) == '↓')
{
index++;
}
var contextEnded = index == depth && input.HasPeek(index) && input.Peek(index) != '→';
if (contextEnded)
{
for (var i = 0; i < index; ++i)
{
input.Next();
}
}
return(contextEnded);
}
else
{
return(false);
}
}
public static Token TakeLine(Input input, TokenType type = TokenType.Other)
{
var start = input.Position;
var startColumn = input.Column;
var startLine = input.Line;
StringBuilder builder = new StringBuilder();
builder.Append(input.Current());
while (input.HasNext() && !Char2.IsNewLine(input.Next()))
{
builder.Append(input.Current());
}
return(new Token()
{
StartIndex = start,
StartColumn = startColumn,
StartLine = startLine,
EndIndex = input.Position,
EndColumn = input.Column,
EndLine = input.Line,
Value = builder.ToString(),
TokenType = type
});
}
public IEnumerable <Token> Lex(string code)
{
var preparedSource = PrepareSource(code);
var input = new Input(preparedSource);
var context = false;
while (input.HasNext())
{
if (input.IsEqualTo("type") ||
input.IsEqualTo("alias") ||
input.IsEqualTo("data") ||
input.IsEqualTo("choice") ||
input.IsEqualTo("open") ||
input.IsEqualTo("view") ||
input.IsEqualTo("flow") ||
input.IsEqualTo("aggregate") ||
input.IsEqualTo("entity"))
{
context = true;
yield return(new Token()
{
TokenType = TokenType.ContextStarted
});
yield return(TokenLexers.Word(input));
}
else if (input.IsEqualTo("extends") ||
input.IsEqualTo("importing") ||
input.IsEqualTo("compose") ||
input.IsEqualTo("loop") ||
input.IsEqualTo("pluck"))
{
yield return(TokenLexers.Word(input));
}
else if (input.IsEqualTo("->"))
{
yield return(TokenLexers.Operators(input, "->"));
}
else if (input.IsEqualTo("::"))
{
yield return(TokenLexers.Operators(input, "::"));
}
else if (!context && Char.IsLetter(input.Current()))
{
yield return(TokenLexers.TakeUntillEndOfContext(input));
yield return(new Token()
{
TokenType = TokenType.ContextEnded
});
}
else if (context && Char2.IsNewLine(input.Current()) && TokenLexers.EndContext(input, 1))
{
context = false;
yield return(new Token()
{
TokenType = TokenType.ContextEnded
});
}
else if (context && Char.IsNumber(input.Current()))
{
yield return(TokenLexers.Number(input));
}
else if (context && Char.IsUpper(input.Current()))
{
yield return(TokenLexers.Identifier(input));
}
else if (context && input.Current() == '\'')
{
yield return(TokenLexers.GenericParameter(input));
}
else if (context && Char.IsLower(input.Current()))
{
yield return(TokenLexers.Word(input));
}
else if (context && input.Current() == '&')
{
yield return(TokenLexers.Take(input, TokenType.And));
}
else if (context && input.Current() == '/')
{
yield return(TokenLexers.Pattern(input));
}
else if (context && input.Current() == '"')
{
yield return(TokenLexers.String(input));
}
else if (context && char.IsNumber(input.Current()))
{
yield return(TokenLexers.Number(input));
}
else if (input.Current() == '{')
{
yield return(TokenLexers.Comment(input));
}
else if (input.Current() == '#')
{
yield return(TokenLexers.Chapter(input));
}
else if (input.Current() == '@')
{
yield return(TokenLexers.Annotation(input));
}
else if (input.Current() == '%')
{
yield return(TokenLexers.Directive(input));
}
else if (input.Current() == ';')
{
yield return(TokenLexers.Take(input, TokenType.EndStatement));
}
else if (Char2.Indent(input.Current()))
{
yield return(TokenLexers.Take(input, TokenType.Indent));
}
else if (Char2.Equal(input.Current()))
{
yield return(TokenLexers.Take(input, TokenType.Equal));
}
else if (Char2.Or(input.Current()))
{
yield return(TokenLexers.Take(input, TokenType.Or));
}
else if (Char2.Separator(input.Current()))
{
yield return(TokenLexers.Take(input, TokenType.Separator));
}
else if (input.Current() == '(')
{
yield return(TokenLexers.Take(input, TokenType.GroupOpen));
}
else if (input.Current() == ')')
{
yield return(TokenLexers.Take(input, TokenType.GroupClosed));
}
else if (input.Current() == ',')
{
yield return(TokenLexers.Take(input, TokenType.ListSeparator));
}
else if (Char2.IsNewLine(input.Current()))
{
var newline = TokenLexers.Take(input, TokenType.NewLine);
newline.Value = "↓";
yield return(newline);
}
else if (Char.IsWhiteSpace(input.Current()))
{
var whiteSpace = TokenLexers.Whitespace(input);
if (!_ignoreWhiteSpace)
{
yield return(whiteSpace);
}
}
else if (!context)
{
yield return(TokenLexers.TakeUntillEndOfContext(input));
}
else
{
input.Next();
}
}
// If we are still inside of a context when the code has been parsed,
// we'll want to end the context, jsut for good measure!
if (context)
{
yield return(new Token()
{
TokenType = TokenType.ContextEnded
});
context = false;
}
yield return(new Token()
{
TokenType = TokenType.EndOfFile
});
}
