private IExpression ParseUnary()
{
while (true)
{
IExpression res = new ErrorExpression();
switch (_tokenizer.GetNextToken())
{
case Token.Number:
res = new Number(_tokenizer.GetValue());
_tokenizer.GetNextToken();
break;
case Token.Negate:
res = new Negate(ParseUnary());
break;
case Token.OpenParenthesis:
res = ParseAddSubtract();
if (_tokenizer.GetCurToken() != Token.CloseParenthesis)
{
_tokenizer.AddException(new MissingCloseParenthesisException(
_tokenizer.GetExpression(),
_tokenizer.GetInd()));
}
_tokenizer.GetNextToken();
break;
case Token.Error:
continue;
}
return(res);
}
}
private static TreeViewItem AsTreeViewItem(ErrorExpression expression)
{
var result = new TreeViewItem();
result.Header = expression.Description;
return(result);
}
private ErrorExpression Error(int startPos, string verbatimImage = null, Expression preceding = null)
{
verbatimImage = verbatimImage ?? (_fString.Substring(startPos, _position - startPos));
var expr = new ErrorExpression(verbatimImage, preceding);
expr.SetLoc(StartIndex + startPos, StartIndex + _position);
return(expr);
}
public virtual TResult Visit(BaseExpression expression)
{
return(expression switch {
Phi a => Visit(a),
Increment a => Visit(a),
Decrement a => Visit(a),
ErrorExpression a => Visit(a),
Bracketed a => Visit(a),
Abs a => Visit(a),
Sqrt a => Visit(a),
Sine a => Visit(a),
Cosine a => Visit(a),
Tangent a => Visit(a),
ArcSine a => Visit(a),
ArcCos a => Visit(a),
ArcTan a => Visit(a),
PostIncrement a => Visit(a),
PreIncrement a => Visit(a),
PostDecrement a => Visit(a),
PreDecrement a => Visit(a),
Add a => Visit(a),
Subtract a => Visit(a),
Multiply a => Visit(a),
Divide a => Visit(a),
Modulo a => Visit(a),
Negate a => Visit(a),
Exponent a => Visit(a),
Or a => Visit(a),
And a => Visit(a),
Not a => Visit(a),
Factorial a => Visit(a),
Variable a => Visit(a),
ConstantNumber a => Visit(a),
ConstantString a => Visit(a),
EqualTo a => Visit(a),
NotEqualTo a => Visit(a),
GreaterThan a => Visit(a),
GreaterThanEqualTo a => Visit(a),
LessThan a => Visit(a),
LessThanEqualTo a => Visit(a),
_ => VisitUnknown(expression)
});
protected override IDataFlowGraphExpressionNode Visit(ErrorExpression err)
{
throw new NotImplementedException();
}
protected override bool Visit(ErrorExpression err) => false;
public override void PostWalk(ErrorExpression node)
{
}
// ErrorExpression
public override bool Walk(ErrorExpression node) { return false; }
// ErrorExpression
public virtual bool Walk(ErrorExpression node)
{
return(true);
}
// ErrorExpression
public override bool Walk(ErrorExpression node)
{
return(Location >= node.StartIndex && Location <= node.EndIndex);
}
protected override IEnumerable <BaseStatement> Visit(ErrorExpression err)
{
yield return(new ErrorStatement());
}
public virtual object Visit (ErrorExpression errorExpression)
{
return null;
}
// ErrorExpression
public override bool Walk(ErrorExpression node) { return Location >= node.StartIndex && Location <= node.EndIndex; }
public override void VisitErrorExpression(ErrorExpression node)
=> Error($"Expected expression, found '{node.Text}'", node);
public override bool Walk(ErrorExpression node)
{
writer.WriteLine("Error");
return(base.Walk(node));
}
private List <Inferred> InferErrorExpression(ErrorExpression node, Scope scope)
{
return(null);
}
[NotNull] protected virtual BaseExpression Visit([NotNull] ErrorExpression err)
{
return(err);
}
// ErrorExpression
public bool Walk(ErrorExpression node)
{
return(Process(node));
}
// ErrorExpression
public override bool Walk(ErrorExpression node)
{
return(ShouldWalkWorker(node));
}
public void PostWalk(ErrorExpression node)
{
PostProcess(node);
}
public override void PostWalk(ErrorExpression node)
{
PostWalkWorker(node);
}
public override bool Walk(ErrorExpression node)
{
HasSideEffects = true;
return(false);
}
[NotNull] protected abstract TResult Visit([NotNull] ErrorExpression err);
public virtual void PostWalk(ErrorExpression node)
{
}
// ErrorExpression
public virtual bool Walk(ErrorExpression node) { return true; }
// ErrorExpression
public override bool Walk(ErrorExpression node)
{
return(false);
}
protected override bool Visit(ErrorExpression err) => throw new NotSupportedException();
public virtual object Visit(ErrorExpression errorExpression)
{
return(null);
}
public override bool Walk(ErrorExpression node) => Save(node, base.Walk(node), _options.Errors);
public override void PostWalk(ErrorExpression node) { }
//constant:
// Integer
// Float
// String
// Boolean
//symbol:
// ReplacementSymbol
// Symbol
//value:
// constant
// symbol
// operation
// scope
//operation: value Operator value
//list-expression: value-source , value-source
//scope: StartScope value-source EndScope
//value-source:
// value
// scope
// function
// operation
//function: symbol StartScope list-expression EndScope | symbol StartScope value-source EndScope
public static Expression Parse(List <Token> tokens)
{
if (tokens == null || tokens.None())
{
return(new NullExpression());
}
var remainder = tokens.ToList();
Expression program = null;
while (remainder.Any())
{
Production parsed = null;
var current = remainder.First();
switch (current.TokenClass)
{
case TokenClass.StartScope:
parsed = new ScopedExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new SeparatedExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new ErrorExpression().Parse(program, remainder);
break;
case TokenClass.Whitespace:
parsed = new WhitespaceExpression().Parse(remainder);
break;
case TokenClass.Symbol:
parsed = new OperationExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new FunctionExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new SymbolExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new ErrorExpression().Parse(program, remainder);
break;
case TokenClass.ReplacementSymbol:
parsed = new OperationExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new ReplacementSymbolExpression().Parse(remainder);
break;
case TokenClass.Float:
case TokenClass.Integer:
parsed = new OperationExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = NumericExpression.TryParseNumeric(remainder);
break;
case TokenClass.String:
parsed = new OperationExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new StringExpression().Parse(remainder);
break;
case TokenClass.Boolean:
parsed = new OperationExpression().Parse(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new BooleanExpression().Parse(remainder);
break;
case TokenClass.Operator:
parsed = NumericExpression.TryParseNumeric(remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new OperationExpression().Parse(program, remainder);
if (parsed.Expression != null)
{
break;
}
parsed = new ErrorExpression().Parse(program, remainder);
break;
case TokenClass.Error:
throw new Exception("Unexpected sequence: " + remainder.First().Lexeme);
default:
throw new ArgumentOutOfRangeException();
}
if (parsed.Expression != null && !(parsed.Expression is WhitespaceExpression))
{
program = parsed.Expression;
}
remainder = parsed.RemainingTokens;
}
if (program == null || remainder.Any())
{
throw new ParserException(remainder.Select(c => c.Lexeme).StringConcat());
}
return(program);
}
public virtual void PostWalk(ErrorExpression node) { }
protected override Type Visit(ErrorExpression err)
{
return(Type.Error);
}