private static IEnumerable <Argument> ParseArguments(ListIterator <Token> iterator)
{
for (; ;)
{
var token = AssertNotEof(iterator.FirstOrDefault());
if (token is PunctuatorToken && token.Value.Equals(")"))
{
yield break;
}
else if (!(token is NameToken))
{
throw new ParserException();
}
var(location, name) = token;
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is PunctuatorToken && token.Value.Equals(":")))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
var value = ParseValue(ref token, iterator);
yield return(new Argument(name, location, value));
}
}
private static OperationDefinition ParseQuery(ref Token token, ListIterator <Token> iterator)
{
string operationName = null;
if (token is NameToken)
{
operationName = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
}
IEnumerable <VariableDefinition> variableDefinitions = null;
if (token is PunctuatorToken && token.Value.Equals("("))
{
variableDefinitions = ParseVariableDefinitions(iterator)
.ToList();
token = AssertNotEof(iterator.FirstOrDefault());
}
var directives = ParseDirectives(ref token, iterator);
if (token is PunctuatorToken && token.Value.Equals("{"))
{
token = AssertNotEof(iterator.FirstOrDefault());
var selectionSet = ParseSelectionSet(ref token, iterator);
return(new OperationDefinition(OperationType.Query, operationName, variableDefinitions, directives, selectionSet));
}
throw new ParserException($"Syntax error at {token.Location}. Expected 'query' or '{{', got {token.Value}");
}
private static IEnumerable <Directive> ParseDirectives(ref Token token, ListIterator <Token> iterator)
{
var result = new List <Directive>();
for (; token is PunctuatorToken && token.Value.Equals("@");)
{
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken))
{
throw new ParserException();
}
var name = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
if (token is PunctuatorToken && token.Value.Equals("("))
{
result.Add(new Directive(name, ParseArguments(iterator)));
}
else
{
result.Add(new Directive(name, null));
}
}
return(result.Count == 0 ? null : result);
}
private static IEnumerable <VariableDefinition> ParseVariableDefinitions(ListIterator <Token> iterator)
{
var token = AssertNotEof(iterator.FirstOrDefault());
for (; ;)
{
if (token is PunctuatorToken && token.Value.Equals(")"))
{
break;
}
if (!(token is PunctuatorToken && token.Value.Equals("$")))
{
throw new ParserException();
}
var location = token.Location;
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken))
{
throw new ParserException();
}
var name = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is PunctuatorToken && token.Value.Equals(":")))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
var type = ParseInputType(ref token, iterator);
Value defaultValue = null;
if (token is PunctuatorToken && token.Value.Equals("="))
{
token = AssertNotEof(iterator.FirstOrDefault());
defaultValue = ParseValue(ref token, iterator);
}
yield return(new VariableDefinition(name, type, defaultValue, location));
}
}
private IEnumerable <Definition> ParseDefinitions(ListIterator <Token> iterator)
{
var token = iterator.FirstOrDefault();
if (token == null)
{
yield break;
}
for (; ;)
{
if (token is NameToken)
{
if (token.Value.Equals("query"))
{
token = AssertNotEof(iterator.FirstOrDefault());
yield return(ParseQuery(ref token, iterator));
}
else if (token.Value.Equals("mutation"))
{
//AssertNotEof(iterator.FirstOrDefault());
yield return(ParseMutation(iterator));
}
else if (token.Value.Equals("fragment"))
{
AssertNotEof(iterator.FirstOrDefault());
yield return(ParseFragment(iterator));
}
}
else if (token is PunctuatorToken && token.Value.Equals("{"))
{
yield return(ParseQuery(ref token, iterator));
}
else
{
throw new ParserException();
}
token = iterator.FirstOrDefault();
if (token == null)
{
break;
}
}
}
private static FragmentDefinition ParseFragment(ListIterator <Token> iterator)
{
var token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken))
{
throw new ParserException();
}
var name = token.Value;
if (name.Equals("on"))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken && token.Value.Equals("on")))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken))
{
throw new ParserException();
}
var type = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
var directives = ParseDirectives(ref token, iterator);
if (!(token is PunctuatorToken && token.Value.Equals("{")))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
var selectionSet = ParseSelectionSet(ref token, iterator);
return(new FragmentDefinition(name, type, directives, selectionSet));
}
private static InlineFragment ParseInlineFragment(ref Token token, ListIterator <Token> iterator)
{
string type = null;
if (token is NameToken)
{
if (!token.Value.Equals("on"))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken))
{
throw new ParserException();
}
type = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
}
if (!(token is PunctuatorToken))
{
throw new ParserException();
}
IEnumerable <Directive> directives = null;
if (token.Value.Equals("@"))
{
directives = ParseDirectives(ref token, iterator);
}
if (!token.Value.Equals("{"))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
var selectionSet = ParseSelectionSet(ref token, iterator);
return(new InlineFragment(type, directives, selectionSet));
}
private static InputType ParseInputType(ref Token token, ListIterator <Token> iterator)
{
if (token is PunctuatorToken && token.Value.Equals("["))
{
token = AssertNotEof(iterator.FirstOrDefault());
var inputType = ParseInputType(ref token, iterator);
// token is currently ']'
token = AssertNotEof(iterator.FirstOrDefault());
var listType = new ListType(inputType);
InputType result = listType;
if (token is PunctuatorToken && token.Value.Equals("!"))
{
token = AssertNotEof(iterator.FirstOrDefault());
result = new NonNullType(listType);
}
return(result);
}
if (!(token is NameToken))
{
throw new ParserException();
}
var namedType = new NamedType(token.Value);
token = AssertNotEof(iterator.FirstOrDefault());
if (token is PunctuatorToken && token.Value.Equals("!"))
{
token = AssertNotEof(iterator.FirstOrDefault());
return(new NonNullType(namedType));
}
return(namedType);
}
private static ObjectField ParseObjectField(ref Token token, ListIterator <Token> iterator)
{
if (!(token is NameToken))
{
throw new ParserException();
}
var name = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is PunctuatorToken && token.Value.Equals(":")))
{
throw new ParserException();
}
token = AssertNotEof(iterator.FirstOrDefault());
var value = ParseValue(ref token, iterator);
return(new ObjectField(name, value));
}
private static FragmentSpread ParseFragmentSpread(ref Token token, ListIterator <Token> iterator)
{
var name = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
IEnumerable <Directive> directives = null;
if (token is PunctuatorToken && token.Value.Equals("@"))
{
directives = ParseDirectives(ref token, iterator);
}
return(new FragmentSpread(name, directives));
}
private static Selection ParseFragmentSelection(ref Token token, ListIterator <Token> iterator)
{
token = AssertNotEof(iterator.FirstOrDefault());
if (token is NameToken)
{
if (token.Value.Equals("on"))
{
return(ParseInlineFragment(ref token, iterator));
}
return(ParseFragmentSpread(ref token, iterator));
}
return(ParseInlineFragment(ref token, iterator));
}
private static Field ParseField(ref Token token, ListIterator <Token> iterator)
{
string alias = null;
var(location, name) = token;
token = AssertNotEof(iterator.FirstOrDefault());
if (token is PunctuatorToken && token.Value.Equals(":"))
{
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken))
{
throw new ParserException();
}
alias = name;
name = token.Value;
token = AssertNotEof(iterator.FirstOrDefault());
}
IEnumerable <Argument> arguments = null;
if (token is PunctuatorToken && token.Value.Equals("("))
{
arguments = ParseArguments(iterator)
.ToList();
token = AssertNotEof(iterator.FirstOrDefault());
}
IEnumerable <Directive> directives = null;
if (token is PunctuatorToken && token.Value.Equals("@"))
{
directives = ParseDirectives(ref token, iterator);
}
IEnumerable <Selection> selectionSet = null;
if (token is PunctuatorToken && token.Value.Equals("{"))
{
token = AssertNotEof(iterator.FirstOrDefault());
selectionSet = ParseSelectionSet(ref token, iterator);
token = AssertNotEof(iterator.FirstOrDefault());
}
return(new Field(name, alias, arguments, directives, selectionSet, location));
}
private static ListValue ParseListValue(ref Token token, ListIterator <Token> iterator)
{
var items = new List <Value>();
for (; ;)
{
token = AssertNotEof(iterator.FirstOrDefault());
if (token is PunctuatorToken && token.Value.Equals("]"))
{
break;
}
items.Add(ParseValue(ref token, iterator));
}
return(new ListValue(items));
}
private static ObjectValue ParseObjectValue(ref Token token, ListIterator <Token> iterator)
{
var fields = new List <ObjectField>();
for (; ;)
{
token = AssertNotEof(iterator.FirstOrDefault());
if (token is PunctuatorToken && token.Value.Equals("}"))
{
break;
}
fields.Add(ParseObjectField(ref token, iterator));
}
return(new ObjectValue(fields));
}
private static Value TryParseValue(ref Token token, ListIterator <Token> iterator)
{
if (token is PunctuatorToken)
{
if (token.Value.Equals("$"))
{
var location = token.Location;
token = AssertNotEof(iterator.FirstOrDefault());
if (!(token is NameToken))
{
throw new ParserException();
}
return(new Variable(token.Value, location));
}
if (token.Value.Equals("{"))
{
return(ParseObjectValue(ref token, iterator));
}
if (token.Value.Equals("["))
{
return(ParseListValue(ref token, iterator));
}
throw new ParserException();
}
if (token is IntValueToken intValueToken)
{
return(new IntValue(intValueToken.IntValue));
}
if (token is FloatValueToken floatValueToken)
{
return(new FloatValue(floatValueToken.DecimalValue));
}
if (token is StringValueToken)
{
return(new StringValue(token.Value));
}
if (token is NameToken)
{
if (token.Value.Equals("true"))
{
return(new BooleanValue(true));
}
if (token.Value.Equals("false"))
{
return(new BooleanValue(false));
}
if (token.Value.Equals("null"))
{
return(new NullValue());
}
return(new EnumValue(token.Value));
}
throw new ParserException();
}
