Example #1
0
func lexObject(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == rightCurl:
			return lexText
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		case isNameBegin(r):
			{
				for {
					r := l.Next()
					if isNameSuffix(r) {
						continue // absorb
					}
					l.Backup()
					l.Emit(itemObject)
					break
				}
				return lexObjectBlock
			}
		default:
			return l.Errorf("Invalid schema. Unexpected %s", l.Input[l.Start:l.Pos])
		}
	}
}
Example #2
0
// Assumes '"' has already been encountered.
func lexLiteral(l *lex.Lexer) lex.StateFn {
	for {
		r := l.Next()
		if r == '\u005c' { // backslash
			r = l.Next()
			continue // This would skip over the escaped rune.
		}

		if r == lex.EOF || isEndLiteral(r) {
			break
		}
	}
	l.Backup()

	l.Emit(itemLiteral)
	l.Next()   // Move to end literal.
	l.Ignore() // Ignore end literal.
	l.Depth++

	r := l.Peek()
	if r == '@' {
		return lexLanguage(l)
	}

	if r == '^' {
		return lexObjectType(l)
	}

	return lexText
}
Example #3
0
func lexObject(l *lex.Lexer) lex.StateFn {
	r := l.Next()
	// The object can be an IRI, blank node or a literal.
	if r == '<' {
		l.Depth++
		return lexUntilClosing(l, itemObject, lexText)
	}

	if r == '_' {
		l.Depth++
		r = l.Next()
		// TODO - Remove this, doesn't conform to the spec.
		if r == 'u' {
			return lexUidNode(l, itemObject, lexText)
		}

		if r == ':' {
			return lexBlankNode(l, itemObject, lexText)
		}
	}
	if r == '"' {
		l.Ignore()
		return lexLiteral(l)
	}

	return l.Errorf("Invalid char: %v at lexObject", r)
}
Example #4
0
// lexInsideMutation lexes the text inside a mutation block.
func lexInsideMutation(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == rightCurl:
			l.Depth--
			l.Emit(itemRightCurl)
			if l.Depth == 0 {
				return lexText
			}
		case r == leftCurl:
			l.Depth++
			l.Emit(itemLeftCurl)
			if l.Depth >= 2 {
				return lexTextMutation
			}
		case r == lex.EOF:
			return l.Errorf("Unclosed mutation action")
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		case isNameBegin(r):
			return lexNameMutation
		default:
			return l.Errorf("Unrecognized character in lexInsideMutation: %#U", r)
		}
	}
}
Example #5
0
func lexInside(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == rightCurl:
			l.Depth -= 1
			l.Emit(itemRightCurl)
			if l.Depth == 0 {
				return lexText
			}
		case r == leftCurl:
			l.Depth += 1
			l.Emit(itemLeftCurl)
		case r == lex.EOF:
			return l.Errorf("unclosed action")
		case isSpace(r) || isEndOfLine(r) || r == ',':
			l.Ignore()
		case isNameBegin(r):
			return lexName
		case r == '#':
			l.Backup()
			return lexComment
		case r == '(':
			l.Emit(itemLeftRound)
			return lexArgInside
		default:
			return l.Errorf("Unrecognized character in lexInside: %#U", r)
		}
	}
}
Example #6
0
func lexArgumentVal(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case isSpace(r):
			l.Ignore()
		}
	}
}
Example #7
0
// lexInside lexes the content inside a query block.
func lexInside(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == period:
			if l.Next() == period && l.Next() == period {
				return lexFragmentSpread
			}
			// We do not expect a period at all. If you do, you may want to
			// backup the two extra periods we try to read.
			return l.Errorf("Unrecognized character in lexInside: %#U", r)
		case r == rightCurl:
			l.Depth--
			l.Emit(itemRightCurl)
			if l.Depth == 0 {
				return lexText
			}
		case r == leftCurl:
			l.Depth++
			l.Emit(itemLeftCurl)
		case r == lex.EOF:
			return l.Errorf("Unclosed action")
		case isSpace(r) || isEndOfLine(r) || r == comma:
			l.Ignore()
		case isNameBegin(r):
			return lexName
		case r == '#':
			l.Backup()
			return lexComment
		case r == leftRound:
			l.Emit(itemLeftRound)
			l.AcceptRun(isSpace)
			l.Ignore()
			k := l.Next()
			if k == '_' || l.Depth != 1 || l.Mode == fragmentMode {
				l.Backup()
				l.Emit(itemArgument)
				return lexArgInside
			}
			// This is a generator function.
			l.Backup()
			l.Emit(itemGenerator)
			l.FilterDepth++
			return lexFilterInside
		case r == ':':
			return lexAlias
		case r == '@':
			return lexDirective
		default:
			return l.Errorf("Unrecognized character in lexInside: %#U", r)
		}
	}
}
Example #8
0
func lexLanguage(l *lex.Lexer) lex.StateFn {
	r := l.Next()
	if r != '@' {
		return l.Errorf("Expected @ prefix for lexLanguage")
	}
	l.Ignore()
	r = l.Next()
	if !isLangTagPrefix(r) {
		return l.Errorf("Invalid language tag prefix: %v", r)
	}
	l.AcceptRun(isLangTag)
	l.Emit(itemLanguage)
	return lexText
}
Example #9
0
func lexAlias(l *lex.Lexer) lex.StateFn {
	l.AcceptRun(isSpace)
	l.Ignore() // Any spaces encountered.
	for {
		r := l.Next()
		if isNameSuffix(r) {
			continue
		}
		l.Backup()
		l.Emit(itemAlias)
		break
	}
	return lexInside
}
Example #10
0
func lexVarInside(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == lex.EOF:
			return l.Errorf("unclosed argument")
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		case isDollar(r):
			return lexVarName
		case r == ':':
			l.Ignore()
			return lexVarType
		case r == equal:
			l.Emit(itemEqual)
			l.Ignore()
			return lexVarDefault
		case r == rightRound:
			l.Emit(itemRightRound)
			return lexText
		case r == comma:
			l.Emit(itemComma)
			l.Ignore()
		default:
			return l.Errorf("variable list invalid")
		}
	}
}
Example #11
0
func lexObjectType(l *lex.Lexer) lex.StateFn {
	r := l.Next()
	if r != '^' {
		return l.Errorf("Expected ^ for lexObjectType")
	}
	r = l.Next()
	if r != '^' {
		return l.Errorf("Expected ^^ for lexObjectType")
	}
	l.Ignore()
	r = l.Next()
	if r != '<' {
		return l.Errorf("Expected < for lexObjectType")
	}
	return lexUntilClosing(l, itemObjectType, lexText)
}
Example #12
0
// lexArgVal lexes and emits the value part of an argument.
func lexArgVal(l *lex.Lexer) lex.StateFn {
	l.AcceptRun(isSpace)
	l.Ignore() // Any spaces encountered.
	for {
		r := l.Next()
		if isSpace(r) || isEndOfLine(r) || r == rightRound || r == comma {
			l.Backup()
			l.Emit(itemArgVal)
			return lexArgInside
		}
		if r == lex.EOF {
			return l.Errorf("Reached lex.EOF while reading var value: %v",
				l.Input[l.Start:l.Pos])
		}
	}
}
Example #13
0
func lexScalarBlock(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == ')':
			l.Emit(itemRightRound)
			return lexText
		case isNameBegin(r):
			l.Backup()
			return lexScalarPair1
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		default:
			return l.Errorf("Invalid schema. Unexpected %s", l.Input[l.Start:l.Pos])
		}
	}
}
Example #14
0
func lexObject(l *lex.Lexer) lex.StateFn {
	r := l.Next()
	if r == '<' {
		l.Depth += 1
		return lexUntilClosing(l, itemObject, lexText)
	}
	if r == '_' {
		l.Depth += 1
		return lexBlankNode(l, itemObject, lexText)
	}
	if r == '"' {
		l.Ignore()
		return lexLiteral(l)
	}

	return l.Errorf("Invalid char: %v at lexObject", r)
}
Example #15
0
func lexObjectBlock(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == leftCurl:
			l.Emit(itemLeftCurl)
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		case r == rightCurl:
			l.Emit(itemRightCurl)
			return lexText
		case isNameBegin(r):
			return lexObjectPair
		default:
			return l.Errorf("Invalid schema. Unexpected %s", l.Input[l.Start:l.Pos])
		}
	}
}
Example #16
0
func lexArgVal(l *lex.Lexer) lex.StateFn {
	l.AcceptRun(isSpace)
	l.Ignore() // Any spaces encountered.
	for {
		r := l.Next()
		if isSpace(r) || isEndOfLine(r) || r == ')' || r == ',' {
			l.Backup()
			l.Emit(itemArgVal)
			return lexArgInside
		}
		if r == lex.EOF {
			return l.Errorf("Reached lex.EOF while reading var value: %v",
				l.Input[l.Start:l.Pos])
		}
	}
	glog.Fatal("This shouldn't be reached.")
	return nil
}
Example #17
0
// lexArgInside is used to lex the arguments inside ().
func lexArgInside(l *lex.Lexer) lex.StateFn {
	for {
		switch r := l.Next(); {
		case r == lex.EOF:
			return l.Errorf("unclosed argument")
		case isSpace(r) || isEndOfLine(r) || r == comma:
			l.Ignore()
		case isNameBegin(r):
			return lexArgName
		case r == ':':
			l.Ignore()
			return lexArgVal
		case r == rightRound:
			l.Emit(itemRightRound)
			return lexInside
		default:
			return l.Errorf("argument list invalid")
		}
	}
}
Example #18
0
// lexFilterInside expects input like (  (equal(...) && f(...)) || g(...)  ).
func lexFilterInside(l *lex.Lexer) lex.StateFn {
	for {
		r := l.Next()
		switch {
		case r == leftRound:
			l.Emit(itemLeftRound)
			l.FilterDepth++
		case r == rightRound:
			if l.FilterDepth == 0 {
				return l.Errorf("Unexpected right round bracket")
			}
			l.FilterDepth--
			l.Emit(itemRightRound)
			if l.FilterDepth == 0 {
				return lexInside // Filter directive is done.
			}
		case r == lex.EOF:
			return l.Errorf("Unclosed directive")
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		case isNameBegin(r):
			return lexFilterFuncName
		case r == '&':
			r2 := l.Next()
			if r2 == '&' {
				l.Emit(itemFilterAnd)
				return lexFilterInside
			}
			return l.Errorf("Expected & but got %v", r2)
		case r == '|':
			r2 := l.Next()
			if r2 == '|' {
				l.Emit(itemFilterOr)
				return lexFilterInside
			}
			return l.Errorf("Expected | but got %v", r2)
		default:
			return l.Errorf("Unrecognized character in lexInside: %#U", r)
		}
	}
}
Example #19
0
// lexText lexes the input string and calls other lex functions.
func lexText(l *lex.Lexer) lex.StateFn {
Loop:
	for {
		switch r := l.Next(); {
		case r == lex.EOF:
			break Loop
		case isNameBegin(r):
			l.Backup()
			return lexStart
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		default:
			return l.Errorf("Invalid schema. Unexpected %s", l.Input[l.Start:l.Pos])
		}
	}
	if l.Pos > l.Start {
		l.Emit(itemText)
	}
	l.Emit(lex.ItemEOF)
	return nil
}
Example #20
0
func lexObjectPair(l *lex.Lexer) lex.StateFn {
	for {
		r := l.Next()
		if isNameSuffix(r) {
			continue // absorb
		}
		l.Backup()
		l.Emit(itemObjectName)
		break
	}

L:
	for {
		switch r := l.Next(); {
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		case r == ':':
			l.Emit(itemCollon)
			break
		case isNameBegin(r):
			l.Backup()
			break L
		default:
			return l.Errorf("Invalid schema. Unexpected %s", l.Input[l.Start:l.Pos])
		}
	}

	for {
		r := l.Next()
		if isNameSuffix(r) {
			continue // absorb
		}
		l.Backup()
		l.Emit(itemObjectType)
		break
	}

	return lexObjectBlock

}
Example #21
0
// lexFilterFuncInside expects input to look like ("...", "...").
func lexFilterFuncInside(l *lex.Lexer) lex.StateFn {
	l.AcceptRun(isSpace)
	l.Ignore() // Any spaces encountered.

	for {
		r := l.Next()
		if isSpace(r) || r == ',' {
			l.Ignore()
		} else if r == leftRound {
			l.Emit(itemLeftRound)
		} else if r == rightRound {
			l.Emit(itemRightRound)
			return lexFilterInside
		} else if isEndLiteral(r) {
			l.Ignore()
			l.AcceptUntil(isEndLiteral) // This call will backup the ending ".
			l.Emit(itemFilterFuncArg)
			l.Next() // Consume " and ignore it.
			l.Ignore()
		} else {
			return l.Errorf("Expected quotation mark in lexFilterFuncArgs")
		}
	}
}
Example #22
0
func lexScalarPair1(l *lex.Lexer) lex.StateFn {
	for {
		r := l.Next()
		if isNameSuffix(r) {
			continue // absorb
		}
		l.Backup()
		// l.Pos would be index of the end of operation type + 1.
		l.Emit(itemScalarName)
		break
	}

L:
	for {
		switch r := l.Next(); {
		case isSpace(r) || isEndOfLine(r):
			l.Ignore()
		case r == ':':
			l.Emit(itemCollon)
			break
		case isNameBegin(r):
			l.Backup()
			break L
		default:
			return l.Errorf("Invalid schema. Unexpected %s", l.Input[l.Start:l.Pos])
		}
	}

	for {
		r := l.Next()
		if isNameSuffix(r) {
			continue // absorb
		}
		l.Backup()
		l.Emit(itemScalarType)
		break
	}

	// Check for the mention of @index.
	var isIndexed bool
L1:
	for {
		switch r := l.Next(); {
		case isSpace(r):
			l.Ignore()
		case isEndOfLine(r):
			break L1
		case r == '@':
			l.Emit(itemAt)
			isIndexed = true
			for {
				r := l.Next()
				if isNameSuffix(r) {
					continue // absorb
				}
				l.Backup()
				// l.Pos would be index of the end of operation type + 1.
				word := l.Input[l.Start:l.Pos]
				if word == "index" {
					l.Emit(itemIndex)
					break L1
				} else {
					return l.Errorf("Invalid mention of index")
				}
			}
			break L1
		default:
			return l.Errorf("Invalid schema. Unexpected %s", l.Input[l.Start:l.Pos])
		}
	}
	if !isIndexed {
		l.Emit(itemDummy)
	}
	return lexScalarBlock
}