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])
}
}
}
// 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
}
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)
}
// 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)
}
}
}
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)
}
}
}
func lexArgumentVal(l *lex.Lexer) lex.StateFn {
for {
switch r := l.Next(); {
case isSpace(r):
l.Ignore()
}
}
}
// 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)
}
}
}
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
}
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
}
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")
}
}
}
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)
}
// 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])
}
}
}
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])
}
}
}
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)
}
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])
}
}
}
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
}
// 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")
}
}
}
// 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)
}
}
}
// 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
}
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
}
// 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")
}
}
}
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
}
