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|
package lexer
import (
"fmt"
"github.com/ChrisTrenkamp/goxpath/xconst"
)
func absLocPathState(l *Lexer) stateFn {
l.emit(XItemAbsLocPath)
return stepState
}
func abbrAbsLocPathState(l *Lexer) stateFn {
l.emit(XItemAbbrAbsLocPath)
return stepState
}
func relLocPathState(l *Lexer) stateFn {
l.emit(XItemRelLocPath)
return stepState
}
func abbrRelLocPathState(l *Lexer) stateFn {
l.emit(XItemAbbrRelLocPath)
return stepState
}
func stepState(l *Lexer) stateFn {
l.skipWS(true)
r := l.next()
for isElemChar(r) {
r = l.next()
}
l.backup()
tok := l.input[l.start:l.pos]
state, err := parseSeparators(l, tok)
if err != nil {
return l.errorf(err.Error())
}
return getNextPathState(l, state)
}
func parseSeparators(l *Lexer, tok string) (XItemType, error) {
l.skipWS(false)
state := XItemType(XItemQName)
r := l.peek()
if string(r) == ":" && string(l.peekAt(2)) == ":" {
var err error
if state, err = getAxis(l, tok); err != nil {
return state, fmt.Errorf(err.Error())
}
} else if string(r) == ":" {
state = XItemNCName
l.emitVal(state, tok)
l.skip(1)
l.skipWS(true)
} else if string(r) == "@" {
state = XItemAbbrAxis
l.emitVal(state, tok)
l.skip(1)
l.skipWS(true)
} else if string(r) == "(" {
var err error
if state, err = getNT(l, tok); err != nil {
return state, fmt.Errorf(err.Error())
}
} else if len(tok) > 0 {
l.emitVal(state, tok)
}
return state, nil
}
func getAxis(l *Lexer, tok string) (XItemType, error) {
var state XItemType
for i := range xconst.AxisNames {
if tok == xconst.AxisNames[i] {
state = XItemAxis
}
}
if state != XItemAxis {
return state, fmt.Errorf("Invalid Axis specifier, %s", tok)
}
l.emitVal(state, tok)
l.skip(2)
l.skipWS(true)
return state, nil
}
func getNT(l *Lexer, tok string) (XItemType, error) {
isNT := false
for _, i := range xconst.NodeTypes {
if tok == i {
isNT = true
break
}
}
if isNT {
return procNT(l, tok)
}
return XItemError, fmt.Errorf("Invalid node-type " + tok)
}
func procNT(l *Lexer, tok string) (XItemType, error) {
state := XItemType(XItemNodeType)
l.emitVal(state, tok)
l.skip(1)
l.skipWS(true)
n := l.peek()
if tok == xconst.NodeTypeProcInst && (string(n) == `"` || string(n) == `'`) {
if err := getStrLit(l, XItemProcLit); err != nil {
return state, fmt.Errorf(err.Error())
}
l.skipWS(true)
n = l.next()
}
if string(n) != ")" {
return state, fmt.Errorf("Missing ) at end of NodeType declaration.")
}
l.skip(1)
return state, nil
}
func procFunc(l *Lexer, tok string) error {
state := XItemType(XItemFunction)
l.emitVal(state, tok)
l.skip(1)
l.skipWS(true)
if string(l.peek()) != ")" {
l.emit(XItemArgument)
for {
for state := startState; state != nil; {
state = state(l)
}
l.skipWS(true)
if string(l.peek()) == "," {
l.emit(XItemArgument)
l.skip(1)
} else if string(l.peek()) == ")" {
l.emit(XItemEndFunction)
l.skip(1)
break
} else if l.peek() == eof {
return fmt.Errorf("Missing ) at end of function declaration.")
}
}
} else {
l.emit(XItemEndFunction)
l.skip(1)
}
return nil
}
func getNextPathState(l *Lexer, state XItemType) stateFn {
isMultiPart := state == XItemAxis || state == XItemAbbrAxis || state == XItemNCName
l.skipWS(true)
for string(l.peek()) == "[" {
if err := getPred(l); err != nil {
return l.errorf(err.Error())
}
}
if string(l.peek()) == "/" && !isMultiPart {
l.skip(1)
if string(l.peek()) == "/" {
l.skip(1)
return abbrRelLocPathState
}
l.skipWS(true)
return relLocPathState
} else if isMultiPart && isElemChar(l.peek()) {
return stepState
}
if isMultiPart {
return l.errorf("Step is not complete")
}
l.emit(XItemEndPath)
return findOperatorState
}
func getPred(l *Lexer) error {
l.emit(XItemPredicate)
l.skip(1)
l.skipWS(true)
if string(l.peek()) == "]" {
return fmt.Errorf("Missing content in predicate.")
}
for state := startState; state != nil; {
state = state(l)
}
l.skipWS(true)
if string(l.peek()) != "]" {
return fmt.Errorf("Missing ] at end of predicate.")
}
l.skip(1)
l.emit(XItemEndPredicate)
l.skipWS(true)
return nil
}
|
