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Diffstat (limited to 'walk/read.go')
-rw-r--r--walk/read.go494
1 files changed, 7 insertions, 487 deletions
diff --git a/walk/read.go b/walk/read.go
index bedb856..f25109c 100644
--- a/walk/read.go
+++ b/walk/read.go
@@ -1,491 +1,11 @@
package walk
-import (
- "bufio"
- "math"
- "strings"
- "strconv"
- "fmt"
-)
-
-type ReadAction int
-const (
- ActionReadValue ReadAction = iota
- ActionAppendPath
- ActionPopPath
- ActionIncrementPath
- ActionAppendPathNull
-)
-
-type JSONInStructure int
-const (
- JSONInMap JSONInStructure = iota
- JSONInArray
-)
-
-type JSONInState int
-const (
- JSONInValueEnd JSONInState = iota
- JSONInValue
- JSONInValueStart
- JSONInString
- JSONInKey
-)
-
-type JSONIn struct {
- path []Atom
- reader *bufio.Reader
- structure []JSONInStructure
- state JSONInState
- readBuffer []Atom
- readIndex int
- readBufferCapacity int
- actionBuffer []ReadAction
- actionIndex int
-}
-
-func NewJSONIn(reader *bufio.Reader) JSONIn {
- return JSONIn {
- path: make([]Atom, 0, 256),
- reader: reader,
- structure: []JSONInStructure{},
- state: JSONInValueStart,
- readBuffer: make([]Atom, 0, 256),
- readIndex: 0,
- readBufferCapacity: 256,
- actionBuffer: make([]ReadAction, 0, 256),
- actionIndex: 0,
- }
-}
-
-func isWhitespace(r rune) bool {
- for _, ws := range " \t\r\n" {
- if r == ws {
- return true
- }
- }
- return false
-}
-
-func isNumberRune(r rune) bool {
- return '0' <= r && r <= '9' || r == '.'
-}
-
-func (in *JSONIn) popPath() {
- if len(in.path) == 0 {
- panic("Tried to pop from empty path")
- }
- finalAtom := in.path[len(in.path) - 1]
- if finalAtom.Typ != AtomStringTerminal {
- in.path = in.path[:len(in.path) - 1]
- return
- }
- i := len(in.path) - 2
- for {
- if i < 0 {
- panic("Missing string begin in path")
- }
- if in.path[i].Typ == AtomStringTerminal {
- break
- }
- i--
- }
- in.path = in.path[:i]
-}
-
-func (in *JSONIn) nextNonWsRune() (rune, error) {
- for {
- r, _, err := in.reader.ReadRune()
- if err != nil {
- return 0, err
- }
- if !isWhitespace(r) {
- return r, nil
- }
- }
-}
-
-func (in *JSONIn) requireString(criteria string) {
- for _, r := range criteria {
- in.require(r)
- }
+type StredReader interface {
+ Read() (WalkItem, error)
+ AssertDone()
}
-func (in *JSONIn) require(criterion rune) {
- r, _, err := in.reader.ReadRune()
- if err != nil {
- panic("Error while reading required rune: " + err.Error())
- }
- if r != criterion {
- panic("Required rune not read")
- }
-}
-
-// Returns the first full value of a list of atoms and also a boolean to indicate if there isn't a value at the beginning
-func firstValue(atoms []Atom) ([]Atom, bool) {
- if len(atoms) == 0 {
- return nil, true
- }
- if atoms[0].Typ != AtomStringTerminal {
- return atoms[0:1], false
- }
- i := 1
- for {
- if i == len(atoms) {
- return nil, true
- }
- if atoms[i].Typ == AtomStringTerminal {
- return atoms[0:i+1], false
- }
- i++
- }
-}
-
-func (in *JSONIn) readValue() []Atom {
- try:
- value, incomplete := firstValue(in.readBuffer[in.readIndex:])
- if incomplete {
- if in.readIndex == 0 {
- newReadBuffer := make([]Atom, len(in.readBuffer), in.readBufferCapacity * 2)
- in.readBufferCapacity *= 2
- copy(newReadBuffer, in.readBuffer)
- in.readBuffer = newReadBuffer
- in.fillReadBuffer()
- goto try
- }
- copy(in.readBuffer, in.readBuffer[in.readIndex:])
- in.readBuffer = in.readBuffer[:len(in.readBuffer) - in.readIndex]
- in.readIndex = 0
- copy(in.actionBuffer, in.actionBuffer[in.actionIndex:])
- in.actionBuffer = in.actionBuffer[:len(in.actionBuffer) - in.actionIndex]
- in.actionIndex = 0
- in.fillReadBuffer()
- goto try
- }
- in.readIndex += len(value)
- return value
-}
-
-func (in *JSONIn) Read() (WalkItem, error) {
- for {
- if in.actionIndex == len(in.actionBuffer) {
- in.actionIndex = 0
- in.readIndex = 0
- in.actionBuffer = in.actionBuffer[:0]
- in.readBuffer = in.readBuffer[:0]
- err := in.fillReadBuffer()
- if len(in.actionBuffer) == 0 {
- return WalkItem{}, err
- }
- }
- action := in.actionBuffer[in.actionIndex]
- in.actionIndex++
- switch action {
- case ActionReadValue:
- value := in.readValue()
- return WalkItem {
- Value: value,
- Path: in.path,
- }, nil
- case ActionAppendPath:
- value := in.readValue()
- in.path = append(in.path, value...)
- case ActionAppendPathNull:
- in.path = append(in.path, NewAtomNull())
- case ActionPopPath:
- in.popPath()
- case ActionIncrementPath:
- prevIndex := in.path[len(in.path) - 1]
- if prevIndex.Typ == AtomNull {
- prevIndex.Typ = AtomNumber
- prevIndex.data = math.Float64bits(0)
- } else if prevIndex.Typ == AtomNumber {
- prevIndex.data = math.Float64bits(math.Float64frombits(prevIndex.data) + 1)
- } else {
- panic("Invalid index in array input. Type: " + fmt.Sprintf("%v", prevIndex.Typ))
- }
- in.path[len(in.path) - 1] = prevIndex
- default:
- panic("Invalid ReadAction")
- }
- }
-}
-
-func (in *JSONIn) AssertDone() {
- if len(in.structure) != 0 || in.state != JSONInValueEnd || in.readIndex < len(in.readBuffer) {
- panic("Input ended on incomplete JSON root")
- }
-}
-
-func (in *JSONIn) pushReadBuffer(atom Atom) bool {
- in.readBuffer = append(in.readBuffer, atom)
- return len(in.readBuffer) == in.readBufferCapacity
-}
-
-func (in *JSONIn) pushActionBuffer(action ReadAction) {
- in.actionBuffer = append(in.actionBuffer, action)
-}
-
-// Appends to the readBuffer until it has reached capacity
-// Also appends to the actionBuffer as needed
-func (in *JSONIn) fillReadBuffer() error {
- switch in.state {
- case JSONInValueStart:
- goto valueStart
- case JSONInValue:
- goto value
- case JSONInValueEnd:
- goto valueEnd
- case JSONInString:
- goto string
- case JSONInKey:
- goto key
- default:
- panic("Invalid JSONInState")
- }
- valueStart: {
- if len(in.structure) == 0 {
- goto value
- }
- innermost := in.structure[len(in.structure) - 1]
- switch innermost {
- case JSONInMap:
- goto mapValue
- case JSONInArray:
- goto arrayValue
- default:
- panic("Invalid JSONInStructure")
- }
- }
- value: {
- r, err := in.nextNonWsRune()
- if err != nil {
- panic("Missing value in JSON")
- }
- switch r {
- case 'n':
- in.requireString("ull")
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomNull()) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- case 'f':
- in.requireString("alse")
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomBool(false)) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- case 't':
- in.requireString("rue")
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomBool(true)) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- case '"':
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomStringTerminal()) {
- in.state = JSONInString
- return nil
- }
- goto string
- case '{':
- in.structure = append(in.structure, JSONInMap)
- in.pushActionBuffer(ActionReadValue)
- in.pushActionBuffer(ActionAppendPathNull)
- if in.pushReadBuffer(NewAtomTerminal(MapBegin)) {
- in.state = JSONInValueStart
- return nil
- }
- goto mapValue
- case '[':
- in.structure = append(in.structure, JSONInArray)
- in.pushActionBuffer(ActionReadValue)
- in.pushActionBuffer(ActionAppendPathNull)
- if in.pushReadBuffer(NewAtomTerminal(ArrayBegin)) {
- in.state = JSONInValueStart
- return nil
- }
- goto arrayValue
- }
- if isNumberRune(r) {
- var builder strings.Builder
- builder.WriteRune(r)
- for {
- r, _, err = in.reader.ReadRune()
- if err != nil {
- break
- }
- if !isNumberRune(r) {
- in.reader.UnreadRune()
- break
- }
- builder.WriteRune(r)
- }
- number, parseError := strconv.ParseFloat(builder.String(), 64)
- if parseError != nil {
- panic("Invalid number")
- }
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomNumber(number)) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- }
- panic("Invalid JSON value starting with: " + string(r))
- }
- string: {
- r, _, err := in.reader.ReadRune()
- if err != nil {
- panic("Missing closing terminal in string input: " + err.Error())
- }
- if r == '"' {
- if in.pushReadBuffer(NewAtomStringTerminal()) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- }
- if r == '\\' {
- r, _, err = in.reader.ReadRune()
- if err != nil {
- panic("Missing rune after \\")
- }
- if in.pushReadBuffer(NewAtomStringRune(r)) {
- in.state = JSONInString
- return nil
- }
- goto string
- }
- if in.pushReadBuffer(NewAtomStringRune(r)) {
- in.state = JSONInString
- return nil
- }
- goto string
- }
- key: {
- var full bool
- for {
- r, _, err := in.reader.ReadRune()
- if err != nil {
- panic("Missing closing terminal in string input: " + err.Error())
- }
- if r == '"' {
- full = in.pushReadBuffer(NewAtomStringTerminal())
- break
- }
- if r == '\\' {
- r, _, err = in.reader.ReadRune()
- if err != nil {
- panic("Missing rune after \\")
- }
- if in.pushReadBuffer(NewAtomStringRune(r)) {
- in.state = JSONInKey
- return nil
- }
- continue
- }
- if in.pushReadBuffer(NewAtomStringRune(r)) {
- in.state = JSONInKey
- return nil
- }
- continue
- }
- r, err := in.nextNonWsRune()
- if err != nil {
- panic("Expected : got: " + err.Error())
- }
- if r != ':' {
- panic("Expected : after key")
- }
- if full {
- in.state = JSONInValue
- return nil
- }
- goto value
- }
- valueEnd: {
- r, err := in.nextNonWsRune()
- if err != nil {
- in.state = JSONInValueEnd
- return err
- }
- if len(in.structure) == 0 {
- panic("More input after root JSON object ends")
- }
- innermost := in.structure[len(in.structure) - 1]
- if innermost == JSONInMap && r == '}' {
- in.structure = in.structure[:len(in.structure) - 1]
- in.pushActionBuffer(ActionPopPath)
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomTerminal(MapEnd)) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- } else if innermost == JSONInArray && r == ']' {
- in.structure = in.structure[:len(in.structure) - 1]
- in.pushActionBuffer(ActionPopPath)
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomTerminal(ArrayEnd)) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- }
- if r != ',' {
- panic("Expected , after JSON value, found: \"" + string(r) + "\"")
- }
- goto valueStart
- }
- mapValue: {
- in.pushActionBuffer(ActionPopPath)
- r, err := in.nextNonWsRune()
- if err != nil {
- panic("Missing value inside object")
- }
- if r == '}' {
- in.structure = in.structure[:len(in.structure) - 1]
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomTerminal(MapEnd)) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- }
- if r != '"' {
- panic("Expected key found something else")
- }
- in.pushActionBuffer(ActionAppendPath)
- if in.pushReadBuffer(NewAtomStringTerminal()) {
- in.state = JSONInKey
- return nil
- }
- goto key
- }
- arrayValue: {
- r, err := in.nextNonWsRune()
- if err != nil {
- panic("Missing value inside array")
- }
- if r == ']' {
- in.structure = in.structure[:len(in.structure) - 1]
- in.pushActionBuffer(ActionPopPath)
- in.pushActionBuffer(ActionReadValue)
- if in.pushReadBuffer(NewAtomTerminal(ArrayEnd)) {
- in.state = JSONInValueEnd
- return nil
- }
- goto valueEnd
- }
- in.reader.UnreadRune()
- in.pushActionBuffer(ActionIncrementPath)
- goto value
- }
-}
+type StredWriter interface {
+ Write(WalkItem) error
+ AssertDone()
+} \ No newline at end of file