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Make error messages describable in multiple languages
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@townewgokgok
townewgokgok committed Feb 26, 2018
1 parent 30c05cb commit a9f9b60
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Showing 3 changed files with 166 additions and 41 deletions.
103 changes: 64 additions & 39 deletions decoder.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -84,50 +84,72 @@ type parser struct {
buffer *bytes.Buffer
}

// ParseError is an error type to be raised by parser
type ParseError struct {
Child error
Err string
Type ErrorType
Args []interface{}
Src []byte
Pos int
}

func (e *ParseError) Error() string {
return e.ErrorInLang("en")
}

// ErrorInLang returns the error message in specified language.
func (e *ParseError) ErrorInLang(lang string) string {
desc, ok := errPosDesc[lang]
if !ok {
desc = errPosDesc["en"]
}
n := 5
ll := ""
if 0 < e.Pos-n {
ll = ".. "
ll = desc[errPos_ellipsisLeft]
}
l := string(substrLimited(e.Src, e.Pos-n, n))
c := string(substrLimited(e.Src, e.Pos, 1))
r := string(substrLimited(e.Src, e.Pos+1, n))
rr := ""
if e.Pos+1+n < len(e.Src) {
rr = " .."
rr = desc[errPos_ellipsisRight]
}
w := fmt.Sprintf(` at [%d] near %s"%s" -> "%s" -> "%s"%s`, e.Pos, ll, l, c, r, rr)
w := fmt.Sprintf(desc[errPos_near], e.Pos, ll, l, c, r, rr)
if l == "" {
if r == "" {
if c == "" {
w = ""
} else {
w = fmt.Sprintf(` at the first character "%s"`, c)
w = fmt.Sprintf(desc[errPos_first], c)
}
} else {
w = fmt.Sprintf(` at the first character "%s" -> "%s"%s`, c, r, rr)
w = fmt.Sprintf(desc[errPos_start], c, r, rr)
}
} else if c == "" {
w = fmt.Sprintf(` at the end of string %s"%s" -> EOS`, ll, l)
w = fmt.Sprintf(desc[errPos_end], ll, l)
} else if r == "" {
w = fmt.Sprintf(` at the last character %s"%s" -> "%s"`, ll, l, c)
w = fmt.Sprintf(desc[errPos_last], ll, l, c)
}
result := fmt.Sprintf(`%s%s`, e.Err, w)
if e.Child != nil {
result += "\n" + e.Child.Error()
msgdef, ok := errorMessage[lang]
if !ok {
msgdef = errorMessage["en"]
}
msgfmt, ok := msgdef[e.Type]
var msg string
if ok {
msg = fmt.Sprintf(msgfmt, e.Args...)
} else {
msg = fmt.Sprintf(msgdef[ErrorType_Internal], fmt.Sprintf("err=%d", int(e.Type)))
}
result := msg + w
//if e.Child != nil {
// result += "\n" + e.Child.Error()
//}
return result
}

func (p *parser) errorf(pos int, err error, format string, args ...interface{}) error {
func (p *parser) errorf(pos int, err error, typ ErrorType, args ...interface{}) error {
i := p.index
src := p.string
switch p.Mode {
Expand All @@ -141,15 +163,16 @@ func (p *parser) errorf(pos int, err error, format string, args ...interface{})
pos += i
return &ParseError{
Child: err,
Err: fmt.Sprintf(format, args...),
Type: typ,
Args: args,
Src: src,
Pos: pos,
}
}

func (p *parser) parse(rison []byte) ([]byte, error) {
if !utf8.Valid(rison) {
return nil, p.errorf(0, nil, `rison must be a valid UTF-8 string`)
return nil, p.errorf(0, nil, ErrorType_Encoding)
}

switch p.Mode {
Expand All @@ -163,16 +186,18 @@ func (p *parser) parse(rison []byte) ([]byte, error) {
p.string = rison
p.index = 0
p.buffer = bytes.NewBuffer(make([]byte, 0, len(rison)))
_, err := p.readValue()
typ, err := p.readValue()
if err != nil {
return nil, err
}
j := p.buffer.Bytes()
p.buffer = nil
if p.index < len(p.string) {
// TODO: error message for large E in exponential number
c := p.string[p.index]
return j, p.errorf(0, nil, `extra character "%c" (0x%02X) after top-level value`, c, c)
if typ == nodeType_number && c == 'E' {
return j, p.errorf(0, nil, ErrorType_InvalidLargeExp)
}
return j, p.errorf(0, nil, ErrorType_ExtraCharacterAfterRison, c)
}
return j, nil
}
Expand All @@ -192,7 +217,7 @@ const (
func (p *parser) readValue() (nodeType, error) {
c, ok := p.next()
if !ok {
return nodeType_invalid, p.errorf(0, nil, `empty expression`)
return nodeType_invalid, p.errorf(0, nil, ErrorType_EmptyString)
}

switch {
Expand All @@ -216,7 +241,7 @@ func (p *parser) readValue() (nodeType, error) {
return nodeType_string, nil
}

return nodeType_invalid, p.errorf(0, nil, `invalid character "%c" (0x%02X)`, c, c)
return nodeType_invalid, p.errorf(0, nil, ErrorType_InvalidCharacter, c)
}

func (p *parser) parseID() (bool, error) {
Expand Down Expand Up @@ -245,7 +270,7 @@ func (p *parser) parseID() (bool, error) {
}
j, err := json.Marshal(string(id))
if err != nil {
return false, p.errorf(0, err, `id "%s" cannot be converted to JSON`, string(id))
return false, p.errorf(0, err, ErrorType_Internal, fmt.Sprintf(`id "%s" cannot be converted to JSON`, string(id)))
}
p.index = i
p.buffer.Write(j)
Expand All @@ -255,7 +280,7 @@ func (p *parser) parseID() (bool, error) {
func (p *parser) parseSpecial() (nodeType, error) {
s := p.string
if len(s) <= p.index {
return nodeType_invalid, p.errorf(0, nil, `"!" at end of input`)
return nodeType_invalid, p.errorf(0, nil, ErrorType_MissingCharacterAfterEscape)
}
c := s[p.index]
p.index++
Expand All @@ -272,7 +297,7 @@ func (p *parser) parseSpecial() (nodeType, error) {
case '(':
return nodeType_array, p.parseArray()
}
return nodeType_invalid, p.errorf(-1, nil, `unknown literal "!%c"`, c)
return nodeType_invalid, p.errorf(-1, nil, ErrorType_InvalidLiteral, c)
}

func (p *parser) parseArray() error {
Expand All @@ -281,18 +306,18 @@ func (p *parser) parseArray() error {
for {
c, ok := p.next()
if !ok {
return p.errorf(0, nil, `unmatched "!("`)
return p.errorf(0, nil, ErrorType_UnmatchedPair, "!(")
}
if c == ')' {
break
}
if notFirst {
if c != ',' {
return p.errorf(-1, nil, `missing ","`)
return p.errorf(-1, nil, ErrorType_MissingCharacter, ',')
}
p.buffer.WriteByte(',')
} else if c == ',' {
return p.errorf(-1, nil, `extra ","`)
return p.errorf(-1, nil, ErrorType_ExtraCharacter, ',')
} else {
p.index--
}
Expand All @@ -312,39 +337,39 @@ func (p *parser) parseObject() error {
for {
c, ok := p.next()
if !ok {
return p.errorf(0, nil, `unmatched "("`)
return p.errorf(0, nil, ErrorType_UnmatchedPair, "(")
}
if c == ')' {
break
}
if notFirst {
if c != ',' {
return p.errorf(-1, nil, `missing ","`)
return p.errorf(-1, nil, ErrorType_MissingCharacter, ',')
}
p.buffer.WriteByte(',')
} else if c == ',' {
return p.errorf(-1, nil, `extra ","`)
return p.errorf(-1, nil, ErrorType_ExtraCharacter, ',')
} else {
p.index--
}
typ, err := p.readValue()
if err != nil {
return p.errorf(0, err, `invalid object key`)
return err
}
if typ != nodeType_string {
return p.errorf(-1, nil, `object key must be a string`)
return p.errorf(-1, nil, ErrorType_InvalidTypeOfObjectKey)
}
c, ok = p.next()
if !ok {
return p.errorf(0, nil, `missing ":"`)
return p.errorf(0, nil, ErrorType_MissingCharacter, ':')
}
if c != ':' {
return p.errorf(-1, nil, `missing ":" or invalid type of object key`)
return p.errorf(-1, nil, ErrorType_MissingCharacter, ':')
}
p.buffer.WriteByte(':')
_, err = p.readValue()
if err != nil {
return p.errorf(0, err, `invalid object value`)
return err
}
notFirst = true
}
Expand All @@ -360,7 +385,7 @@ func (p *parser) parseQuotedString() error {
for {
if len(s) <= i {
p.index = i
return p.errorf(0, nil, `unmatched "'"`)
return p.errorf(0, nil, ErrorType_UnmatchedPair, "'")
}
c := s[i]
i++
Expand All @@ -377,7 +402,7 @@ func (p *parser) parseQuotedString() error {
result = append(result, c)
} else {
p.index = i
return p.errorf(0, nil, `invalid string escape "!%c"`, c)
return p.errorf(0, nil, ErrorType_InvalidStringEscape, c)
}
start = i
}
Expand All @@ -388,7 +413,7 @@ func (p *parser) parseQuotedString() error {
p.index = i
j, err := json.Marshal(string(result))
if err != nil {
return p.errorf(0, err, `invalid string "%s"`, string(result))
return p.errorf(0, err, ErrorType_Internal, fmt.Sprintf(`invalid string "%s"`, string(result)))
}
p.buffer.Write(j)
return nil
Expand Down Expand Up @@ -448,16 +473,16 @@ func (p *parser) parseNumber() error {
p.index = i
t := s[start:i]
if string(t) == "-" {
return p.errorf(0, nil, `invalid number`)
return p.errorf(0, nil, ErrorType_InvalidNumber, "-")
}
var result interface{}
err := json.Unmarshal(t, &result)
if err != nil {
return p.errorf(0, err, `invalid number "%s"`, string(t))
return p.errorf(0, err, ErrorType_InvalidNumber, string(t))
}
j, err := json.Marshal(result)
if err != nil {
return p.errorf(0, err, `invalid number "%s"`, string(t))
return p.errorf(0, err, ErrorType_InvalidNumber, string(t))
}
p.buffer.Write(j)
return nil
Expand Down
89 changes: 89 additions & 0 deletions errors.go
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,89 @@
package rison

// ErrorType is an enum type of error
type ErrorType int

const (
ErrorType_Internal ErrorType = iota
ErrorType_Encoding
ErrorType_EmptyString
ErrorType_UnmatchedPair
ErrorType_MissingCharacter
ErrorType_MissingCharacterAfterEscape
ErrorType_ExtraCharacter
ErrorType_ExtraCharacterAfterRison
ErrorType_InvalidLiteral
ErrorType_InvalidCharacter
ErrorType_InvalidTypeOfObjectKey
ErrorType_InvalidStringEscape
ErrorType_InvalidNumber
ErrorType_InvalidLargeExp
)

var errorMessage = map[string]map[ErrorType]string{
"en": {
ErrorType_Internal: `internal error: %s`,
ErrorType_Encoding: `Rison must be a valid UTF-8 string`,
ErrorType_EmptyString: `empty string`,
ErrorType_UnmatchedPair: `unmatched "%s"`,
ErrorType_MissingCharacter: `missing "%c"`,
ErrorType_MissingCharacterAfterEscape: `missing character after "!"`,
ErrorType_ExtraCharacter: `extra character "%c"`,
ErrorType_ExtraCharacterAfterRison: `extra character "%c" after valid Rison`,
ErrorType_InvalidLiteral: `invalid literal "!%c"`,
ErrorType_InvalidCharacter: `invalid character "%c"`,
ErrorType_InvalidTypeOfObjectKey: `object key must be a string`,
ErrorType_InvalidStringEscape: `invalid string escape "!%c"`,
ErrorType_InvalidNumber: `invalid number "%s"`,
ErrorType_InvalidLargeExp: `large case "E" for exponent cannot be used`,
},
"ja": {
ErrorType_Internal: `内部エラー: %s`,
ErrorType_Encoding: `Risonは正しいUTF-8文字列である必要があります`,
ErrorType_EmptyString: `文字列が空です`,
ErrorType_UnmatchedPair: `"%s" が閉じていません`,
ErrorType_MissingCharacter: `"%c" が必要です`,
ErrorType_MissingCharacterAfterEscape: `"!" の後に文字が必要です`,
ErrorType_ExtraCharacter: `"%c" が余分です`,
ErrorType_ExtraCharacterAfterRison: `正しいRisonの後に余分な文字 "%c" が見つかりました`,
ErrorType_InvalidLiteral: `不正なリテラル "!%c" が見つかりました`,
ErrorType_InvalidCharacter: `不正な文字 "%c" が見つかりました`,
ErrorType_InvalidTypeOfObjectKey: `オブジェクトキーは文字列である必要があります`,
ErrorType_InvalidStringEscape: `不正なエスケープ文字列 "!%c" が見つかりました`,
ErrorType_InvalidNumber: `不正な数値 "%s" が見つかりました`,
ErrorType_InvalidLargeExp: `指数表記に大文字の "E" は使用できません`,
},
}

type errPos int

const (
errPos_near errPos = iota
errPos_first
errPos_start
errPos_end
errPos_last
errPos_ellipsisLeft
errPos_ellipsisRight
)

var errPosDesc = map[string]map[errPos]string{
"en": {
errPos_near: ` (at [%d] near %s"%s" -> "%s" -> "%s"%s)`,
errPos_first: ` (at the first character "%s")`,
errPos_start: ` (at the first character "%s" -> "%s"%s)`,
errPos_end: ` (at the end of string %s"%s" -> EOS)`,
errPos_last: ` (at the last character %s"%s" -> "%s")`,
errPos_ellipsisLeft: `.. `,
errPos_ellipsisRight: ` ..`,
},
"ja": {
errPos_near: ` (場所: [%d]付近: %s"%s" → "%s" → "%s"%s)`,
errPos_first: ` (場所: 先頭文字: "%s")`,
errPos_start: ` (場所: 先頭文字付近: "%s" → "%s"%s)`,
errPos_end: ` (場所: 文字列終端: %s"%s" → EOS)`,
errPos_last: ` (場所: 終端文字: %s"%s" → "%s")`,
errPos_ellipsisLeft: `〜 `,
errPos_ellipsisRight: ` 〜`,
},
}
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