diff options
Diffstat (limited to 'vendor/github.com/pelletier/go-toml/v2/parser.go')
-rw-r--r-- | vendor/github.com/pelletier/go-toml/v2/parser.go | 1086 |
1 files changed, 1086 insertions, 0 deletions
diff --git a/vendor/github.com/pelletier/go-toml/v2/parser.go b/vendor/github.com/pelletier/go-toml/v2/parser.go new file mode 100644 index 00000000..9859a795 --- /dev/null +++ b/vendor/github.com/pelletier/go-toml/v2/parser.go @@ -0,0 +1,1086 @@ +package toml + +import ( + "bytes" + "unicode" + + "github.com/pelletier/go-toml/v2/internal/ast" + "github.com/pelletier/go-toml/v2/internal/danger" +) + +type parser struct { + builder ast.Builder + ref ast.Reference + data []byte + left []byte + err error + first bool +} + +func (p *parser) Range(b []byte) ast.Range { + return ast.Range{ + Offset: uint32(danger.SubsliceOffset(p.data, b)), + Length: uint32(len(b)), + } +} + +func (p *parser) Raw(raw ast.Range) []byte { + return p.data[raw.Offset : raw.Offset+raw.Length] +} + +func (p *parser) Reset(b []byte) { + p.builder.Reset() + p.ref = ast.InvalidReference + p.data = b + p.left = b + p.err = nil + p.first = true +} + +//nolint:cyclop +func (p *parser) NextExpression() bool { + if len(p.left) == 0 || p.err != nil { + return false + } + + p.builder.Reset() + p.ref = ast.InvalidReference + + for { + if len(p.left) == 0 || p.err != nil { + return false + } + + if !p.first { + p.left, p.err = p.parseNewline(p.left) + } + + if len(p.left) == 0 || p.err != nil { + return false + } + + p.ref, p.left, p.err = p.parseExpression(p.left) + + if p.err != nil { + return false + } + + p.first = false + + if p.ref.Valid() { + return true + } + } +} + +func (p *parser) Expression() *ast.Node { + return p.builder.NodeAt(p.ref) +} + +func (p *parser) Error() error { + return p.err +} + +func (p *parser) parseNewline(b []byte) ([]byte, error) { + if b[0] == '\n' { + return b[1:], nil + } + + if b[0] == '\r' { + _, rest, err := scanWindowsNewline(b) + return rest, err + } + + return nil, newDecodeError(b[0:1], "expected newline but got %#U", b[0]) +} + +func (p *parser) parseExpression(b []byte) (ast.Reference, []byte, error) { + // expression = ws [ comment ] + // expression =/ ws keyval ws [ comment ] + // expression =/ ws table ws [ comment ] + ref := ast.InvalidReference + + b = p.parseWhitespace(b) + + if len(b) == 0 { + return ref, b, nil + } + + if b[0] == '#' { + _, rest, err := scanComment(b) + return ref, rest, err + } + + if b[0] == '\n' || b[0] == '\r' { + return ref, b, nil + } + + var err error + if b[0] == '[' { + ref, b, err = p.parseTable(b) + } else { + ref, b, err = p.parseKeyval(b) + } + + if err != nil { + return ref, nil, err + } + + b = p.parseWhitespace(b) + + if len(b) > 0 && b[0] == '#' { + _, rest, err := scanComment(b) + return ref, rest, err + } + + return ref, b, nil +} + +func (p *parser) parseTable(b []byte) (ast.Reference, []byte, error) { + // table = std-table / array-table + if len(b) > 1 && b[1] == '[' { + return p.parseArrayTable(b) + } + + return p.parseStdTable(b) +} + +func (p *parser) parseArrayTable(b []byte) (ast.Reference, []byte, error) { + // array-table = array-table-open key array-table-close + // array-table-open = %x5B.5B ws ; [[ Double left square bracket + // array-table-close = ws %x5D.5D ; ]] Double right square bracket + ref := p.builder.Push(ast.Node{ + Kind: ast.ArrayTable, + }) + + b = b[2:] + b = p.parseWhitespace(b) + + k, b, err := p.parseKey(b) + if err != nil { + return ref, nil, err + } + + p.builder.AttachChild(ref, k) + b = p.parseWhitespace(b) + + b, err = expect(']', b) + if err != nil { + return ref, nil, err + } + + b, err = expect(']', b) + + return ref, b, err +} + +func (p *parser) parseStdTable(b []byte) (ast.Reference, []byte, error) { + // std-table = std-table-open key std-table-close + // std-table-open = %x5B ws ; [ Left square bracket + // std-table-close = ws %x5D ; ] Right square bracket + ref := p.builder.Push(ast.Node{ + Kind: ast.Table, + }) + + b = b[1:] + b = p.parseWhitespace(b) + + key, b, err := p.parseKey(b) + if err != nil { + return ref, nil, err + } + + p.builder.AttachChild(ref, key) + + b = p.parseWhitespace(b) + + b, err = expect(']', b) + + return ref, b, err +} + +func (p *parser) parseKeyval(b []byte) (ast.Reference, []byte, error) { + // keyval = key keyval-sep val + ref := p.builder.Push(ast.Node{ + Kind: ast.KeyValue, + }) + + key, b, err := p.parseKey(b) + if err != nil { + return ast.InvalidReference, nil, err + } + + // keyval-sep = ws %x3D ws ; = + + b = p.parseWhitespace(b) + + if len(b) == 0 { + return ast.InvalidReference, nil, newDecodeError(b, "expected = after a key, but the document ends there") + } + + b, err = expect('=', b) + if err != nil { + return ast.InvalidReference, nil, err + } + + b = p.parseWhitespace(b) + + valRef, b, err := p.parseVal(b) + if err != nil { + return ref, b, err + } + + p.builder.Chain(valRef, key) + p.builder.AttachChild(ref, valRef) + + return ref, b, err +} + +//nolint:cyclop,funlen +func (p *parser) parseVal(b []byte) (ast.Reference, []byte, error) { + // val = string / boolean / array / inline-table / date-time / float / integer + ref := ast.InvalidReference + + if len(b) == 0 { + return ref, nil, newDecodeError(b, "expected value, not eof") + } + + var err error + c := b[0] + + switch c { + case '"': + var raw []byte + var v []byte + if scanFollowsMultilineBasicStringDelimiter(b) { + raw, v, b, err = p.parseMultilineBasicString(b) + } else { + raw, v, b, err = p.parseBasicString(b) + } + + if err == nil { + ref = p.builder.Push(ast.Node{ + Kind: ast.String, + Raw: p.Range(raw), + Data: v, + }) + } + + return ref, b, err + case '\'': + var raw []byte + var v []byte + if scanFollowsMultilineLiteralStringDelimiter(b) { + raw, v, b, err = p.parseMultilineLiteralString(b) + } else { + raw, v, b, err = p.parseLiteralString(b) + } + + if err == nil { + ref = p.builder.Push(ast.Node{ + Kind: ast.String, + Raw: p.Range(raw), + Data: v, + }) + } + + return ref, b, err + case 't': + if !scanFollowsTrue(b) { + return ref, nil, newDecodeError(atmost(b, 4), "expected 'true'") + } + + ref = p.builder.Push(ast.Node{ + Kind: ast.Bool, + Data: b[:4], + }) + + return ref, b[4:], nil + case 'f': + if !scanFollowsFalse(b) { + return ref, nil, newDecodeError(atmost(b, 5), "expected 'false'") + } + + ref = p.builder.Push(ast.Node{ + Kind: ast.Bool, + Data: b[:5], + }) + + return ref, b[5:], nil + case '[': + return p.parseValArray(b) + case '{': + return p.parseInlineTable(b) + default: + return p.parseIntOrFloatOrDateTime(b) + } +} + +func atmost(b []byte, n int) []byte { + if n >= len(b) { + return b + } + + return b[:n] +} + +func (p *parser) parseLiteralString(b []byte) ([]byte, []byte, []byte, error) { + v, rest, err := scanLiteralString(b) + if err != nil { + return nil, nil, nil, err + } + + return v, v[1 : len(v)-1], rest, nil +} + +func (p *parser) parseInlineTable(b []byte) (ast.Reference, []byte, error) { + // inline-table = inline-table-open [ inline-table-keyvals ] inline-table-close + // inline-table-open = %x7B ws ; { + // inline-table-close = ws %x7D ; } + // inline-table-sep = ws %x2C ws ; , Comma + // inline-table-keyvals = keyval [ inline-table-sep inline-table-keyvals ] + parent := p.builder.Push(ast.Node{ + Kind: ast.InlineTable, + }) + + first := true + + var child ast.Reference + + b = b[1:] + + var err error + + for len(b) > 0 { + previousB := b + b = p.parseWhitespace(b) + + if len(b) == 0 { + return parent, nil, newDecodeError(previousB[:1], "inline table is incomplete") + } + + if b[0] == '}' { + break + } + + if !first { + b, err = expect(',', b) + if err != nil { + return parent, nil, err + } + b = p.parseWhitespace(b) + } + + var kv ast.Reference + + kv, b, err = p.parseKeyval(b) + if err != nil { + return parent, nil, err + } + + if first { + p.builder.AttachChild(parent, kv) + } else { + p.builder.Chain(child, kv) + } + child = kv + + first = false + } + + rest, err := expect('}', b) + + return parent, rest, err +} + +//nolint:funlen,cyclop +func (p *parser) parseValArray(b []byte) (ast.Reference, []byte, error) { + // array = array-open [ array-values ] ws-comment-newline array-close + // array-open = %x5B ; [ + // array-close = %x5D ; ] + // array-values = ws-comment-newline val ws-comment-newline array-sep array-values + // array-values =/ ws-comment-newline val ws-comment-newline [ array-sep ] + // array-sep = %x2C ; , Comma + // ws-comment-newline = *( wschar / [ comment ] newline ) + arrayStart := b + b = b[1:] + + parent := p.builder.Push(ast.Node{ + Kind: ast.Array, + }) + + first := true + + var lastChild ast.Reference + + var err error + for len(b) > 0 { + b, err = p.parseOptionalWhitespaceCommentNewline(b) + if err != nil { + return parent, nil, err + } + + if len(b) == 0 { + return parent, nil, newDecodeError(arrayStart[:1], "array is incomplete") + } + + if b[0] == ']' { + break + } + + if b[0] == ',' { + if first { + return parent, nil, newDecodeError(b[0:1], "array cannot start with comma") + } + b = b[1:] + + b, err = p.parseOptionalWhitespaceCommentNewline(b) + if err != nil { + return parent, nil, err + } + } else if !first { + return parent, nil, newDecodeError(b[0:1], "array elements must be separated by commas") + } + + // TOML allows trailing commas in arrays. + if len(b) > 0 && b[0] == ']' { + break + } + + var valueRef ast.Reference + valueRef, b, err = p.parseVal(b) + if err != nil { + return parent, nil, err + } + + if first { + p.builder.AttachChild(parent, valueRef) + } else { + p.builder.Chain(lastChild, valueRef) + } + lastChild = valueRef + + b, err = p.parseOptionalWhitespaceCommentNewline(b) + if err != nil { + return parent, nil, err + } + first = false + } + + rest, err := expect(']', b) + + return parent, rest, err +} + +func (p *parser) parseOptionalWhitespaceCommentNewline(b []byte) ([]byte, error) { + for len(b) > 0 { + var err error + b = p.parseWhitespace(b) + + if len(b) > 0 && b[0] == '#' { + _, b, err = scanComment(b) + if err != nil { + return nil, err + } + } + + if len(b) == 0 { + break + } + + if b[0] == '\n' || b[0] == '\r' { + b, err = p.parseNewline(b) + if err != nil { + return nil, err + } + } else { + break + } + } + + return b, nil +} + +func (p *parser) parseMultilineLiteralString(b []byte) ([]byte, []byte, []byte, error) { + token, rest, err := scanMultilineLiteralString(b) + if err != nil { + return nil, nil, nil, err + } + + i := 3 + + // skip the immediate new line + if token[i] == '\n' { + i++ + } else if token[i] == '\r' && token[i+1] == '\n' { + i += 2 + } + + return token, token[i : len(token)-3], rest, err +} + +//nolint:funlen,gocognit,cyclop +func (p *parser) parseMultilineBasicString(b []byte) ([]byte, []byte, []byte, error) { + // ml-basic-string = ml-basic-string-delim [ newline ] ml-basic-body + // ml-basic-string-delim + // ml-basic-string-delim = 3quotation-mark + // ml-basic-body = *mlb-content *( mlb-quotes 1*mlb-content ) [ mlb-quotes ] + // + // mlb-content = mlb-char / newline / mlb-escaped-nl + // mlb-char = mlb-unescaped / escaped + // mlb-quotes = 1*2quotation-mark + // mlb-unescaped = wschar / %x21 / %x23-5B / %x5D-7E / non-ascii + // mlb-escaped-nl = escape ws newline *( wschar / newline ) + token, escaped, rest, err := scanMultilineBasicString(b) + if err != nil { + return nil, nil, nil, err + } + + i := 3 + + // skip the immediate new line + if token[i] == '\n' { + i++ + } else if token[i] == '\r' && token[i+1] == '\n' { + i += 2 + } + + // fast path + startIdx := i + endIdx := len(token) - len(`"""`) + + if !escaped { + str := token[startIdx:endIdx] + verr := utf8TomlValidAlreadyEscaped(str) + if verr.Zero() { + return token, str, rest, nil + } + return nil, nil, nil, newDecodeError(str[verr.Index:verr.Index+verr.Size], "invalid UTF-8") + } + + var builder bytes.Buffer + + // The scanner ensures that the token starts and ends with quotes and that + // escapes are balanced. + for i < len(token)-3 { + c := token[i] + + //nolint:nestif + if c == '\\' { + // When the last non-whitespace character on a line is an unescaped \, + // it will be trimmed along with all whitespace (including newlines) up + // to the next non-whitespace character or closing delimiter. + + isLastNonWhitespaceOnLine := false + j := 1 + findEOLLoop: + for ; j < len(token)-3-i; j++ { + switch token[i+j] { + case ' ', '\t': + continue + case '\r': + if token[i+j+1] == '\n' { + continue + } + case '\n': + isLastNonWhitespaceOnLine = true + } + break findEOLLoop + } + if isLastNonWhitespaceOnLine { + i += j + for ; i < len(token)-3; i++ { + c := token[i] + if !(c == '\n' || c == '\r' || c == ' ' || c == '\t') { + i-- + break + } + } + i++ + continue + } + + // handle escaping + i++ + c = token[i] + + switch c { + case '"', '\\': + builder.WriteByte(c) + case 'b': + builder.WriteByte('\b') + case 'f': + builder.WriteByte('\f') + case 'n': + builder.WriteByte('\n') + case 'r': + builder.WriteByte('\r') + case 't': + builder.WriteByte('\t') + case 'e': + builder.WriteByte(0x1B) + case 'u': + x, err := hexToRune(atmost(token[i+1:], 4), 4) + if err != nil { + return nil, nil, nil, err + } + builder.WriteRune(x) + i += 4 + case 'U': + x, err := hexToRune(atmost(token[i+1:], 8), 8) + if err != nil { + return nil, nil, nil, err + } + + builder.WriteRune(x) + i += 8 + default: + return nil, nil, nil, newDecodeError(token[i:i+1], "invalid escaped character %#U", c) + } + i++ + } else { + size := utf8ValidNext(token[i:]) + if size == 0 { + return nil, nil, nil, newDecodeError(token[i:i+1], "invalid character %#U", c) + } + builder.Write(token[i : i+size]) + i += size + } + } + + return token, builder.Bytes(), rest, nil +} + +func (p *parser) parseKey(b []byte) (ast.Reference, []byte, error) { + // key = simple-key / dotted-key + // simple-key = quoted-key / unquoted-key + // + // unquoted-key = 1*( ALPHA / DIGIT / %x2D / %x5F ) ; A-Z / a-z / 0-9 / - / _ + // quoted-key = basic-string / literal-string + // dotted-key = simple-key 1*( dot-sep simple-key ) + // + // dot-sep = ws %x2E ws ; . Period + raw, key, b, err := p.parseSimpleKey(b) + if err != nil { + return ast.InvalidReference, nil, err + } + + ref := p.builder.Push(ast.Node{ + Kind: ast.Key, + Raw: p.Range(raw), + Data: key, + }) + + for { + b = p.parseWhitespace(b) + if len(b) > 0 && b[0] == '.' { + b = p.parseWhitespace(b[1:]) + + raw, key, b, err = p.parseSimpleKey(b) + if err != nil { + return ref, nil, err + } + + p.builder.PushAndChain(ast.Node{ + Kind: ast.Key, + Raw: p.Range(raw), + Data: key, + }) + } else { + break + } + } + + return ref, b, nil +} + +func (p *parser) parseSimpleKey(b []byte) (raw, key, rest []byte, err error) { + if len(b) == 0 { + return nil, nil, nil, newDecodeError(b, "expected key but found none") + } + + // simple-key = quoted-key / unquoted-key + // unquoted-key = 1*( ALPHA / DIGIT / %x2D / %x5F ) ; A-Z / a-z / 0-9 / - / _ + // quoted-key = basic-string / literal-string + switch { + case b[0] == '\'': + return p.parseLiteralString(b) + case b[0] == '"': + return p.parseBasicString(b) + case isUnquotedKeyChar(b[0]): + key, rest = scanUnquotedKey(b) + return key, key, rest, nil + default: + return nil, nil, nil, newDecodeError(b[0:1], "invalid character at start of key: %c", b[0]) + } +} + +//nolint:funlen,cyclop +func (p *parser) parseBasicString(b []byte) ([]byte, []byte, []byte, error) { + // basic-string = quotation-mark *basic-char quotation-mark + // quotation-mark = %x22 ; " + // basic-char = basic-unescaped / escaped + // basic-unescaped = wschar / %x21 / %x23-5B / %x5D-7E / non-ascii + // escaped = escape escape-seq-char + // escape-seq-char = %x22 ; " quotation mark U+0022 + // escape-seq-char =/ %x5C ; \ reverse solidus U+005C + // escape-seq-char =/ %x62 ; b backspace U+0008 + // escape-seq-char =/ %x66 ; f form feed U+000C + // escape-seq-char =/ %x6E ; n line feed U+000A + // escape-seq-char =/ %x72 ; r carriage return U+000D + // escape-seq-char =/ %x74 ; t tab U+0009 + // escape-seq-char =/ %x75 4HEXDIG ; uXXXX U+XXXX + // escape-seq-char =/ %x55 8HEXDIG ; UXXXXXXXX U+XXXXXXXX + token, escaped, rest, err := scanBasicString(b) + if err != nil { + return nil, nil, nil, err + } + + startIdx := len(`"`) + endIdx := len(token) - len(`"`) + + // Fast path. If there is no escape sequence, the string should just be + // an UTF-8 encoded string, which is the same as Go. In that case, + // validate the string and return a direct reference to the buffer. + if !escaped { + str := token[startIdx:endIdx] + verr := utf8TomlValidAlreadyEscaped(str) + if verr.Zero() { + return token, str, rest, nil + } + return nil, nil, nil, newDecodeError(str[verr.Index:verr.Index+verr.Size], "invalid UTF-8") + } + + i := startIdx + + var builder bytes.Buffer + + // The scanner ensures that the token starts and ends with quotes and that + // escapes are balanced. + for i < len(token)-1 { + c := token[i] + if c == '\\' { + i++ + c = token[i] + + switch c { + case '"', '\\': + builder.WriteByte(c) + case 'b': + builder.WriteByte('\b') + case 'f': + builder.WriteByte('\f') + case 'n': + builder.WriteByte('\n') + case 'r': + builder.WriteByte('\r') + case 't': + builder.WriteByte('\t') + case 'e': + builder.WriteByte(0x1B) + case 'u': + x, err := hexToRune(token[i+1:len(token)-1], 4) + if err != nil { + return nil, nil, nil, err + } + + builder.WriteRune(x) + i += 4 + case 'U': + x, err := hexToRune(token[i+1:len(token)-1], 8) + if err != nil { + return nil, nil, nil, err + } + + builder.WriteRune(x) + i += 8 + default: + return nil, nil, nil, newDecodeError(token[i:i+1], "invalid escaped character %#U", c) + } + i++ + } else { + size := utf8ValidNext(token[i:]) + if size == 0 { + return nil, nil, nil, newDecodeError(token[i:i+1], "invalid character %#U", c) + } + builder.Write(token[i : i+size]) + i += size + } + } + + return token, builder.Bytes(), rest, nil +} + +func hexToRune(b []byte, length int) (rune, error) { + if len(b) < length { + return -1, newDecodeError(b, "unicode point needs %d character, not %d", length, len(b)) + } + b = b[:length] + + var r uint32 + for i, c := range b { + d := uint32(0) + switch { + case '0' <= c && c <= '9': + d = uint32(c - '0') + case 'a' <= c && c <= 'f': + d = uint32(c - 'a' + 10) + case 'A' <= c && c <= 'F': + d = uint32(c - 'A' + 10) + default: + return -1, newDecodeError(b[i:i+1], "non-hex character") + } + r = r*16 + d + } + + if r > unicode.MaxRune || 0xD800 <= r && r < 0xE000 { + return -1, newDecodeError(b, "escape sequence is invalid Unicode code point") + } + + return rune(r), nil +} + +func (p *parser) parseWhitespace(b []byte) []byte { + // ws = *wschar + // wschar = %x20 ; Space + // wschar =/ %x09 ; Horizontal tab + _, rest := scanWhitespace(b) + + return rest +} + +//nolint:cyclop +func (p *parser) parseIntOrFloatOrDateTime(b []byte) (ast.Reference, []byte, error) { + switch b[0] { + case 'i': + if !scanFollowsInf(b) { + return ast.InvalidReference, nil, newDecodeError(atmost(b, 3), "expected 'inf'") + } + + return p.builder.Push(ast.Node{ + Kind: ast.Float, + Data: b[:3], + }), b[3:], nil + case 'n': + if !scanFollowsNan(b) { + return ast.InvalidReference, nil, newDecodeError(atmost(b, 3), "expected 'nan'") + } + + return p.builder.Push(ast.Node{ + Kind: ast.Float, + Data: b[:3], + }), b[3:], nil + case '+', '-': + return p.scanIntOrFloat(b) + } + + if len(b) < 3 { + return p.scanIntOrFloat(b) + } + + s := 5 + if len(b) < s { + s = len(b) + } + + for idx, c := range b[:s] { + if isDigit(c) { + continue + } + + if idx == 2 && c == ':' || (idx == 4 && c == '-') { + return p.scanDateTime(b) + } + + break + } + + return p.scanIntOrFloat(b) +} + +func (p *parser) scanDateTime(b []byte) (ast.Reference, []byte, error) { + // scans for contiguous characters in [0-9T:Z.+-], and up to one space if + // followed by a digit. + hasDate := false + hasTime := false + hasTz := false + seenSpace := false + + i := 0 +byteLoop: + for ; i < len(b); i++ { + c := b[i] + + switch { + case isDigit(c): + case c == '-': + hasDate = true + const minOffsetOfTz = 8 + if i >= minOffsetOfTz { + hasTz = true + } + case c == 'T' || c == 't' || c == ':' || c == '.': + hasTime = true + case c == '+' || c == '-' || c == 'Z' || c == 'z': + hasTz = true + case c == ' ': + if !seenSpace && i+1 < len(b) && isDigit(b[i+1]) { + i += 2 + // Avoid reaching past the end of the document in case the time + // is malformed. See TestIssue585. + if i >= len(b) { + i-- + } + seenSpace = true + hasTime = true + } else { + break byteLoop + } + default: + break byteLoop + } + } + + var kind ast.Kind + + if hasTime { + if hasDate { + if hasTz { + kind = ast.DateTime + } else { + kind = ast.LocalDateTime + } + } else { + kind = ast.LocalTime + } + } else { + kind = ast.LocalDate + } + + return p.builder.Push(ast.Node{ + Kind: kind, + Data: b[:i], + }), b[i:], nil +} + +//nolint:funlen,gocognit,cyclop +func (p *parser) scanIntOrFloat(b []byte) (ast.Reference, []byte, error) { + i := 0 + + if len(b) > 2 && b[0] == '0' && b[1] != '.' && b[1] != 'e' && b[1] != 'E' { + var isValidRune validRuneFn + + switch b[1] { + case 'x': + isValidRune = isValidHexRune + case 'o': + isValidRune = isValidOctalRune + case 'b': + isValidRune = isValidBinaryRune + default: + i++ + } + + if isValidRune != nil { + i += 2 + for ; i < len(b); i++ { + if !isValidRune(b[i]) { + break + } + } + } + + return p.builder.Push(ast.Node{ + Kind: ast.Integer, + Data: b[:i], + }), b[i:], nil + } + + isFloat := false + + for ; i < len(b); i++ { + c := b[i] + + if c >= '0' && c <= '9' || c == '+' || c == '-' || c == '_' { + continue + } + + if c == '.' || c == 'e' || c == 'E' { + isFloat = true + + continue + } + + if c == 'i' { + if scanFollowsInf(b[i:]) { + return p.builder.Push(ast.Node{ + Kind: ast.Float, + Data: b[:i+3], + }), b[i+3:], nil + } + + return ast.InvalidReference, nil, newDecodeError(b[i:i+1], "unexpected character 'i' while scanning for a number") + } + + if c == 'n' { + if scanFollowsNan(b[i:]) { + return p.builder.Push(ast.Node{ + Kind: ast.Float, + Data: b[:i+3], + }), b[i+3:], nil + } + + return ast.InvalidReference, nil, newDecodeError(b[i:i+1], "unexpected character 'n' while scanning for a number") + } + + break + } + + if i == 0 { + return ast.InvalidReference, b, newDecodeError(b, "incomplete number") + } + + kind := ast.Integer + + if isFloat { + kind = ast.Float + } + + return p.builder.Push(ast.Node{ + Kind: kind, + Data: b[:i], + }), b[i:], nil +} + +func isDigit(r byte) bool { + return r >= '0' && r <= '9' +} + +type validRuneFn func(r byte) bool + +func isValidHexRune(r byte) bool { + return r >= 'a' && r <= 'f' || + r >= 'A' && r <= 'F' || + r >= '0' && r <= '9' || + r == '_' +} + +func isValidOctalRune(r byte) bool { + return r >= '0' && r <= '7' || r == '_' +} + +func isValidBinaryRune(r byte) bool { + return r == '0' || r == '1' || r == '_' +} + +func expect(x byte, b []byte) ([]byte, error) { + if len(b) == 0 { + return nil, newDecodeError(b, "expected character %c but the document ended here", x) + } + + if b[0] != x { + return nil, newDecodeError(b[0:1], "expected character %c", x) + } + + return b[1:], nil +} |