diff options
Diffstat (limited to 'src/encoding/csv/reader.go')
| -rw-r--r-- | src/encoding/csv/reader.go | 71 |
1 files changed, 60 insertions, 11 deletions
diff --git a/src/encoding/csv/reader.go b/src/encoding/csv/reader.go index c40aa506b0..f860f4f25f 100644 --- a/src/encoding/csv/reader.go +++ b/src/encoding/csv/reader.go @@ -66,7 +66,7 @@ import ( type ParseError struct { StartLine int // Line where the record starts Line int // Line where the error occurred - Column int // Column (rune index) where the error occurred + Column int // Column (1-based byte index) where the error occurred Err error // The actual error } @@ -162,6 +162,10 @@ type Reader struct { // The i'th field ends at offset fieldIndexes[i] in recordBuffer. fieldIndexes []int + // fieldPositions is an index of field positions for the + // last record returned by Read. + fieldPositions []position + // lastRecord is a record cache and only used when ReuseRecord == true. lastRecord []string } @@ -192,6 +196,25 @@ func (r *Reader) Read() (record []string, err error) { return record, err } +// FieldPos returns the line and column corresponding to +// the start of the field with the given index in the slice most recently +// returned by Read. Numbering of lines and columns starts at 1; +// columns are counted in bytes, not runes. +// +// If this is called with an out-of-bounds index, it panics. +func (r *Reader) FieldPos(field int) (line, column int) { + if field < 0 || field >= len(r.fieldPositions) { + panic("out of range index passed to FieldPos") + } + p := &r.fieldPositions[field] + return p.line, p.col +} + +// pos holds the position of a field in the current line. +type position struct { + line, col int +} + // ReadAll reads all the remaining records from r. // Each record is a slice of fields. // A successful call returns err == nil, not err == io.EOF. Because ReadAll is @@ -260,7 +283,7 @@ func (r *Reader) readRecord(dst []string) ([]string, error) { } // Read line (automatically skipping past empty lines and any comments). - var line, fullLine []byte + var line []byte var errRead error for errRead == nil { line, errRead = r.readLine() @@ -272,7 +295,6 @@ func (r *Reader) readRecord(dst []string) ([]string, error) { line = nil continue // Skip empty lines } - fullLine = line break } if errRead == io.EOF { @@ -286,10 +308,20 @@ func (r *Reader) readRecord(dst []string) ([]string, error) { recLine := r.numLine // Starting line for record r.recordBuffer = r.recordBuffer[:0] r.fieldIndexes = r.fieldIndexes[:0] + r.fieldPositions = r.fieldPositions[:0] + pos := position{line: r.numLine, col: 1} parseField: for { if r.TrimLeadingSpace { - line = bytes.TrimLeftFunc(line, unicode.IsSpace) + i := bytes.IndexFunc(line, func(r rune) bool { + return !unicode.IsSpace(r) + }) + if i < 0 { + i = len(line) + pos.col -= lengthNL(line) + } + line = line[i:] + pos.col += i } if len(line) == 0 || line[0] != '"' { // Non-quoted string field @@ -303,48 +335,56 @@ parseField: // Check to make sure a quote does not appear in field. if !r.LazyQuotes { if j := bytes.IndexByte(field, '"'); j >= 0 { - col := utf8.RuneCount(fullLine[:len(fullLine)-len(line[j:])]) + col := pos.col + j err = &ParseError{StartLine: recLine, Line: r.numLine, Column: col, Err: ErrBareQuote} break parseField } } r.recordBuffer = append(r.recordBuffer, field...) r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + r.fieldPositions = append(r.fieldPositions, pos) if i >= 0 { line = line[i+commaLen:] + pos.col += i + commaLen continue parseField } break parseField } else { // Quoted string field + fieldPos := pos line = line[quoteLen:] + pos.col += quoteLen for { i := bytes.IndexByte(line, '"') if i >= 0 { // Hit next quote. r.recordBuffer = append(r.recordBuffer, line[:i]...) line = line[i+quoteLen:] + pos.col += i + quoteLen switch rn := nextRune(line); { case rn == '"': // `""` sequence (append quote). r.recordBuffer = append(r.recordBuffer, '"') line = line[quoteLen:] + pos.col += quoteLen case rn == r.Comma: // `",` sequence (end of field). line = line[commaLen:] + pos.col += commaLen r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + r.fieldPositions = append(r.fieldPositions, fieldPos) continue parseField case lengthNL(line) == len(line): // `"\n` sequence (end of line). r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + r.fieldPositions = append(r.fieldPositions, fieldPos) break parseField case r.LazyQuotes: // `"` sequence (bare quote). r.recordBuffer = append(r.recordBuffer, '"') default: // `"*` sequence (invalid non-escaped quote). - col := utf8.RuneCount(fullLine[:len(fullLine)-len(line)-quoteLen]) - err = &ParseError{StartLine: recLine, Line: r.numLine, Column: col, Err: ErrQuote} + err = &ParseError{StartLine: recLine, Line: r.numLine, Column: pos.col - quoteLen, Err: ErrQuote} break parseField } } else if len(line) > 0 { @@ -353,19 +393,23 @@ parseField: if errRead != nil { break parseField } + pos.col += len(line) line, errRead = r.readLine() + if len(line) > 0 { + pos.line++ + pos.col = 1 + } if errRead == io.EOF { errRead = nil } - fullLine = line } else { // Abrupt end of file (EOF or error). if !r.LazyQuotes && errRead == nil { - col := utf8.RuneCount(fullLine) - err = &ParseError{StartLine: recLine, Line: r.numLine, Column: col, Err: ErrQuote} + err = &ParseError{StartLine: recLine, Line: pos.line, Column: pos.col, Err: ErrQuote} break parseField } r.fieldIndexes = append(r.fieldIndexes, len(r.recordBuffer)) + r.fieldPositions = append(r.fieldPositions, fieldPos) break parseField } } @@ -392,7 +436,12 @@ parseField: // Check or update the expected fields per record. if r.FieldsPerRecord > 0 { if len(dst) != r.FieldsPerRecord && err == nil { - err = &ParseError{StartLine: recLine, Line: recLine, Err: ErrFieldCount} + err = &ParseError{ + StartLine: recLine, + Line: recLine, + Column: 1, + Err: ErrFieldCount, + } } } else if r.FieldsPerRecord == 0 { r.FieldsPerRecord = len(dst) |