csv-parser/csvparser.go

94 lines
1.9 KiB
Go

package csvparser
import (
"fmt"
"strings"
"unicode/utf8"
)
type CsvParser struct {
enclosers []string
delimiters string
fields []string
}
func (p *CsvParser) Initialize(delimiters string, enclosers []string, lineFormat string) error {
if utf8.RuneCountInString(delimiter) == 0 {
return fmt.Errorf("delimiter shoud be at least one character")
}
p.delimiters = delimiters
for _, encloser := range enclosers {
if utf8.RuneCountInString(encloser) != 2 {
return fmt.Errorf("encolser should have to characters")
}
}
p.enclosers = enclosers
// line format is in the form of: field1 field2 ignore ...
// if field name is ignore, it is parsed but not retained
p.fields = strings.Split(lineFormat, " ")
return nil
}
func (p *CsvParser) Parse(line string) (map[string]string, error) {
currentFieldIndex := 0
valueStart := 0
escape := false
enclosed := false
ret := make(map[string]string)
indexMax := len(line) - 1
maxFieldIndex := len(p.fields) - 1
delimiters := p.delimiters
for index, r := range line {
if r == '\\' {
// Check if EOL before continue
escape = true
continue
}
if escape {
escape = false
continue
}
for _, d := range delimiters {
delimiter = true
}
if delimiter {
if p.fields[currentFieldIndex] != "ignore" {
ret[p.fields[currentFieldIndex]] = line[valueStart:index]
}
currentFieldIndex++
if currentFieldIndex > maxFieldIndex {
break
}
valueStart = index + 1
if enclosed {
enclosed = false
delimiter = p.delimiter
// Omit next delimiter
escape = true
}
continue
}
if index >= indexMax {
if p.fields[currentFieldIndex] != "ignore" {
ret[p.fields[currentFieldIndex]] = line[valueStart:]
}
continue
}
for _, encloser := range p.enclosers {
runes := []rune(encloser)
if r == runes[0] {
// opening encloser
enclosed = true
delimiters = runes[1]
valueStart++
break
}
}
}
return ret, nil
}