grokify/mogo

package csvutil

import (
    "fmt"
    "math"
    "os"

    "github.com/grokify/mogo/type/stringsutil"
)

// ReadFileOneColListToGrid parses a file with one value per row.
func ReadFileOneColListToGrid(filename string, colCount int, validateLength bool) ([][]string, error) {
    bytes, err := os.ReadFile(filename)
    if err != nil {
        return [][]string{}, err
    }
    return ParseOneColListToGrid(stringsutil.SplitLines(string(bytes)), colCount, validateLength)
}

// ParseOneColListToGrid parses a set of lines with one value per row.
func ParseOneColListToGrid(lines []string, colCount int, validateLength bool) ([][]string, error) {
    rows := [][]string{}
    curRow := []string{}
    colCountFloat := float64(colCount)

    for i, line := range lines {
        curRow = append(curRow, line)
        if math.Mod(float64(i+1), colCountFloat) == 0 {
            if len(curRow) > 0 {
                rows = append(rows, curRow)
                curRow = []string{}
            }
        }
    }
    if len(curRow) > 0 {
        rows = append(rows, curRow)
    }
    if validateLength {
        for _, row := range rows {
            if len(row) != colCount {
                return rows, fmt.Errorf("error row length: want [%d] have [%d]", colCount, len(row))
            }
        }
    }
    return rows, nil
}