grokify/mogo

package stringsutil

import "fmt"

// Matrix2DColRowIndex returns the row index where the string supplied is first
// encountered for a supplied column index.
func Matrix2DColRowIndex[C comparable](mat [][]C, colIdx uint, s C) (int, error) {
    xint := int(colIdx)
    for y, row := range mat {
        if xint >= len(row) {
            return -1, fmt.Errorf("index out of range [%d] with length %d", xint, len(row))
        }
        if row[xint] == s {
            return y, nil
        }
    }
    return -1, nil
}