Syncing Things

go/matrix/matrix.go

@@ -1,32 +1,76 @@
 package matrix
 
-import "strings"
+import (
+	"errors"
+	"strconv"
+	"strings"
+)
 
+// Matrix is a grid of ints
 type Matrix struct {
 	vals [][]int
 }
 
+// New creates a new Matrix from a string of numbers
 func New(in string) (*Matrix, error) {
 	ret := Matrix{}
 	rows := strings.Split(in, "\n")
+	for i := range rows {
+		flds := strings.Fields(rows[i])
+		var ints []int
+		for j := range flds {
+			if v, err := strconv.Atoi(flds[j]); err != nil {
+				return &ret, err
+			} else {
+				ints = append(ints, v)
+			}
+		}
+		ret.vals = append(ret.vals, ints)
+	}
+	numInRow := -1
+	for i := range ret.vals {
+		if numInRow != -1 {
+			if len(ret.vals[i]) != numInRow {
+				return &ret, errors.New("All rows must be equal length")
+			}
+		}
+		numInRow = len(ret.vals[i])
+	}
 	return &ret, nil
 }
 
+// Rows returns the values of the rows in the matrix
 func (m *Matrix) Rows() [][]int {
-	return m.vals
-}
-
-func (m *Matrix) Cols() [][]int {
-	ret := [][]int{}
-	if len(m.vals) > 0 {
-		//		for i := 0; i < len(m.vals[0]); i++ {
-		//		}
+	var ret [][]int
+	for i := range m.vals {
+		var row []int
+		for j := range m.vals[i] {
+			row = append(row, m.vals[i][j])
+		}
+		ret = append(ret, row)
 	}
 	return ret
 }
 
+// Cols returns the values of the cols in the matrix
+func (m *Matrix) Cols() [][]int {
+	var ret [][]int
+	for i := range m.vals[0] {
+		var row []int
+		for j := range m.vals {
+			row = append(row, m.vals[j][i])
+		}
+		ret = append(ret, row)
+	}
+	return ret
+}
+
+// Set sets the value at r,c to val
 func (m *Matrix) Set(r, c int, val int) bool {
-	if len(m.vals) < r || len(m.vals[r]) < c {
+	if r < 0 || c < 0 {
+		return false
+	}
+	if len(m.vals) <= r || len(m.vals[r]) <= c {
 		return false
 	}
 	m.vals[r][c] = val