More idiomatic fromBytes function (#20)

Author: irfanbozkurt

field/goldilocks_quintic_extension/goldilocks_quintic_extension.go

@@ -57,36 +57,16 @@ func FromCanonicalLittleEndianBytes(in []byte) (Element, error) {
 		return Element{}, fmt.Errorf("input bytes len should be 40 but is %d", len(in))
 	}
 
-	elemBytesLittleEndian := [5][]byte{
-		{in[0], in[1], in[2], in[3], in[4], in[5], in[6], in[7]},
-		{in[8], in[9], in[10], in[11], in[12], in[13], in[14], in[15]},
-		{in[16], in[17], in[18], in[19], in[20], in[21], in[22], in[23]},
-		{in[24], in[25], in[26], in[27], in[28], in[29], in[30], in[31]},
-		{in[32], in[33], in[34], in[35], in[36], in[37], in[38], in[39]},
+	var elem Element
+	for i := 0; i < 5; i++ {
+		e, err := g.FromCanonicalLittleEndianBytes(in[i*8 : (i+1)*8])
+		if err != nil {
+			return Element{}, fmt.Errorf("failed to convert bytes to goldilocks: %w", err)
+		}
+		elem[i] = *e
 	}
 
-	e1, err := g.FromCanonicalLittleEndianBytes(elemBytesLittleEndian[0])
-	if err != nil {
-		return Element{}, fmt.Errorf("failed to convert bytes to field element: %w", err)
-	}
-	e2, err := g.FromCanonicalLittleEndianBytes(elemBytesLittleEndian[1])
-	if err != nil {
-		return Element{}, fmt.Errorf("failed to convert bytes to field element: %w", err)
-	}
-	e3, err := g.FromCanonicalLittleEndianBytes(elemBytesLittleEndian[2])
-	if err != nil {
-		return Element{}, fmt.Errorf("failed to convert bytes to field element: %w", err)
-	}
-	e4, err := g.FromCanonicalLittleEndianBytes(elemBytesLittleEndian[3])
-	if err != nil {
-		return Element{}, fmt.Errorf("failed to convert bytes to field element: %w", err)
-	}
-	e5, err := g.FromCanonicalLittleEndianBytes(elemBytesLittleEndian[4])
-	if err != nil {
-		return Element{}, fmt.Errorf("failed to convert bytes to field element: %w", err)
-	}
-
-	return Element{*e1, *e2, *e3, *e4, *e5}, nil
+	return elem, nil
 }
 
 func Sample() Element {