func parseHTMLCell(n *html.Node) (Cell, error) {
switch v, _ := htmlutil.GetAttr(n, "class"); v {
case "whitegrey":
return &ValueCell{Val: bitset.Interval(1, 9)}, nil
case "grey":
return &ClueCell{}, nil
case "infocellgrey":
if v, h, err := getClues(n); err != nil {
return nil, err
} else {
return &ClueCell{VClue: v, HClue: h}, nil
}
default:
return nil, gridErr("Unknown or missing cell class")
}
}
func NewGrid(h, w int) *Grid {
if h < 2 || w < 2 {
panic("A grid must be at least 2x2")
}
g := &Grid{cells: make([][]Cell, h), h: h, w: w}
g.cells[0] = make([]Cell, w)
for j := range g.cells[0] {
g.cells[0][j] = &ClueCell{}
}
for i := 1; i < h; i++ {
g.cells[i] = make([]Cell, w)
g.cells[i][0] = &ClueCell{}
for j := 1; j < w; j++ {
g.cells[i][j] = &ValueCell{Val: bitset.Interval(1, 9)}
}
}
return g
}
func parseCell(s string) Cell {
if len(s) != 5 {
return nil
}
if s == " " {
return &ValueCell{Val: bitset.Interval(1, 9)}
}
if s[2] == '\\' {
if v, h := parseClue(s[:2]), parseClue(s[3:]); v == errClue || h == errClue {
return nil
} else {
return &ClueCell{VClue: v, HClue: h}
}
}
e, err := strconv.Atoi(s)
if err != nil || e < 1 || 9 < e {
return nil
}
return &ValueCell{Val: bitset.Set(bitset.Element(e))}
}