Written the first version of a text reader, with

tests

assets/normal.txt

@@ -0,0 +1,11 @@
+##### #####
+#     #   #
+##### ### #
+#   #     #
+# # ##### #
+# #       #
+### ### # #
+#   #   # #
+# ####### #
+#     #   #
+##### #####

assets/trivial.txt

@@ -0,0 +1,3 @@
+## ##
+#   #
+### #

io/reader/text.go

@@ -0,0 +1,125 @@
+package reader
+
+import (
+	"bufio"
+	"fmt"
+	"maze-solver/maze"
+	"os"
+)
+
+type TextReader struct {
+	PathChar, WallChar byte
+}
+
+func (r *TextReader) Read(filename string) (*maze.Maze, error) {
+	nodesByCoord := make(map[maze.Coordinates]*maze.Node)
+	var lines []string
+
+	ret := &maze.Maze{}
+
+	if _, err := os.Stat(filename); err != nil {
+		return nil, err
+	}
+
+	file, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	scanner := bufio.NewScanner(file)
+	scanner.Split(bufio.ScanLines)
+
+	y := 0
+	var line string
+	for scanner.Scan() {
+		line = scanner.Text()
+
+		if len(lines) == 0 {
+			lines = make([]string, 0, len(line))
+		}
+
+		for x := 1; x < len(line)-1; x++ {
+			char := line[x]
+			var left_char, right_char, above_char byte
+
+			if y > 0 {
+				left_char = line[x-1]
+				right_char = line[x+1]
+				above_char = lines[y-1][x]
+			}
+
+			// Parse first line to get entrance
+			if y == 0 && char == r.PathChar {
+				coords := maze.Coordinates{X: x, Y: y}
+				node := maze.NewNode(coords)
+				ret.Nodes = append(ret.Nodes, node)
+				nodesByCoord[coords] = node
+				continue
+			}
+
+			// Parse middle of the maze
+			if y > 0 && char == r.PathChar &&
+				(left_char == r.WallChar && right_char == r.PathChar ||
+					left_char == r.PathChar && right_char == r.WallChar ||
+					above_char == r.PathChar && (left_char == r.PathChar || right_char == r.PathChar)) {
+				coords := maze.Coordinates{X: x, Y: y}
+				node := maze.NewNode(coords)
+				ret.Nodes = append(ret.Nodes, node)
+				nodesByCoord[coords] = node
+
+				r.lookupNeighbourAbove(&lines, node, &nodesByCoord)
+				if left_char == r.PathChar && right_char == r.WallChar ||
+					above_char == r.PathChar && (left_char == r.PathChar || right_char == r.PathChar) {
+					r.lookupNeighbourLeft(&line, node, &nodesByCoord)
+				}
+			}
+		}
+		lines = append(lines, line)
+		y++
+	}
+	y--
+	// Parse last line to get exit
+	for x, rune := range line {
+		char := byte(rune)
+		if char == r.PathChar {
+			fmt.Printf("last line number: %v\n", y)
+			coords := maze.Coordinates{X: x, Y: y}
+			node := maze.NewNode(coords)
+			r.lookupNeighbourAbove(&lines, node, &nodesByCoord)
+			ret.Nodes = append(ret.Nodes, node)
+			break
+		}
+	}
+
+	return ret, nil
+}
+
+func (r *TextReader) lookupNeighbourAbove(lines *[]string, node *maze.Node, nodesByCoord *map[maze.Coordinates]*maze.Node) {
+	for y := node.Coords.Y - 1; y >= 0; y-- {
+		if (*lines)[y][node.Coords.X] == r.WallChar {
+			break
+		}
+
+		neighbour, ok := (*nodesByCoord)[maze.Coordinates{X: node.Coords.X, Y: y}]
+		if ok {
+			node.Up = neighbour
+			neighbour.Down = node
+		}
+	}
+}
+
+func (r *TextReader) lookupNeighbourLeft(line *string, node *maze.Node, nodesByCoord *map[maze.Coordinates]*maze.Node) {
+	for x := node.Coords.X - 1; x > 0; x-- {
+		if (*line)[x] == r.WallChar {
+			panic(fmt.Sprintf("Found no node before wall while looking to the left at neighbours of node %v", node))
+		}
+
+		neighbour, ok := (*nodesByCoord)[maze.Coordinates{X: x, Y: node.Coords.Y}]
+		if ok {
+			node.Left = neighbour
+			fmt.Printf("Setting left of %v to %v\n", node.Coords, neighbour.Coords)
+			neighbour.Right = node
+			break
+		}
+	}
+}

io/reader/text_test.go

@@ -0,0 +1,81 @@
+package reader
+
+import (
+	"fmt"
+	"maze-solver/maze"
+	"maze-solver/utils"
+	"testing"
+)
+
+func TestTextRead(t *testing.T) {
+	/* trivial.txt
+	   ## ##
+	   #   #
+	   ### #
+
+	   Nodes are
+	   ##0##
+	   #123#
+	   ###4#
+	*/
+	nodes := make([]*maze.Node, 5)
+
+	nodes[0] = maze.NewNode(maze.Coordinates{X: 2, Y: 0})
+
+	nodes[1] = maze.NewNode(maze.Coordinates{X: 1, Y: 1})
+	nodes[2] = maze.NewNode(maze.Coordinates{X: 2, Y: 1})
+	nodes[3] = maze.NewNode(maze.Coordinates{X: 3, Y: 1})
+
+	nodes[4] = maze.NewNode(maze.Coordinates{X: 3, Y: 2})
+
+	nodes[0].Down = nodes[2]
+
+	nodes[1].Right = nodes[2]
+
+	nodes[2].Up = nodes[0]
+	nodes[2].Left = nodes[1]
+	nodes[2].Right = nodes[3]
+
+	nodes[3].Left = nodes[2]
+	nodes[3].Down = nodes[4]
+
+	nodes[4].Up = nodes[3]
+
+	reader := TextReader{
+		PathChar: ' ',
+		WallChar: '#',
+	}
+
+	filename := "../../assets/trivial.txt"
+	got, err := reader.Read(filename)
+	utils.Check(err, "Couldn't create maze from %q", filename)
+
+	if len(nodes) != len(got.Nodes) {
+		t.Fatalf("Didn't get the same size of nodes: %v, want %v", len(got.Nodes), len(nodes))
+	}
+
+	for i, got := range got.Nodes {
+		fmt.Println(i)
+		expected := nodes[i]
+
+		checkNode(t, i, got, expected, "")
+		checkNode(t, i, got.Left, expected.Left, "left")
+		checkNode(t, i, got.Right, expected.Right, "Right")
+		checkNode(t, i, got.Up, expected.Up, "Up")
+		checkNode(t, i, got.Down, expected.Down, "Down")
+	}
+}
+
+func checkNode(t *testing.T, i int, got *maze.Node, expected *maze.Node, side string) {
+	if expected == nil {
+		return
+	}
+
+	if got == nil {
+		t.Fatalf("No %s node of %v, want %v", side, i, expected.Coords)
+	}
+
+	if got.Coords != expected.Coords {
+		t.Fatalf("Coords %s node of %v: %v, but want %v", side, i, got.Coords, expected.Coords)
+	}
+}