make repl an engine feature

engine/repl.go

@@ -0,0 +1,98 @@
+package engine
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"strings"
+)
+
+func (g *Game) REPL(src io.Reader, dst io.Writer, assets fs.FS) error {
+	sc := bufio.NewScanner(src)
+	for sc.Scan() {
+		tok := strings.Split(sc.Text(), " ")
+		if len(tok) == 0 {
+			continue
+		}
+		switch tok[0] {
+		case "quit":
+			os.Exit(0)
+		case "pause":
+			g.Disable()
+		case "resume", "unpause":
+			g.Enable()
+		case "save":
+			if len(tok) != 2 {
+				fmt.Fprintln(dst, "Usage: save ID")
+				break
+			}
+			id := tok[1]
+			c := g.Component(id)
+			if c == nil {
+				fmt.Fprintf(dst, "Component %q not found\n", id)
+				break
+			}
+			s, ok := c.(Saver)
+			if !ok {
+				fmt.Fprintf(dst, "Component %q not a Saver (type %T)\n", id, c)
+				break
+			}
+			if err := s.Save(); err != nil {
+				fmt.Fprintf(dst, "Couldn't save %q: %v\n", id, err)
+			}
+		case "reload":
+			g.Disable()
+			g.Hide()
+			if err := g.Load(assets); err != nil {
+				fmt.Fprintf(dst, "Couldn't load: %v\n", err)
+				break
+			}
+			g.Prepare()
+			g.Enable()
+			g.Show()
+		case "tree":
+
+			var c interface{} = g
+			if len(tok) == 2 {
+				// subtree
+				id := tok[1]
+				c = g.Component(id)
+				if c == nil {
+					fmt.Fprintf(dst, "Component %q not found\n", id)
+					break
+				}
+			}
+			type item struct {
+				c     interface{}
+				depth int
+			}
+			stack := []item{{c, 0}}
+			for len(stack) > 0 {
+				tail := len(stack) - 1
+				x := stack[tail]
+				stack = stack[:tail]
+				c := x.c
+
+				indent := ""
+				if x.depth > 0 {
+					indent = strings.Repeat("  ", x.depth-1) + "↳ "
+				}
+				i, ok := c.(Identifier)
+				if ok {
+					fmt.Fprintf(dst, "%s%T %s\n", indent, c, i.Ident())
+				} else {
+					fmt.Fprintf(dst, "%s%T\n", indent, c)
+				}
+
+				if s, ok := c.(Scanner); ok {
+					for _, y := range s.Scan() {
+						stack = append(stack, item{y, x.depth + 1})
+					}
+				}
+			}
+		}
+	}
+	return sc.Err()
+}

main.go

@@ -1,12 +1,10 @@
 package main
 
 import (
-	"bufio"
 	_ "image/png"
 	"log"
 	"os"
 	"runtime"
-	"strings"
 
 	"drjosh.dev/gurgle/engine"
 	"drjosh.dev/gurgle/game"
@@ -38,104 +36,13 @@ func main() {
 	}
 	g.Prepare()
 
+	if runtime.GOOS != "js" {
 		// Run a repl on the console.
-	go repl(g)
+		go g.REPL(os.Stdin, os.Stdout, game.Assets)
+	}
 
 	// ... while the game also runs
 	if err := ebiten.RunGame(g); err != nil {
 		log.Fatalf("Game error: %v", err)
 	}
 }
-
-func repl(g *engine.Game) {
-	if runtime.GOOS == "js" {
-		// can't os.Stdin on js
-		return
-	}
-	sc := bufio.NewScanner(os.Stdin)
-	for sc.Scan() {
-		tok := strings.Split(sc.Text(), " ")
-		if len(tok) == 0 {
-			continue
-		}
-		switch tok[0] {
-		case "quit":
-			os.Exit(0)
-		case "pause":
-			g.Disable()
-		case "resume", "unpause":
-			g.Enable()
-		case "save":
-			if len(tok) != 2 {
-				log.Print("Usage: save ID")
-				break
-			}
-			id := tok[1]
-			c := g.Component(id)
-			if c == nil {
-				log.Printf("Component %q not found", id)
-				break
-			}
-			s, ok := c.(engine.Saver)
-			if !ok {
-				log.Printf("Component %q not a Saver (type %T)", id, c)
-				break
-			}
-			if err := s.Save(); err != nil {
-				log.Printf("Couldn't save %q: %v", id, err)
-			}
-		case "reload":
-			g.Disable()
-			g.Hide()
-			if err := g.Load(game.Assets); err != nil {
-				log.Printf("Couldn't load: %v", err)
-				break
-			}
-			g.Prepare()
-			g.Enable()
-			g.Show()
-		case "tree":
-			var c interface{} = g
-			if len(tok) == 2 {
-				// subtree
-				id := tok[1]
-				c = g.Component(id)
-				if c == nil {
-					log.Printf("Component %q not found", id)
-					break
-				}
-			}
-			type item struct {
-				c     interface{}
-				depth int
-			}
-			stack := []item{{c, 0}}
-			for len(stack) > 0 {
-				tail := len(stack) - 1
-				x := stack[tail]
-				stack = stack[:tail]
-				c := x.c
-
-				indent := ""
-				if x.depth > 0 {
-					indent = strings.Repeat("  ", x.depth-1) + "↳ "
-				}
-				i, ok := c.(engine.Identifier)
-				if ok {
-					log.Printf("%s%T %s", indent, c, i.Ident())
-				} else {
-					log.Printf("%s%T", indent, c)
-				}
-
-				if s, ok := c.(engine.Scanner); ok {
-					for _, y := range s.Scan() {
-						stack = append(stack, item{y, x.depth + 1})
-					}
-				}
-			}
-		}
-	}
-	if err := sc.Err(); err != nil {
-		log.Fatalf("Couldn't scan stdin: %v", err)
-	}
-}