Decompose io.go End and status (refactor step 7)

End's --More-- handling moves into promptMore; status's redraw-skip
check moves into statusUnchanged. io.go is complexity-clean. Behavior
unchanged.

game/io.go

@@ -58,29 +58,8 @@ func (m *MessageLine) End() int {
 		m.Huh = m.buf.String()
 	}
 
-	if m.Mpos != 0 {
+	if m.Mpos != 0 && m.promptMore() == Escape {
-		m.look(false)
+		return Escape
-		m.scr.Std.MvAddStr(0, m.Mpos, "--More--")
-		m.scr.Refresh()
-
-		if !m.MsgEsc {
-			m.waitForSpace()
-		} else {
-			for {
-				ch := m.readChar()
-				if ch == ' ' {
-					break
-				}
-
-				if ch == Escape {
-					m.buf.Reset()
-					m.Mpos = 0
-					m.newpos = 0
-
-					return Escape
-				}
-			}
-		}
 	}
 	// All messages should start with uppercase, except ones that start
 	// with a pack addressing character
@@ -101,6 +80,36 @@ func (m *MessageLine) End() int {
 	return ^Escape
 }
 
+// promptMore shows the --More-- prompt and waits for the reader to
+// acknowledge; Escape means the player bailed out (the Mpos block of
+// io.c endmsg).
+func (m *MessageLine) promptMore() int {
+	m.look(false)
+	m.scr.Std.MvAddStr(0, m.Mpos, "--More--")
+	m.scr.Refresh()
+
+	if !m.MsgEsc {
+		m.waitForSpace()
+
+		return ^Escape
+	}
+
+	for {
+		ch := m.readChar()
+		if ch == ' ' {
+			return ^Escape
+		}
+
+		if ch == Escape {
+			m.buf.Reset()
+			m.Mpos = 0
+			m.newpos = 0
+
+			return Escape
+		}
+	}
+}
+
 // attach wires the message line to its display and input; NewGame and
 // Restore call it once the screen and game exist.
 func (m *MessageLine) attach(scr *Screen, look func(bool), readChar func() byte) {
@@ -193,9 +202,7 @@ func (g *RogueGame) status() {
 		temp = p.CurArmor.ArmorClass
 	}
 
-	if s.init && s.hp == p.Stats.HP && s.exp == p.Stats.Exp &&
+	if g.statusUnchanged(temp) {
-		s.pur == p.Purse && s.arm == temp && s.str == p.Stats.Str &&
-		s.lvl == g.Depth && s.hungry == p.HungryState && !g.StatMsg {
 		return
 	}
 
@@ -238,6 +245,18 @@ func (g *RogueGame) status() {
 	g.move(oy, ox)
 }
 
+// statusUnchanged reports whether the status line still shows current
+// values, so it need not be redrawn (the shadow-variable check of io.c
+// status). temp is the effective armor class.
+func (g *RogueGame) statusUnchanged(temp int) bool {
+	s := &g.statusCache
+	p := &g.Player
+
+	return s.init && s.hp == p.Stats.HP && s.exp == p.Stats.Exp &&
+		s.pur == p.Purse && s.arm == temp && s.str == p.Stats.Str &&
+		s.lvl == g.Depth && s.hungry == p.HungryState && !g.StatMsg
+}
+
 // waitFor sits around until the guy types the right key (io.c wait_for).
 func (g *RogueGame) waitFor(ch byte) {
 	if ch == '\n' {