Fix it

Pointer vs. value receivers are... interesting.

cardsim/stats.go

@@ -118,8 +118,9 @@ func (s statFunc[T]) Visible() bool {
 	return s.visible
 }
 
-// ExtractStats pulls all exported stats out of a struct. It puts fields before
-// method.
+// ExtractStats pulls all exported stats out of a struct. It puts methods before
+// fields. If the calculated name of a method conflicts with the calculated
+// name of a stat from a field, the method wins.
 //
 // A field is a stat if it is of some Stat type or is tagged with `cardsim:"stat"`,
 // `cardsim:"hidden"` (invisible stat), `cardsim:"round2"` (or any integer, 2 is
@@ -148,6 +149,60 @@ func ExtractStats(x any) []Stat {
 	typ := v.Type()
 
 	var ret []Stat
+
+	known := make(map[string]bool)
+	for _, vv := range []reflect.Value{v, v.Addr()} {
+		xt := vv.Type()
+		lim := xt.NumMethod()
+		for i := 0; i < lim; i++ {
+			m := xt.Method(i)
+			if !m.IsExported() {
+				continue
+			}
+			tm := m.Type
+			if tm.NumIn() != 1 {
+				// 1 arg -- receiver
+				continue
+			}
+			if tm.NumOut() != 1 {
+				continue
+			}
+			nameParts := explode(m.Name)
+			if len(nameParts) < 2 {
+				continue
+			}
+			isHidden := false
+			if nameParts[0] == "Hidden" {
+				isHidden = true
+				nameParts = nameParts[1:]
+			}
+			if nameParts[0] != "Stat" {
+				continue
+			}
+			n := strings.Join(nameParts[1:], " ")
+			if n == "" {
+				continue
+			}
+			if known[n] {
+				continue
+			}
+			known[n] = true
+			val := vv.Method(i).Call([]reflect.Value{})
+			if len(val) != 1 {
+				// This shouldn't happen - we already checked Out. Weird.
+				continue
+			}
+			if !val[0].CanInterface() {
+				continue
+			}
+			ret = append(ret, &StatLiteral{
+				Name:      n,
+				Value:     fmt.Sprint(val[0].Interface()),
+				IsVisible: !isHidden,
+			})
+		}
+	}
+
 	fields := reflect.VisibleFields(typ)
 	for _, sf := range fields {
 		if !sf.IsExported() {
@@ -157,7 +212,12 @@ func ExtractStats(x any) []Stat {
 		if !f.CanInterface() {
 			continue
 		}
-		if s, ok := f.Interface().(Stat); ok {
+		iface := f.Interface()
+		if s, ok := iface.(Stat); ok {
+			if known[s.StatName()] {
+				continue
+			}
+			known[s.StatName()] = true
 			ret = append(ret, s)
 			continue
 		}
@@ -181,14 +241,19 @@ func ExtractStats(x any) []Stat {
 				t = t[5:]
 				n, _ := strconv.Atoi(t)
 				fs := fmt.Sprintf("%%.%df", n)
-				val = fmt.Sprintf(fs, f.Interface())
+				val = fmt.Sprintf(fs, iface)
 			} else if isStat {
-				val = fmt.Sprint(f.Interface())
+				val = fmt.Sprint(iface)
 			} else {
 				continue // not identifiably a stat
 			}
+			nm := strings.Join(explode(sf.Name), " ")
+			if known[nm] {
+				continue
+			}
+			known[nm] = true
 			ret = append(ret, &StatLiteral{
-				Name:      strings.Join(explode(sf.Name), " "),
+				Name:      nm,
 				Value:     val,
 				IsVisible: !isHidden,
 			})
@@ -197,50 +262,6 @@ func ExtractStats(x any) []Stat {
 		// Else, not a stat.
 	}
 
-	lim := typ.NumMethod()
-	for i := 0; i < lim; i++ {
-		m := typ.Method(i)
-		if !m.IsExported() {
-			continue
-		}
-		tm := m.Type
-		if tm.NumIn() != 1 {
-			// 1 arg -- receiver
-			continue
-		}
-		if tm.NumOut() != 1 {
-			continue
-		}
-		nameParts := explode(m.Name)
-		if len(nameParts) < 2 {
-			continue
-		}
-		isHidden := false
-		if nameParts[0] == "Hidden" {
-			isHidden = true
-			nameParts = nameParts[1:]
-		}
-		if nameParts[0] != "Stat" {
-			continue
-		}
-		n := strings.Join(nameParts[1:], ": ")
-		if n == "" {
-			continue
-		}
-		val := v.Method(i).Call([]reflect.Value{})
-		if len(val) != 1 {
-			// This shouldn't happen - we already checked Out. Weird.
-			continue
-		}
-		if !val[0].CanInterface() {
-			continue
-		}
-		ret = append(ret, &StatLiteral{
-			Name:      n,
-			Value:     fmt.Sprint(val[0].Interface()),
-			IsVisible: !isHidden,
-		})
-	}
 	return ret
 }