Fix it

Pointer vs. value receivers are... interesting.

.gitignore

@@ -21,3 +21,5 @@
 # Go workspace file
 go.work
 
+# Visual studio Code exclusions
+.vscode/settings.json

README.md

@@ -2,6 +2,8 @@
 
 Basic engine for NationStates-like "make decisions on issues" simulation games. Very incomplete.
 
+[![Go Reference](https://pkg.go.dev/badge/git.chromaticdragon.app/kistaro/CardSimEngine.svg)](https://pkg.go.dev/git.chromaticdragon.app/kistaro/CardSimEngine)
+
 ## General turn model
 
 1. Player has a hand of cards. Each card has one or more actions available.

cardsim/errors.go

@@ -55,6 +55,9 @@ func Warningf(f string, args ...any) *Warning {
 // IsSeriousError returns whether e is a non-warning error. If e is nil, this
 // returns false.
 func IsSeriousError(e error) bool {
+	if e == nil {
+		return false
+	}
 	return !errors.Is(e, AnyWarning)
 }
 

cardsim/player.go

@@ -463,3 +463,20 @@ func (p *Player[C]) ReportError(e error) {
 func (p *Player[C]) CanAct() bool {
 	return p.ActionsRemaining > 0 && (len(p.Hand) > 0 || len(p.PermanentActions) > 0)
 }
+
+// Debug adds a message to the player's temporary messages if their debug level
+// is at least the level specified.
+func (p *Player[C]) Debug(minLevel int, msg Message) {
+	if p.DebugLevel < minLevel || msg == nil {
+		return
+	}
+	p.TemporaryMessages = append(p.TemporaryMessages, msg)
+}
+
+// Emit adds a message to the player's temporary messages.
+func (p *Player[C]) Emit(msg Message) {
+	if msg == nil {
+		return
+	}
+	p.TemporaryMessages = append(p.TemporaryMessages, msg)
+}

cardsim/rules.go

@@ -141,7 +141,7 @@ func (r *RuleCollection[C]) performInsert(k *keyedRule[C]) {
 	r.rules[k.id] = k
 
 	s := r.byStep[k.Step()]
-	if s == nil {
+	if len(s) == 0 {
 		r.steps = nil
 	}
 	s = append(s, k.id)
@@ -326,7 +326,7 @@ func (r *RuleCollection[C]) Run(p *Player[C]) error {
 	steps := r.steps
 	if steps == nil {
 		// Step set changed, recalculate.
-		steps := make([]int, 0, len(r.byStep))
+		steps = make([]int, 0, len(r.byStep))
 		for step := range r.byStep {
 			steps = append(steps, step)
 		}
@@ -334,18 +334,21 @@ func (r *RuleCollection[C]) Run(p *Player[C]) error {
 		r.steps = steps
 	}
 
+	p.Debug(2, Msgf("Executing steps: %v", steps))
+
 	var errs ErrorCollector
 	for _, step := range steps {
 		stepRules := r.byStep[step]
-		p.Rand.Shuffle(len(stepRules), func(i, j int) {
-			stepRules[i], stepRules[j] = stepRules[j], stepRules[i]
-		})
+		p.Debug(3, Msgf("Executing step %d; length %d", step, len(stepRules)))
+		ShuffleAll(stepRules, p.Rand)
 		var remove []RuleID
 		halt := false
 		for _, id := range stepRules {
 			rule := r.rules[id]
+			p.Debug(4, Msgf("Executing rule %x (labeled %q)", id, rule.Label()))
 			err := rule.Enact(p)
 			if err != nil {
+				p.Debug(2, Msgf("Rule %x (%q): error: %v", id, rule.Label(), err))
 				ignore := false
 				if errors.Is(err, ErrDeleteRule) {
 					remove = append(remove, id)
@@ -377,10 +380,14 @@ func (r *RuleCollection[C]) Run(p *Player[C]) error {
 			}
 		}
 		if halt {
-			return errs.Emit()
+			ret := errs.Emit()
+			p.Debug(2, Msgf("Rules stopping early. Result: %v", ret))
+			return ret
 		}
 	}
-	return errs.Emit()
+	ret := errs.Emit()
+	p.Debug(2, Msgf("Rules complete. Result: %v", ret))
+	return ret
 }
 
 func (r *RuleCollection[C]) applyDelayedUpdates() {

cardsim/stats.go

@@ -4,7 +4,11 @@ import (
 	"fmt"
 	"reflect"
 	"sort"
+	"strconv"
 	"strings"
+	"unicode"
+
+	"golang.org/x/exp/constraints"
 )
 
 // A StatsCollection contains stats.
@@ -114,9 +118,26 @@ func (s statFunc[T]) Visible() bool {
 	return s.visible
 }
 
-// ExtractStats pulls all exported Stat fields (not functions) out of a struct.
-// If x cannot be resolved to a struct, it panics. It unwraps interfaces and
-// follows pointers to try to find a struct.
+// 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
+// just an example), or `cardsim:"hiddenround3"`. `hiddenstat`, `statround`, and
+// `hiddenstatround` are also accepted, but other orders of these directives
+// are not. A "round" stat must be a float type and it will be rounded to
+// this number of decimal places.
+//
+// A method is a Stat if it takes 0 arguments, returns exactly 1 value, and
+// starts with Stat or HiddenStat.
+//
+// The name of these inferred stats is calculated by breaking the name into
+// separate words before each capital letter, unless there are consecutive
+// capital letters, which it interprets as an initialism (followed by the
+// start of another word, if it's not at the end). To insert a space between
+// consecutive capital letters, insert an underscore (`_`). This name inference
+// trims "Stat" and "HiddenStat" off the front of method names.
 func ExtractStats(x any) []Stat {
 	v := reflect.ValueOf(x)
 	for k := v.Kind(); k == reflect.Pointer || k == reflect.Interface; k = v.Kind() {
@@ -125,19 +146,122 @@ func ExtractStats(x any) []Stat {
 	if v.Kind() != reflect.Struct {
 		panic(fmt.Errorf("%T is not a struct", x))
 	}
+	typ := v.Type()
 
 	var ret []Stat
-	lim := v.NumField()
-	for i := 0; i < lim; i++ {
-		f := v.Field(i)
+
+	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() {
+			continue
+		}
+		f := v.FieldByIndex(sf.Index)
 		if !f.CanInterface() {
 			continue
 		}
-		x := f.Interface()
-		if s, ok := x.(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
 		}
+		if t := sf.Tag.Get("cardsim"); t != "" {
+			isStat := false
+			isHidden := false
+			t = strings.ToLower(t)
+			t = strings.TrimSpace(t)
+			if strings.HasPrefix(t, "hidden") {
+				isStat = true
+				isHidden = true
+				t = t[6:]
+			}
+			if strings.HasPrefix(t, "stat") {
+				isStat = true
+				t = t[4:]
+			}
+			var val string
+			if strings.HasPrefix(t, "round") {
+				isStat = true
+				t = t[5:]
+				n, _ := strconv.Atoi(t)
+				fs := fmt.Sprintf("%%.%df", n)
+				val = fmt.Sprintf(fs, iface)
+			} else if isStat {
+				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:      nm,
+				Value:     val,
+				IsVisible: !isHidden,
+			})
+			continue
+		}
+		// Else, not a stat.
 	}
+
 	return ret
 }
 
@@ -173,3 +297,105 @@ func (s statSorter) Less(i, j int) bool {
 	// Names differ only by capitalization, if that.
 	return lhs.StatName() < rhs.StatName()
 }
+
+// StatLiteral stores a ready-to-emit stat value.
+type StatLiteral struct {
+	Name      string
+	Value     string
+	IsVisible bool
+}
+
+func (s *StatLiteral) StatName() string {
+	return s.Name
+}
+
+func (s *StatLiteral) String() string {
+	return s.Value
+}
+
+func (s *StatLiteral) Visible() bool {
+	return s.IsVisible
+}
+
+func EmitStat(name string, v any) *StatLiteral {
+	return &StatLiteral{
+		Name:      name,
+		Value:     fmt.Sprint(v),
+		IsVisible: true,
+	}
+}
+
+func EmitHiddenStat(name string, v any) *StatLiteral {
+	return &StatLiteral{
+		Name:      name,
+		Value:     fmt.Sprint(v),
+		IsVisible: false,
+	}
+}
+
+func Statf(name string, f string, args ...any) *StatLiteral {
+	return &StatLiteral{
+		Name:      name,
+		Value:     fmt.Sprintf(f, args...),
+		IsVisible: true,
+	}
+}
+
+func HiddentStatf(name string, f string, args ...any) *StatLiteral {
+	return &StatLiteral{
+		Name:      name,
+		Value:     fmt.Sprintf(f, args...),
+		IsVisible: false,
+	}
+}
+
+func RoundStat[N constraints.Float](name string, val N, decimals int) *StatLiteral {
+	f := fmt.Sprintf("%%.%df", decimals)
+	return &StatLiteral{
+		Name:      name,
+		Value:     fmt.Sprintf(f, val),
+		IsVisible: true,
+	}
+}
+
+func RoundHiddenStat[N constraints.Float](name string, val N, decimals int) *StatLiteral {
+	r := RoundStat(name, val, decimals)
+	r.IsVisible = false
+	return r
+}
+
+// explode turns CamelCase into multiple strings. It recognizes initialisms. To
+// split consecutive capital letters into separate words instead of recognizing
+// them as an initialism, insert underscores.
+func explode(s string) []string {
+	var parts []string
+	started := 0
+	initialism := false
+	for i, r := range s {
+		if unicode.IsUpper(r) {
+			if initialism || (started == i) {
+				continue
+			}
+			if started == i-1 {
+				initialism = true
+				continue
+			}
+			parts = append(parts, s[started:i])
+			started = i
+			continue
+		}
+		if r == '_' {
+			parts = append(parts, s[started:i])
+			initialism = false
+			started = i + 1
+			continue
+		}
+		if initialism {
+			parts = append(parts, s[started:i-1])
+			initialism = false
+			started = i - 1
+		}
+	}
+	parts = append(parts, s[started:])
+	return parts
+}

cardsim/terminalui.go

@@ -8,13 +8,14 @@ import (
 )
 
 func RunSimpleTerminalUI[C StatsCollection](p *Player[C]) error {
-	for {
-		err := p.StartNextTurn()
-		if p.DebugLevel < 1 && IsSeriousError(err) {
-			return err
-		}
-		p.ReportError(err)
 
+	err := p.StartNextTurn()
+	if p.DebugLevel < 1 && IsSeriousError(err) {
+		return err
+	}
+	p.ReportError(err)
+
+	for {
 		for p.CanAct() {
 			isCard, cardIdx, choiceIdx, err := pickNextAction(p)
 			p.ReportError(err)
@@ -135,7 +136,7 @@ func pickNextAction[C StatsCollection](p *Player[C]) (isCard bool, cardIdx int,
 				cls()
 				displayOnePanel(p, p.InfoPanels[i-1])
 				wait()
-			} else if i < handOffset {
+			} else if i <= handOffset {
 				i = i - actionsOffset - 1
 				option, promptErr := promptCard(p, p.PermanentActions[i])
 				if option >= 0 || IsSeriousError(promptErr) {
@@ -143,7 +144,7 @@ func pickNextAction[C StatsCollection](p *Player[C]) (isCard bool, cardIdx int,
 				}
 			} else {
 				i = i - handOffset - 1
-				option, promptErr := promptCard(p, p.Hand[i-handOffset-1])
+				option, promptErr := promptCard(p, p.Hand[i])
 				if option >= 0 || IsSeriousError(promptErr) {
 					return true, i, option, nil
 				}
@@ -205,14 +206,11 @@ func displayMessageSection[C StatsCollection](p *Player[C]) bool {
 	if len(p.TemporaryMessages) == 0 {
 		return false
 	}
-	hasPrevious := false
 	for _, m := range p.TemporaryMessages {
 		if m != nil {
-			if hasPrevious {
-				lightDivider()
-			}
 			display(m)
-			hasPrevious = true
+		} else {
+			fmt.Println()
 		}
 	}
 	return true
@@ -265,7 +263,7 @@ func promptCard[C StatsCollection](p *Player[C], card Card[C]) (optionIdx int, e
 		}
 		fmt.Println()
 		if valid {
-			fmt.Printf("Go (B)ack, (Q)uit, or enact a choice (1 - %d)? > ", len(opts)+1)
+			fmt.Printf("Go (B)ack, (Q)uit, or enact a choice (1 - %d)? > ", len(opts))
 		} else {
 			fmt.Print("Go (B)ack or (Q)uit? > ")
 		}
@@ -374,6 +372,7 @@ func statsMode[C StatsCollection](p *Player[C]) error {
 			} else if v <= 0 || v > n {
 				fmt.Println("There's no info panel with that index.")
 			} else {
+				cls()
 				err := displayOnePanel(p, p.InfoPanels[v-1])
 				errs.Add(err)
 				if IsSeriousError(err) {
@@ -507,7 +506,7 @@ func review[C StatsCollection](p *Player[C]) error {
 				cls()
 				displayOnePanel(p, p.InfoPanels[i-1])
 				wait()
-			} else if i < handOffset {
+			} else if i <= handOffset {
 				i = i - actionsOffset - 1
 				_, _, err := displayCard(p, p.PermanentActions[i], false)
 				errs.Add(err)

go.mod

@@ -1,3 +1,11 @@
-module cardSimEngine
+module git.chromaticdragon.app/kistaro/CardSimEngine
 
 go 1.20
+
+require github.com/kr/pretty v0.3.1
+
+require (
+	github.com/kr/text v0.2.0 // indirect
+	github.com/rogpeppe/go-internal v1.9.0 // indirect
+	golang.org/x/exp v0.0.0-20230321023759-10a507213a29
+)

go.sum

@@ -0,0 +1,10 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+golang.org/x/exp v0.0.0-20230321023759-10a507213a29 h1:ooxPy7fPvB4kwsA2h+iBNHkAbp/4JxTSwCmvdjEYmug=
+golang.org/x/exp v0.0.0-20230321023759-10a507213a29/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=

smoketest/cards.go

@@ -1,9 +1,10 @@
 package main
 
 import (
-	"cardSimEngine/cardsim"
 	"errors"
 	"fmt"
+
+	"git.chromaticdragon.app/kistaro/CardSimEngine/cardsim"
 )
 
 // Type aliases, unlike distinctly named types, are fully substitutable for

smoketest/collection.go

@@ -1,16 +1,21 @@
 package main
 
 import (
-	"cardSimEngine/cardsim"
+	"git.chromaticdragon.app/kistaro/CardSimEngine/cardsim"
 )
 
 // SmokeTestCollection is a stats collection for the simple test sim.
 type SmokeTestCollection struct {
 	Number cardsim.Stored[int]
-	Total  cardsim.Stored[int]
+	Total  cardsim.Stored[int64]
 	Turns  cardsim.Invisible[int]
 
 	Flavor cardsim.Stored[string]
+
+	Things       int     `cardsim:"stat"`
+	MoreThings   int     `cardsim:"hidden"`
+	FloatyThings float64 `cardsim:"round1"`
+	Label        string  `cardsim:"stat"`
 }
 
 func (c *SmokeTestCollection) Average() float64 {
@@ -23,3 +28,7 @@ func (c *SmokeTestCollection) Stats() []cardsim.Stat {
 	cardsim.SortStats(stats)
 	return stats
 }
+
+func (c *SmokeTestCollection) StatTotalThings() float64 {
+	return float64(c.Things+c.MoreThings) + c.FloatyThings
+}

smoketest/main.go

@@ -2,8 +2,11 @@
 package main
 
 import (
-	"cardSimEngine/cardsim"
 	"fmt"
+
+	"git.chromaticdragon.app/kistaro/CardSimEngine/cardsim"
+
+	"github.com/kr/pretty"
 )
 
 func main() {
@@ -25,6 +28,10 @@ func main() {
 				Name:  "Flavor",
 				Value: "Lemon",
 			},
+			Things:       5,
+			MoreThings:   9,
+			FloatyThings: 123.456,
+			Label:        "whee",
 		},
 	)
 	p.Name = "Dave"
@@ -38,6 +45,7 @@ func main() {
 			Name:  cardsim.MsgStr("Stats"),
 			Intro: cardsim.MsgStr("Hi! These are the smoke test stats."),
 		},
+		ruledumper{},
 	}
 	p.Prompt = prompt{}
 	p.DebugLevel = 5
@@ -54,9 +62,22 @@ func main() {
 type prompt struct{}
 
 func (prompt) Title(p *cardsim.Player[*SmokeTestCollection]) cardsim.Message {
-	return cardsim.MsgStr("Prompt title -- should not be visible?")
+	return cardsim.MsgStr("Smoke Test")
 }
 
 func (prompt) Info(p *cardsim.Player[*SmokeTestCollection]) ([]cardsim.Message, error) {
-	return []cardsim.Message{cardsim.MsgStr("Here, have some stuff.")}, nil
+	return []cardsim.Message{
+		cardsim.MsgStr("Here, have some stuff."),
+		cardsim.Msgf("It's turn %d according to the player and turn %d according to me.", p.TurnNumber, p.Stats.Turns.Value),
+	}, nil
+}
+
+type ruledumper struct{}
+
+func (ruledumper) Title(p *player) cardsim.Message {
+	return cardsim.MsgStr("Rule Dumper")
+}
+
+func (ruledumper) Info(p *player) ([]cardsim.Message, error) {
+	return []cardsim.Message{cardsim.Msgf("%# v", pretty.Formatter(p.Rules))}, nil
 }

smoketest/rules.go

@@ -1,8 +1,9 @@
 package main
 
 import (
-	"cardSimEngine/cardsim"
 	"math"
+
+	"git.chromaticdragon.app/kistaro/CardSimEngine/cardsim"
 )
 
 var (