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/card.go

@@ -49,7 +49,8 @@ type CardOption[C StatsCollection] interface {
 	// a warning, the game crashes.
 	//
 	// After an option is enacted, the card is deleted. If a card should be
-	// repeatable, Enact must return it to the deck (on every option).
+	// repeatable, Enact must return it to the deck (on every option) or
+	// the card needs to reinsert itself with its Then function.
 	Enact(p *Player[C]) (Message, error)
 
 	// Enabled returns whether this option can curently be enacted.
@@ -63,7 +64,8 @@ type BasicCard[C StatsCollection] struct {
 	IsUrgent    bool
 	CardText    Message
 	CardOptions []CardOption[C]
-	AfterOption func(p *Player[C], option CardOption[C]) error
+	// AfterOption is given the card itself as its first argument.
+	AfterOption func(c Card[C], p *Player[C], option CardOption[C]) error
 }
 
 // Title implements Card.
@@ -91,7 +93,7 @@ func (b *BasicCard[C]) Then(p *Player[C], option CardOption[C]) error {
 	if b.AfterOption == nil {
 		return nil
 	}
-	return b.AfterOption(p, option)
+	return b.AfterOption(b, p, option)
 }
 
 // Drawn implements Card.

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

@@ -227,7 +227,7 @@ func (p *Player[C]) Simulate() error {
 
 	if p.DebugLevel > 0 && !errs.IsEmpty() {
 		p.ChapterBreak()
-		p.TemporaryMessages = append(p.TemporaryMessages, Msgf("%d ERRORS AND WARNINGS:", len(errs.Errs)))
+		p.TemporaryMessages = append(p.TemporaryMessages, Msgf("%d ERRORS AND WARNINGS while simulating turn:", len(errs.Errs)))
 		for i, e := range errs.Errs {
 			yikes := " "
 			if IsSeriousError(e) {
@@ -260,18 +260,34 @@ func (p *Player[C]) StartNextTurn() error {
 	return errs.Emit()
 }
 
+// Draw draws a card into the hand, informing the card that it has been drawn.
+// If more than a million cards refuse to enter the hand, this crashes with
+// ErrUncooperativeCards. If the deck does not have enough cards, this
+// returns WarningTooFewCards.
+func (p *Player[C]) Draw() error {
+	for attempts := 0; attempts < 1000000; attempts++ {
+		if p.Deck.Len() == 0 {
+			return WarningTooFewCards
+		}
+		c := p.Deck.Draw()
+		if c.Drawn(p) {
+			p.Hand = append(p.Hand, c)
+			return nil
+		}
+	}
+	return ErrUncooperativeCards
+}
+
 // FillHand draws up to the hand limit, informing cards that they have been
 // drawn. If more than a million cards refuse to enter the hand, this crashes
 // with ErrUncooperativeCards. If the deck does not have enough cards, this
 // returns WarningTooFewCards.
 func (p *Player[C]) FillHand() error {
-	failureLimit := 1000000
+	var lastErr error
-	for failureLimit > 0 && p.Deck.Len() > 0 && len(p.Hand) < p.HandLimit {
+	for p.Deck.Len() > 0 && len(p.Hand) < p.HandLimit {
-		c := p.Deck.Draw()
+		lastErr = p.Draw()
-		if c.Drawn(p) {
+		if IsSeriousError(lastErr) {
-			p.Hand = append(p.Hand, c)
+			return lastErr
-		} else {
-			failureLimit--
 		}
 	}
 
@@ -279,10 +295,6 @@ func (p *Player[C]) FillHand() error {
 		return nil
 	}
 
-	if failureLimit <= 0 {
-		return ErrUncooperativeCards
-	}
-
 	return WarningTooFewCards
 }
 
@@ -451,3 +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) {
+		p.Debug(3, Msgf("Executing step %d; length %d", step, len(stepRules)))
-			stepRules[i], stepRules[j] = stepRules[j], stepRules[i]
+		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.
+// ExtractStats pulls all exported stats out of a struct. It puts methods before
-// If x cannot be resolved to a struct, it panics. It unwraps interfaces and
+// fields. If the calculated name of a method conflicts with the calculated
-// follows pointers to try to find a struct.
+// 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()
+
+	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++ {
-		f := v.Field(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()
+		iface := f.Interface()
-		if s, ok := x.(Stat); ok {
+		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

@@ -8,15 +8,23 @@ import (
 )
 
 func RunSimpleTerminalUI[C StatsCollection](p *Player[C]) error {
-	for {
+
 	err := p.StartNextTurn()
 	if p.DebugLevel < 1 && IsSeriousError(err) {
 		return err
 	}
 	p.ReportError(err)
 
+	for {
 		for p.CanAct() {
-			isCard, cardIdx, choiceIdx := pickNextAction(p)
+			isCard, cardIdx, choiceIdx, err := pickNextAction(p)
+			p.ReportError(err)
+			if IsSeriousError(err) {
+				if p.DebugLevel < 1 {
+					return err
+				}
+				continue
+			}
 			var msg Message
 			if isCard {
 				msg, err = p.EnactCard(cardIdx, choiceIdx)
@@ -24,24 +32,36 @@ func RunSimpleTerminalUI[C StatsCollection](p *Player[C]) error {
 				msg, err = p.EnactPermanentAction(cardIdx, choiceIdx)
 			}
 			p.ReportError(err)
-			if p.DebugLevel < 1 && IsSeriousError(err) {
+			if IsSeriousError(err) {
+				if p.DebugLevel < 1 {
 					return err
 				}
+				continue
+			}
 			display(msg)
 			wait()
 		}
 
-		review(p)
+		// Allow player to review state before continuing simulation.
+		// Errors from review mode are reported *after* the simulation
+		// step because the first thing Simulate does is throw out old
+		// messages -- like these errors.
+		reviewErr := review(p)
+		if p.DebugLevel < 1 && IsSeriousError(err) {
+			return reviewErr
+		}
 		err = p.Simulate()
 		if p.DebugLevel < 1 && IsSeriousError(err) {
 			return err
 		}
+		// Simulation errors are already in messages; now add the review error.
+		p.ReportError(reviewErr)
 
 		if p.DebugLevel < 1 && p.State.Over() {
 			return nil
 		}
 	}
-	return nil
+	// loop forever until the game ends or the player quits
 }
 
 func display(m Message) {
@@ -57,8 +77,7 @@ func wait() {
 	fmt.Scanln()
 }
 
-func pickNextAction[C StatsCollection](p *Player[C]) (isCard bool, cardIdx int, choiceIdx int) {
+func displayMainMenu[C StatsCollection](p *Player[C]) (actionsOffset, handOffset, max int) {
-	for {
 	cls()
 	needsDivider := displayMessageSection(p)
 	if needsDivider {
@@ -66,61 +85,68 @@ func pickNextAction[C StatsCollection](p *Player[C]) (isCard bool, cardIdx int,
 	}
 	displayOnePanel(p, p.Prompt)
 	divider()
-		actionsOffset := displayStatsMenu(p)
+	actionsOffset = displayStatsMenu(p)
 	if actionsOffset > 0 {
 		divider()
 	}
-		handOffset := displayPermanentActionsMenu(p, actionsOffset)
+	handOffset = displayPermanentActionsMenu(p, actionsOffset)
-		max := displayHandMenu(p, handOffset)
+	if handOffset > actionsOffset {
+		fmt.Println()
+	}
+	max = displayHandMenu(p, handOffset)
+	return // uses named return values
+}
+
+func pickNextAction[C StatsCollection](p *Player[C]) (isCard bool, cardIdx int, choiceIdx int, err error) {
+	for {
+		actionsOffset, handOffset, max := displayMainMenu(p)
 
 		divider()
-		var input string
+		fmt.Printf("%d actions remaining.\n", p.ActionsRemaining)
-		fmt.Printf("Show just (M)essages, (S)tats, (A)ctions, make a choice (1-%d), or (Q)uit? >", max+1)
+		fmt.Printf("Show just (M)essages, (I)nfo Panels, (A)ctions, or consider an item (1-%d), or (Q)uit? > ", max)
-		fmt.Scanln(&input)
+		input := getResponse()
-		input = strings.TrimSpace(input)
-		input = strings.ToLower(input)
 		switch input {
 		// Special cases
-		case "m":
+		case "m", "msg", "message", "messages":
 			cls()
-			displayMessageSection(p)
+			if displayMessageSection(p) {
+				divider()
+			}
+			displayOnePanel(p, p.Prompt)
 			wait()
-		case "s":
+		case "s", "stat", "stats", "i", "info", "p", "panel", "panels", "infopanel", "infopanels":
 			statsMode(p)
-		case "a":
+		case "a", "act", "actions":
-			actionsMode(p)
+			var committed bool
-		case "q":
+			isCard, cardIdx, choiceIdx, committed, err = actionsMode(p, true)
+			if committed {
+				return
+			}
+		case "q", "quit", "exit":
 			confirmQuit()
 		default:
 			i, err := strconv.Atoi(input)
 			if err != nil {
 				fmt.Println("Sorry, I don't understand.")
 				wait()
-				return pickNextAction(p)
+			} else if i > max {
-			}
+				fmt.Println("That's not on this menu. If the menu is too big to read, choose a detail view.")
-			if i > max {
-				fmt.Println("That's not a valid action.")
 				wait()
-				return pickNextAction(p)
+			} else if i <= actionsOffset {
-			}
-			i -= 1
-			if i < actionsOffset {
 				cls()
-				displayOnePanel(p, p.InfoPanels[i])
+				displayOnePanel(p, p.InfoPanels[i-1])
 				wait()
-			} else if i < handOffset {
+			} else if i <= handOffset {
-				cls()
+				i = i - actionsOffset - 1
-				i -= actionsOffset
+				option, promptErr := promptCard(p, p.PermanentActions[i])
-				option, ok := promptPermanentAction(p, i)
+				if option >= 0 || IsSeriousError(promptErr) {
-				if ok {
+					return false, i, option, promptErr
-					return false, i, option
 				}
 			} else {
-				cls()
+				i = i - handOffset - 1
-				i -= handOffset
+				option, promptErr := promptCard(p, p.Hand[i])
-				option, ok := promptCard(p, i)
+				if option >= 0 || IsSeriousError(promptErr) {
-				if ok {
+					return true, i, option, nil
-					return true, i, option
 				}
 			}
 		}
@@ -131,7 +157,21 @@ func cls() {
 	fmt.Println("\033[H\033[2J")
 }
 
+func getResponse() string {
+	var input string
+	fmt.Scanln(&input)
+	input = strings.TrimSpace(input)
+	input = strings.ToLower(input)
+	return input
+}
+
 func divider() {
+	fmt.Println()
+	fmt.Println(ChapterBreak.String())
+	fmt.Println()
+}
+
+func lightDivider() {
 	fmt.Println()
 	fmt.Println(SectionBreak.String())
 	fmt.Println()
@@ -139,12 +179,9 @@ func divider() {
 
 func confirmQuit() {
 	divider()
-	fmt.Println("Are you sure you want to quit? (Y/N) ")
+	fmt.Println("Are you sure you want to quit? (Y/N) > ")
-	var s string
+	s := getResponse()
-	fmt.Scanln(&s)
+	if s == "y" || s == "yes" {
-	s = strings.TrimSpace(s)
-	s = strings.ToLower(s)
-	if strings.HasPrefix(s, "y") {
 		fmt.Println("Bye!")
 		os.Exit(0)
 	}
@@ -169,7 +206,13 @@ func displayMessageSection[C StatsCollection](p *Player[C]) bool {
 	if len(p.TemporaryMessages) == 0 {
 		return false
 	}
-	display(MultiMessage(p.TemporaryMessages))
+	for _, m := range p.TemporaryMessages {
+		if m != nil {
+			display(m)
+		} else {
+			fmt.Println()
+		}
+	}
 	return true
 }
 
@@ -180,7 +223,306 @@ func displayStatsMenu[C StatsCollection](p *Player[C]) int {
 	fmt.Println("Info Panels")
 	fmt.Println("-----------")
 	for i, s := range p.InfoPanels {
-		fmt.Printf("[%2d]: %s", i+1, s.Title(p).String())
+		fmt.Printf("[%2d]: %s\n", i+1, s.Title(p).String())
 	}
 	return len(p.InfoPanels)
 }
+
+func displayPermanentActionsMenu[C StatsCollection](p *Player[C], offset int) int {
+	if len(p.PermanentActions) == 0 {
+		return offset
+	}
+	fmt.Println("Always Available")
+	fmt.Println("----------------")
+	for i, s := range p.PermanentActions {
+		fmt.Printf("[%2d]: %s\n", i+offset+1, s.Title(p))
+	}
+	return offset + len(p.PermanentActions)
+}
+
+func displayHandMenu[C StatsCollection](p *Player[C], offset int) int {
+	if len(p.Hand) == 0 {
+		return offset
+	}
+	fmt.Println("Hand")
+	fmt.Println("----")
+	for i, s := range p.Hand {
+		fmt.Printf("[%2d]: %s\n", i+offset+1, s.Title(p))
+	}
+	return offset + len(p.Hand)
+}
+
+// promptCard asks the player to take an action on a card. Returns the option
+// they chose, or -1 if there was a serious error or they cancelled selection.
+func promptCard[C StatsCollection](p *Player[C], card Card[C]) (optionIdx int, err error) {
+	// Iterate until the player makes a valid choice.
+	for {
+		opts, valid, err := displayCard(p, card, true)
+		if IsSeriousError(err) {
+			return -1, err
+		}
+		fmt.Println()
+		if valid {
+			fmt.Printf("Go (B)ack, (Q)uit, or enact a choice (1 - %d)? > ", len(opts))
+		} else {
+			fmt.Print("Go (B)ack or (Q)uit? > ")
+		}
+		read := getResponse()
+		switch read {
+		case "b", "back":
+			return -1, err
+		case "q", "quit":
+			confirmQuit()
+		default:
+			i, convErr := strconv.Atoi(read)
+			if convErr != nil {
+				fmt.Println("Sorry, I don't understand.")
+				wait()
+			} else if !valid {
+				fmt.Println("You can't enact anything here.")
+				wait()
+			} else if i <= 0 || i > len(opts) {
+				fmt.Println("That's not one of the options.")
+				wait()
+			} else if !opts[i-1].Enabled(p) {
+				fmt.Println("That option is not available to you right now.")
+				wait()
+			} else {
+				return i - 1, err
+			}
+		}
+		// Invalid selection made -- loop to prompt again.
+	}
+}
+
+func displayCard[C StatsCollection](p *Player[C], card Card[C], canAct bool) ([]CardOption[C], bool, error) {
+	cls()
+	t := card.Title(p).String()
+	urgent := card.Urgent(p)
+	if urgent {
+		t = "[URGENT!] " + t
+	}
+	fmt.Println(t)
+	fmt.Println(strings.Repeat("-", len(t)))
+	fmt.Println()
+	event, err := card.EventText(p)
+	if IsSeriousError(err) {
+		return nil, false, err
+	}
+	var errs ErrorCollector
+	errs.Add(err)
+	fmt.Println(event.String())
+	fmt.Println()
+	fmt.Println(SectionBreak.String())
+	fmt.Println()
+	if !urgent && p.HasUrgentCards() {
+		fmt.Println("<You have more urgent matters to attend to! You cannot act on this right now.>")
+		fmt.Println()
+		canAct = false
+	}
+	opts, optErr := card.Options(p)
+	errs.Add(optErr)
+	if IsSeriousError(optErr) {
+		return nil, false, errs.Emit()
+	}
+	valid := false
+	for i, opt := range opts {
+		pfx := "[xx]:"
+		if opt.Enabled(p) {
+			if canAct {
+				pfx = fmt.Sprintf("[%2d]:", i+1)
+				valid = true
+			} else {
+				pfx = "[--]:"
+			}
+		}
+		t, err := opt.OptionText(p)
+		errs.Add(err)
+		if IsSeriousError(err) {
+			return nil, false, errs.Emit()
+		}
+		fmt.Println(pfx, t.String())
+	}
+	return opts, valid, errs.Emit()
+}
+
+func statsMode[C StatsCollection](p *Player[C]) error {
+	var errs ErrorCollector
+	for {
+		cls()
+		n := displayStatsMenu(p)
+		if n <= 0 {
+			fmt.Println("No info panels are available.")
+			wait()
+			return errs.Emit()
+		}
+		fmt.Println()
+		fmt.Printf("Go (B)ack, (Q)uit, or view an info panel (1-%d)? > ", n)
+		s := getResponse()
+		switch s {
+		case "b", "back":
+			return errs.Emit()
+		case "q", "quit":
+			confirmQuit()
+		default:
+			v, err := strconv.Atoi(s)
+			if err != nil {
+				fmt.Println("Sorry, I don't understand.")
+				wait()
+			} 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) {
+					return errs.Emit()
+				}
+				wait()
+			}
+		}
+		// Loop to re-display info panels menu.
+	}
+}
+
+func actionsMode[C StatsCollection](p *Player[C], canAct bool) (isCard bool, cardIdx, choiceIdx int, committed bool, err error) {
+	var errs ErrorCollector
+	for {
+		cls()
+		pOff := displayPermanentActionsMenu(p, 0)
+		if pOff > 0 {
+			fmt.Println()
+		}
+		max := displayHandMenu(p, pOff)
+
+		if max <= 0 {
+			fmt.Println("There are no actions available and no cards in hand.")
+			fmt.Println("That's a problem. The game is stuck.")
+			confirmQuit()
+			errs.Add(WarningStalemate)
+			return false, -1, -1, true, errs.Emit()
+		}
+
+		fmt.Println()
+		if canAct {
+			fmt.Printf("Go (B)ack, (Q)uit, or consider an action (1-%d)? > ", max)
+		} else {
+			fmt.Printf("Go (B)ack, (Q)uit, or view an action (1-%d)? > ", max)
+		}
+		input := getResponse()
+		switch input {
+		case "b", "back":
+			return false, -1, -1, false, errs.Emit()
+		case "q", "quit":
+			confirmQuit()
+		default:
+			v, err := strconv.Atoi(input)
+			if err != nil {
+				fmt.Println("Sorry, I don't understand.")
+				wait()
+			} else if v < 1 || v > max {
+				fmt.Println("That's not a card or action.")
+				wait()
+			} else if v <= pOff {
+				v--
+				if canAct {
+					optIdx, err := promptCard(p, p.PermanentActions[v])
+					errs.Add(err)
+					if optIdx >= 0 || IsSeriousError(err) {
+						return false, v, optIdx, true, errs.Emit()
+					}
+				} else {
+					_, _, err := displayCard(p, p.PermanentActions[v], false)
+					errs.Add(err)
+					if IsSeriousError(err) {
+						return false, -1, -1, true, errs.Emit()
+					}
+					wait()
+				}
+			} else {
+				v = v - pOff - 1
+				if canAct {
+					optIdx, err := promptCard(p, p.Hand[v])
+					errs.Add(err)
+					if optIdx >= 0 || IsSeriousError(err) {
+						return true, v, optIdx, false, errs.Emit()
+					}
+				} else {
+					_, _, err := displayCard(p, p.Hand[v], false)
+					errs.Add(err)
+					if IsSeriousError(err) {
+						return false, -1, -1, false, errs.Emit()
+					}
+					wait()
+				}
+			}
+		}
+		// Re-prompt to get a valid choice.
+	}
+}
+
+func review[C StatsCollection](p *Player[C]) error {
+	var errs ErrorCollector
+	for {
+		actionsOffset, handOffset, max := displayMainMenu(p)
+		divider()
+		fmt.Println("No actions remaining.")
+		fmt.Printf("(C)ontinue, review just (M)essages, (I)nfo Panels, (A)ctions, or an item (1-%d), or (Q)uit? > ", max)
+		input := getResponse()
+		switch input {
+		// Special cases
+		case "m", "msg", "message", "messages":
+			cls()
+			if displayMessageSection(p) {
+				divider()
+			}
+			displayOnePanel(p, p.Prompt)
+			wait()
+		case "s", "stat", "stats", "i", "info", "p", "panel", "panels", "infopanel", "infopanels":
+			err := statsMode(p)
+			errs.Add(err)
+			if IsSeriousError(err) {
+				return errs.Emit()
+			}
+		case "a", "act", "actions":
+			_, _, _, _, err := actionsMode(p, false)
+			errs.Add(err)
+			if IsSeriousError(err) {
+				return errs.Emit()
+			}
+		case "q", "quit", "exit":
+			confirmQuit()
+		case "c", "continue", "ok":
+			return errs.Emit()
+		default:
+			i, err := strconv.Atoi(input)
+			if err != nil {
+				fmt.Println("Sorry, I don't understand.")
+				wait()
+			} else if i <= 0 || i > max {
+				fmt.Println("That's not on this menu. If the menu is too big to read, choose a detail view.")
+				wait()
+			} else if i <= actionsOffset {
+				cls()
+				displayOnePanel(p, p.InfoPanels[i-1])
+				wait()
+			} else if i <= handOffset {
+				i = i - actionsOffset - 1
+				_, _, err := displayCard(p, p.PermanentActions[i], false)
+				errs.Add(err)
+				if IsSeriousError(err) {
+					return errs.Emit()
+				}
+				wait()
+			} else {
+				i = i - handOffset - 1
+				_, _, err := displayCard(p, p.Hand[i], false)
+				errs.Add(err)
+				if IsSeriousError(err) {
+					return errs.Emit()
+				}
+				wait()
+			}
+		}
+	}
+}

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

@@ -0,0 +1,163 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+
+	"git.chromaticdragon.app/kistaro/CardSimEngine/cardsim"
+)
+
+// Type aliases, unlike distinctly named types, are fully substitutable for
+// the original type. This trims off some annoying-to-type things.
+type player = cardsim.Player[*SmokeTestCollection]
+type card = cardsim.Card[*SmokeTestCollection]
+type cardOption = cardsim.CardOption[*SmokeTestCollection]
+
+func makeAdditionCard(amt int) cardsim.Card[*SmokeTestCollection] {
+	c := &cardsim.BasicCard[*SmokeTestCollection]{
+		CardTitle: cardsim.Msgf("Additive %d", amt),
+		CardText:  cardsim.Msgf("You can change the Number by %d.", amt),
+		CardOptions: []cardsim.CardOption[*SmokeTestCollection]{
+			&cardsim.BasicOption[*SmokeTestCollection]{
+				Text: cardsim.Msgf("Add %d", amt),
+				Effect: func(p *player) error {
+					p.Stats.Number.Value += amt
+					return nil
+				},
+				Output: cardsim.MsgStr("Added."),
+			},
+			&cardsim.BasicOption[*SmokeTestCollection]{
+				Text: cardsim.Msgf("Subtract %d", amt),
+				Effect: func(p *player) error {
+					p.Stats.Number.Value -= amt
+					return nil
+				},
+				Output: cardsim.MsgStr("Subtracted."),
+			},
+		},
+		AfterOption: func(c card, p *player, _ cardOption) error {
+			p.Deck.InsertRandomBottom(0.5, c)
+			return nil
+		},
+	}
+	return c
+}
+
+func makeMultiplicationCard(amt int) cardsim.Card[*SmokeTestCollection] {
+	c := &cardsim.BasicCard[*SmokeTestCollection]{
+		CardTitle: cardsim.Msgf("Multiplicative %d", amt),
+		CardText:  cardsim.Msgf("You can multiply or divide the Number by %d, or maybe divide the Number by that.", amt),
+		CardOptions: []cardsim.CardOption[*SmokeTestCollection]{
+			&cardsim.BasicOption[*SmokeTestCollection]{
+				Text: cardsim.Msgf("Multiply by %d", amt),
+				Effect: func(p *player) error {
+					p.Stats.Number.Value *= amt
+					return nil
+				},
+				Output: cardsim.MsgStr("Multiplied."),
+			},
+			&cardsim.BasicOption[*SmokeTestCollection]{
+				Text: cardsim.Msgf("Integer divide by %d", amt),
+				Effect: func(p *player) error {
+					p.Stats.Number.Value /= amt
+					return nil
+				},
+				Output: cardsim.MsgStr("Divided."),
+			},
+			inverseDivision(amt),
+		},
+		AfterOption: func(c card, p *player, _ cardOption) error {
+			p.Deck.InsertRandomBottom(0.5, c)
+			return nil
+		},
+	}
+	return c
+}
+
+type inverseDivision int
+
+func (i inverseDivision) OptionText(p *player) (cardsim.Message, error) {
+	if p.Stats.Number.Value == 0 {
+		return cardsim.MsgStr("You can't divide by zero!"), nil
+	}
+	return cardsim.Msgf("Divide %d by the Number", int(i)), nil
+}
+
+func (i inverseDivision) Enact(p *player) (cardsim.Message, error) {
+	if p.Stats.Number.Value == 0 {
+		return nil, errors.New("you can't divide by zero!")
+	}
+	p.Stats.Number.Value = int(i) / p.Stats.Number.Value
+	return cardsim.MsgStr("Inverse divided."), nil
+}
+
+func (i inverseDivision) Enabled(p *player) bool {
+	return p.Stats.Number.Value != 0
+}
+
+func initDeck(d *cardsim.Deck[*SmokeTestCollection]) {
+	addMe := []int{
+		0, 1, 2, 5, 10, 50, 100, 1000, 2500, 500000, 9876543,
+	}
+	for _, n := range addMe {
+		d.Insert(cardsim.BottomOfDeck, makeAdditionCard(n))
+	}
+
+	multiplyMe := []int{
+		2, 4, 8, 16, 32, 64, 128, 512, 1024, 9999, 84720413,
+	}
+	for _, n := range multiplyMe {
+		d.Insert(cardsim.BottomOfDeck, makeMultiplicationCard(n))
+	}
+	if err := d.Shuffle(); cardsim.IsSeriousError(err) {
+		panic(err)
+	} else if err != nil {
+		fmt.Printf("Error shuffling: %v\n", err)
+	}
+}
+
+func installPermanentActions(pa *[]card) {
+	*pa = []card{
+		&cardsim.BasicCard[*SmokeTestCollection]{
+			CardTitle: cardsim.MsgStr("Reset to 0"),
+			CardText:  cardsim.MsgStr("Resets Number to 0."),
+			CardOptions: []cardOption{
+				&cardsim.BasicOption[*SmokeTestCollection]{
+					Text: cardsim.MsgStr("Reset to 0."),
+					Effect: func(p *player) error {
+						p.Stats.Number.Value = 0
+						return nil
+					},
+					Output: cardsim.MsgStr("Done."),
+				},
+			},
+		},
+		&cardsim.BasicCard[*SmokeTestCollection]{
+			CardTitle: cardsim.MsgStr("Reset to 1000000"),
+			CardText:  cardsim.MsgStr("Resets Number to one million."),
+			CardOptions: []cardOption{
+				&cardsim.BasicOption[*SmokeTestCollection]{
+					Text: cardsim.MsgStr("Reset to 1,000,000"),
+					Effect: func(p *player) error {
+						p.Stats.Number.Value = 1000000
+						return nil
+					},
+					Output: cardsim.MsgStr("Done."),
+				},
+			},
+		},
+		&cardsim.BasicCard[*SmokeTestCollection]{
+			CardTitle: cardsim.MsgStr("Draw a card"),
+			CardText:  cardsim.MsgStr("Draw an extra card."),
+			CardOptions: []cardOption{
+				&cardsim.BasicOption[*SmokeTestCollection]{
+					Text: cardsim.MsgStr("Draw an extra card."),
+					Effect: func(p *player) error {
+						return p.Draw()
+					},
+					Output: cardsim.MsgStr("Drawn. Probably."),
+				},
+			},
+		},
+	}
+}

smoketest/collection.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"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[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 {
+	return float64(c.Total.Value) / float64(c.Turns.Value)
+}
+
+func (c *SmokeTestCollection) Stats() []cardsim.Stat {
+	stats := cardsim.ExtractStats(c)
+	stats = append(stats, cardsim.StatFunc("Average", c.Average))
+	cardsim.SortStats(stats)
+	return stats
+}
+
+func (c *SmokeTestCollection) StatTotalThings() float64 {
+	return float64(c.Things+c.MoreThings) + c.FloatyThings
+}

smoketest/main.go

@@ -0,0 +1,83 @@
+// Binary smoketest runs a very simple cardsim thing.
+package main
+
+import (
+	"fmt"
+
+	"git.chromaticdragon.app/kistaro/CardSimEngine/cardsim"
+
+	"github.com/kr/pretty"
+)
+
+func main() {
+	p := cardsim.InitPlayer(
+		&SmokeTestCollection{
+			Number: cardsim.Stored[int]{
+				Name:  "Number",
+				Value: 0,
+			},
+			Total: cardsim.Stored[int64]{
+				Name:  "Total",
+				Value: 0,
+			},
+			Turns: cardsim.Invisible[int]{
+				Name:  "Turns",
+				Value: 0,
+			},
+			Flavor: cardsim.Stored[string]{
+				Name:  "Flavor",
+				Value: "Lemon",
+			},
+			Things:       5,
+			MoreThings:   9,
+			FloatyThings: 123.456,
+			Label:        "whee",
+		},
+	)
+	p.Name = "Dave"
+	p.HandLimit = 3
+	p.ActionsPerTurn = 2
+	installRules(p.Rules)
+	initDeck(p.Deck)
+	installPermanentActions(&p.PermanentActions)
+	p.InfoPanels = []cardsim.InfoPanel[*SmokeTestCollection]{
+		&cardsim.BasicStatsPanel[*SmokeTestCollection]{
+			Name:  cardsim.MsgStr("Stats"),
+			Intro: cardsim.MsgStr("Hi! These are the smoke test stats."),
+		},
+		ruledumper{},
+	}
+	p.Prompt = prompt{}
+	p.DebugLevel = 5
+
+	err := cardsim.RunSimpleTerminalUI(p)
+	if err != nil {
+		fmt.Println("Terminated with error:")
+		fmt.Println(err)
+	} else {
+		fmt.Println("Terminated without error.")
+	}
+}
+
+type prompt struct{}
+
+func (prompt) Title(p *cardsim.Player[*SmokeTestCollection]) cardsim.Message {
+	return cardsim.MsgStr("Smoke Test")
+}
+
+func (prompt) Info(p *cardsim.Player[*SmokeTestCollection]) ([]cardsim.Message, error) {
+	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

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"math"
+
+	"git.chromaticdragon.app/kistaro/CardSimEngine/cardsim"
+)
+
+var (
+	updateTotal = cardsim.RuleFunc[*SmokeTestCollection]{
+		Name: "updateTotal",
+		Seq:  1,
+		F: func(p *cardsim.Player[*SmokeTestCollection]) error {
+			p.Stats.Total.Value += int64(p.Stats.Number.Value)
+			return nil
+		},
+	}
+
+	countTurn = cardsim.RuleFunc[*SmokeTestCollection]{
+		Name: "countTurn",
+		Seq:  math.MinInt,
+		F: func(p *cardsim.Player[*SmokeTestCollection]) error {
+			p.Stats.Turns.Value++
+			return nil
+		},
+	}
+)
+
+func installRules(rules *cardsim.RuleCollection[*SmokeTestCollection]) {
+	rules.Insert(&updateTotal)
+	rules.Insert(&countTurn)
+}