Enhance calc package with function calls

go.mod

@@ -17,7 +17,7 @@ require (
 	github.com/pmezard/go-difflib v1.0.0
 	github.com/r3labs/diff/v3 v3.0.2
 	github.com/ripta/hypercmd v0.6.0
-	github.com/ripta/reals v0.0.0-20251220032726-c99f163d5c5c
+	github.com/ripta/reals v0.0.0-20260614185130-b214700ec783
 	github.com/ripta/unihan v0.0.0-20250404091138-c307c698a880
 	github.com/rogpeppe/go-internal v1.15.0
 	github.com/spf13/cobra v1.10.2
@@ -58,12 +58,12 @@ require (
 	github.com/vmihailenco/tagparser/v2 v2.0.0 // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
-	golang.org/x/exp v0.0.0-20260603202125-055de637280b // indirect
+	golang.org/x/exp v0.0.0-20260611194520-c48552f49976 // indirect
 	golang.org/x/mod v0.37.0 // indirect
 	golang.org/x/oauth2 v0.36.0 // indirect
 	golang.org/x/sync v0.21.0 // indirect
 	golang.org/x/sys v0.46.0 // indirect
-	golang.org/x/tools v0.45.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20260608224507-4308a22a1bab // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20260608224507-4308a22a1bab // indirect
+	golang.org/x/tools v0.46.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20260610212136-7ab31c22f7ad // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260610212136-7ab31c22f7ad // indirect
 )

go.sum

@@ -73,8 +73,8 @@ github.com/r3labs/diff/v3 v3.0.2 h1:yVuxAY1V6MeM4+HNur92xkS39kB/N+cFi2hMkY06BbA=
 github.com/r3labs/diff/v3 v3.0.2/go.mod h1:Cy542hv0BAEmhDYWtGxXRQ4kqRsVIcEjG9gChUlTmkw=
 github.com/ripta/hypercmd v0.6.0 h1:lUxdqhP/cR/Spu8Yi0Ve60Tw8+LYPkBdkhaplDf7fbo=
 github.com/ripta/hypercmd v0.6.0/go.mod h1:8QnmkN5AFLtPDl5LnGExQdSG/CMEhAk9GqBpYJWScrw=
-github.com/ripta/reals v0.0.0-20251220032726-c99f163d5c5c h1:4bBR+jNoWIs1roinlXrVDUtmSvqjtNbrJ3cuQtFci5g=
-github.com/ripta/reals v0.0.0-20251220032726-c99f163d5c5c/go.mod h1:WErCt40puDDQdpVq8Hg1DzjB0svufA8WboSYG4BI2+E=
+github.com/ripta/reals v0.0.0-20260614185130-b214700ec783 h1:C9fMjkM7wA0VJFYwPf8BCmIxBnqLSqv7KNo88ugJYOo=
+github.com/ripta/reals v0.0.0-20260614185130-b214700ec783/go.mod h1:HJD35VfuiXMIOHm9kFC3c637WX/sznn9gES6ajLTUKk=
 github.com/ripta/unihan v0.0.0-20250404091138-c307c698a880 h1:ZzDUYlZP/LHJmkh+PtgRZHEKa+eNVefq6YR8BnUCQ2I=
 github.com/ripta/unihan v0.0.0-20250404091138-c307c698a880/go.mod h1:ZLBfCas48lym/27GOsyFjRo7OGejoGHzOTdUdoRtDqU=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
@@ -111,12 +111,12 @@ go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 golang.org/x/crypto v0.53.0 h1:QZ4Muo8THX6CizN2vPPd5fBGHyogrdK9fG4wLPFUsto=
 golang.org/x/crypto v0.53.0/go.mod h1:DNLU434OwVakk9PzuwV8w62mAJpRJL3vsgcfp4Qnsio=
-golang.org/x/exp v0.0.0-20260603202125-055de637280b h1:v1uXiEBHo8QA0LiGCo7UgHMzHT4Kdfpl2zmtH5vaP1Q=
-golang.org/x/exp v0.0.0-20260603202125-055de637280b/go.mod h1:d2fgXJLVs4dYDHUk5lwMIfzRzSrWCfGZb0ZqeLa/Vcw=
+golang.org/x/exp v0.0.0-20260611194520-c48552f49976 h1:X8Hz2ImujgbmetVuW+w2YkyZChE3cBpZi2P158rTG9M=
+golang.org/x/exp v0.0.0-20260611194520-c48552f49976/go.mod h1:vnf4pv9iKZXY58sQE1L86zmNWJ4159e1RkcWiLCkeEY=
 golang.org/x/mod v0.37.0 h1:vF1DjpVEshcIqoEaauuHebaLk1O1forxjxBaVn884JQ=
 golang.org/x/mod v0.37.0/go.mod h1:m8S8VeM9r4dzDwjrKO0a1sZP3YjeMamRRlD+fmR2Q/0=
-golang.org/x/net v0.55.0 h1:bcvxaJn3e1U6InsFWt1JUq1aSjnRxLzT2rtD2KfkDF8=
-golang.org/x/net v0.55.0/go.mod h1:L5U2KuzuOe1lY7Z+aWVIKK6qEeJXnXV9yzGA+WCHJww=
+golang.org/x/net v0.56.0 h1:Rw8j/hFzGvJUZwNBXnAtf5sVDVt+65SK2C7IxCxZt5o=
+golang.org/x/net v0.56.0/go.mod h1:D3Ku6r+V6JROoZK144D2XfMHFcMq/0zSfLelVTCFKec=
 golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
 golang.org/x/oauth2 v0.36.0/go.mod h1:YDBUJMTkDnJS+A4BP4eZBjCqtokkg1hODuPjwiGPO7Q=
 golang.org/x/sync v0.21.0 h1:HLII4xRRTtCRkxYp4HNFF0Js/Og6q2i++KXbg0gHCwM=
@@ -131,12 +131,12 @@ golang.org/x/text v0.38.0 h1:sXmwo9DwP3OK9EZ7PqAdaooSGozfl/3a6/xJcbzPRhE=
 golang.org/x/text v0.38.0/go.mod h1:YXZt3QhHUKYT53r2lLKFIVi6Ao1jdzrTR/KQ09qyxF4=
 golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
 golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
-golang.org/x/tools v0.45.0 h1:18qN3FAooORvApf5XjCXgsuayZOEtXf6JK18I3+ONa8=
-golang.org/x/tools v0.45.0/go.mod h1:LuUGqqaXcXMEFEruIVJVm5mgDD8vww/z/SR1gQ4uE/0=
-google.golang.org/genproto/googleapis/api v0.0.0-20260608224507-4308a22a1bab h1:Foefixyu0l973HSYkX8Etw/fPxAmKRhyMGwuqXFiVI0=
-google.golang.org/genproto/googleapis/api v0.0.0-20260608224507-4308a22a1bab/go.mod h1:KdNqO+rCIWgFumrNBSEDlDNrkrQnpkax7Tv1WxNY8V4=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260608224507-4308a22a1bab h1:cY0oV1VnAqvaim8VsR8ZyEKAudzbRJMRGwD3W/L7yOw=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260608224507-4308a22a1bab/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
+golang.org/x/tools v0.46.0 h1:7jTurBkPZu4moS/Uy4OQT1M+QBlsj3wejyZwsT8Z7rk=
+golang.org/x/tools v0.46.0/go.mod h1:FrD85F8l+NWL+9XWBSyVSHO6Ne4jutsfIFba7AWQ5Ys=
+google.golang.org/genproto/googleapis/api v0.0.0-20260610212136-7ab31c22f7ad h1:3iLyITS/sySRwbUKoC7ogfj2Yr1Cjs0pfaRKj5U5HEw=
+google.golang.org/genproto/googleapis/api v0.0.0-20260610212136-7ab31c22f7ad/go.mod h1:KdNqO+rCIWgFumrNBSEDlDNrkrQnpkax7Tv1WxNY8V4=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260610212136-7ab31c22f7ad h1:45WmJvIV6C2+O/jjLkPUH+F3aOj/1miDoU2DD0+NWbg=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260610212136-7ab31c22f7ad/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=

pkg/calc/calculator.go

@@ -198,8 +198,7 @@ func init() {
 			return c.handleSet(args)
 		},
 		".show": func(c *Calculator, args []string) error {
-			c.handleShow()
-			return nil
+			return c.handleShow(args)
 		},
 		".toggle": func(c *Calculator, args []string) error {
 			return c.handleToggle(args)
@@ -424,8 +423,33 @@ func (c *Calculator) handleLoad(args []string) error {
 	return nil
 }
 
-// handleShow displays current settings
-func (c *Calculator) handleShow() {
+// showTopics maps each .show topic to its handler. Topics accept any
+// unambiguous prefix, like every other meta-command.
+var showTopics = map[string]func(*Calculator){
+	"settings":  (*Calculator).showSettings,
+	"functions": (*Calculator).showFunctions,
+}
+
+// handleShow displays settings or the function library, selected by an optional
+// topic. No topic shows settings; a topic selects its listing by unambiguous
+// prefix.
+func (c *Calculator) handleShow(args []string) error {
+	topic := "settings"
+	if len(args) > 0 {
+		topic = args[0]
+	}
+
+	show, err := findByPrefix(topic, showTopics)
+	if err != nil {
+		return err
+	}
+
+	show(c)
+	return nil
+}
+
+// showSettings prints each setting's current value.
+func (c *Calculator) showSettings() {
 	fmt.Println("settings:")
 	for name, setting := range settingsRegistry {
 		switch setting.Type {
@@ -437,11 +461,38 @@ func (c *Calculator) handleShow() {
 	}
 }
 
+// showFunctions lists the registered functions grouped by category. Trig
+// functions take and return radians; convert degrees explicitly, e.g.
+// sin(45 * PI / 180).
+func (c *Calculator) showFunctions() {
+	fns := parser.Functions()
+
+	width := 0
+	for _, f := range fns {
+		if len(f.Signature) > width {
+			width = len(f.Signature)
+		}
+	}
+
+	group := ""
+	for _, f := range fns {
+		if f.Group != group {
+			if group != "" {
+				fmt.Println()
+			}
+			group = f.Group
+			fmt.Printf("%s:\n", group)
+		}
+		fmt.Printf("  %-*s  %s\n", width, f.Signature, f.Summary)
+	}
+}
+
 // handleHelp displays available meta-commands
 func (c *Calculator) handleHelp() {
 	fmt.Println("Available commands:")
 	fmt.Println("  .set <setting> <value>  - Change a setting")
 	fmt.Println("  .show                   - Show current settings")
+	fmt.Println("  .show functions         - List available functions")
 	fmt.Println("  .toggle <setting>       - Toggle a boolean setting")
 	fmt.Println("  .save [path]            - Save session (default: ~/.local/state/rt/calc/session.txt)")
 	fmt.Println("  .load [path]            - Load session (default: ~/.local/state/rt/calc/session.txt)")

pkg/calc/calculator_test.go

@@ -67,6 +67,26 @@ var handleMetaCommandTests = []handleMetaCommandTest{
 		cmd:     ".sho",
 		wantErr: false,
 	},
+	{
+		name:    ".show functions",
+		cmd:     ".show functions",
+		wantErr: false,
+	},
+	{
+		name:    ".sh functions prefix",
+		cmd:     ".sh functions",
+		wantErr: false,
+	},
+	{
+		name:    ".sh f resolves functions topic by prefix",
+		cmd:     ".sh f",
+		wantErr: false,
+	},
+	{
+		name:    ".show unknown topic",
+		cmd:     ".show bogus",
+		wantErr: true,
+	},
 }
 
 func TestHandleMetaCommand(t *testing.T) {
@@ -86,6 +106,25 @@ func TestHandleMetaCommand(t *testing.T) {
 	}
 }
 
+func TestHandleShowTopics(t *testing.T) {
+	t.Parallel()
+
+	c := &Calculator{DecimalPlaces: 30}
+
+	if err := c.handleShow(nil); err != nil {
+		t.Errorf("handleShow(nil) = %v, want nil", err)
+	}
+	if err := c.handleShow([]string{"settings"}); err != nil {
+		t.Errorf("handleShow(settings) = %v, want nil", err)
+	}
+	if err := c.handleShow([]string{"functions"}); err != nil {
+		t.Errorf("handleShow(functions) = %v, want nil", err)
+	}
+	if err := c.handleShow([]string{"bogus"}); err == nil {
+		t.Error("handleShow(bogus) = nil, want error")
+	}
+}
+
 type parseBoolTest struct {
 	name    string
 	input   string

pkg/calc/lexer/lex_expression.go

@@ -88,6 +88,10 @@ func lexExpression(l *L) lexingState {
 		l.Emit(tokens.RPAREN)
 		return lexExpression
 
+	case r == ',':
+		l.Emit(tokens.COMMA)
+		return lexExpression
+
 	case r == '$':
 		return lexLineIdent
 

pkg/calc/lexer/lexer_test.go

@@ -85,6 +85,19 @@ var tokenTests = []tokenTest{
 		},
 		wantErr: "too many decimal points",
 	},
+	{
+		name:  "function call with comma-separated arguments",
+		input: "max(1, 2)",
+		want: []tokenExpectation{
+			{Type: tokens.IDENT, Value: "max", Col: 1},
+			{Type: tokens.LPAREN, Value: "(", Col: 4},
+			{Type: tokens.LIT_INT, Value: "1", Col: 5},
+			{Type: tokens.COMMA, Value: ",", Col: 6},
+			{Type: tokens.WHITESPACE, Value: " ", Col: 7},
+			{Type: tokens.LIT_INT, Value: "2", Col: 8},
+			{Type: tokens.RPAREN, Value: ")", Col: 9},
+		},
+	},
 	{
 		name:  "minus operator and identifier",
 		input: "-foo",