Added custom printers

cmd/cmsh/fancy.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"ucl.lmika.dev/repl"
+	"ucl.lmika.dev/ucl"
+)
+
+type FancyType struct {
+	Foo string
+	Bar string
+}
+
+var newFancyDoc = repl.Doc{
+	Brief: "returns something fancy",
+	Detailed: `
+		This will create and return something fancy.
+	`,
+}
+
+func newFancy(ctx context.Context, args ucl.CallArgs) (any, error) {
+	return FancyType{Foo: "is foo", Bar: "is bar"}, nil
+}
+
+func manyFancies(ctx context.Context, args ucl.CallArgs) (any, error) {
+	return []FancyType{
+		{Foo: "foo 1", Bar: "bar 1"},
+		{Foo: "foo 2", Bar: "bar 2"},
+		{Foo: "foo 3", Bar: "bar 3"},
+	}, nil
+}
+
+func displayFancy(w io.Writer, f FancyType, concise bool) error {
+	if concise {
+		_, err := fmt.Fprintf(w, "%s:%s", f.Foo, f.Bar)
+		return err
+	}
+
+	fmt.Fprintf(w, "Foo.. %s\n", f.Foo)
+	fmt.Fprintf(w, "Bar.. %s\n", f.Bar)
+	return nil
+}
+
+func displayFancies(w io.Writer, fs []FancyType, concise bool) error {
+	if concise {
+		_, err := fmt.Fprintf(w, "%d fancies", len(fs))
+		return err
+	}
+
+	fmt.Fprintln(w, "FOO\tBAR")
+	for _, f := range fs {
+		fmt.Fprintf(w, "%v\t%v\n", f.Foo, f.Bar)
+	}
+	return nil
+}

cmd/cmsh/main.go

@@ -33,6 +33,11 @@ func main() {
 			It then terminates.
 		`,
 	})
+	instRepl.SetCommand("new-fancy", newFancy, newFancyDoc)
+	instRepl.SetCommand("many-fancies", manyFancies)
+
+	repl.AddTypePrinter(instRepl, displayFancy)
+	repl.AddTypePrinter(instRepl, displayFancies)
 
 	for {
 		line, err := rl.Readline()