gno.land/r/moul/demo/importdemo/v0⧉

1// Package importdemo shows a realm importing and composing packages from2// ANOTHER namespace — the whole point of the demo.3//4// v2 imported gno.land/p/archive/dom, which is published on no chain we target5// (absent on both sapphire and pearl), so it type-checked locally but could6// never be deployed: `addpkg` failed with7// `could not import gno.land/p/archive/dom (unknown import path)`. v2 is8// archived (`ignore = true`); this version rebuilds the same thread-of-posts9// idea on foreign packages that are actually on chain — `p/nt/avl/v0` for10// ordered storage and `p/nt/ufmt/v0` for formatting.11//12// Deliberately keeps no realm state: Render builds the thread on each call, so13// output depends only on the code and the demo is reproducible.14package importdemo1516import (17	"strconv"18	"strings"1920	"gno.land/p/nt/avl/v0"21	"gno.land/p/nt/ufmt/v0"22)2324// thread is a titled list of posts, kept in an avl.Tree so iteration is ordered25// by key rather than by insertion — the same guarantee the realm needs for a26// stable Render.27type thread struct {28	name  string29	posts *avl.Tree // zero-padded index -> *post30	n     int31}3233type post struct {34	title string35	body  string36}3738func newThread(name string) *thread {39	return &thread{name: name, posts: avl.NewTree()}40}4142// addPost appends a post. The key is zero-padded so avl's lexicographic order43// matches insertion order past 9 entries ("10" would otherwise sort before "9").44func (t *thread) addPost(title, body string) {45	t.posts.Set(padIdx(t.n), &post{title: title, body: body})46	t.n++47}4849// padIdx renders i as a fixed-width, zero-padded key.50//51// Done by hand on purpose: gno's ufmt supports NO width or padding flags, so52// ufmt.Sprintf("%03d", 7) yields "7", not "007" — silently, with no error. Keys53// built that way sort as "0","1","10","11","2", which quietly reorders every54// thread past nine posts (TestOrderSurvivesPastNinePosts covers exactly this).55func padIdx(i int) string {56	s := strconv.Itoa(i)57	for len(s) < 3 {58		s = "0" + s59	}60	return s61}6263// String renders the thread as Markdown.64func (t *thread) String() string {65	var b strings.Builder66	b.WriteString(ufmt.Sprintf("# [thread] %s\n\n", t.name))67	t.posts.Iterate("", "", func(_ string, v any) bool {68		p := v.(*post)69		b.WriteString(ufmt.Sprintf("## %s\n%s\n", p.title, p.body))70		return false71	})72	return b.String()73}7475// Render renders the demo thread for gnoweb.76func Render(path string) string {77	t := newThread("Hello!")78	t.addPost("Foo", "foo foo foo")79	t.addPost("Bar", "bar bar bar")80	return t.String()81}82