Sigil

-- Sigil console  (Ctrl+Enter to run)
-- reads like pseudocode: no prefixes, no ceremony

-- build a small supply chain — idempotent, safe to run repeatedly
local hubs = {
  { name = "london",    region = "uk",  capacity = 4200 },
  { name = "paris",     region = "fr",  capacity = 3100 },
  { name = "amsterdam", region = "nl",  capacity = 5800 },
  { name = "berlin",    region = "de",  capacity = 2900 },
}

for _, hub in ipairs(hubs) do
  if not exists(hub.name) then
    create(hub.name)
  end
  edit(hub.name, "type",     "hub")
  edit(hub.name, "region",   hub.region)
  edit(hub.name, "capacity", hub.capacity)
end

-- connect with named routes
link("london",    "paris",     "eurostar")
link("paris",     "amsterdam", "thalys")
link("amsterdam", "berlin",    "ice")
link("london",    "amsterdam", "ferry")
link("berlin",    "paris",     "ice")

-- read everything back and render a summary table
local rows = ""
for _, name in ipairs(allNodes()) do
  local cap  = attr(name, "capacity") or "—"
  local reg  = attr(name, "region")   or "—"
  local out  = linksFrom(name)
  local inc  = linksTo(name)

local dests = {}
  for _, l in ipairs(out) do
    table.insert(dests, l.to .. " <span class='muted'>via " .. l.label .. "</span>")
  end

rows = rows .. "<tr>"
  rows = rows .. "<td>" .. name .. "</td>"
  rows = rows .. "<td>" .. reg .. "</td>"
  rows = rows .. "<td>" .. tostring(cap) .. "</td>"
  rows = rows .. "<td>" .. tostring(#inc) .. "</td>"
  rows = rows .. "<td>" .. (#dests > 0 and table.concat(dests, ", ") or "<span class='muted'>—</span>") .. "</td>"
  rows = rows .. "</tr>"
end

return_html(
  "<table class='data-table'>" ..
  "<thead><tr>" ..
  "<th>hub</th><th>region</th><th>capacity</th><th>inbound</th><th>routes out</th>" ..
  "</tr></thead><tbody>" ..
  rows ..
  "</tbody></table>"
)