Scripts and Events

Scripts and Events

The two scripting systems are not the same kind of thing.

Open Doctrines (#OD/MapEngine/1) is imperative and line-based. A script runs top to bottom when the map loads; waitUntil suspends it until a condition holds. So a script is really a sequence of stages, each gated by one comparison. It also has if/else, foreach, while, arrays and include.

Greater Diplomacy 5 is declarative. Each nation owns a list of events; each event is a set of conditions joined by AND/OR/XOR/NOR/NAND and a set of actions, tested once a turn.

The overlap is the shape both can express: a gate, and things that happen when it opens. Everything outside it is reported by name and carried unchanged rather than half-translated.

Open Doctrines → GD5

Each top-level waitUntil starts a new stage, and each stage becomes one event.

#OD/MapEngine/1
set country.GER.treasury 5000          ← stage 0, fires at load
waitUntil map.turn >= 12
set country.GER.at_war_with RUS true   ← Turn Number >= 12, Declare War
set province.42.owner GER              ← and Give Territory, same event

The event's owner is inferred from the set country.X.… lines it contains.

Open Doctrines	GD5 condition
map.turn <op> N	Turn Number
var.NAME <op> V	Variable
country.X.at_war_with Y	At War With
country.X.allied_with Y	In Faction With

Open Doctrines	GD5 action
set country.X.at_war_with Y true / false	Declare War / Send Ceasefire
set country.X.allied_with Y true	Join Faction
set province.N.owner ISO	Give Territory
set var.NAME V	Set Variable
set country.X.name "…"	Edit Name

Not translated: foreach, while, if/else, array, list. GD5's event system has no control flow, so a loop over a country's provinces has no honest rendering as an event and guessing one would silently change what the map does. Reported as script.unsupported; the script itself survives in the sidecar and returns intact.

set country.X.treasury, set province.N.population and set map.date have no GD5 action and are reported as script.action.

GD5 → Open Doctrines

Each event becomes one entry script.

#OD/MapEngine/1
# Barbarossa
# Translated from a Greater Diplomacy 5 scripted event owned by GER.
waitUntil map.turn >= 24
set country.GER.at_war_with RUS true

Consecutive waitUntils are gates in sequence, which is an AND over time, so AND chains translate exactly. Open Doctrines has no boolean operators at all, so OR, XOR, NOR and NAND cannot be expressed: the first condition becomes the gate, the rest are written into the script as comments, and script.chain says so. Actions with no counterpart (Spawn Unit, Queue Claims, Edit Color) become comments under script.action.

Unknown event types pass through

GD5 has around thirty condition types and twenty action types, and gains more. Any this library does not model is read under its own name with a gd5: prefix and written straight back out unchanged.

So GD5 → Open Doctrines → GD5 is lossless for every event type, including ones added to the game after this was written. Only the Open Doctrines side has to understand a condition to express it; the GD5 side only has to carry it.

Libraries never run on their own

A file whose first non-blank line is #OD/MapEngine/1 is an entry point. A file without it is a library, reached only through include. Dragoman never turns a library into an event — doing so would start running code that was only ever meant to be included.

Turning it off

--no-scripts leaves scripts and events alone entirely. They are still carried, so nothing is lost; they simply are not translated into the other shape.