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# Summary of GDL Syntax

Whitespace is never significant, except to separate two symbols or within a string or escaped symbols.

Regular expression for symbol is `[-a-z0-9A-Z]*` or `|[^|]*|`.

Number is `[-]*[0-9][0-9]*` optional `[d]*[0-9][0-9]*`, `[+]*[0-9][0-9]*`.

String is `"[^"]*"`.

Comments extend from `;` to end of the line, or may be everything enclosed between `#|` and `|#` (which nest properly).

    form ::= module-form
            | ( include module-name [ variant-setting ]* )
            | ( if test-form [ symbol ] )
            | ( else [ symbol ] )
            | ( end-if [ symbol ] )
            | world-form
            | area-form
            | side-form
            | side-defaults-form
            | independent-units-form
            | doctrine-form
            | player-form
            | agreement-form
            | unit-form
            | unit-defaults-form
            | scorekeeper-form
            | exu-form
            | evt-form
            | unit-type-form
            | terrain-type-form
            | material-type-form
            | advance-type-form
            | namer-form
            | table-form
            | add-form
            | imf-form
            | palette-form
            | color-form
            | ( define symbol value )
            | ( set symbol value )
            | ( undefine symbol value )
            | ( print value )
            | value

    module-form ::= ( game-module [ module-name ]
            [ game-module-property-binding ]* )

    module-name ::= string

    game-module-property-binding ::= ( game-module-property-name value )

    game-module-property-name ::=
              base-game | title | blurb | picture-name | instructions
            | notes | design-notes | program-version
            | base-module | default-base-module | variants | version

    variant-definition ::=
            ( [ string ] var-type [ var-default ] [ var-range ] [ var-clause ]* )

    var-type ::= world-size | world-seen | see-all
            | sequential | real-time | symbol

    var-default ::= value

    var-range ::= ( value value )

    var-clause ::= ( [ string ] value [ form ]* )

    variant-setting ::= ( var-type value )

    world-form ::= ( world [ circumference ] [ world-property-binding ]* )

    world-property-binding ::= ( world-property-name value )

    world-property-name ::=
            axial-tilt | circumference | day-length | year-length

    circumference ::= value

    area-form ::= ( area [ width [ height ] ] [ area-restriction ]
            [ area-property-binding ]* )

    area-restriction ::= ( restrict width height a-x a-y )

    area-property-binding ::= ( area-property-name value )
            | ( terrain [ layer-subform ]* [ string ]* )
            | ( aux-terrain terrain-type [ layer-subform ]* [ string ]* )
            | ( features feature-list [ layer-subform ]* [ string ]* )
            | ( material material-type [ layer-subform ]* [ string ]* )
            | ( people-sides [ layer-subform ]* [ string ]* )
            | ( control-sides [ layer-subform ]* [ string ]* )
            | ( elevations [ layer-subform ]* [ string ]* )
            | ( temperatures [ layer-subform ]* [ string ]* )
            | ( winds [ layer-subform ]* [ string ]* )
            | ( clouds [ layer-subform ]* [ string ]* )
            | ( cloud-bottoms [ layer-subform ]* [ string ]* )
            | ( cloud-heights [ layer-subform ]* [ string ]* )

    area-property-name ::= width | height | latitude | longitude | cell-width

    layer-subform ::= ( constant n )
            | ( subarea a-x a-y width height )
            | ( xform mul add )
            | ( by-bits )
            | ( by-char string )
            | ( by-name name-list )

    width ::= value

    height ::= value

    a-x ::= value

    a-y ::= value

    n ::= value

    mul ::= value

    add ::= value

    side-form ::= ( side [ side-id ] [ side-property-binding ]* )

    side-defaults-form ::= ( side-defaults [ side-property-binding ]* )

    side-property-binding ::= ( side-property-name value )

    side-property-name ::=
              name | long-name | short-name | noun | plural-noun
            | adjective | color | emblem-name | names-locked
            | class | active | status
            | advantage | advantage-min | advantage-max
            | controlled-by | trusts | trades | next-numbers | unit-namers
            | feature-namers | tech | init-tech | terrain-view | unit-view
            | unit-view-dates | turn-time-used | total-time-used | timeouts
            | timeouts-used | finished-turn | willing-to-draw
            | doctrines | doctrines-locked
            | self-unit | priority | scores | ui-data | ai-data | player

    doctrine-form ::= ( doctrine ... )

    player-form ::= ( player [ player-id ] [ player-property-binding ]* )

    player-id ::= number

    player-property-binding ::= ( player-property-name value )

    player-property-name ::= name | config-name | display-name | ai-type-name
            | password | initial-advantage

    agreement-form ::= ( agreement [ agreement-id ] [ agree-prop-bdg ]* )

    agreement-id ::= value

    agree-prop-bdg ::= ( agreement-property-name value )

    agreement-property-name ::= type-name | title | terms | drafters
            | proposers | signers | willing-to-sign | known-to | enforcement
            | state

    unit-form ::= ( unit [ unit-id ] [ unit-property-bdg ]* )
            | ( unit-type-name u-x u-y u-side [ unit-property-bdg ]* )

    unit-defaults-form ::= ( unit-defaults [ reset ] [ unit-property-bdg ]* )

    unit-property-bdg ::=
              ( unit-property-name value )
            | ( act action-type-name [ action-property-binding ]* )
            | ( plan plan-type-name [ plan-property-binding ]* )
            | ( task task-type-name [ task-property-binding ]* )
            | ( x [ unit-x-property-binding ]* )

    unit-property-name ::=
              @ | # | cp | cxp | hp | in | m | mo | n | nb
            | opinions | s | tp | z

    unit-id ::= value

    u-x ::= value

    u-y ::= value

    u-side ::= value

    unit-x-property-binding ::=
              ( unit-x-property-name value )
              ( symbol value )

    unit-x-property-name ::= appear | disappear

    action-type-name ::=
              add-terrain | alter-terrain | attack | build
            | capture | change-side
            | change-type | create-at | create-in | detonate | disband
            | enter
            | fire-at | fire-into | move | none | overrun | produce
            | remove-terrain | repair | research | toolup | transfer
            | transfer-part

    action-property-binding ::=
              ( action-property-name value )

    action-property-name ::= a | aa | acp | acp0 | am

    plan-type-name ::=
              defensive | exploratory | none | offensive | passive | random

    plan-property-binding ::=
              ( plan-property-name value )
            | ( goal goal-type-name ... )

    plan-property-name ::=
              ai-control | asleep | delayed | formation | goal | reserve
            | supply-alarm | supply-is-low

    goal-type-name ::=
              cell-is-occupied | has-material-type | has-unit-type
            | has-unit-type-near | keep-formation | lost-game
            | no-goal | positions-known | vicinity-is-held
            | vicinity-is-known | won-game | world-is-known

    task-type-name ::=
              build | capture | do-action | hit-position | hit-unit
            | move-dir
            | move-to | none | occupy | pickup | repair | research
            | resupply | sentry

    scorekeeper-form ::= ( scorekeeper [ sk-id ] [ sk-property-binding ]* )

    sk-id ::= value

    sk-property-binding ::= ( sk-property-name value )

    sk-property-name ::=
              applies-to | do | initial | known-to | messages | title
            | trigger | triggered | when

    sk-when ::= after-action | after-event | after-turn | before-turn

    exu-form ::= ( exu id type x y side [ exu-property-binding ]* )

    exu-property-binding ::= ( exu-property-name value )

    exu-property-name ::= n | nb | z

    evt-form ::= ( evt turn evt-type-name observers [ value ]* )

    evt-type-name ::=
              action-done | action-error | action-ok
            | cannot-do | cannot-leave-world | capture-failed
            | capture-succeeded | destination-full | fire-into-outside-world
            | game-ended | game-restarted | game-saved
            | game-started | insufficient-acp | insufficient-material
            | insufficient-mp | log-ended | log-started
            | overrun-failed | overrun-succeeded | side-joined
            | side-lost | side-withdrew | side-won
            | too-far | too-near | unit-acquired
            | unit-assaulted | unit-captured | unit-completed
            | unit-created | unit-damaged | unit-disbanded
            | unit-garrisoned | unit-killed | unit-left-world
            | unit-moved | unit-name-changed | unit-started-with
            | unit-starved | unit-type-changed | unit-vanished
            | unit-wrecked

    unit-type-form ::=
            ( unit-type unit-type-name [ unit-type-property-binding ]* )

    unit-type-name ::= symbol

    unit-type-property-binding ::= ( unit-type-property-name value )

    unit-type-property-name ::=
              acp-damage-effect | acp-max | acp-min
            | acp-per-turn | acp-per-turn-max | acp-per-turn-min
            | acp-season-effect | acp-temperature-effect
            | acp-to-change-side
            | acp-to-detonate | acp-to-disband | acp-to-fire
            | acp-to-move | acp-to-transfer-part | action-priority
            | already-seen | already-seen-independent | assign-number
            | available | can-be-self | capacity | char | color
            | consumption-temperature-effect | country-units-max
            | cp | cp-per-self-build | cp-to-self-build | cxp-max
            | cxp-on-capture-effect
            | description-format | detonate-on-death | direct-control
            | elevation-at-max-range | free-acp
            | free-mp | generic-name | has-opinions | help
            | hit-falloff-range
            | hp-max | hp-per-detonation | hp-per-disband | hp-recovery
            | image-name
            | independent-growth-chance | independent-near-start
            | independent-takeover-chance | initial-seen-radius | long-name
            | move-range | mp-to-leave-world | name | name-internal | namer
            | notes | occupant-total-max | parts-max | point-value
            | possible-sides | range | range-min
            | revolt-chance | see-always | see-occupants
            | self-changeable | self-resurrects | short-name
            | speed | speed-damage-effect | speed-max
            | speed-min | speed-wind-angle-effect | speed-wind-effect
            | spot-action | spy-chance | spy-range
            | stack-order | start-with | tech-from-ownership
            | tech-leakage | tech-max | tech-per-turn-max
            | tech-to-build | tech-to-own | tech-to-see
            | tech-to-use | temperature-attrition | type-in-game-max
            | type-per-side-max | unit-growth-chance | unit-takeover-chance
            | vision-bend | vision-range | wrecked-type
            | zz-b | zz-bb | zz-bw | zz-c | zz-cc | zz-cm | zz-transport

    terrain-type-form ::=
            ( terrain-type terrain-type-name [ terrain-type-property-bdg ]* ) )

    terrain-type-name ::= symbol

    terrain-type-property-bdg ::= ( terrain-type-property-name value )

    terrain-type-property-name ::=
              alt-percentile-max | alt-percentile-min
            | capacity | char | clouds-max | clouds-min
            | country-growth-chance
            | country-people-chance | country-takeover-chance
            | country-terrain-max | country-terrain-min
            | elevation-max | elevation-min
            | help | image-name | independent-people-chance
            | liquid | maze-passage-occurrence | maze-room-occurrence
            | name | notes | occurrence | people-max
            | river-chance | subtype | subtype-x
            | temperature-average | temperature-max | temperature-min
            | temperature-variability | thickness | wet-percentile-max
            | wet-percentile-min | wind-force-average | wind-force-max
            | wind-force-min | wind-force-variability | wind-variability
            | zz-fr

    material-type-form ::=
            ( material-type material-type-name [ m-type-property-binding ]* ) )

    material-type-name ::= symbol

    m-type-property-binding ::= ( m-type-property-name value )

    m-type-property-name ::=
              char | help | image-name | initial-treasury
            | name | notes | people | resource-icon | treasury

    advance-type-form ::=
            ( advance-type advance-type-name [ m-type-property-binding ]* ) )

    advance-type-name ::= symbol

    a-type-property-binding ::= ( a-type-property-name value )

    a-type-property-name ::=
              char | help | image-name | name | notes | occurrence | rp

    namer-form ::= ( namer [ namer-id ] naming-method state )

    namer-id ::= value

    naming-method ::=
              junky
            | ( random [ string ]* )
            | ( grammar symbol number [ grammar-rule ]* )

    grammar-rule ::= ( symbol ( [ rule-type ] [ weight ] data )

    rule-type ::= any | or | reject | capitalize

    state ::= value

    table-form ::= ( table table-name [ add ] [ table-clause ]* )

    table-clause ::=
              value
            | ( type-or-types type-or-types value )

    table-name ::=
              uu-table-name | ut-table-name | um-table-name
            | tt-table-name | tm-table-name | mm-table-name

    uu-table-name ::=
            | acp-for-retreat | acp-occupant-effect | acp-to-attack
            | acp-to-be-fired-on | acp-to-build | acp-to-capture
            | acp-to-change-type | acp-to-create | acp-to-defend
            | acp-to-enter-unit | acp-to-repair | acp-to-research
            | acp-to-toolup | attack-range | attack-range-min
            | bridge | build-range | can-enter-independent
            | capture-chance | control-chance | control-chance-adjacent
            | control-chance-at | control-range | cp-on-creation
            | cp-per-build | create-range | cxp-per-capture
            | cxp-per-combat | damage | damage-cxp-effect
            | detonate-on-approach-range | detonate-on-capture
            | detonate-on-hit | detonation-damage-adjacent
            | detonation-damage-at | detonation-unit-range
            | ferry-on-departure | ferry-on-entry | hit-at-max-range-effect
            | hit-chance | hit-cxp-effect | hp-min
            | hp-per-repair | hp-to-garrison | hp-to-repair
            | independent-capture-chance
            | mp-to-enter-unit | mp-to-enter-zoc
            | mp-to-leave-unit | mp-to-leave-zoc | mp-to-traverse-zoc
            | occupant-can-construct | occupant-can-have-occupants
            | occupant-combat | occupant-escape-chance | occupant-max
            | occupant-vision | protection | retreat-chance | road-chance
            | scuttle-chance | see-chance | see-chance-adjacent
            | see-chance-at | speed-occupant-effect | spy-quality
            | stack-protection
            | surrender-chance | surrender-chance-per-attack
            | surrender-range | tech-crossover | tech-per-research
            | temperature-protection | tp-attrition | tp-crossover
            | tp-max | tp-per-toolup | tp-to-build
            | unit-capacity-x | unit-size-as-occupant
            | withdraw-chance-per-attack
            | zoc-range | zz-basic-capture-worth | zz-basic-hit-worth
            | zz-basic-transport-worth

    ut-table-name ::=
              accident-damage | accident-hit-chance | accident-vanish-chance
            | acp-night-effect | acp-to-add-terrain | acp-to-remove-terrain
            | alter-terrain-range | altitude-max | altitude-min
            | attack-terrain-effect | attrition | defend-terrain-effect
            | detonation-accident-chance
            | detonation-terrain-damage-chance | detonation-terrain-range
            | eye-height | favored-terrain | independent-density
            | mp-to-enter-terrain | mp-to-leave-terrain | mp-to-traverse
            | people-surrender-chance | productivity | terrain-capacity-x
            | unit-size-in-terrain | vanishes-on | visibility
            | vision-night-effect | wrecks-on | zoc-from-terrain-effect
            | zoc-into-terrain

    um-table-name ::=
              acp-to-load | acp-to-produce | acp-to-unload
            | base-consumption | base-production | consumption-as-occupant
            | consumption-on-creation
            | consumption-per-attack | consumption-per-build
            | consumption-per-move | consumption-per-repair | hit-by
            | hp-per-starve | in-length | load-max
            | material-per-production | material-to-act | material-to-build
            | material-to-change-type | material-to-create
            | material-to-fight
            | material-to-move | material-to-produce | material-to-repair
            | occupant-base-production | out-length | people-see-chance
            | people-surrender-effect | productivity-max | productivity-min
            | recycleable-material
            | supply-on-completion | supply-on-creation
            | supply-per-disband | unit-initial-supply | unit-storage-x
            | unload-max

    tt-table-name ::=
              adjacent-terrain-effect
            | coating-depth-max | coating-depth-min
            | drawable-terrain | road-into-chance | terrain-damaged-type

    tm-table-name ::=
              change-on-exhaustion-chance | consumption-per-add-terrain
            | material-per-remove-terrain | see-material-always
            | terrain-consumption | terrain-exhaustion-type
            | terrain-initial-supply | terrain-production
            | terrain-storage-x

    mm-table-name ::= people-consumption | people-production

    add-form ::= ( add type-or-types property-name value )

    imf-form ::= ( imf string [ imf-property-binding ]* [ image ]* )

    imf-property-binding ::= ...

    image ::= ( ( w h [ tile ] ) [ image-property-binding ]*
            [ subimage * ] )

    image-property-binding ::= ( image-property-name value )

    image-property-name ::= actual | embed | embed-at | palette | pixel-size
            | row-bytes

    subimage ::= ( subimage-type string * )

    subimage-type ::= color | mono | mask

    palette-form ::= ( palette ... )

    color-form ::= ( color string r g b )

    type-or-types ::= type | symbol | ( [ type | symbol ]* )

    value ::=
              number
            | symbol
            | global-variable
            | predefined-symbols
            | ( [ value ]* )
            | ( operation-name [ value ]* )

    operation-name ::=
              quote | list | append | remove | /= | < | <= | = | > | >=

    global-constant ::=
              true | false
            | u* | t* | m*
            | non-unit | non-terrain | non-material
            | border | cell | coating | connection
            | over-all | over-border | over-nothing | over-own
            | no-x | river-x | road-x | valley-x

    global-variable ::=
              action-messages | advantage-default | advantage-max
            | advantage-min | alt-blob-density | alt-blob-height
            | alt-blob-size | alt-smoothing | calendar
            | country-radius-max | country-radius-min
            | country-separation-max
            | country-separation-min | edge-terrain | elapsed-real-time
            | event-messages | extra-turn-chance | feature-namers
            | feature-types | grid-color | growth-stop-chance
            | initial-date | initial-day-part | initial-year-part
            | last-turn | maze-passage-density | maze-room-density
            | player-sides-locked | random-events | random-state
            | real-time-for-game | real-time-per-side | real-time-per-turn
            | river-sink-terrain | scorefile-name | season-names
            | see-all | see-terrain-always | see-weather-always
            | self-required | side-library | sides-max
            | sides-min | synthesis-methods | temperature-floor
            | temperature-floor-elevation | temperature-moderation-range
            | temperature-year-cycle
            | terrain-seen | turn | units-in-game-max
            | units-per-side-max | unseen-char | unseen-color
            | unseen-image-name | use-side-priority | wet-blob-density
            | wet-blob-height | wet-blob-size | wet-smoothing
            | wind-mix-range

    synthesis-methods ::=
              make-countries | make-earthlike-terrain
            | make-fractal-percentile-terrain | make-independent-units
            | make-initial-materials | make-maze-terrain
            | make-random-date | make-random-terrain | make-rivers
            | make-roads | make-weather | name-geographical-features
            | name-units-randomly

    random-event-method ::=
              accidents-in-terrain | attrition-in-terrain
            | units-revolt | unit-surrender

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