nes-pascal

Built-in types

English

NES Pascal provides five built-in types. Each occupies one byte, but the types are distinct and are not implicitly converted. It also supports user-defined enumerations, which are nominal one-byte types, and named records, which are nominal fixed-layout aggregate types. The runtime also predefines the ordinary four-byte nes_rect record used by the collision helpers; it is not a sixth scalar built-in type.

`nes_color`

nes_color occupies one byte and represents an NES palette value. Its allowed range is $00..$3F.

The same range is enforced for scalar assignments, universal background-color calls, full background and sprite palettes, and individual palette colors. Values are never wrapped or masked into range.

Valid:

const
    BackgroundColor: nes_color = $21;

Invalid:

const
    BackgroundColor: nes_color = $80;

Expected diagnostic:

E4002 path/to/source.nsp:4:34

Value $80 is not valid for type nes_color.

Allowed range: $00..$3F.

`byte`

byte occupies one byte and accepts hexadecimal values from $00 through $FF.

const
    Maximum: byte = $FF;

A larger value produces E4003.

`boolean`

boolean occupies one byte. false is represented by zero and true by one. No hexadecimal-to-boolean conversion is allowed.

const
    RenderingEnabled: boolean = true;

Assignments and operator operands must obey the exact type rules described in Assignments and Expressions.

`sprite`

sprite is a strongly typed hardware OAM index. It occupies one byte, but its allowed values are $00..$3F, selecting the NES’s 64 hardware sprites.

var
    PlayerSprite: sprite;

begin
    PlayerSprite := nes.sprite_create();
end;

A value above $3F produces E4008. sprite is not implicitly interchangeable with byte, does not support arithmetic or inc/dec, and is passed directly to the hardware sprite API. nes.sprite_create() produces a statically reserved sprite value; it is not a general function or runtime object allocation.

`metasprite`

metasprite is an opaque one-byte identity for a statically created logical object composed of several hardware sprites. It is not an OAM index and no hexadecimal literal can be converted to it.

var
    Player: metasprite;

begin
    nes.import_metasprite(player);
    Player := nes.metasprite_create(player.idle_0);
end;

Each creation site has a stable identity and statically owned component slots. The type supports assignment and the metasprite API, but not arithmetic, comparisons, inc, dec, constants, or procedure parameters. E4009 rejects numeric values in a metasprite context.

Imported frame and animation names are internal compile-time symbol kinds, not user-declarable built-in types. Frame symbols select creation/manual frames; animation symbols are accepted only by the sprite-animation API. Neither can be stored in a variable or synthesized from a byte.

Procedure value parameters currently support only byte and boolean. nes_color, sprite, and metasprite remain valid global types but produce E4005 when used as a parameter type. nes_color and sprite also support typed constants; metasprite identities come only from creation sites.

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