nes-pascal

Assignments

English

Assignment uses :=:

BackgroundColor := $21;
Counter := $FF;
Enabled := true;

The right-hand side may be:

a hexadecimal literal;
true or false;
a constant reference;
a previously assigned variable reference;
an enum member or previously assigned enum variable of the exact same enum type;
a typed field of a previously assigned record or record-array element;
a byte arithmetic expression;
a comparison or Boolean expression whose result is boolean.

Both sides must have exactly the same type. There are no implicit conversions. Reading a variable before an earlier assignment is a compilation error. Constants cannot be assignment targets.

An individual record field may be an assignment target and retains its exact declared type. Whole-record assignment is not supported; assign fields individually. See Records.

Value parameters are initialized local copies and may also be assignment targets inside their declaring procedure. Assigning a parameter does not modify the caller’s argument.

Definite-assignment analysis follows structured control flow. The detailed rules for branches, loops, and procedure calls are documented with those constructs.

Assignment diagnostics preserve the earliest primary error:

E4002 reports a nes_color value outside $00..$3F;
E4004 reports incompatible source and target types, including hexadecimal literals assigned to boolean;
E3008 reports a variable read before assignment.

Whole-program checks such as E3003 run only after statement-level semantic analysis succeeds. See the diagnostics reference for the complete index, explanations, examples, and suggested fixes.

Initialized byte variables can also be changed with inc and dec.

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