gnd

The uint8 operation converts one input value to an 8-bit unsigned integer. The operand may be:

• an integer literal in decimal (123) or hexadecimal (0x7B);
• a numeric value already stored in a variable;
• a string literal that encodes a decimal or hexadecimal integer;
• a floating-point value whose fractional part is exactly zero.

Conversion succeeds only when the value fits in the range 0 … 255. If the operand is negative, exceeds 255, cannot be parsed as an integer, or is a float with a fractional part, uint8 raises an error. The operation never mutates its input; it returns a new value whose concrete type is 8-bit unsigned integer.

Syntax

[ $destination ] uint8 value

• $destination is optional; if omitted, the converted value is assigned to _.

• Exactly one operand must follow uint8. Writing uint8 with no operand is shorthand for uint8 _.

Examples

Convert a decimal literal:

$byte uint8 200          # $byte holds uint8 value 200

Convert a hexadecimal string:

$hex  let "0xFF"
$max  uint8 $hex         # $max is 255

Convert the current _ in place:

let  42
uint8                    # same as uint8 _

Overflow triggers an error:

uint8 300                # error: value exceeds 255

Negative numbers are rejected:

uint8 -1                 # error: negative value not allowed

Fractions are rejected:

uint8 3.5                # error: fractional part not allowed

uint8 always yields a single uint8 value, never rebinds existing variables, and adheres to Gendo’s single-assignment rule.