type_annotations.casa

# Type annotations on variable assignments
#
# The = name:type syntax allows explicit type annotation when assigning variables.
# This is useful for narrowing inferred or bare 'option' types to concrete types.
import "std"

# Basic type annotations
42 = x: int
"hello" = greeting: str
true = flag: bool
# Print annotated variables
x print "\n" print
greeting print "\n" print
flag print "\n" print
# Type annotations with option types
42 Option::Some = maybe_val: Option[int]
Option::None = empty_val: Option[int]
# Check option values
if maybe_val.is_some then
    "maybe_val has value: " print
    maybe_val.unwrap print "\n" print
fi
if empty_val.is_none then
    "empty_val is none\n" print
fi
# Type annotations in functions

fn make_pair a:int b:int -> int int {
    a = first: int
    b = second: int
    first second
}
10 20 make_pair = y: int = z: int
z print "\n" print
y print "\n" print
# Reassignment with annotated variable
100 = x
x print "\n" print