never

Primitive never type for code paths that do not return normally.

Aliases: never

Syntax: never

Category#

type

Related#

• panic
• exit

Examples#

radix/corpus/numquam/numquam.fab (canonical · keyword)#

Primitive never type for code paths that do not return normally.

# =============================================================================
# never — Primitive never type for code paths that do not return normally.
# =============================================================================
#
# What this teaches:
#   • Diverging functions — `never` marks functions like `panic` that never return to the caller.
#   • Type-system bottom — `never` is the bottom type, compatible with any return position.
#
# Common mistakes:
#   • Using never for functions that might sometimes return normally — never is only for code paths that never return.
#
# See also: panic, exit
# =============================================================================

# never — diverging return type
#
# GRAMMAR:
#   returnType :← 'never'
#
# EXPECTED OUTPUT:
#   Scalar stdout smoke (see body).
#
# BACKEND:
#   Cross-ref: panic/mori.fab.
#

fn fail(string message) → never {
    panic message
}