Examples for 'rlang::is_function'

### ** Examples

# Primitive functions are not closures:
is_closure(base::c)

is_primitive(base::c)

# On the other hand, internal functions are wrapped in a closure
# and appear as such from the R side:
is_closure(base::eval)

# Both closures and primitives are functions:
is_function(base::c)

is_function(base::eval)

# Many primitive functions evaluate arguments eagerly:
is_primitive_eager(base::c)

is_primitive_eager(base::list)

is_primitive_eager(base::`+`)

# However, primitives that operate on expressions, like quote() or
# substitute(), are lazy:
is_primitive_lazy(base::quote)

is_primitive_lazy(base::substitute)