lazyeval (version 0.2.2)

is_lang: Is an object a language object?

Description

These helpers are consistent wrappers around their base R equivalents. A language object is either an atomic vector (typically a scalar), a name (aka a symbol), a call, or a pairlist (used for function arguments).

Usage

is_lang(x)
is_name(x)
is_call(x)
is_pairlist(x)
is_atomic(x)

Arguments

x

An object to test.

See Also

as_name() and as_call() for coercion functions.

Examples

# NOT RUN {
q1 <- quote(1)
is_lang(q1)
is_atomic(q1)

q2 <- quote(x)
is_lang(q2)
is_name(q2)

q3 <- quote(x + 1)
is_lang(q3)
is_call(q3)
# }