Check whether a parse table contains a tilde
is_tilde_expr(pd, tilde_pos = c(1, 2))is_asymmetric_tilde_expr(pd)
is_symmetric_tilde_expr(pd)
A parse table.
Integer vector indicating row-indices that should be checked for tilde. See 'Details'.
A tilde is on the top row in the parse table if it is an asymmetric tilde
expression (like ~column
), in the second row if it is a symmetric tilde
expression (like a~b
).