compose_visitor: compose visitor functions

In TobCap/walkast: Walking Abstruct Syntax Tree of R

Description

compose visitor functions

Usage

lhs %then% rhs

Arguments

lhs	visitor object
rhs	visitor object

Value

composed visitor object

Examples

add1 <- make_visitor(
  leaf = function(x) if(is.numeric(x)) x + 1 else x
)
mul2 <- make_visitor(
  leaf = function(x) if(is.numeric(x)) x * 2 else x
)
walk_ast(quote(1 + 2 * 3), add1)
walk_ast(quote(1 + 2 * 3), mul2)
walk_ast(quote(1 + 2 * 3), add1 %then% mul2)
walk_ast(quote(1 + 2 * 3), mul2 %then% add1)

TobCap/walkast documentation built on May 9, 2019, 4:51 p.m.