tree_rewrite: Rewrite the tree with a list of replacements

In astgrepr: Parse and Manipulate R Code

Rewrite the tree with a list of replacements

Description

Rewrite the tree with a list of replacements

Usage

tree_rewrite(root, replacements)

Arguments

root	The root tree, obtained via tree_root()
replacements	A list of replacements, obtained via node_replace() or node_replace_all().

Value

A string character corresponding to the code used to build the tree root but with replacements applied.

Examples

src <- "x <- c(1, 2, 3)
any(duplicated(x), na.rm = TRUE)
any(duplicated(x))
if (any(is.na(x))) {
  TRUE
}
any(is.na(y))"

root <- tree_new(src) |>
  tree_root()


### Only replace the first nodes found by each rule

nodes_to_replace <- root |>
  node_find(
    ast_rule(id = "any_na", pattern = "any(is.na($VAR))"),
    ast_rule(id = "any_dup", pattern = "any(duplicated($VAR))")
  )

fixes <- nodes_to_replace |>
  node_replace(
    any_na = "anyNA(~~VAR~~)",
    any_dup = "anyDuplicated(~~VAR~~) > 0"
  )

# original code
cat(src)

# new code
tree_rewrite(root, fixes)


### Replace all nodes found by each rule

nodes_to_replace <- root |>
  node_find_all(
    ast_rule(id = "any_na", pattern = "any(is.na($VAR))"),
    ast_rule(id = "any_dup", pattern = "any(duplicated($VAR))")
  )

fixes <- nodes_to_replace |>
  node_replace_all(
    any_na = "anyNA(~~VAR~~)",
    any_dup = "anyDuplicated(~~VAR~~) > 0"
  )

# original code
cat(src)

# new code
tree_rewrite(root, fixes)

astgrepr documentation built on June 8, 2025, 11:05 a.m.