data.table based implementation.

# S3 method for relop_rename_columns
ex_data_table_step(
  optree,
  ...,
  tables = list(),
  source_usage = NULL,
  source_limit = NULL,
  env = parent.frame()
)

Arguments

optree

relop operations tree.

...

not used, force later arguments to bind by name.

tables

named list map from table names used in nodes to data.tables and data.frames.

source_usage

list mapping source table names to vectors of columns used.

source_limit

if not null limit all table sources to no more than this many rows (used for debugging).

env

environment to work in.

Examples

dL <- build_frame( "x", "y" | 2L , "b" | 1L , "a" | 3L , "c" ) rquery_pipeline <- local_td(dL) %.>% rename_columns(., c("x" = "y", "y" = "x")) dL %.>% rquery_pipeline
#> y x #> 1 2 b #> 2 1 a #> 3 3 c