evaluate provides tools that allow you to recreate the parsing,
evaluation and display of R code, with enough information that you can
accurately recreate what happens at the command line. Evaluate + replay
works very similarly to source(), but is written in such a
way to make it easy to adapt for other output formats, such as html or
latex.
library(evaluate)There are three components to the evaluate package:
parse_all(), a version of parse that keeps expressions
with their original source code, maintaining formatting and
comments.evaluate(), which evaluates each expression produced by
parse_all(), tracking all output, messages, warnings, and
errors as their occur, and interleaving them in the correct order with
the original source and value of the expression.replay(), which outputs these pieces in a way that
makes it look like you’ve entered the code at the command line. This
function also serves as a template for other output formats.