README.md

In brodieG/matchcall: Match Calls From Dynamic Stack

matchcall

As of R 3.2.0 match.call gained an envir parameter that fixes most of the issues this package is designed to address. Additionally, "fixing" the ..1, etc. issue is probably not a good idea since we lose the evaluation environment for the promises since dots may have been forwarded several times.

Overview

Similar to match.call, but is designed specifically to match calls from the dynamic call stack. Which call is matched is controlled by the n argument, which is analgous to the n argument for sys.parent. Also addresses some potentially unexpected behavior with match.call with calls involving dots in corner cases.

You can also use match.call to match arbitrary calls from the call stack, but it is simpler to do so using match_call, particularly when the call stack and the lexical stack are not the same. See examples for illustration of differences between match.call and match_call.

match_call will also include unspecified defaults and missing arguments if requested.

For a more detailed discussion of the exact nature of the dots corner case issues with match.call, see the vignette. Briefly: these crop up when there are multiple calls using dots involved.

For more details, see:

• Vignette
• ?match_call

Installation Instructions

This package is still in early development and only available on github:

library(devtools)
install_github("brodieg/matchcall")

brodieG/matchcall documentation built on May 13, 2019, 7:46 a.m.