search for: do_unquote

Your example x = 5 exp = parse(text="f(uq(x)) + y +z") # expression: f(uq(x)) +y + z do_unquote(expr) # -> the language object f(5) + y + z could be done with the following wrapper for bquote my_do_unquote <- function(language, envir = parent.frame()) { if (is.expression(language)) { # bquote does not go into expressions, only calls as.expression(lapply(la...

...is used for something else there, but again that's conjecture on my part. Best, ~G On Fri, Mar 17, 2017 at 12:53 PM, William Dunlap <wdunlap at tibco.com> wrote: > Your example > x = 5 > exp = parse(text="f(uq(x)) + y +z") # expression: f(uq(x)) +y + z > do_unquote(expr) > # -> the language object f(5) + y + z > could be done with the following wrapper for bquote > my_do_unquote <- function(language, envir = parent.frame()) { > if (is.expression(language)) { > # bquote does not go into expressions, only calls >...

>After off list discussions with Jonathan Carrol and with >Michael Lawrence I think it's doable, unambiguous, >and even imo pretty intuitive for an "unquote" operator. For those of us who are not CS/Lisp mavens, what is an "unquote" operator? Can you expression quoting and unquoting in R syntax and show a few examples where is is useful, intuitive, and fits in to

...interpolation) is essentially substituting part of an unevaluated expression with its evaluated value inlined. The unquote operator, then, is the way of marking which parts of the expression should be substituted in that way (i.e. interpolated). i.e. if uq() is the unquote "operator" and do_unquote interpolates, then if we have x = 5 exp = parse(text="f(uq(x)) + y +z") # expression: f(uq(x)) +y + z Then do_unquote would give you the *expression* f(5) + y + z In terms of what it does that the tilde does not, it would give you the ability to partially evaluate the captured formul...