Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
tree: b2eccd3443
Fetching contributors…

Cannot retrieve contributors at this time

175 lines (169 sloc) 4.339 kB
R Under development (unstable) (2012-03-05 r58592)
Copyright (C) 2012 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: x86_64-unknown-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.
R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.
> #### eval / parse / deparse / substitute etc
>
> ##- From: Peter Dalgaard BSA <p.dalgaard@biostat.ku.dk>
> ##- Subject: Re: source() / eval() bug ??? (PR#96)
> ##- Date: 20 Jan 1999 14:56:24 +0100
> e1 <- parse(text='c(F=(f <- .3), "Tail area" = 2 * if(f < 1) 30 else 90)')[[1]]
> e1
c(F = (f <- 0.3), `Tail area` = 2 * if (f < 1) 30 else 90)
> str(eval(e1))
Named num [1:2] 0.3 60
- attr(*, "names")= chr [1:2] "F" "Tail area"
> mode(e1)
[1] "call"
>
> ( e2 <- quote(c(a=1,b=2)) )
c(a = 1, b = 2)
> names(e2)[2] <- "a b c"
> e2
c(`a b c` = 1, b = 2)
> parse(text=deparse(e2))
expression(c(`a b c` = 1, b = 2))
>
> ##- From: Peter Dalgaard BSA <p.dalgaard@biostat.ku.dk>
> ##- Date: 22 Jan 1999 11:47
>
> ( e3 <- quote(c(F=1,"tail area"=pf(1,1,1))) )
c(F = 1, `tail area` = pf(1, 1, 1))
> eval(e3)
F tail area
1.0 0.5
> names(e3)
[1] "" "F" "tail area"
>
> names(e3)[2] <- "Variance ratio"
> e3
c(`Variance ratio` = 1, `tail area` = pf(1, 1, 1))
> eval(e3)
Variance ratio tail area
1.0 0.5
>
>
> ##- From: Peter Dalgaard BSA <p.dalgaard@biostat.ku.dk>
> ##- Date: 2 Sep 1999
>
> ## The first failed in 0.65.0 :
> attach(list(x=1))
> evalq(dim(x) <- 1,as.environment(2))
> dput(get("x", envir=as.environment(2)), control="all")
structure(1, .Dim = 1L)
>
> e <- local({x <- 1;environment()})
> evalq(dim(x) <- 1,e)
> dput(get("x",envir=e), control="all")
structure(1, .Dim = 1L)
>
> ### Substitute, Eval, Parse, etc
>
> ## PR#3 : "..." matching
> ## Revised March 7 2001 -pd
> A <- function(x, y, ...) {
+ B <- function(a, b, ...) { match.call() }
+ B(x+y, ...)
+ }
> (aa <- A(1,2,3))
B(a = x + y, b = 3)
> all.equal(as.list(aa),
+ list(as.name("B"), a = expression(x+y)[[1]], b = 3))
[1] TRUE
> (a2 <- A(1,2, named = 3)) #A(1,2, named = 3)
B(a = x + y, named = 3)
> all.equal(as.list(a2),
+ list(as.name("B"), a = expression(x+y)[[1]], named = 3))
[1] TRUE
>
> CC <- function(...) match.call()
> DD <- function(...) CC(...)
> a3 <- DD(1,2,3)
> all.equal(as.list(a3),
+ list(as.name("CC"), 1, 2, 3))
[1] TRUE
>
> ## More dots issues: March 19 2001 -pd
> ## Didn't work up to and including 1.2.2
>
> f <- function(...) {
+ val <- match.call(expand.dots=FALSE)$...
+ x <- val[[1]]
+ eval.parent(substitute(missing(x)))
+ }
> g <- function(...) h(f(...))
> h <- function(...) list(...)
> k <- function(...) g(...)
> X <- k(a=)
> all.equal(X, list(TRUE))
[1] TRUE
>
> ## Bug PR#24
> f <- function(x,...) substitute(list(x,...))
> deparse(f(a, b)) == "list(a, b)" &&
+ deparse(f(b, a)) == "list(b, a)" &&
+ deparse(f(x, y)) == "list(x, y)" &&
+ deparse(f(y, x)) == "list(y, x)"
[1] TRUE
>
> tt <- function(x) { is.vector(x); deparse(substitute(x)) }
> a <- list(b=3); tt(a$b) == "a$b" # tends to break when ...
[1] TRUE
>
>
> ## Parser:
> 1 <
+ 2
[1] TRUE
> 2 <=
+ 3
[1] TRUE
> 4 >=
+ 3
[1] TRUE
> 3 >
+ 2
[1] TRUE
> 2 ==
+ 2
[1] TRUE
> ## bug till ...
> 1 !=
+ 3
[1] TRUE
>
> all(NULL == NULL)
[1] TRUE
>
> ## PR #656 (related)
> u <- runif(1); length(find(".Random.seed")) == 1
[1] TRUE
>
> MyVaR <<- "val";length(find("MyVaR")) == 1
[1] TRUE
> rm(MyVaR); length(find("MyVaR")) == 0
[1] TRUE
>
>
> ## Martin Maechler: rare bad bug in sys.function() {or match.arg()} (PR#1409)
> callme <- function(a = 1, mm = c("Abc", "Bde")) {
+ mm <- match.arg(mm); cat("mm = "); str(mm) ; invisible()
+ }
> ## The first two were as desired:
> callme()
mm = chr "Abc"
> callme(mm="B")
mm = chr "Bde"
> mycaller <- function(x = 1, callme = pi) { callme(x) }
> mycaller()## wrongly gave `mm = NULL' now = "Abc"
mm = chr "Abc"
>
Jump to Line
Something went wrong with that request. Please try again.