r - 记录当前函数名称

Question

我有一些自定义日志函数，它们是 cat 的扩展。一个基本的例子是这样的:

catt<-function(..., file = "", sep = " ", fill = FALSE, labels = NULL,
    append = FALSE)
{
    cat(..., format(Sys.time(), "(%Y-%m-%d %H:%M:%S)"), "\n", file = file, 
        sep = sep, fill = fill, labels = labels, append = append)
}

现在，我经常使用(自制)函数，并使用其中一些日志函数来查看进度，效果很好。不过，我注意到的是，我几乎总是像这样使用这些函数:

somefunc<-function(blabla)
{
  catt("somefunc: start")
  #do some very useful stuff here
  catt("somefunc: some time later")
  #even more useful stuff
  catt("somefunc: the end")
}

请注意对 catt 的每次调用如何以调用它的函数的名称开头。非常整洁，直到我开始重构我的代码和重命名函数等。

感谢 Brian Ripley 的一些旧的 R-list 帖子，如果我没记错的话，我找到了这段代码来获取“当前函数名称”:

catw<-function(..., file = "", sep = " ", fill = FALSE, labels = NULL,
    append = FALSE)
{
    curcall<-sys.call(sys.parent(n=1))
    prefix<-paste(match.call(call=curcall)[[1]], ":", sep="")
    cat(prefix, ..., format(Sys.time(), "(%Y-%m-%d %H:%M:%S)"), "\n",
        file = file, sep = sep, fill = fill, labels = labels, append = append)
}

这很好，但并不总是有效，因为:

我的函数散落着 lapply 中使用的匿名函数
函数类型，像这样:

aFunc<-function(somedataframe)
{
  result<-lapply(seq_along(somedataframe), function(i){
  catw("working on col", i, "/", ncol(somedataframe))
  #do some more stuff here and return something
  return(sum(is.na(somedataframe[[i]])))
  }
}

-> 对于这些情况，显然(并且可以理解)我的 sys.parent 函数中的 catw 调用中需要 n=3。

我偶尔会使用 do.call :它似乎是我当前的实现
也不起作用(我再一次有点理解它，虽然
我还没有完全弄清楚。

所以，我的问题是:有没有办法在调用堆栈中找到第一个命名函数(跳过日志函数本身，也许还有其他一些“众所周知的”异常)，这将允许我为所有人编写一个单一版本的 catw案例(这样我就可以愉快地重构而不必担心我的日志记录代码)？你会怎么做这样的事情？

编辑 :应该支持这些情况:

testa<-function(par1)
{
    catw("Hello from testa, par1=", par1)
    for(i in 1:2) catw("normal loop from testa, item", i)
    rv<-sapply(1:2, function(i){catw("sapply from testa, item", i);return(i)})
    return(rv)
}

testb<-function(par1, par2)
{
    catw("Hello from testb, par1=", par1)
    for(i in 1:2) catw("normal loop from testb, item", i)
    rv<-sapply(1:2, function(i){catw("sapply from testb, item", i);return(i)})

    catw("Will now call testa from testb")
    rv2<-testa(par1)
    catw("Back from testa call in testb")

    catw("Will now do.call testa from testb")
    rv2<-do.call(testa, list(par1))
    catw("Back from testa do.call in testb")

    return(list(rv, rv2))
}

testa(123)
testb(123,456)
do.call(testb, list(123,456))

Answer 1

编辑:完全重写函数

此函数的新版本使用调用堆栈，sys.calls() , 而不是 match.call .

调用栈包含完整的调用函数。所以现在的诀窍是只提取你真正想要的部分。我在 clean_cs 中使用了一些手动清理方法。功能。这将评估调用堆栈中的第一个单词并返回少量已知边缘情况的所需参数，特别是 lapply , sapply和 do.call .

这种方法的唯一缺点是它会一直返回函数名称到调用堆栈的顶部。也许合乎逻辑的下一步是将这些函数与指定的环境/命名空间进行比较，并基于此包含/排除函数名称......

我会停在这里。它回答了问题中的用例。

新功能:

catw <- function(..., callstack=sys.calls()){
  cs <- callstack
  cs <- clean_cs(cs)
  #browser()
  message(paste(cs, ...))
}

clean_cs <- function(x){
  val <- sapply(x, function(xt){
    z <- strsplit(paste(xt, collapse="\t"), "\t")[[1]]
    switch(z[1],
        "lapply" = z[3], 
        "sapply" = z[3],
        "do.call" = z[2], 
        "function" = "FUN",
        "source" = "###",
        "eval.with.vis" = "###",
        z[1]
        )
    })
  val[grepl("\\<function\\>", val)] <- "FUN"
  val <- val[!grepl("(###|FUN)", val)]
  val <- head(val, -1)
  paste(val, collapse="|")
}

检测结果:

testa Hello from testa, par1= 123
testa normal loop from testa, item 1
testa normal loop from testa, item 2
testa sapply from testa, item 1
testa sapply from testa, item 2


testb Hello from testb, par1= 123
testb normal loop from testb, item 1
testb normal loop from testb, item 2
testb sapply from testb, item 1
testb sapply from testb, item 2
testb Will now call testa from testb
testb|testa Hello from testa, par1= 123
testb|testa normal loop from testa, item 1
testb|testa normal loop from testa, item 2
testb|testa sapply from testa, item 1
testb|testa sapply from testa, item 2
testb Back from testa call in testb
testb Will now do.call testa from testb
testb|testa Hello from testa, par1= 123
testb|testa normal loop from testa, item 1
testb|testa normal loop from testa, item 2
testb|testa sapply from testa, item 1
testb|testa sapply from testa, item 2
testb Back from testa do.call in testb


testb Hello from testb, par1= 123
testb normal loop from testb, item 1
testb normal loop from testb, item 2
testb sapply from testb, item 1
testb sapply from testb, item 2
testb Will now call testa from testb
testb|testa Hello from testa, par1= 123
testb|testa normal loop from testa, item 1
testb|testa normal loop from testa, item 2
testb|testa sapply from testa, item 1
testb|testa sapply from testa, item 2
testb Back from testa call in testb
testb Will now do.call testa from testb
testb|testa Hello from testa, par1= 123
testb|testa normal loop from testa, item 1
testb|testa normal loop from testa, item 2
testb|testa sapply from testa, item 1
testb|testa sapply from testa, item 2
testb Back from testa do.call in testb