今天下午本来写着写着代码，突然就觉得R里面不能像python一样用tuple或者dictionary来一下子输入多个参数值，这实在是太太太让人不爽了，作为一种函数式的编程语言做不到这一点就太伤自尊了诶。所以干脆就不务正业地浪费了三个小时自己写了一个类似的功能实现。

具体思路是这样：引入了一个新的S3类"dict"，用来存放把某个函数所需要一次性赋值的形参值和形参名，然后通过UseDict函数来使用。dict由$Values和$Names两部分构成。Values是一个list，用于存放你想一次性输入的参数值；Names是个character型向量，用于指定你要一次性赋值的形参名称。如果要应用的函数里没有"..."参数的话，Names可以留空，也可以短于Values的长度，会自动补齐。否则就必须让Values和Names一一对应。

一个简单的用法示例：

<br />
fun1=function(x,y,z,u) x+y+z+u<br />
dict1=dict(1:3)<br />
dict2=dict(1:3,c('x','z'))<br />
dict3=dict(1:3,c('y','z','u'))<br />
UseDict(fun1,dict1,u=4)<br />
#Automatically fills the Values entry in dict1 from the first formal argument name "x", i.e. x=1, y=2, z=3.<br />
UseDict(fun1,dict2,y=4)<br />
#Automatically fills the Values entry in dict1 from the last given name in the entry "z" alongwith the formal arguments of the function "fun", i.e. x=1, z=2, u=3.<br />
UseDict(fun1,dict3,x=4)<br />
#Intuitively.<br />
fun2=function(x,y,z,u,...) paste(x+y+z+u,unlist(list(...)),sep=';')<br />
UseDict(fun2,dict2,y=4,a=5)<br />
#Error.<br />
UseDict(fun2,dict3,x=4,a=5)<br />
#No problem.<br />

具体的代码在下边，有需要的自己复制一下就好了。如果有bug请及时告诉我一声:)

<br />
dict=<br />
  function(sVal,cNames=NULL)#sVal demands a list or anything that can be coerced into a list.<br />
  {<br />
    sVal=as.list(sVal)<br />
    dict=list(Values=sVal,Names=cNames)<br />
    class(dict)='dict'<br />
    dict<br />
  }</p>
<p>UseDict=<br />
  function(fun,dict=NULL,...)<br />
  {<br />
    cDotsNames=names(match.call())<br />
    cDotsNames=cDotsNames[cDotsNames!='dict']<br />
    cArgNames=names(formals(fun))<br />
    if(is.null(dict))<br />
      fun(...) else<br />
      {<br />
        cDictNames=dict$Names<br />
        sValues=dict$Values<br />
        iNameLength=length(cDictNames)<br />
        iValueLength=length(sValues)<br />
        if(!'...'%in%cArgNames)<br />
        {<br />
          if(!iNameLength)<br />
            cDictNames=cArgNames[seq_len(iValueLength)] else#Can easily obtain the *apply style way to auto-match argument names by modifying this line.<br />
            {<br />
              if(any(!cDictNames%in%cArgNames))<br />
                stop('There are wrong argument name(s) in the input "dict".')<br />
              if(iNameLength<iValueLength)<br />
                cDictNames=c(cDictNames,cArgNames[seq(match(cDictNames[iNameLength],cArgNames)+1,length.out=iValueLength-iNameLength)])<br />
            }<br />
        } else<br />
        {<br />
          if(iNameLength<iValueLength)<br />
            stop('Please specify every argument name included in the input "dict" because there is a "..." argument in the given "fun".\n  And if this is not possible, then it is neither possible to use this function.')<br />
        }<br />
        if(any(is.na(cDictNames)))<br />
          stop('Automatic argument match failed. Try to specify every argument name included in the input "dict" instead.')<br />
        sDotsList=vector('list')<br />
        for(i in seq_len(iValueLength))<br />
          if(cDictNames[i]%in%cArgNames)<br />
            formals(fun)[[cDictNames[i]]]=sValues[[i]] else<br />
              sDotsList[[cDictNames[i]]]=sValues[[i]]<br />
        if(any(cDictNames%in%cDotsNames))<br />
          stop('Values were assigned to some formal argument(s) more than once in the "dict" and "..." parts.')<br />
        eval(as.call(append(append(list(quote(fun)),sDotsList),list(...))))<br />
      }<br />
  }<br />

</p>