R语言源代码查看

    edit(getAnywhere)
    # result:
    function (x) 
    {
      if (tryCatch(!is.character(x), error = function(e) TRUE)) 
    x <- as.character(substitute(x))
      objs <- list()
      where <- character()
      visible <- logical()
      if (length(pos <- find(x, numeric = TRUE))) {
    objs <- lapply(pos, function(pos, x) get(x, pos = pos), 
      x = x)
    where <- names(pos)
    visible <- rep.int(TRUE, length(pos))
      }
      if (length(grep(".", x, fixed = TRUE))) {
    np <- length(parts <- strsplit(x, ".", fixed = TRUE)[[1L]])
    for (i in 2:np) {
      gen <- paste(parts[1L:(i - 1)], collapse = ".")
      cl <- paste(parts[i:np], collapse = ".")
      if (gen == "" || cl == "") 
        next
      Call <- substitute(getS3method(gen, cl, TRUE), list(gen = gen, 
        cl = cl))
      f <- eval.parent(Call)
      if (!is.null(f) && !is.null(environment(f))) {
        ev <- topenv(environment(f), baseenv())
        nmev <- if (isNamespace(ev)) 
          getNamespaceName(ev)
        else NULL
        objs <- c(objs, list(f))
        msg <- paste("registered S3 method for", gen)
        if (!is.null(nmev)) 
          msg <- paste(msg, "from namespace", nmev)
        where <- c(where, msg)
        visible <- c(visible, FALSE)
      }
    }
      }
      for (i in loadedNamespaces()) {
    ns <- asNamespace(i)
    if (exists(x, envir = ns, inherits = FALSE)) {
      f <- get(x, envir = ns, inherits = FALSE)
      objs <- c(objs, list(f))
      where <- c(where, paste0("namespace:", i))
      visible <- c(visible, FALSE)
    }
      }
      ln <- length(objs)
      dups <- rep.int(FALSE, ln)
      if (ln > 1L) 
    for (i in 2L:ln) for (j in 1L:(i - 1L)) if (identical(objs[[i]], 
      objs[[j]], ignore.environment = TRUE)) {
      dups[i] <- TRUE
      break
    }
      structure(list(name = x, objs = objs, where = where, visible = visible, 
    dups = dups), class = "getAnywhere")
    }
    
    
    
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
    

    getAnywhere(methods)
    # reulst :
    A single object matching ‘methods’ was found
    It was found in the following places
      package:utils
      namespace:utils
    with value
    
    function (generic.function, class) 
    {
    envir <- parent.frame()
    if (!missing(generic.function) && !is.character(generic.function)) {
        what <- substitute(generic.function)
        if (is.function(generic.function) && is.call(what) && 
            (deparse(what[[1L]])[1L] %in% c("::", ":::"))) {
            generic.function <- as.character(what[[3L]])
            envir <- asNamespace(as.character(what[[2L]]))
        }
        else generic.function <- deparse(what)
    }
    if (!missing(class) && !is.character(class)) 
        class <- paste(deparse(substitute(class)))
    s3 <- .S3methods(generic.function, class, envir)
    s4 <- if (.isMethodsDispatchOn()) {
        methods::.S4methods(generic.function, class)
    }
    else NULL
    .MethodsFunction(s3, s4, missing(generic.function))
    }
    <bytecode: 0x000001a5618bcdc8>
    <environment: namespace:utils>
    
    
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
    

    > methods(generic.function = "print")[1:3]
    [1] "print.acf"   "print.anova" "print.aov"
    
    
      
      
    

    > methods(class = "POSIXct")[1:10]
     [1] "[.POSIXct"                 "[[.POSIXct"               
     [3] "[<-.POSIXct"               "as.data.frame.POSIXct"    
     [5] "as.Date.POSIXct"           "as.list.POSIXct"          
     [7] "as.POSIXlt.POSIXct"        "c.POSIXct"                
     [9] "coerce,oldClass,S3-method" "format.POSIXct"