警告中引用名称

Question

这似乎是一个简单的问题，但我找不到答案。我有一个包含调用参数名称的字符向量。在函数中，如果其中一些错误，我想提出警告，并引用名称。

bad = c("a", "b", "c") 
warning(paste("Variables", paste(bad, collapse = ", "), "are wrong")) 

这给：

Warning message: 
Variables a, b, c are wrong 

，但我需要：

Warning message: 
Variables 'a', 'b', 'c' are wrong 

我想做到这一点，而无需使用外部包。

Answer 1

我们可以使用ASCII撇号他\'

warning(paste("Variables", paste0("\'", bad, "\'", collapse = ", "), "are wrong")) 

# Warning message: 
# Variables 'a', 'b', 'c' are wrong 

或单引号由sQuote

warning(paste("Variables", paste(sQuote(bad), collapse = ", "), "are wrong")) 

# Warning message: 
# Variables ‘a’, ‘b’, ‘c’ are wrong 

或双引号通过dQuote

warning(paste("Variables", paste(dQuote(bad), collapse = ", "), "are wrong")) 

# Warning message: 
# Variables “a”, “b”, “c” are wrong 

Answer 2

这是你在找什么？

bad = c("'a'", "'b'", "'c'") 
warning(paste("Variables", paste(bad, collapse = ", "), "are wrong")) 

，如果你想节省一些打字，你可以写类似

quotify <- function(x) paste0("'", x, "'") 

bad = quotify(c("a", "b", "c")) 
warning(paste("Variables", paste(bad, collapse = ", "), "are wrong")) 

Answer 3

您可以使用此方法：

warning("Variables ", paste0("'", bad, "'", collapse = ", "), " are wrong") 
# Warning message: 
# Variables 'a', 'b', 'c' are wrong 

替代版本为双引号：

warning("Variables ", paste0("\"", bad, "\"", collapse = ", "), " are wrong") 
# Warning message: 
# Variables "a", "b", "c" are wrong