自定义R重启功能,该功能不';流产
自定义R重启功能,该功能不';流产,r,R,invokeRestart(“muffleWarning”)中的muffleWarning是如何实现的?我问是因为 在以下代码中: e <-expression({ warning("Step 1",immediate.=TRUE) warning("Step 2",immediate.=TRUE) }) r <- withRestarts(withCallingHandlers(eval(e) ,
invokeRestart(“muffleWarning”)
中的muffleWarning
是如何实现的?我问是因为
在以下代码中:
e <-expression({
warning("Step 1",immediate.=TRUE)
warning("Step 2",immediate.=TRUE)
})
r <- withRestarts(withCallingHandlers(eval(e)
,warning=function(co){
print(co) #1
invokeRestart("mymuffleWarn",co)
})
, mymuffleWarn=function(co) print(conditionMessage(co)))
eR源代码的灰色显示:
.signalSimpleWarning <- function(msg, call)
withRestarts({
.Internal(.signalCondition(simpleWarning(msg, call), msg, call))
.Internal(.dfltWarn(msg, call))
}, muffleWarning = function() NULL)
这是从
static void vsignalWarning(SEXP call, const char *format, va_list ap)
{
char buf[BUFSIZE];
SEXP hooksym, hcall, qcall;
hooksym = install(".signalSimpleWarning");
if (SYMVALUE(hooksym) != R_UnboundValue &&
SYMVALUE(R_QuoteSymbol) != R_UnboundValue) {
PROTECT(qcall = LCONS(R_QuoteSymbol, LCONS(call, R_NilValue)));
PROTECT(hcall = LCONS(qcall, R_NilValue));
Rvsnprintf(buf, BUFSIZE - 1, format, ap);
hcall = LCONS(mkString(buf), hcall);
PROTECT(hcall = LCONS(hooksym, hcall));
eval(hcall, R_GlobalEnv);
UNPROTECT(3);
}
else vwarningcall_dflt(call, format, ap);
}
void warningcall(SEXP call, const char *format, ...)
{
va_list(ap);
va_start(ap, format);
vsignalWarning(call, format, ap);
va_end(ap);
}
该函数用于在C代码中生成警告,也可从支持warning()
的C函数do\u warning
调用
因此,每当发出警告时,muffleWarning
处理程序始终可用