打破父母循环在TCL [英] Breaking parent loop in tcl

问题描述

我在while循环中有一个for循环。

以下是代码：

  while {[gets $ thefile line]> = 0} {
 for {set i 1} {$ i <$ count_table} {incr i} {
 if { regexppattern_ $ i$ line} {
 for {set break_lines 1} {$ break_lines< $ nb_lines} {incr break_lines} {
 if {[gets $ thefile line_ $ break_lines]< 0} break 
} 
} 
 #some其他进程做
} 
  

我想在分析的文件中跳过 $ nb_lines 来做更多的事情。这里break，打破for循环，所以它不起作用。

for循环可以使while循环断开吗？
但破解只是1（或更多）行，我想继续解析文件中断后进一步处理行

谢谢 break 命令（和 continue code>）也不会执行多级循环退出。国际海事组织，最简单的解决方法只是重构的代码，所以你可以返回退出外部循环。但是，如果你不能这样做，那么你可以使用类似的东西（对于8.5和更高版本）：



  proc magictrap {code body} {
 if {$ code< = 4} {errorbad magic code}; ＃如果{[catch {uplevel 1 $ body} msg opt] == $ code} return 
 return -options $ opt $ msg 
} 
 proc为Tcl 
保留的值更低magicthrow代码{返回代码$代码不要紧，这是什么} 
 
，而{[获取$文件行]> = 0} {
 magictrap 5 {
 {for {set i 1} {$ i <$ count_table} {incr i} {
 if {[regexppattern_ $ i$ line]} {
 for {set break_lines 1} {$ break_lines< ; $ nb_lines} {incr break_lines} {
 if {[gets $ thefile line_ $ break_lines]< 0} {magicthrow 5} 
} 
} 
} 
} 
 #s其他进程做
} 
  

5 不是很特别（这只是一个自定义结果代码; Tcl保留0-4，但是其他人却不知道），但是你需要为自己选择一个值，这样它才不会与程序中的其他用途重叠。 （大多数情况下可以重做代码，所以它在8.4之前也可以工作，但是重新抛出一个异常比较复杂。）



请注意自定义的异常代码是Tcl的深魔法部分。如果可以的话，请使用普通的重构。

I have a for loop in a while loop. I have a condition to break the while in the for loop.

Here is the code :

while {[gets $thefile line] >= 0} {
   for {set i 1} {$i<$count_table} {incr i} {
   if { [regexp "pattern_$i" $line] } {
      for {set break_lines 1} {$break_lines<$nb_lines} {incr break_lines} {
         if {[gets $thefile line_$break_lines] < 0} break
      }
   }
   #some other process to do
}

I want to skip $nb_lines in the file parsed to do other thing further. Here the break, breaks the for loop, so it doesn't work.

Can the for loop make the while loop broken ? But the break is just for 1 (or more) lines, i want to continue to parse the file after the break to process line further

Thanks

解决方案

The break command (and continue too) doesn't do multi-level loop exit. IMO, the simplest workaround is to just refactor the code so you can return to exit the outer loop. However, if you can't do that, then you can use something like this instead (for 8.5 and later):

proc magictrap {code body} {
    if {$code <= 4} {error "bad magic code"}; # Lower values reserved for Tcl
    if {[catch {uplevel 1 $body} msg opt] == $code} return
    return -options $opt $msg
}
proc magicthrow code {return -code $code "doesn't matter what this is"}

while {[gets $thefile line] >= 0} {
   magictrap 5 {
      for {set i 1} {$i<$count_table} {incr i} {
         if { [regexp "pattern_$i" $line] } {
            for {set break_lines 1} {$break_lines<$nb_lines} {incr break_lines} {
               if {[gets $thefile line_$break_lines] < 0} {magicthrow 5}
            }
         }
      }
   }
   #some other process to do
}

The 5 isn't very special (it's just a custom result code; Tcl reserves 0–4, but leaves the others alone) but you need to pick a value for yourself so that it doesn't overlap with any other uses in your program. (It is mostly possible to redo the code so it works with 8.4 and before too, but it's quite a bit more complex to rethrow an exception there.)

Be aware that custom exception codes are a "deep magic" part of Tcl. Please use ordinary refactoring instead if you can.

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