Question

我有一个像

这样的字符串

<? if $items.var1.var2 == $items2.var1.var2 ?>

我想替换它看起来像这样的字符串

<? if $items->{var1}->{var2} == $items2->{var1}->{var2} ?>

所以这样的字符串我想替换没有引用'$ items2.var1.var2'这样的字符串

 <? if $items.var1.var2 == '$items2.var1.var2' ?>

任何人都可以帮助我吗？

Answer 1

因此，只有当后跟偶数引号时才需要替换点/变量。在Python中，例如：

>>> re.sub(r"\.(\w+)(?=(?:[^']*'[^']*')*[^']*$)", r"->{\1}",
...         "<? if $items.var1.var2 == '$items2.var1.var2' ?>")
"<? if $items->{var1}->{var2} == '$items2.var1.var2' ?>"

<强>解释

\.       # Match .
(\w+)    # Match an alnum word and capture it
(?=      # Assert that it's possible to match:
 (?:     # Match this (don't capture):
  [^']*' # Any number of non-quotes, followed by a '
  [^']*' # The same again
 )*      # any number of times, including 0
 [^']*   # Match any number of non-quotes 
 $       # until the end of the string.
)        # End of lookahead assertion.

Answer 2

这适用于perl：

$str =~ s/\.(?=(\w|\.)+(?!'|"|\.)\W)/->/g;
#explained:
$str =~ s/
        \.             #A literal .
        (?=            #Followed by
          (\w|\.)+     #More than one word char or literal .
          (?!'|"|\.)   #Terminated by a \W (non-word char) that's not ',", or .
          \W
        )
        /->/gx;

至少对你的例子而言。 http://codepad.org/a4L43hDr

正则表达式替换变量指针替换

2 个答案: