How Can I Reliably Detect Semi-Colon Terminated C for and While Loops Using Python?

Regular Expression to Detect Semi-Colon Terminated C for & While Loops

In Python, crafting a regular expression that identifies C for or while loops terminated with a semi-colon can be a challenge. This article addresses the need for such a regex, tackling the complexities of balanced substrings and the presence of functions within loop arguments.

The Challenge of Balanced Substrings

Initially, the proposed regex used a named group, 'balanced,' to capture balanced substrings within the loop arguments. However, this approach faltered when loop arguments contained functions, causing the regular expression to break.

A Simplified Approach

To overcome the complexity of regular expressions, the suggested alternative employs a straightforward routine without using a regex:

• Define a position counter pos to the opening parenthesis after for or while.
• Establish an open bracket counter openBr to zero.
• Iterate pos, incrementing openBr for opening brackets and decrementing it for closing brackets.
• The iteration stops when openBr returns to zero, indicating the closing bracket of the loop.
• Check if a semi-colon follows the closing bracket.

This approach offers a reliable solution for detecting loops with semi-colon termination, even in the presence of functions in loop arguments.

The above is the detailed content of How Can I Reliably Detect Semi-Colon Terminated C for and While Loops Using Python?. For more information, please follow other related articles on the PHP Chinese website!