Question

This is for an assignment. If anybody else who is doing this assignment finds this code then please don’t copy it.

EDIT: Apologies, as this work is now copyable, please credit me and I will ask my professor more on what he thinks of the matter.

So I have some file which contains something like this

public Test();
  Code:
   Stack=1, Locals=1, Args_size=1
   0:   aload_0
   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V
   4:   return
  LineNumberTable: 
   line 3: 0


public static void main(java.lang.String[]);
  Code:
   Stack=3, Locals=3, Args_size=1
   0:   new #2; //class java/util/Scanner
   3:   dup
   4:   getstatic   #3; //Field java/lang/System.in:Ljava/io/InputStream;
   7:   invokespecial   #4; //Method java/util/Scanner."<init>":(Ljava/io/InputStream;)V
   10:  astore_1
   11:  aload_1
   12:  invokevirtual   #5; //Method java/util/Scanner.nextLine:()Ljava/lang/String;
   15:  astore_2
   16:  getstatic   #6; //Field java/lang/System.out:Ljava/io/PrintStream;
   19:  aload_2
   20:  invokestatic    #7; //Method add_periods:(Ljava/lang/String;)Ljava/lang/String;
   23:  invokevirtual   #8; //Method java/io/PrintStream.println:(Ljava/lang/String;)V
   26:  return
  LineNumberTable: 
   line 6: 0
   line 8: 11
   line 9: 16
   line 10: 26

and I am trying to separate the output so that the first output will be the following.

public Test();
  Code:
   Stack=1, Locals=1, Args_size=1
   0:   aload_0
   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V
   4:   return
  LineNumberTable: 
   line 3: 0

and the second output would be the second method. Assume that I can’t use split using double new line characters as delimiters due to the fact that some of the output not shown here will be grabbed that I would rather not grab.

I have a regular expression that looks like the following.

files.scan(/.*\)\;\n(.+\n)*/)

What the regular expression is trying to do is the following:
The first part of the regular expression .*\)\; is trying to match the method name and it works fine.
The second part is supposed to match every single line after it and stop until it sees a double new line character at which stage it fails due to there being a double new line character.
What it returns instead is the last line of every single method and I don’t know why.
The same regex in python as shown below gets the whole piece of code but this doesn’t

ANSWER=re.search(r'.*\);\n(.+\n)*', STRING)

Can anyone explain why it isn’t working?

As this is an assignment after all please don’t give code to solve the problem that I am trying to do. I appreciate that, thanks.

Answer 1

The problem is that scan returns an array of only the group matches (the parenthesized parts of the regexp) if there are any groups. To avoid the parenthesized parts becoming a group you can modify your regexp to use (?:...) instead of (...). scanwill return an array of the whole matches.

Or, you can hand over a block to scan which has access to the groups as well as to the whole match through the variables $1, $2, … and $&.

See Ruby’s doc for scan.