parsing text in blocks and line too

[A.T.Hofkamp]

On 2007-04-12, flyzone at technologist.com <flyzone at technologist.com> wrote:
> Goodmorning people :)
> I have just started to learn this language and i have a logical
> problem.
> I need to write a program to parse various file of text.
> Here two sample:
>
> ---------------
> trial text bla bla bla bla error
>       bla bla bla bla bla
>       bla bla bla on more lines
> trial text bla bla bla bla warning bla
>       bla bla more bla to be grouped with warning
>       bla bla bla on more lines
>       could be one two or ten lines also withouth the tab beginning
> again text
> text can contain also blank lines
> text no delimiters....
> --------------
> Apr  8 04:02:08 machine text on one line
> Apr  8 04:02:09 machine this is an error
> Apr  8 04:02:10 machine this is a warning
> --------------

I would first read groups of lines that belong together, then decide on each
group whether it is an error, warning, or whatever.
To preserve order in a group of lines, you can use lists.

>From your example you could first compute a list of lists, like

[ [ "trial text bla bla bla bla error",
    "      bla bla bla bla bla",
    "      bla bla bla on more lines" ],
  [ "trial text bla bla bla bla warning bla",
    "      bla bla more bla to be grouped with warning",
    "      bla bla bla on more lines",
    "      could be one two or ten lines also withouth the tab beginning" ],
  [ "again text" ],
  [ "text can contain also blank lines" ],
  [ ],
  [ "text no delimiters...." ]
]

Just above the "text no delimiters...." line I have added an empty line, and I
translated that to an empty group of lines (denoted with the empty list).

By traversing the groups (ie over the outermost list), you can now decide for
each group what type of output it is, and act accordingly.

> Hope someone could give me some tips.

Sure, however, in general it is appreciated if you first show your own efforts
before asking the list for a solution.

Albert