How to apply rules of grammar?

Blaster

@mrjj
Let me explain myself better.
I have a fairly large text and after clicking on a button, the application should apply the rules to the text, and I say the rules because it is not one are several.
What makes it difficult is that the rules have to be in a file because they depend on other factors.
My problems are:
How do I write the rules in a file so that the application can understand them?
How, after reading them, do I apply them to my text?

mrjj

@Blaster
But how is your rule defined?
That will determine how u can save them.

Can you show 1 rule?

Blaster

@mrjj
I already told you that I do not know how to express them, but in principle, the one I set as an example, would be:
xx -> x
xyxy -> xy
I don't know, something like that

mrjj

@Blaster
well im asking you to express a rule in english :)

If only action is text replacement then format could be

Text to find, text to replace tp

but i not sure what rules can be.

A rule is only Text To Find, Text to replace with or is a rule something else?

Blaster

@mrjj
There are other rules and it is not just text to replace. The idea of this rule is to find the occurrence of consecutive patterns and leave only one occurrence, which is what I find difficult to express

mrjj

@Blaster

Well one way is just to use name for what function to call

TriggerText, Action, Param1
afffd, one_occurrence, none
HHH, text_replace, thetext

This is epic esy to read in with Qt.

But I would first write up all rules and what data it needs to operate.
That would give you idea on what format is needed.

Blaster

@mrjj
It's a good idea, but what I want is not having to write a function for each rule

VRonin

@Blaster said in How to apply rules of grammar?:

The idea of this rule is to find the occurrence of consecutive patterns and leave only one occurrence

put the patterns in a file, one by line. for each line do a replace with QRegularExpression replacing "(?:%1)+" with "%1" where %1 is the pattern

? Offline

Hi! Don't know anything about hieroglyphs, but if the language they represent has a context-free grammar, then you can express the rules in Backus-Naur form and process the source text with Flex and Bison.

kshegunov

@Wieland said in How to apply rules of grammar?:

if the language they represent has a context-free grammar

I have not encountered a natural (i.e. human) language that can be prescribed by a context-free grammar. Otherwise I completely agree, for what it's worth. :)

Blaster

@Wieland said in How to apply rules of grammar?:

Hi! Don't know anything about hieroglyphs, but if the language they represent has a context-free grammar, then you can express the rules in Backus-Naur form and process the source text with Flex and Bison

An example please

? Offline

@Blaster https://en.wikipedia.org/wiki/Context-free_grammar, https://en.wikipedia.org/wiki/Backus–Naur_form

Blaster

@VRonin
In this case ... how do I make the regular expression capture the occurrence of equal letters without defining what the letter

VRonin

@Blaster said in How to apply rules of grammar?:

I was thinking of loading a file with the rules

without defining what the letter

I'm confused now...

let's say you have a UTF-8 text file (rules.txt) that contains:

x
xy

You can use

QString stringToTranslate("xyxyxx");
QFile rulesFile("rules.txt");
if(rulesFile.open(QFile::ReadOnly | QFile::Text)){
QTextStream rulesStream(&rulesFile);
rulesStream.setCodec("UTF-8");
QString line;
while (stream.readLineInto(&line))
stringToTranslate.replace(QRegularExpression("(?:"+QRegularExpression::escape(line)+")+",line);
}
qDebug() << "Translated String: "+stringToTranslate;

Is this what you wanted?

Blaster

@VRonin
What I really want to know is how to make a regular expression that checks the multiple occurrence of any pattern, not including some specific character in the expression.
Something like, for example

"x{2,}"

that would match any string containing 2 or more repeated characters regardless of the character

Blaster

@Wieland
It is not grammar free of context, it is a gramática similar to the one of our languages

VRonin

Imagine the input is xxxyxy do you want the output to be xxy or xy?

Blaster

@VRonin
Just xy

VRonin

I know it's very inefficient but my brain can't optimise on Monday. At least it works:


QString removeDuplicates(QString source){
    for(int matchLen = source.size()/2; matchLen>0;--matchLen){
        for(int startOfset=0;(2*matchLen)+startOfset<=source.size();){
            if(source.midRef(startOfset,matchLen)==source.midRef(matchLen+startOfset,matchLen))
                source.remove(matchLen+startOfset,matchLen);
            else
                ++startOfset;
        }
    }
    return source;
}

Blaster

@VRonin
I appreciate the effort, but I need to avoid using functions and that's why I'm talking about regular expressions. The code before the last one helps a lot.