How to apply rules of grammar?

[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

[A Former User]

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

[A Former User]

@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.

[VRonin]

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

but I need to avoid using functions

I'm confused... can I ask why?

The code before the last one helps a lot

QString stringToTranslate("zxxxyxyxyxxzz");

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

qDebug() << "Translated String: "+stringToTranslate;

[Blaster]

@VRonin
That helps, because I can put in the file all the combinations and then apply them to the string

[VRonin]

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

how to make a regular expression that checks the multiple occurrence of any pattern

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

because I can put in the file all the combinations and then apply them to the string

I'm totally lost now. If somebody else has ideas please step forward

[Blaster]

@VRonin
Let's see, I am Cuban guy and my English is not very strong, I only defend a little.
I explain to you better so you understand.
I have an application in which it is necessary to apply certain rules, one of which I mentioned to you, that of the patterns. This application does not work only in a language and I need to make that the processing of the rules be independent of the language of the application, so I need the rules in a file to be able to make changes when you want to change in some rules or to be able to add a new rule without having to program again