Android Question Converting a string

[Sergey_New]

Please tell me how to convert the string "21/01/2020" to "01/21/2020".
I need this to get ticks from a date in "MM.dd.yyyy" format using DateTime.DateParse

 

[Sergey_New]

Not sure, maybe yes, maybe no. Never used AI for programming.

 

[LucaMs]

Not sure, maybe yes, maybe no. Never used AI for programming.

ChatGPT:

' --- costruzione della regex a pezzi (B4X) ---
' qualificatori opzionali come ABT, AFT, FROM, TO, ecc.
Dim reQualifier As String = "(?:(?:ABT|AFT|BEF|BET|CAL|EST|FROM|TO))\s"
Dim reQualifierGroup As String = "(" & reQualifier & ")?" ' gruppo 1 - opzionale

' possibili formati di data:
Dim reDayMonthYear As String = "(?:\d{0,2}\s\D{3}\s\d{1,4})"   ' es. "12 MAR 1990"
Dim reDotDate       As String = "(?:\d{1,2}\.\d{1,2}\.\d{1,4})" ' es. "12.3.1990"
Dim reYear         As String = "\d{1,4}"                       ' es. "1990"

' unione dei formati di data (non-capturing internamente)
Dim reDate As String = "(?:" & reDayMonthYear & "|" & reDotDate & "|" & reYear & ")"

' separatore di intervallo (AND o TO) come gruppo opzionale
Dim reRangeSepGroup As String = "((?:AND|TO))?" ' gruppo 3 nella composizione finale

' seconda data opzionale (gruppo 4)
Dim secondDateGroup As String = "(" & reDate & ")?" ' gruppo 4 - opzionale

' composizione finale (corrisponde alla regex originale)
Dim patDate As String = reQualifierGroup & reDate & "\s?" & reRangeSepGroup & "\s?" & secondDateGroup

To test:

Dim source As String = "FROM 12 MAR 1990 TO 1995"
Dim m As Matcher = Regex.Matcher(patDate, source)
If m.Find = True Then
    Log("Match completo: " & m.Group(0))
    Log("Qualifier (gr.1): " & m.Group(1))   ' es. "FROM "
    Log("Date1     (gr.2): " & m.Group(2))   ' es. "12 MAR 1990"
    Log("RangeSep  (gr.3): " & m.Group(3))   ' es. "TO"
    Log("Date2     (gr.4): " & m.Group(4))   ' es. "1995" (può essere null)
End If

 

[Sergey_New]

To test:

Thanks, that's what I do.

Sub date_parse(dates As String) As String(4)
    Dim m As Matcher = Regex.Matcher(patDate,dates)
    Dim pref1 As String
    Dim date1 As String
    Dim pref2 As String
    Dim date2 As String
    Do While m.Find
        pref1 = m.Group(1)
        date1 = m.Group(2)
        pref2 = m.Group(3)
        date2 = m.Group(4)
    Loop
    If pref1=Null Then
        pref1=""
    Else
        pref1=pref1.Trim
        pref1=Starter.loc.Localize(pref1)
    End If
    If pref2=Null Then
        pref2=""
    Else
        pref2=Starter.loc.Localize(pref2.Trim)
    End If
    If date1.Length>4 Then
        date1=ConvertDate(date1)
    End If
    If date2<>Null Then
        If date2.Length>4 Then
            date2=ConvertDate(date2)
        End If
    Else
        date2=""
    End If
    Return Array As String(pref1,date1,pref2,date2)
End Sub

The problem will be with the date "FROM MAR 12 1990 TO 1995"
We need to somehow supplement the pattern for the formats "MM.dd.yyyy", "MM/dd/yyyy", "MM-dd-yyyy", "yyyy/MM/dd", "yyyy-MM-dd"

 

[LucaMs]

We need to somehow supplement the pattern for the formats "MM.dd.yyyy", "MM/dd/yyyy", "MM-dd-yyyy", "yyyy/MM/dd", "yyyy-MM-dd"

We? ChatGPT

Trying to ask it...

it provided two (equivalent) versions:
1.

' formati già presenti
Dim reDayMonthYear As String = "(?:\d{0,2}\s\D{3}\s\d{1,4})"   ' es. "12 MAR 1990"
Dim reDotDate       As String = "(?:\d{1,2}\.\d{1,2}\.\d{1,4})" ' es. "12.3.1990"
Dim reYear          As String = "\d{1,4}"                       ' es. "1990"

' nuovi formati numerici
Dim reMM_DD_YYYY_Dot As String = "(?:\d{1,2}\.\d{1,2}\.\d{4})"
Dim reMM_DD_YYYY_Slash As String = "(?:\d{1,2}/\d{1,2}/\d{4})"
Dim reMM_DD_YYYY_Dash As String = "(?:\d{1,2}-\d{1,2}-\d{4})"
Dim reYYYY_MM_DD_Slash As String = "(?:\d{4}/\d{1,2}/\d{1,2})"
Dim reYYYY_MM_DD_Dash As String = "(?:\d{4}-\d{1,2}-\d{1,2})"

' unione di tutti i formati
Dim reDate As String = "(?:" & reDayMonthYear & "|" & reDotDate & "|" & reYear & "|" & reMM_DD_YYYY_Dot & "|" & reMM_DD_YYYY_Slash & "|" & reMM_DD_YYYY_Dash & "|" & reYYYY_MM_DD_Slash & "|" & reYYYY_MM_DD_Dash & ")"

2.

' --- costruzione regex aggiornata ---
Dim reQualifier As String = "(?:(?:ABT|AFT|BEF|BET|CAL|EST|FROM|TO))\s"
Dim reQualifierGroup As String = "(" & reQualifier & ")?"

' formati di data supportati
Dim reDayMonthYear As String = "(?:\d{0,2}\s\D{3}\s\d{1,4})"   ' es. 12 MAR 1990
Dim reDotDate      As String = "(?:\d{1,2}\.\d{1,2}\.\d{1,4})" ' es. 12.03.1990
Dim reSlashDate    As String = "(?:\d{1,2}/\d{1,2}/\d{1,4})"   ' es. 12/03/1990
Dim reDashDate     As String = "(?:\d{1,2}-\d{1,2}-\d{1,4})"   ' es. 12-03-1990
Dim reYearFirstSlash As String = "(?:\d{4}/\d{1,2}/\d{1,2})"   ' es. 1990/03/12
Dim reYearFirstDash  As String = "(?:\d{4}-\d{1,2}-\d{1,2})"   ' es. 1990-03-12
Dim reYear         As String = "\d{1,4}"                       ' es. 1990

' unione dei formati in un'unica regex
Dim reDate As String = "(?:" & reDayMonthYear & "|" & reDotDate & "|" & reSlashDate & "|" & reDashDate & "|" & reYearFirstSlash & "|" & reYearFirstDash & "|" & reYear & ")"

' separatore AND|TO
Dim reRangeSepGroup As String = "((?:AND|TO))?"

' seconda data opzionale
Dim secondDateGroup As String = "(" & reDate & ")?"

' regex finale
Dim patDate As String = reQualifierGroup & reDate & "\s?" & reRangeSepGroup & "\s?" & secondDateGroup

 

[Sergey_New]

We?

Google translator

it provided two (equivalent) versions:

I'll try to figure it out.

 

[Sergey_New]

Both options do not work.
Example attached.

 

[LucaMs]

Both options do not work.
Example attached.

Try asking some AIs, they are free (not always, not forever).

https://chatgpt.com/

https://copilot.microsoft.com/

https://gemini.google.com/?hl=en

https://www.perplexity.ai/

 

[Sergey_New]

ry asking some AIs

I don't have access to these links, and I don't know how to ask AI questions about programming.

 

[LucaMs]

I don't have access to these links, and I don't know how to ask AI questions about programming.

It's not hard!

Ask in your language:

Translate the following code into B4X code:

Dim patDate As String="((??:ABT|AFT|BEF|BET|CAL|EST|FROM|TO))\s)?((?:\d{0,2}\s\D{3}\s\d{1,4})|(?:\d{1,2}\.\d{1,2}\.\d{1,4})|\d{1,4})\s?((?:AND|TO))?\s?((?:\d{0,2}\s\D{3}\s\d{1,4})|(?:\d{1,2}\.\d{1,2}\.\d{1,4})|\d{1,4})?"

 

[Sergey_New]

It's not hard!

I don't have access to these links

Translate the following code into B4X code

I don't get it, this is the B4X code

 

[LucaMs]

I don't have access to these links

Are there any AI sites in Russia? Try them.

 

[Sergey_New]

Are there any AI sites in Russia?

Yes, and Chinese ones too.
But how to ask a question? Just attach a pattern?

 

[LucaMs]

But how to ask a question?

Exactly so:

https://www.b4x.com/android/forum/threads/converting-a-string.168560/post-1033221

or, better:

"Переведите следующий код в код B4X:"

Dim patDate As String="((?:(?:ABT|AFT|BEF|BET|CAL|EST|FROM|TO))\s)?((?:\d{0,2}\s\D{3}\s\d{1,4})|(?:\d{1,2}\.\d{1,2}\.\d{1,4})|\d{1,4})\s?((?:AND|TO))?\s?((?:\d{0,2}\s\D{3}\s\d{1,4})|(?:\d{1,2}\.\d{1,2}\.\d{1,4})|\d{1,4})?"

 

[Sergey_New]

I'll try, thanks!

 

[emexes]

I feel like this could be a useful part of the regex pattern:

(\d{1,2}|\d{4}|[a-zA-Z]{3})

regex101: build, test, and debug regex

Regular expression tester with syntax highlighting, explanation, cheat sheet for PHP/PCRE, Python, GO, JavaScript, Java, C#/.NET, Rust.

regex101.com

and also that regex is going to become more and more unwieldy as you try to cover more and more variations, so that eventually you're going to end up using a B4X Sub to parse it, especially if you are also to handle from-to- date ranges.

Are these dates coming from user input, or from a file?

Also what are the prefixes "cal" and "est"?

Is "cal" for "calendar", or for "calculate"?

The "est" reminds me of a book catalogue assignment at uni that needed to be able to represent approximate dates as well as actual dates.

With the prefixes, I'd be moving towards the VAX VMS CLI approach of recognising the minimum unique start of keywords, eg for the prefix "before" you'd also recognise "bef", "befo", "befor" and "before", and "after" would recognise "aft", "afte" and "after".

Same with the mmm representation for months - I have a vague recollection that some date formatting routines expect/emit "july" (not "jul") for July. And not that you're interpreting day-of-week (yet) but I have often seen Tuesday shortened to "tues" and less-often Thursday shortened to "thurs".

It's nice to have the shortened versions but it's also nice to let the user just type the whole prefix instead of having to remember the short versions.

Especially for "abt" which is not the first 3 letters of "about". "abt" is a good shortening, but it's one more thing to remember.

 

[emexes]

Maybe this might spark some new parsing ideas too:

Dim TestDate() As String = Array As String( _
    "from 1st July 2020 to 09-09-25", _
    "August 1st, 1291", _
    "09/09/2025" _
)

For Each TD As String In TestDate
    Dim DateElement() As String = Regex.Split("[^\w]+", TD)    'splits string into alphanumeric-plus-underscore words - use [^0-9A-Za-z] if underscores are a problem
  
    Log(TD)
    For Each E As String In DateElement
        Log(TAB & E & TAB & Regex.Replace("[^0-9]", E, ""))
    Next
Next

from 1st July 2020 to 09-09-25
    from 
    1st     1
    July 
    2020    2020
    to 
    09      09
    09      09
    25      25
August 1st, 1291
    August 
    1st     1
    1291    1291
09/09/2025
    09      09
    09      09
    2025    2025

 

[emexes]

To handle " to " date ranges, maybe:

Dim TestDate() As String = Array As String( _
    "from 1st July 2020 to 09-09-25", _
    "August 1st, 1291", _
    "09/09/2025" _
)

For Each TD As String In TestDate
    Dim DateElement() As String = Regex.Split("[^\w]+", TD)
    
    Log(TD)
    
    Dim DateRange() As String = Regex.Split("\s+[Tt][Oo]\s+", TD)
    For Each D As String In DateRange
        Log(TAB & D)
    Next
Next

from 1st July 2020 to 09-09-25
    from 1st July 2020
    09-09-25
August 1st, 1291
    August 1st, 1291
09/09/2025
    09/09/2025

 

[Sergey_New]

Also what are the prefixes

Prefixes are taken from the data file and cannot be changed.
This is their purpose:
ABT = About, meaning the date is not exact.
CAL = Calculated mathematically, for example, from an event date and age.
EST = Estimated based on an algorithm using some other event date.
AFT = Event happened after the given date.
BEF = Event happened before the given date.
BET = Event happened some time between date 1 AND date 2.
FROM = Indicates the beginning of a happening or state.
TO = Indicates the ending of a happening or state.
AND = Indicates that an event took place at some time between two dates.

 

[Sergey_New]

Maybe this might spark some new parsing ideas too

Thank you!
I have already written above that my pattern copes well with parsing dates, except for individual date formats.
Since the code is large, I will try to extract the necessary code from the program and create a small example. It needs to add changes for date formats that cannot be processed yet.

 

[emexes]

Prefixes are taken from the data file and cannot be changed.

Ah well, that simplifies things then - one less thing to do.