RegexLib█ OVERVIEW
This library contains regular expression (regex) search functions which are helpful, in particular, in reading configuration inputs.
feedRgx(): Searches for the first occurrence of `regex` pattern in the `src` and returns `src` split into parts as a tuple: ` `. If no match returns ` `
countRgx(): Counts `regex` occurrences in the `src`.
matchRgx(): Finds given `occurence` of `regex` pattern in `src` string.
NB! countRgx() and matchRgx() do not support `^` (beginning of the string placeholder), lookbehind some other complex patterns, because they works by cutting off the part of the string up to the first found occurence (inclusive) and then continuing the search on the remainder of the string. E.g. in a four line source `(?<= ).+ ` should match the second and the third lines but matchRgx only matches the second line since after matching it continues to search in the remainder AFTER the match only.
█ FULL LIST OF FUNCTIONS AND PARAMETERS
method feedRgx(src, regex)
Searches for the first occurrence of ` regex ` pattern in the ` src ` and returns ` src ` split into parts as a tuple: ` `. If no match returns ` `
Namespace types: series string, simple string, input string, const string
Parameters:
src (string) : (string) String to search for the regex pattern
regex (string) : (string) RegEx pattern
Returns: A tuple ` ` where `begS` is the part of the `src` string from the beginning up to the
first occurence of the `regex` pattern (or up to the end if not found), `matchS` - the first occurrence of the
regex pattern and `endS` the part of the strinf following the first occurrence of the `regex` pattern.
method countRgx(src, regex)
Counts `regex` occurrences in the `src`. ___NB!___ _Does not support `^` (beginning of the string
placeholder), lookbehind some other complex patterns, because it works by cutting off the part of the string up to
the first found occurence (inclusive) and then continuing the search on the remainder of the string. E.g. in a four line source `(?<= ).+ ` should match the second and the third lines but matchRgx only
matches the second line since after matching it continues to search in the remainder AFTER the match only. _
Namespace types: series string, simple string, input string, const string
Parameters:
src (string) : (string) String in which the regex pattern occurences are to be counted
regex (string) : (string) RegEx pattern
Returns: The number of occurrences of the `regex` pattern in the `src` string.
method matchRgx(src, regex, occurrence)
Finds given `occurence` of `regex` pattern in `src` string. ___NB!___ _Does not support `^` (beginning of the string placeholder), lookbehind and some other complex patterns, because it works by cutting off the part of the string up to the first found occurence (inclusive) and then continuing the search on the remainder of the string. E.g. in a four line source `(?<= ).+ ` should match the second and the third lines but matchRgx only matches the second line since after matching it continues to search in the remainder AFTER the match only. _
Namespace types: series string, simple string, input string, const string
Parameters:
src (string) : (string) String to search for the regex pattern
regex (string) : (string) RegEx pattern
occurrence (int) : (int) (Default is 1) The number of the occurrence to search for. If this params exceeds the actual
number of occurrences of the pattern in the `src` string the following tuple is returned
Returns: A tuple, matchS - matched substring, matchPos - position of the match, matchL - match length
█ HOW TO USE
See DEMO section in the script.
You can test regex patterns by playing around with script input settings.
Another usage example can be found in my CSVParser and HTFMAs libraries.
Regex
composite_ticker_cleanerLibrary "composite_ticker_cleaner"
Extract a clean symbol from a composite ticker. E.g., (BINANCE:BTCUSD+KRAKEN:BTCUSD)/2 as input will return BTCUSD or BINANCE:BTCUSD
composite_ticker_cleaner_extract_first(symbol, keepexchange)
Extract the first symbol out of the supplied string (usually ticker.standard(syminfo.tickerid) )
Parameters:
symbol : string input string to search in
keepexchange : bool (optional) Keep exchange in the returned ticker? By default, we only return the symbol without the exchange.
Returns: first occurrence of a symbol
composite_ticker_cleaner_extract_first(keepexchange)
Extract the first symbol out of the current tickerid (as provided by ticker.standard(syminfo.tickerid) )
Parameters:
keepexchange : bool (optional) Keep exchange in the returned ticker? By default, we only return the symbol without the exchange.
Returns: first occurrence of a symbol in the current tickerid
This is inspired by the work I did on this indicator:
I needed a similar functionality in another script, so instead of duplicating code, I thought generalizing the process in a library could be helpful for me and others, and will be easier to maintain and upgrade with new features if I need to.
