`renameToCamelCase` for columns with names starting with capital letter should lowercase it

[belovrv]

[zaleslaw]

@belovrv what kind of CamelCase do you want?

• CamelCase?
• camelCase? (style lowerCamelCase) <-------- this one, isn't it?

Why am I asking? Because for now, looks like the function doing what you want, it makes from column name "another_name" -> "anotherName"

Or do you want to get in this case "AnotherName" ? But it's uppercase CamelCase

For now, we have no documentation for this function, please give some examples of usage or share some insights

[zaleslaw]

@Jolanrensen how do you estimate this code?

For me, it looks like a strange 2-3 level repeating function s with recursive call.

If it's a common pattern to apply changes in the dataframe, could you advise how to interpret correctly the code?

public fun <T> DataFrame<T>.renameToCamelCase(): DataFrame<T> {
    return rename {
        dfs { it.isColumnGroup() && it.name() matches DELIMITED_STRING_REGEX }
    }.toCamelCase()
        .rename {
            dfs { !it.isColumnGroup() && it.name() matches DELIMITED_STRING_REGEX }
        }.toCamelCase()
        .update {
            dfsOf<AnyFrame>()
        }.with { it.renameToCamelCase() }
}

[Jolanrensen]

@zaleslaw
It says:
First, recursively rename all column groups to camel case,
then recursively rename all other columns to camel case,
then finally, take all frame columns recursively and call renameToCamelCase() on all dataframes inside.

It might look clearer after my rename:

public fun <T> DataFrame<T>.renameToCamelCase(): DataFrame<T> = this
    .rename {
        // rename groups first, because groups and their children cannot be renamed/moved at the same time
        groups { it.name() matches DELIMITED_STRING_REGEX }.recursively()
    }.toCamelCase()

    .rename {
        cols { it.name() matches DELIMITED_STRING_REGEX }.recursively(includeGroups = false)
    }.toCamelCase()

    .update {
        colsOf<AnyFrame>().recursively()
    }.with { it.renameToCamelCase() }

[belovrv]

Now if you have ColumnName, it will convert it to ColumnName, and I prefer columnName, which is Kotlin style property