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Programming-Idioms

  • C#
  • Scheme
  • Ruby

Idiom #362 Create delimited list

From list a, create the text s specifying the contents of a, such that items are separated by delimiter d and items containg 1 or more spaces are quoted with quote character q.
Example: "A "," B"," C ",D,E,F

s = a.map{_1.include?(" ") ? q + _1 + q : _1 }.join(d)

In Ruby >= 3.4 _1 can be replaced by it
String s = a.stream()
    .map(x -> {
        if (!x.contains(" ")) return x;
        return q + x + q;
    })
    .reduce((x, y) -> x + d + y)
    .get();
New implementation...
< > ⌨
Bart 
s = a.map{_1.include?(" ") ? q + _1 + q : _1 }.join(d)
String s = a.stream()
    .map(x -> {
        if (!x.contains(" ")) return x;
        return q + x + q;
    })
    .reduce((x, y) -> x + d + y)
    .get();
class X extends ArrayList<String> {
    char d, q;
    X(char d, char q) {
        this.d = d;
        this.q = q;
    }
    @Override
    public boolean add(String s) {
        if (s.contains(" ")) s = q + s + q;
        return super.add(s);
    }
    @Override
    public String toString() {
        return join(valueOf(d), this);
    }
}
X x = new X(d, q);
a.forEach(x::add);
String s = x.toString();
  a.Delimiter := d;
  a.QuoteChar := q;
  a.StrictDelimiter := False;
  a.AlwaysQuote := False;
  s := a.DelimitedText;