Picocli: arbitrary length of paired parameters - picocli

Question

In Picocli, is it possible to pair parameters of an arbitrary length? For example:
grades Abby 4.0 Billy 3.5 Caily 3.5 Danny 4.0
where each pair must have a name and a grade but the total length is unknown, i.e.:
grades <name> <grade> [<name> <grade>]*
A parameter map is the closest that appears might work, e.g.
#Parameters(index = "0..*") Map<String, float> grades;
would parse:
grades Abby=4.0 Billy=3.5 Caily=3.5 Danny=4.0
into the map but it'd be nicer if the equals wasn't there...

Answer 1

Update: picocli 4.3 has been released with improved support for positional parameters in argument groups.
#Command(name = "grades", mixinStandardHelpOptions = true, version = "grades 1.0")
public class Grades implements Runnable {
static class StudentGrade {
#Parameters(index = "0") String name;
#Parameters(index = "1") BigDecimal grade;
}
#ArgGroup(exclusive = false, multiplicity = "1..*")
List<StudentGrade> gradeList;
#Override
public void run() {
gradeList.forEach(e -> System.out.println(e.name + ": " + e.grade));
}
public static void main(String[] args) {
System.exit(new CommandLine(new Grades()).execute(args));
}
}
Running the above program with this input:
Alice 3.5 Betty 4.0 "X Æ A-12" 3.5 Zaphod 3.4
Produces the following output:
Alice: 3.5
Betty: 4.0
X Æ A-12: 3.5
Zaphod: 3.4
Prior to picocli 4.3, applications can do the following to accomplish this:
import picocli.CommandLine;
import picocli.CommandLine.Command;
import picocli.CommandLine.Parameters;
import java.math.BigDecimal;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
#Command(name = "grades", mixinStandardHelpOptions = true, version = "grades 1.0")
public class Grades implements Runnable {
#Parameters(arity = "2",
description = "Each pair must have a name and a grade.",
paramLabel = "(NAME GRADE)...", hideParamSyntax = true)
List<String> gradeList;
#Override
public void run() {
System.out.println(gradeList);
Map<String, BigDecimal> map = new LinkedHashMap<>();
for (int i = 0; i < gradeList.size(); i += 2) {
map.put(gradeList.get(i), new BigDecimal(gradeList.get(i + 1)));
}
}
public static void main(String[] args) {
int exitCode = new CommandLine(new Grades()).execute(args);
System.exit(exitCode);
}
}