feat: impl GetAll and GetAllSeq

Author: steverusso

cli.go

@@ -88,6 +88,7 @@ package cli
 import (
 	"errors"
 	"fmt"
+	"iter"
 	"os"
 	"slices"
 	"strings"
@@ -211,6 +212,34 @@ func GetOrFunc[T any](c *Command, id string, fn func() T) T {
 	return fn()
 }
 
+// GetAll returns all parsed values present for the given id. It converts each value to
+// the given type T through an untested type assertion (so this will panic if any value
+// found can't be converted to type T).
+func GetAll[T any](c *Command, id string) []T {
+	vals := make([]T, 0, len(c.Inputs)/3)
+	for i := range c.Inputs {
+		if c.Inputs[i].ID == id {
+			vals = append(vals, c.Inputs[i].Value.(T))
+		}
+	}
+	return vals
+}
+
+// GetAllSeq returns an iterator over each parsed value that has the given id. The
+// iterator yields the same values that would be returned by [GetAll](c, id) but without
+// constructing the slice.
+func GetAllSeq[T any](c *Command, id string) iter.Seq[T] {
+	return func(yield func(T) bool) {
+		for i := range c.Inputs {
+			if c.Inputs[i].ID == id {
+				if !yield(c.Inputs[i].Value.(T)) {
+					return
+				}
+			}
+		}
+	}
+}
+
 // ParseOrExit will parse input based on this CommandInfo. If help was requested, it
 // will print the help message and exit the program successfully (status code 0). If
 // there is any other error, it will print the error and exit the program with failure

examples_test.go

@@ -492,3 +492,35 @@ func ExampleLookup_positionalArgs() {
 	// a: "hello", true
 	// b: "", false
 }
+
+func ExampleGetAll() {
+	c := cli.New().
+		Opt(cli.NewIntOpt("a").Default("0")).
+		ParseOrExit("-a", "1", "-a", "2", "-a", "3")
+
+	a := cli.GetAll[int](c, "a")
+
+	fmt.Printf("%+#v\n", a)
+	// Output:
+	// []int{0, 1, 2, 3}
+}
+
+func ExampleGetAllSeq() {
+	c := cli.New().
+		Opt(cli.NewOpt("a").Default("Lorem")).
+		ParseOrExit(
+			"-a", "ipsum",
+			"-a", "dolor",
+			"-a", "sit",
+			"-a", "amet")
+
+	for str := range cli.GetAllSeq[string](c, "a") {
+		fmt.Printf("%v\n", str)
+	}
+	// Output:
+	// Lorem
+	// ipsum
+	// dolor
+	// sit
+	// amet
+}