1 files changed, 103 insertions, 0 deletions

diff --git a/src/list.zig b/src/list.zig
new file mode 100644
index 0000000..d97ba87
--- /dev/null
+++ b/src/list.zig
@@ -0,0 +1,103 @@
+const std = @import("std");
+const zup = @import("zup");
+
+const Allocator = std.mem.Allocator;
+const ArrayList = std.ArrayList;
+const Installation = zup.Installation;
+const Installations = zup.Installations;
+
+pub const params =
+    \\--active         List the active version
+    \\-a, --all        List the active, available, and installed versions
+    \\-A, --available  List available versions
+    \\-i, --installed  List installed versions
+;
+pub const description = "Lists Zig versions.  Default is `--active -i`.";
+pub const min_args = 0;
+pub const max_args = 0;
+
+pub fn main(comptime Result: type, allocator: Allocator, res: Result) !void {
+    var list_active = res.args.active;
+    var list_available = res.args.available;
+    var list_installed = res.args.installed;
+
+    if (res.args.all) {
+        list_active = true;
+        list_available = true;
+        list_installed = true;
+    } else if (!list_active and !list_available and !list_installed) {
+        list_active = true;
+        list_installed = true;
+    }
+
+    if (list_active) {
+        var active = try Installation.getActiveName(allocator);
+        defer if (active) |s| allocator.free(s);
+        try printActive(active);
+    }
+
+    if (list_installed) {
+        var installed = try Installation.getInstalledList(allocator);
+        defer Installation.deinitMap(allocator, &installed);
+        try printInstalledList(allocator, installed);
+    }
+
+    if (list_available) {
+        var available = try Installation.getAvailableList(allocator);
+        defer Installation.deinitMap(allocator, &available);
+        try printAvailableList(allocator, available);
+    }
+}
+
+// TODO: zig-bug active should be ?[]const u8
+fn printActive(active: ?[]u8) !void {
+    const writer = std.io.getStdOut().writer();
+    try writer.writeAll("Active installation: ");
+    if (active) |act| {
+        try writer.writeAll(act);
+    } else {
+        try writer.writeAll("NONE");
+    }
+
+    try writer.writeByte('\n');
+}
+
+fn printAvailableList(allocator: Allocator, avail: Installations) !void {
+    const writer = std.io.getStdOut().writer();
+    try writer.writeAll("Available versions:\n");
+    try printList(allocator, avail);
+}
+
+fn printInstalledList(allocator: Allocator, installed: Installations) !void {
+    const writer = std.io.getStdOut().writer();
+    try writer.writeAll("Installed versions:\n");
+    try printList(allocator, installed);
+}
+
+fn printList(allocator: Allocator, installations: Installations) !void {
+    const InstallationAndName = struct {
+        name: []const u8,
+        installation: Installation,
+
+        const Self = @This();
+
+        pub fn lessThan(_: void, lhs: Self, rhs: Self) bool {
+            return lhs.installation.version.order(rhs.installation.version) == .lt;
+        }
+    };
+
+    var list = try ArrayList(InstallationAndName).initCapacity(allocator, installations.unmanaged.size);
+    defer list.deinit();
+
+    var it = installations.iterator();
+    while (it.next()) |kv| {
+        list.appendAssumeCapacity(.{ .name = kv.key_ptr.*, .installation = kv.value_ptr.* });
+    }
+
+    std.sort.sort(InstallationAndName, list.items, {}, InstallationAndName.lessThan);
+
+    const writer = std.io.getStdOut().writer();
+    for (list.items) |item| {
+        try writer.print("  {s}: {}\n", .{ item.name, item.installation.version });
+    }
+}