refactor: obtain arguments through process initialization

std/process/arguments.hon

@@ -1,18 +1,11 @@
-# the bootstrap Init currently exposes only io; macOS provides process-lifetime argv storage.
-@hide:file
-_NSGetArgc c_func() @c_int
-
-@hide:file
-_NSGetArgv c_func() @*[*;0]u8
-
-argument_count proc() usize {
-    return usize(_NSGetArgc()^)
+argument_count proc(args Args) usize {
+    return args.values.len
 }
 
-#! returns a borrowed, zero-terminated slice; storage lasts for the process lifetime.
-argument proc(index usize) ?[;0]u8 {
-    if (index >= argument_count()) return null
-    pointer :: _NSGetArgv()^[index]
+#! returns a borrowed, zero-terminated slice, valid while the supplied argument storage lives.
+argument proc(args Args, index usize) ?[;0]u8 {
+    if (index >= argument_count(args)) return null
+    pointer :: args.values[index]
     length := usize(0)
     while (pointer[length] != 0) length += 1
     return pointer[..length;0]

std/process/arguments.test.hon

@@ -0,0 +1,27 @@
+import "@std/testing"
+import "@std/mem"
+
+borrows_supplied_arguments test {
+    first [3;0]mut u8 := ['r', 'u', 'n']
+    empty [0;0]u8 := []
+    spaced [9;0]u8 := ['t', 'w', 'o', ' ', 'w', 'o', 'r', 'd', 's']
+    pointers [3][*;0]u8 :: [(&first).ptr, (&empty).ptr, (&spaced).ptr]
+    args :: Args{ values = pointers[..] }
+    try testing.expect_equal(usize(3), argument_count(args))
+    if (argument(args, 0)) |value| {
+        first[0] = 'f'
+        try testing.expect(mem.eql(value, "fun"))
+    } else { try testing.expect(false) }
+    if (argument(args, 1)) |value| {
+        try testing.expect_equal(usize(0), value.len)
+    } else { try testing.expect(false) }
+    if (argument(args, 2)) |value| {
+        try testing.expect(mem.eql(value, "two words"))
+    } else { try testing.expect(false) }
+    try testing.expect(argument(args, 3) == null)
+    try testing.expect(argument(args, maxval!(usize)) == null)
+
+    none :: Args{ values = pointers[0..0] }
+    try testing.expect_equal(usize(0), argument_count(none))
+    try testing.expect(argument(none, 0) == null)
+}

std/process/process.hon

@@ -2,4 +2,10 @@ import "@std/io"
 
 Init :: struct {
     io io.Io
+    args Args
+}
+
+#! borrows the argument pointer array and its zero-terminated strings; owns no storage.
+Args :: struct {
+    values [][*;0]u8
 }