013 a for loop is a link of a grid write chain

✓ Passing This code compiles and runs correctly.

Code

// PINS: a `for` LOOP is a legal next link of a grid write's chain, in all three
// positions a five-baton-old claim said it was not.
//
// THE CLAIM, carried in koru-libs/raylib/tests/boids.k:27-29 and in five
// consecutive session batons: "a store write followed by |> for(..) does not
// compose, and nested in an arm it silently accumulates nothing." Both halves
// are false on this tree, and the pin is here so nobody carries it a sixth time.
//
// 697_012 pinned the chain tail when the next link is a `print` or a second
// WRITE. A `for` was never the next link anywhere in the corpus, so the fix
// that stopped grid writes discarding their tail was never measured against a
// loop — the commonest thing anyone would actually pipe a write into.
//
// THREE POSITIONS, and the third is the one the claim called silent:
//   HEAD      — write at the flow head, `for` as its next link.
//   SAME COLUMN — the loop accumulates into the very column the preceding write
//                 seeded, so it must observe that write, not the pre-state.
//   IN AN ARM — write and `for` both inside a `! each` arm. Named "silently
//               accumulates nothing"; it accumulates exactly.
//
// LAYOUT, and it is the one live constraint here: the `|> for(..)` link must sit
// on the SAME LINE as the write. Written as an indented continuation line it is
// refused with KORU010 whether the loop's arms are at column 0 or indented under
// it, because the arms have no construct to attach to. boids.k writes every
// chain link on its own continuation line, which is how a layout refusal was
// read as "does not compose" and became a semantic claim about the store.
import std/io
import std/grid

std/grid:new(g, size: 4) { n: 0[i64], sum: 0[i64] }

// HEAD: the write lands and the loop after it runs.
std/grid:stored { g[0].n: g[0].n + 1 } |> for(0..3)
! each _ |> std/grid:stored { g[1].sum: g[1].sum + 1 }

// SAME COLUMN: 10 seeded by the write, then three increments observing it.
std/grid:stored { g[2].sum: 10 } |> for(0..3)
! each _ |> std/grid:stored { g[2].sum: g[2].sum + 1 }

// IN AN ARM: two outer iterations, each writing then running its own loop.
for(0..2)
! each _ |> std/grid:stored { g[3].n: g[3].n + 1 } |> for(0..3)
    ! each _ |> std/grid:stored { g[3].sum: g[3].sum + 1 }

std/io:print.ln("head {{ g[0].n:d }},{{ g[1].sum:d }} same {{ g[2].sum:d }} arm {{ g[3].n:d }},{{ g[3].sum:d }}")

input.k

Actual

head 1,3 same 13 arm 2,6

Expected output

✓ Zig✓ JavaScript

head 1,3 same 13 arm 2,6

Emitted Zig source

// Access compiler flags via the per-user compiler_env module
const CompilerEnv = @import("compiler_env").CompilerEnv;

pub const panic = if (@import("builtin").mode == .Debug)
    @import("std").debug.FullPanic(@import("std").debug.defaultPanic)
else
    @import("std").debug.simple_panic;


const __koru_bare = struct {
    extern fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: usize) c_int;
    extern fn free(ptr: ?*anyopaque) void;
    fn bareAlloc(_: *anyopaque, len: usize, alignment: @import("std").mem.Alignment, _: usize) ?[*]u8 {
        var p: ?*anyopaque = null;
        const a = @max(alignment.toByteUnits(), @sizeOf(usize));
        if (posix_memalign(&p, a, len) != 0) return null;
        return @ptrCast(p);
    }
    fn bareResize(_: *anyopaque, _: []u8, _: @import("std").mem.Alignment, _: usize, _: usize) bool { return false; }
    fn bareRemap(_: *anyopaque, _: []u8, _: @import("std").mem.Alignment, _: usize, _: usize) ?[*]u8 { return null; }
    fn bareFree(_: *anyopaque, memory: []u8, _: @import("std").mem.Alignment, _: usize) void { free(@ptrCast(memory.ptr)); }
    const vtable = @import("std").mem.Allocator.VTable{ .alloc = bareAlloc, .resize = bareResize, .remap = bareRemap, .free = bareFree };
    const allocator = @import("std").mem.Allocator{ .ptr = undefined, .vtable = &vtable };
};
const __koru_backing = if (@import("builtin").link_libc) @import("std").heap.c_allocator else if (@import("builtin").os.tag == .freestanding) __koru_bare.allocator else @import("std").heap.page_allocator;
var __koru_leak_count: usize = 0;
fn __koru_alloc(ctx: *anyopaque, len: usize, alignment: @import("std").mem.Alignment, ret_addr: usize) ?[*]u8 {
    _ = ctx;
    const r = __koru_backing.rawAlloc(len, alignment, ret_addr);
    if (comptime @import("builtin").mode == .Debug) {
        if (r != null) __koru_leak_count += 1;
    }
    return r;
}
fn __koru_resize(ctx: *anyopaque, memory: []u8, alignment: @import("std").mem.Alignment, new_len: usize, ret_addr: usize) bool {
    _ = ctx;
    return __koru_backing.rawResize(memory, alignment, new_len, ret_addr);
}
fn __koru_remap(ctx: *anyopaque, memory: []u8, alignment: @import("std").mem.Alignment, new_len: usize, ret_addr: usize) ?[*]u8 {
    _ = ctx;
    return __koru_backing.rawRemap(memory, alignment, new_len, ret_addr);
}
fn __koru_free(ctx: *anyopaque, memory: []u8, alignment: @import("std").mem.Alignment, ret_addr: usize) void {
    _ = ctx;
    __koru_backing.rawFree(memory, alignment, ret_addr);
    if (comptime @import("builtin").mode == .Debug) {
        __koru_leak_count -= 1;
    }
}
const __koru_vtable = @import("std").mem.Allocator.VTable{ .alloc = __koru_alloc, .resize = __koru_resize, .remap = __koru_remap, .free = __koru_free };
pub fn koru_allocator() @import("std").mem.Allocator {
    return .{ .ptr = undefined, .vtable = &__koru_vtable };
}

pub inline fn __koru_intcast(comptime T: type, x: anytype) T {
    if (comptime (@import("builtin").mode == .Debug or @import("builtin").mode == .ReleaseSafe))
        return @as(T, @intCast(x));
    const dst = @typeInfo(T);
    const src = @typeInfo(@TypeOf(x));
    if (comptime (dst == .int and src == .int and dst.int.bits == src.int.bits and dst.int.signedness != src.int.signedness))
        return @as(T, @bitCast(x));
    return @as(T, @intCast(x));
}

pub fn koru_leak_check() void {
    if (comptime @import("builtin").mode != .Debug) return;
    if (__koru_leak_count == 0) return;
    if (comptime @import("builtin").target.os.tag == .freestanding) {
        if (comptime @import("builtin").cpu.arch == .wasm32 or @import("builtin").cpu.arch == .wasm64) {
            @panic("KORU LEAK CHECK FAILED: the produced program leaked");
        } else {
            const __klc = struct { extern var stdout: ?*anyopaque; extern fn fputs(__s: [*:0]const u8, __st: ?*anyopaque) c_int; };
            var __lb: [128]u8 = undefined;
            const __lm = "KORU LEAK CHECK FAILED: allocations still outstanding at end of run: ";
            @memcpy(__lb[0..__lm.len], __lm);
            var __ln: usize = __lm.len;
            var __lv = __koru_leak_count;
            var __ld: [20]u8 = undefined;
            var __lk: usize = 0;
            while (__lv > 0) : (__lk += 1) { __ld[__lk] = @intCast('0' + __lv % 10); __lv /= 10; }
            for (0..__lk) |__li| { __lb[__ln] = __ld[__lk - 1 - __li]; __ln += 1; }
            __lb[__ln] = '\n'; __ln += 1; __lb[__ln] = 0;
            _ = __klc.fputs(@as([*:0]const u8, @ptrCast(&__lb)), __klc.stdout);
            @trap();
        }
    } else {
        @import("std").debug.print("KORU LEAK CHECK FAILED: the produced program leaked (trace above)\n", .{});
        @import("std").process.exit(1);
    }
}

pub const main_module = struct {
    const __KoruGridT_g = struct {
    n: [4]i64 = [_]i64{0} ** 4,
    sum: [4]i64 = [_]i64{0} ** 4,
    const __koru_size: usize = 4;
    fn __koru_wide(v: anytype) i64 {
        return if (@TypeOf(v) == comptime_int) v else @intCast(v);
    }
    fn __koru_at(i_raw: anytype) usize {
        const i = __koru_wide(i_raw);
        if (i < 0 or @as(usize, @intCast(i)) >= 4) @panic("std/grid: index out of range for grid 'g' (size 4) - a grid is addressed by position, and wrapping is the program's to write as `% 4`");
        return @as(usize, @intCast(i));
    }
};
var __koru_grid_g: __KoruGridT_g = .{};
    // >>> FLOW: tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:34  ~input:__grid_write_L34_4122()
    pub fn flow0() void {
        _ = main_module.__grid_write_L34_4122_event.handler(.{ .__koru_gwx0 = main_module.__KoruGridT_g.__koru_wide(0), .__koru_gwv0 = (&main_module.__koru_grid_g.n)[main_module.__KoruGridT_g.__koru_at(0)] + 1 });
        
    for (0..3) |__koru_item5| {
        { const _auto_6 = __koru_item5; _ = &_auto_6;         _ = main_module.__grid_write_L35_9a15_event.handler(.{ .__koru_gwx0 = main_module.__KoruGridT_g.__koru_wide(1), .__koru_gwv0 = (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(1)] + 1 });
 }
        
    }
    {  }
    }
    // >>> FLOW: tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:38  ~input:__grid_write_L38_a53d()
    pub fn flow1() void {
        _ = main_module.__grid_write_L38_a53d_event.handler(.{ .__koru_gwx0 = main_module.__KoruGridT_g.__koru_wide(2), .__koru_gwv0 = 10 });
        
    for (0..3) |__koru_item6| {
        { const _auto_8 = __koru_item6; _ = &_auto_8;         _ = main_module.__grid_write_L39_a41b_event.handler(.{ .__koru_gwx0 = main_module.__KoruGridT_g.__koru_wide(2), .__koru_gwv0 = (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(2)] + 1 });
 }
        
    }
    {  }
    }
    // >>> FLOW: tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:42  ~std.control:for()
    pub fn flow2() void {
        
    for (0..2) |__koru_item8| {
        { const _auto_10 = __koru_item8; _ = &_auto_10;         const result_e0_0 = main_module.__grid_write_L43_957d_event.handler(.{ .__koru_gwx0 = main_module.__KoruGridT_g.__koru_wide(3), .__koru_gwv0 = (&main_module.__koru_grid_g.n)[main_module.__KoruGridT_g.__koru_at(3)] + 1 });
        _ = &result_e0_0;
        
    for (0..3) |__koru_item7| {
        { const _auto_11 = __koru_item7; _ = &_auto_11;         _ = main_module.__grid_write_L44_9d5f_event.handler(.{ .__koru_gwx0 = main_module.__KoruGridT_g.__koru_wide(3), .__koru_gwv0 = (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(3)] + 1 });
 }
        
    }
    {  }
 }
        
    }
    {  }
    }
    // >>> FLOW: tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:46  ~std.io:print.impl()
    pub fn flow3() void {
        (struct { fn __kout(__fd: i32, __b: []const u8) void { if (@import("builtin").os.tag == .freestanding) { const __kc = struct { extern var stdout: ?*anyopaque; extern var stderr: ?*anyopaque; extern fn fputs(__s: [*:0]const u8, __st: ?*anyopaque) c_int; }; var __kt: [4096]u8 = undefined; for (0..(__b.len + __kt.len - 2) / (__kt.len - 1)) |__ki| { const __kn = @min(__kt.len - 1, __b.len - __ki * (__kt.len - 1)); @memcpy(__kt[0..__kn], __b[__ki * (__kt.len - 1)..][0..__kn]); __kt[__kn] = 0; @import("std").mem.doNotOptimizeAway(__kc.fputs(@as([*:0]const u8, @ptrCast(&__kt)), if (__fd == 2) __kc.stderr else __kc.stdout)); } } else { @import("std").mem.doNotOptimizeAway(@import("std").posix.write(__fd, __b) catch @as(usize, 0)); } } fn __kw(comptime __f: []const u8, __a: anytype) void { var __kb: [65536]u8 = undefined; const __ks = @import("std").fmt.bufPrint(&__kb, __f, __a) catch __kb[0..0]; __kout(1, __ks); } }).__kw("head {d},{d} same {d} arm {d},{d}\n", .{(&main_module.__koru_grid_g.n)[main_module.__KoruGridT_g.__koru_at(0)], (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(1)], (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(2)], (&main_module.__koru_grid_g.n)[main_module.__KoruGridT_g.__koru_at(3)], (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(3)]});
    }
    pub fn koru_start_flow() void {
        const result_0 = koru_koru.start_event.handler(.{  });
        const result_0_done = result_0.done;
        _ = &result_0_done;
    }
    pub fn koru_end_flow() void {
        const result_0 = koru_koru.end_event.handler(.{  });
        const result_0_done = result_0.done;
        _ = &result_0_done;
    }
    pub const __grid_write_L35_9a15_event = struct {
        pub const Input = struct {
            __koru_gwx0: i64,
            __koru_gwv0: i64,
        };
        pub const Output = void;
        pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
            return __koru_handler_impl(__koru_event_input.__koru_gwx0, __koru_event_input.__koru_gwv0);
        }
        fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64) @This().Output {
            const __koru_event_input: @This().Input = .{ .__koru_gwx0 = __koru_p_0, .__koru_gwv0 = __koru_p_1 };
            // >>> PROC: __grid_write_L35_9a15  [tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:35]
            const __koru_gwx0 = __koru_event_input.__koru_gwx0;
            const __koru_gwv0 = __koru_event_input.__koru_gwv0;
            _ = &__koru_gwx0;
            _ = &__koru_gwv0;
            _ = &__koru_event_input;
            (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(__koru_gwx0)] = __koru_gwv0;

        }
    };
    pub const __grid_write_L34_4122_event = struct {
        pub const Input = struct {
            __koru_gwx0: i64,
            __koru_gwv0: i64,
        };
        pub const Output = void;
        pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
            return __koru_handler_impl(__koru_event_input.__koru_gwx0, __koru_event_input.__koru_gwv0);
        }
        fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64) @This().Output {
            const __koru_event_input: @This().Input = .{ .__koru_gwx0 = __koru_p_0, .__koru_gwv0 = __koru_p_1 };
            // >>> PROC: __grid_write_L34_4122  [tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:34]
            const __koru_gwx0 = __koru_event_input.__koru_gwx0;
            const __koru_gwv0 = __koru_event_input.__koru_gwv0;
            _ = &__koru_gwx0;
            _ = &__koru_gwv0;
            _ = &__koru_event_input;
            (&main_module.__koru_grid_g.n)[main_module.__KoruGridT_g.__koru_at(__koru_gwx0)] = __koru_gwv0;

        }
    };
    pub const __grid_write_L39_a41b_event = struct {
        pub const Input = struct {
            __koru_gwx0: i64,
            __koru_gwv0: i64,
        };
        pub const Output = void;
        pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
            return __koru_handler_impl(__koru_event_input.__koru_gwx0, __koru_event_input.__koru_gwv0);
        }
        fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64) @This().Output {
            const __koru_event_input: @This().Input = .{ .__koru_gwx0 = __koru_p_0, .__koru_gwv0 = __koru_p_1 };
            // >>> PROC: __grid_write_L39_a41b  [tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:39]
            const __koru_gwx0 = __koru_event_input.__koru_gwx0;
            const __koru_gwv0 = __koru_event_input.__koru_gwv0;
            _ = &__koru_gwx0;
            _ = &__koru_gwv0;
            _ = &__koru_event_input;
            (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(__koru_gwx0)] = __koru_gwv0;

        }
    };
    pub const __grid_write_L38_a53d_event = struct {
        pub const Input = struct {
            __koru_gwx0: i64,
            __koru_gwv0: i64,
        };
        pub const Output = void;
        pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
            return __koru_handler_impl(__koru_event_input.__koru_gwx0, __koru_event_input.__koru_gwv0);
        }
        fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64) @This().Output {
            const __koru_event_input: @This().Input = .{ .__koru_gwx0 = __koru_p_0, .__koru_gwv0 = __koru_p_1 };
            // >>> PROC: __grid_write_L38_a53d  [tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:38]
            const __koru_gwx0 = __koru_event_input.__koru_gwx0;
            const __koru_gwv0 = __koru_event_input.__koru_gwv0;
            _ = &__koru_gwx0;
            _ = &__koru_gwv0;
            _ = &__koru_event_input;
            (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(__koru_gwx0)] = __koru_gwv0;

        }
    };
    pub const __grid_write_L44_9d5f_event = struct {
        pub const Input = struct {
            __koru_gwx0: i64,
            __koru_gwv0: i64,
        };
        pub const Output = void;
        pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
            return __koru_handler_impl(__koru_event_input.__koru_gwx0, __koru_event_input.__koru_gwv0);
        }
        fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64) @This().Output {
            const __koru_event_input: @This().Input = .{ .__koru_gwx0 = __koru_p_0, .__koru_gwv0 = __koru_p_1 };
            // >>> PROC: __grid_write_L44_9d5f  [tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:44]
            const __koru_gwx0 = __koru_event_input.__koru_gwx0;
            const __koru_gwv0 = __koru_event_input.__koru_gwv0;
            _ = &__koru_gwx0;
            _ = &__koru_gwv0;
            _ = &__koru_event_input;
            (&main_module.__koru_grid_g.sum)[main_module.__KoruGridT_g.__koru_at(__koru_gwx0)] = __koru_gwv0;

        }
    };
    pub const __grid_write_L43_957d_event = struct {
        pub const Input = struct {
            __koru_gwx0: i64,
            __koru_gwv0: i64,
        };
        pub const Output = void;
        pub inline fn handler(__koru_event_input: @This().Input) @This().Output {
            return __koru_handler_impl(__koru_event_input.__koru_gwx0, __koru_event_input.__koru_gwv0);
        }
        fn __koru_handler_impl(__koru_p_0: i64, __koru_p_1: i64) @This().Output {
            const __koru_event_input: @This().Input = .{ .__koru_gwx0 = __koru_p_0, .__koru_gwv0 = __koru_p_1 };
            // >>> PROC: __grid_write_L43_957d  [tests/regression/600_STDLIB/697_GRID/697_013_a_for_loop_is_a_link_of_a_grid_write_chain/input.k:43]
            const __koru_gwx0 = __koru_event_input.__koru_gwx0;
            const __koru_gwv0 = __koru_event_input.__koru_gwv0;
            _ = &__koru_gwx0;
            _ = &__koru_gwv0;
            _ = &__koru_event_input;
            (&main_module.__koru_grid_g.n)[main_module.__KoruGridT_g.__koru_at(__koru_gwx0)] = __koru_gwv0;

        }
    };
};

pub const koru_koru = struct {
    pub const start_event = struct {
        pub const Input = struct {
        };
        pub const Output = union(enum(u8)) {
            done: struct {
            },
        };
        pub fn handler(__koru_event_input: @This().Input) @This().Output {
            _ = &__koru_event_input;
            return .{ .done = .{} };
        }
    };
    pub const end_event = struct {
        pub const Input = struct {
        };
        pub const Output = union(enum(u8)) {
            done: struct {
            },
        };
        pub fn handler(__koru_event_input: @This().Input) @This().Output {
            _ = &__koru_event_input;
            return .{ .done = .{} };
        }
    };
};
pub fn main() void {
    main_module.koru_start_flow();
    main_module.flow0();
    main_module.flow1();
    main_module.flow2();
    main_module.flow3();
    main_module.koru_end_flow();
    if (comptime @import("builtin").mode == .Debug) koru_leak_check();
}

test {
    @import("std").testing.refAllDeclsRecursive(@This());
}

Flows

flow ~new click a branch to expand · @labels scroll to their anchor

new (g, size: 4, source: n: 0[i64], sum: 0[i64])

flow ~stored click a branch to expand · @labels scroll to their anchor

stored (source: g[0].n: g[0].n + 1)

flow ~stored click a branch to expand · @labels scroll to their anchor

stored (source: g[2].sum: 10)

flow ~for click a branch to expand · @labels scroll to their anchor

for (0..2)

flow ~print.ln click a branch to expand · @labels scroll to their anchor

print.ln (expr: "head {{ g[0].n:d }},{{ g[1].sum:d }} same {{ g[2].sum:d }} arm {{ g[3].n:d }},{{ g[3].sum:d }}")

Test Configuration

MUST_RUN LANGUAGES: zig js

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