haskell: Phase 17 — import declarations anywhere among top-level decls

hk-collect-module-body previously ran a fixed import-loop at the start
and then a separate decl-loop; merged into a single hk-body-step
dispatcher that routes `import` to the imports list and everything else
to hk-parse-decl. Both call sites (initial step + post-semicolon loop)
use the dispatcher. The eval side reads imports as a list (not by AST
position) so mid-stream imports feed into hk-bind-decls! unchanged.

tests/parse-extras.sx 12 → 17: very-top, mid-stream, post-main,
two-imports-different-positions, unqualified-mid-file. Regression
sweep clean: eval 66/0, exceptions 14/0, typecheck 15/0, records 14/0,
ioref 13/0, map 26/0, set 17/0.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/haskell/parser.sx

@@ -1733,10 +1733,18 @@
                   (= (hk-peek-type) "eof")
                   (hk-match? "vrbrace" nil)
                   (hk-match? "rbrace" nil))))
+            (define
+              hk-body-step
+              (fn
+                ()
+                (cond
+                  ((hk-match? "reserved" "import")
+                    (append! imports (hk-parse-import)))
+                  (:else (append! decls (hk-parse-decl))))))
             (when
               (not (hk-body-at-end?))
               (do
-                (append! decls (hk-parse-decl))
+                (hk-body-step)
                 (define
                   hk-body-loop
                   (fn
@@ -1747,7 +1755,7 @@
                         (hk-advance!)
                         (when
                           (not (hk-body-at-end?))
-                          (append! decls (hk-parse-decl)))
+                          (hk-body-step))
                         (hk-body-loop)))))
                 (hk-body-loop)))
             (list imports decls))))

lib/haskell/tests/parse-extras.sx

@@ -61,3 +61,42 @@
   "no regression: section-right still works"
   (hk-deep-force (hk-run "main = (+ 3) 4"))
   7)
+
+(hk-test
+  "import: still works as the very first decl"
+  (hk-deep-force
+    (hk-run "import qualified Data.IORef as I
+main = do { r <- I.newIORef 7; I.readIORef r }"))
+  (list "IO" 7))
+
+(hk-test
+  "import: between decls — after main"
+  (hk-deep-force
+    (hk-run "main = do { r <- I.newIORef 11; I.readIORef r }
+import qualified Data.IORef as I"))
+  (list "IO" 11))
+
+(hk-test
+  "import: between two decls — uses helper after import"
+  (hk-deep-force
+    (hk-run "f x = x + 100
+import qualified Data.IORef as I
+main = do { r <- I.newIORef 5; I.modifyIORef r f; I.readIORef r }"))
+  (list "IO" 105))
+
+(hk-test
+  "import: two imports in different positions"
+  (hk-deep-force
+    (hk-run "import qualified Data.IORef as I
+helper x = x * 2
+import qualified Data.Map as M
+main = do { r <- I.newIORef (helper 21); I.readIORef r }"))
+  (list "IO" 42))
+
+(hk-test
+  "import: unqualified, mid-file"
+  (hk-deep-force
+    (hk-run "go x = x
+import Data.IORef
+main = go 9"))
+  9)

plans/haskell-completeness.md

@@ -320,7 +320,7 @@ larger conformance programs and removes one-line workarounds in test sources.
   `return (42 :: Int)`. Parser currently rejects `::` in `aexp` position;
   desugar should drop the annotation (we have no inference at this layer
   yet, so it's a parse-only pass-through).
-- [ ] `import` declarations anywhere at the start of a module — currently
+- [x] `import` declarations anywhere at the start of a module — currently
   only the very-top-of-file form is recognised. Real test programs that
   mix prelude code with `import qualified Data.IORef` need this.
 - [ ] Multi-line top-level `where` blocks (`where { ... }` with explicit
@@ -420,6 +420,18 @@ constraints (qualified types `[ClassName var] => type`).
 
 _Newest first._
 
+**2026-05-10** — Phase 17 second box: `import` declarations anywhere among
+top-level decls. `hk-collect-module-body` previously ran a fixed
+import-loop at the start, then a separate decl-loop; merged into a single
+`hk-body-step` dispatcher that routes `import` to the imports list and
+everything else to `hk-parse-decl`. Each call site (initial step + post-
+semicolon loop) now uses the dispatcher. Imports collected mid-stream
+still feed into `hk-bind-decls!` correctly because the eval side reads
+them via the imports list, not by AST position. tests/parse-extras.sx
+12 → 17 covering very-top, mid-stream, post-main, two-imports-different-
+positions, and unqualified mid-file. Regression: eval 66/0, exceptions
+14/0, typecheck 15/0, records 14/0, ioref 13/0, map 26/0, set 17/0.
+
 **2026-05-08** — Phase 17 first box: expression type annotations `(x :: Int)`,
 `f (1 :: Int)`, `(\x -> x+1) :: Int -> Int`. Parser's `hk-parse-parens`
 gains a `::` arm after the first inner expression: consume `::`, parse a