PLT: Major module loading surgery.

This is a dangerous commit. If you use PLT and don't like to live on
the edge, just stick with tag 0.0.9 until 0.0.10 is out.

4 files changed, 172 insertions, 18 deletions

diff --git a/scheme/plt/geiser/enter.ss b/scheme/plt/geiser/enter.ss
new file mode 100644
index 0000000..b81ba48
--- /dev/null
+++ b/scheme/plt/geiser/enter.ss
@@ -0,0 +1,103 @@
+;;; enter.ss -- custom module loaders
+
+;; Copyright (C) 2010 Jose Antonio Ortega Ruiz
+
+;; This program is free software; you can redistribute it and/or
+;; modify it under the terms of the Modified BSD License. You should
+;; have received a copy of the license along with this program. If
+;; not, see <http://www.xfree86.org/3.3.6/COPYRIGHT2.html#5>.
+
+;; Start date: Wed Mar 31, 2010 21:53
+
+#lang scheme/base
+
+(require syntax/modcode
+         (for-syntax scheme/base))
+
+(provide get-namespace enter-module module-loader module-loaded?)
+
+(define-struct mod (name timestamp depends))
+
+(define loaded (make-hash))
+
+(define (module-loaded? path)
+  (with-handlers ((exn? (lambda (_) #f)))
+    (let ((rp (module-path-index-resolve (module-path-index-join path #f))))
+      (hash-has-key? loaded (resolved-module-path-name rp)))))
+
+(define (enter-module mod)
+  (dynamic-require mod #f)
+  (check-latest mod))
+
+(define (module-loader orig)
+  (enter-load/use-compiled orig #f))
+
+(define (notify re? path)
+  (when re?
+    (fprintf (current-error-port) " [re-loading ~a]\n" path)))
+
+(define inhibit-eval (make-parameter #f))
+
+(define (get-namespace mod)
+  (parameterize ([inhibit-eval #t])
+    (module->namespace mod)))
+
+(define ((enter-load/use-compiled orig re?) path name)
+  (when (inhibit-eval)
+    (raise (make-exn:fail "namespace not found"
+                          (current-continuation-marks))))
+  (if name
+      ;; Module load:
+      (let ([code (get-module-code path "compiled" compile
+                                   (lambda (ext loader?)
+                                     (load-extension ext)
+                                     #f)
+                                   #:notify (lambda (chosen)
+                                              (notify re? chosen)))]
+            [path (normal-case-path
+                   (simplify-path
+                    (path->complete-path path
+                                         (or (current-load-relative-directory)
+                                             (current-directory)))))])
+        ;; Record module timestamp and dependencies:
+        (let ([mod (make-mod name
+                             (get-timestamp path)
+                             (if code
+                                 (apply append
+                                        (map cdr (module-compiled-imports code)))
+                                 null))])
+          (hash-set! loaded path mod))
+        ;; Evaluate the module:
+        (eval code))
+      ;; Not a module:
+      (begin
+        (notify re? path)
+        (orig path name))))
+
+(define (get-timestamp path)
+  (file-or-directory-modify-seconds path #f (lambda () -inf.0)))
+
+(define (check-latest mod)
+  (let ([mpi (module-path-index-join mod #f)]
+        [done (make-hash)])
+    (let loop ([mpi mpi])
+      (let* ([rpath (module-path-index-resolve mpi)]
+             [path (resolved-module-path-name rpath)])
+        (when (path? path)
+	  (let ([path (normal-case-path path)])
+            (unless (hash-ref done path #f)
+              (hash-set! done path #t)
+              (let ([mod (hash-ref loaded path #f)])
+                (when mod
+                  (for-each loop (mod-depends mod))
+                  (let ([ts (get-timestamp path)])
+                    (when (ts . > . (mod-timestamp mod))
+                      (let ([orig (current-load/use-compiled)])
+                        (parameterize ([current-load/use-compiled
+                                        (enter-load/use-compiled orig #f)]
+                                       [current-module-declare-name rpath])
+                          ((enter-load/use-compiled orig #t)
+                           path
+                           (mod-name mod)))))))))))))))
+
+;;; enter.ss ends here
diff --git a/scheme/plt/geiser/main.ss b/scheme/plt/geiser/main.ss
index d342b15..f157ac6 100644
--- a/scheme/plt/geiser/main.ss
+++ b/scheme/plt/geiser/main.ss
@@ -13,8 +13,7 @@
 
 #lang scheme/base
 
-(provide geiser:init
-         geiser:eval
+(provide geiser:eval
          geiser:compile
          geiser:load-file
          geiser:compile-file
@@ -47,8 +46,4 @@
 (define geiser:module-exports module-exports)
 (define geiser:macroexpand macroexpand)
 
-(define (geiser:init)
-  (compile-enforce-module-constants #f)
-  (current-prompt-read (compose (make-repl-reader (current-prompt-read))
-                                current-namespace)))
-
+;;; main.ss ends here
diff --git a/scheme/plt/geiser/modules.ss b/scheme/plt/geiser/modules.ss
index 9842174..829cf77 100644
--- a/scheme/plt/geiser/modules.ss
+++ b/scheme/plt/geiser/modules.ss
@@ -20,7 +20,7 @@
          module-list
          module-exports)
 
-(require srfi/13 scheme/enter syntax/modresolve syntax/modcode)
+(require srfi/13 syntax/modresolve syntax/modcode geiser/enter)
 
 (define (ensure-module-spec spec)
   (cond ((symbol? spec) spec)
@@ -28,22 +28,22 @@
         (else `(file ,spec))))
 
 (define (module-spec->namespace spec (lang #f))
-  (let ((spec (ensure-module-spec spec)))
-    (if spec
-        (with-handlers ((exn?
-                         (lambda (_)
-                           (with-handlers
-                               ((exn? (const (current-namespace))))
+  (let ((spec (ensure-module-spec spec))
+        (try-lang (lambda (_)
+                    (with-handlers ((exn? (const (current-namespace))))
+                      (and lang
+                           (begin
                              (load-module lang #f (current-namespace))
-                             (module->namespace lang)))))
-          (module->namespace spec))
+                             (module->namespace lang)))))))
+    (or (and spec
+             (with-handlers ((exn? try-lang)) (get-namespace spec)))
         (current-namespace))))
 
 (define nowhere (open-output-nowhere))
 
 (define (load-module spec (port #f) (ns #f))
   (parameterize ((current-error-port (or port nowhere)))
-    (eval #`(enter! #,(ensure-module-spec spec)))
+    (enter-module (ensure-module-spec spec))
     (when (namespace? ns)
       (current-namespace ns))))
 
@@ -79,7 +79,6 @@
         ((symbol? path) (symbol->string path))
         (else "")))
 
-
 (define (skippable-dir? path)
   (call-with-values (lambda () (split-path path))
     (lambda (_ basename __)
diff --git a/scheme/plt/geiser/user.ss b/scheme/plt/geiser/user.ss
new file mode 100644
index 0000000..48b7dd5
--- /dev/null
+++ b/scheme/plt/geiser/user.ss
@@ -0,0 +1,57 @@
+;;; user.ss -- global bindings visible to geiser users
+
+;; Copyright (C) 2010 Jose Antonio Ortega Ruiz
+
+;; This program is free software; you can redistribute it and/or
+;; modify it under the terms of the Modified BSD License. You should
+;; have received a copy of the license along with this program. If
+;; not, see <http://www.xfree86.org/3.3.6/COPYRIGHT2.html#5>.
+
+;; Start date: Wed Mar 31, 2010 22:24
+
+#lang scheme/base
+
+(provide enter!)
+
+(require geiser/enter geiser/eval (for-syntax scheme/base))
+
+(define-syntax (enter! stx)
+  (syntax-case stx ()
+    [(enter! mod)
+     (if (or (not (syntax-e #'mod))
+             (module-path? (syntax->datum #'mod)))
+         #'(do-enter! 'mod)
+         (raise-syntax-error
+          #f
+          "not a valid module path, and not #f"
+          stx
+          #'mod))]
+    [_ (raise-syntax-error
+        #f
+        "bad syntax; should be `(enter! <module-path-or-#f>)'"
+        stx)]))
+
+(define orig-namespace (current-namespace))
+
+(define (do-enter! mod)
+  (if mod
+      (begin
+        (enter-module mod)
+        (let ([ns (module->namespace mod)])
+          (current-namespace ns)
+          (namespace-require 'geiser/user)))
+      (current-namespace orig-namespace)))
+
+
+(define orig-loader (current-load/use-compiled))
+
+(define (init)
+  (compile-enforce-module-constants #f)
+  (current-load/use-compiled (module-loader orig-loader))
+  (current-prompt-read (compose (make-repl-reader (current-prompt-read))
+                                current-namespace)))
+
+(init)
+
+;;; user.ss ends here
+