support absolute paths in import map

lib/blob.asm

@@ -3,9 +3,9 @@
 ;
 
 .import
-    dev: "https://ufork.org/lib/dev.asm"
-    std: "https://ufork.org/lib/std.asm"
-    list: "https://ufork.org/lib/list.asm"
+    dev: "./dev.asm"
+    std: "./std.asm"
+    list: "./list.asm"
 
 ;
 ; initialized blob builder

lib/blob_io.asm

@@ -3,9 +3,9 @@
 ;
 
 .import
-    dev: "https://ufork.org/lib/dev.asm"
-    std: "https://ufork.org/lib/std.asm"
-    blob: "https://ufork.org/lib/blob.asm"
+    dev: "./dev.asm"
+    std: "./std.asm"
+    blob: "./blob.asm"
 
 ;
 ; input stream-requestor interface to a blob

lib/blob_peg.asm

@@ -3,8 +3,8 @@
 ;
 
 .import
-    dev: "https://ufork.org/lib/dev.asm"
-    std: "https://ufork.org/lib/std.asm"
+    dev: "./dev.asm"
+    std: "./std.asm"
 
 ;;  digit = [0-9]
 digit_rng:

lib/cell.asm

@@ -3,9 +3,9 @@
 ;;;
 
 .import
-    dev: "https://ufork.org/lib/dev.asm"
-    std: "https://ufork.org/lib/std.asm"
-    lib: "https://ufork.org/lib/lib.asm"
+    dev: "./dev.asm"
+    std: "./std.asm"
+    lib: "./lib.asm"
 
 read_op:
     ref 0

lib/deque.asm

@@ -3,8 +3,8 @@
 ;
 
 .import
-    std: "https://ufork.org/lib/std.asm"
-    list: "https://ufork.org/lib/list.asm"
+    std: "./std.asm"
+    list: "./list.asm"
 
 new:                        ; ( -- deque )
     deque new               ; k deque

lib/dict.asm

@@ -3,7 +3,7 @@
 ;
 
 .import
-    std: "https://ufork.org/lib/std.asm"
+    std: "./std.asm"
 
 has:                        ; ( dict key -- bool )
     roll -3                 ; k dict key

lib/div_mod.asm

@@ -1,8 +1,8 @@
 ; Euclidean division and remainder/modulus
 
 .import
-    std: "https://ufork.org/lib/std.asm"
-    dev: "https://ufork.org/lib/dev.asm"
+    std: "./std.asm"
+    dev: "./dev.asm"
 
 ; Euclidean division is a slow, but simple, algorithm.
 ; It solves the equations: <latex> n = dq + r </latex>,

lib/lib.scm

@@ -2,7 +2,7 @@
 ;;; Actor idioms in Scheme
 ;;;
 
-(import dev "https://ufork.org/lib/dev.asm")  ; for testing...
+(import dev "./dev.asm")  ; for testing...
 
 (define sink-beh (BEH _))
 

lib/line_buffer.asm

@@ -1,8 +1,8 @@
 ; Line buffering utilities for the I/O device.
 
 .import
-    std: "https://ufork.org/lib/std.asm"
-    dev: "https://ufork.org/lib/dev.asm"
+    std: "./std.asm"
+    dev: "./dev.asm"
 
 ; Accumulate characters one-at-a-time until '\n'.
 ; When a `line` is complete, send it to `cust`.

lib/list.asm

@@ -3,8 +3,8 @@
 ;
 
 .import
-    dev: "https://ufork.org/lib/dev.asm"
-    std: "https://ufork.org/lib/std.asm"
+    dev: "./dev.asm"
+    std: "./std.asm"
 
 len:                        ; ( list -- len )
     roll -2                 ; k list

vm/js/ufork.js

@@ -1188,16 +1188,14 @@ function make_core({
         return exports_object;
     }
 
-    function h_map_src(src) {
+    function u_map_src(src) {
         if (src !== undefined) {
             const alias = Object.keys(import_map).find(function (key) {
                 return src.startsWith(key);
             });
-            return (
-                alias !== undefined
-                ? src.replace(alias, import_map[alias])
-                : src
-            );
+            if (alias !== undefined) {
+                return src.replace(alias, import_map[alias]);
+            }
         }
     }
 
@@ -1242,8 +1240,26 @@ function make_core({
 
                 return Promise.all(Object.values(ir.ast.import).map(
                     function (import_src) {
+                        import_src = u_map_src(import_src) ?? import_src;
                         return h_import_promise(
-                            new URL(h_map_src(import_src), src).href
+
+// We need to resolve the import specifier if it is relative.
+
+                            import_src.startsWith(".")
+                            ? (
+
+// The URL constructor chokes when 'base' is an absolute path, rather than a
+// fully qualified URL. We work around this using a dummy origin so that we can
+// produce an absolute path if 'src' is an absolute path.
+
+                                src.startsWith("/")
+                                ? new URL(
+                                    import_src,
+                                    new URL(src, "http://_")
+                                ).pathname
+                                : new URL(import_src, src).href
+                            )
+                            : import_src
                         );
                     }
                 )).then(function (imported_modules) {
@@ -1265,7 +1281,7 @@ function make_core({
 // imports.
 
         return unpromise(function () {
-            return h_import_promise(h_map_src(src), content);
+            return h_import_promise(u_map_src(src) ?? src, content);
         });
     }