497 - strengthen the concept of 'space'

'default-scope' is now 'default-space'
'closure-generator' is now 'next-space-generator'
The connection to high-level syntax for closures is now tenuous, so
we'll call the 'outer scope' the 'next space'.

So, let's try to create a few sentences with all these related ideas:

  Names map to addresses offset from a default-space when it's provided.

  Spaces can be strung together. The zeroth variable points to the next
  space, the one that is accessed when a variable has /space:1.

  To map a name to an address in the next space, you need to know what
  function generated that space. A corollary is that the space passed in
  to a function should always be generated by a single function.

Spaces can be used to construct lexical scopes and objects.

11 files changed, 170 insertions, 136 deletions

diff --git a/channel.mu b/channel.mu
index cb1721af..854ab858 100644
--- a/channel.mu
+++ b/channel.mu
@@ -1,6 +1,6 @@
 (function producer [
   ; produce numbers 1 to 5 on a channel
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (chan:channel-address <- next-input)
   ; n = 0
   (n:integer <- copy 0:literal)
@@ -24,7 +24,7 @@
 
 (function consumer [
   ; consume and print integers from a channel
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (chan:channel-address <- next-input)
   { begin
     ; read a tagged value from the channel
diff --git a/chessboard-rawterm.mu b/chessboard-rawterm.mu
index 03cb867e..36ad5ad6 100644
--- a/chessboard-rawterm.mu
+++ b/chessboard-rawterm.mu
@@ -8,7 +8,7 @@
 (address board-address (board))
 
 (function read-board [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (initial-position:list-address <- init-list R:literal P:literal _:literal _:literal _:literal _:literal p:literal r:literal
                                               N:literal P:literal _:literal _:literal _:literal _:literal p:literal n:literal
                                               B:literal P:literal _:literal _:literal _:literal _:literal p:literal b:literal
@@ -36,7 +36,7 @@
 ])
 
 (function read-file [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (cursor:list-address <- next-input)
   (result:file-address <- new file:literal 8:literal)
   (row:integer <- copy 0:literal)
@@ -54,7 +54,7 @@
 ])
 
 (function print-board [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (b:board-address <- next-input)
   (row:integer <- copy 7:literal)
   ; print each row
@@ -167,7 +167,7 @@
 ])
 
 (function make-move [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (b:board-address <- next-input)
   (m:move-address <- next-input)
   (x:integer-integer-pair <- get m:move-address/deref from:offset)
@@ -186,7 +186,7 @@
 ])
 
 (function main [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (b:board-address <- read-board)
   (console-on)
   { begin
diff --git a/chessboard.mu b/chessboard.mu
index 71e3da92..e9fbd101 100644
--- a/chessboard.mu
+++ b/chessboard.mu
@@ -8,7 +8,7 @@
 (address board-address (board))
 
 (function read-board [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (initial-position:list-address <- init-list R:literal P:literal _:literal _:literal _:literal _:literal p:literal r:literal
                                               N:literal P:literal _:literal _:literal _:literal _:literal p:literal n:literal
                                               B:literal P:literal _:literal _:literal _:literal _:literal p:literal b:literal
@@ -39,7 +39,7 @@
 ])
 
 (function read-file [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (cursor:list-address <- next-input)
   (result:file-address <- new file:literal 8:literal)
   (row:integer <- copy 0:literal)
@@ -60,7 +60,7 @@
 ])
 
 (function print-board [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (b:board-address <- next-input)
   (row:integer <- copy 7:literal)
   ; print each row
@@ -87,7 +87,7 @@
 
 (function main [
 ;?   (print-primitive (("\u2654 \u265a" literal)))
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (b:board-address <- read-board)
   (print-board b:board-address)
 ])
diff --git a/counters.mu b/counters.mu
new file mode 100644
index 00000000..cd8825ce
--- /dev/null
+++ b/counters.mu
@@ -0,0 +1,33 @@
+(function init-counter [
+  (default-space:space-address <- new space:literal 30:literal)
+  (n:integer <- next-input)
+  (reply default-space:space-address)
+ ])
+
+(function increment-counter [
+  (default-space:space-address <- new space:literal 30:literal)
+  (0:space-address/names:init-counter <- next-input)  ; setup outer space
+  (x:integer <- next-input)
+  (n:integer/space:1 <- add n:integer/space:1 x:integer)
+  (reply n:integer/space:1)
+ ])
+
+(function main [
+  (default-space:space-address <- new space:literal 30:literal)
+  ; counter A
+  (a:space-address <- init-counter 34:literal)
+  ; counter B
+  (b:space-address <- init-counter 23:literal)
+  ; increment both by 2 but in different ways
+  (increment-counter a:space-address 1:literal)
+  (bres:integer <- increment-counter b:space-address 2:literal)
+  (ares:integer <- increment-counter a:space-address 1:literal)
+  ; check results
+  (print-primitive (("Contents of counters a: " literal)))
+  (print-primitive ares:integer)
+  (print-primitive ((" b: " literal)))
+  (print-primitive bres:integer)
+  (print-primitive (("\n" literal)))
+ ])
+
+; compare http://www.paulgraham.com/accgen.html
diff --git a/edit.mu b/edit.mu
index 706d5de4..ebf43161 100644
--- a/edit.mu
+++ b/edit.mu
@@ -1,7 +1,7 @@
 ; a screen is an array of pointers to lines, in turn arrays of characters
 
 (function new-screen [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (nrows:integer <- next-input)
   (ncols:integer <- next-input)
   (result:screen-address <- new screen:literal nrows:integer)
diff --git a/factorial.mu b/factorial.mu
index 580b30d4..e1c6007f 100644
--- a/factorial.mu
+++ b/factorial.mu
@@ -1,5 +1,5 @@
 (function factorial [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (n:integer <- next-input)
   { begin
     ; if n=0 return 1
diff --git a/fork.mu b/fork.mu
index 1cf7aa71..ba19e3af 100644
--- a/fork.mu
+++ b/fork.mu
@@ -1,6 +1,6 @@
 (function main [
   (fork thread2:fn)
-  (default-scope:scope-address <- new scope:literal 2:literal)
+  (default-space:space-address <- new space:literal 2:literal)
   (x:integer <- copy 34:literal)
   { begin
     (print-primitive x:integer)
@@ -9,7 +9,7 @@
 ])
 
 (function thread2 [
-  (default-scope:scope-address <- new scope:literal 2:literal)
+  (default-space:space-address <- new space:literal 2:literal)
   (y:integer <- copy 35:literal)
   { begin
     (print-primitive y:integer)
diff --git a/generic.mu b/generic.mu
index 2a487a96..4486e8bc 100644
--- a/generic.mu
+++ b/generic.mu
@@ -3,7 +3,7 @@
 
 ; factorial n = n*factorial(n-1)
 (function factorial [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (n:integer <- input 0:literal)
   more-clauses
   (x:integer <- subtract n:integer 1:literal)
diff --git a/mu.arc b/mu.arc
index e574f65f..cb18200f 100644
--- a/mu.arc
+++ b/mu.arc
@@ -111,8 +111,9 @@
   (= type* (table))  ; name -> type info
   (= memory* (table))  ; address -> value
   (= function* (table))  ; name -> [instructions]
-  (= location* (table))  ; function -> {name -> index into default-scope}
-  (= closure-generator* (table))  ; function -> name of function generating scope for the scope passed into it
+  (= location* (table))  ; function -> {name -> index into default-space}
+  (= next-space-generator* (table))  ; function -> name of function generating next space
+  ; each function's next space will usually always come from a single function
   )
 (enq clear initialization-fns*)
 
@@ -138,8 +139,8 @@
               character (obj size 1)  ; int32 like a Go rune
               character-address (obj size 1  address t  elem '(character))
               ; isolating function calls
-              scope (obj array t  elem '(location))  ; by convention index 0 points to outer scope
-              scope-address (obj size 1  address t  elem '(scope))
+              space (obj array t  elem '(location))  ; by convention index 0 points to outer space
+              space-address (obj size 1  address t  elem '(space))
               ; arrays consist of an integer length followed by that many
               ; elements, all of the same type
               integer-array (obj array t  elem '(integer))
@@ -693,14 +694,14 @@
 ;   immediate addressing - 'literal' and 'offset'
 ;   direct addressing - default
 ;   indirect addressing - 'deref'
-;   relative addressing - if routine* has 'default-scope'
+;   relative addressing - if routine* has 'default-space'
 
 (def m (loc)  ; read memory, respecting metadata
   (point return
     (when (literal? loc)
       (return v.loc))
-    (when (is v.loc 'default-scope)
-      (return rep.routine*!call-stack.0!default-scope))
+    (when (is v.loc 'default-space)
+      (return rep.routine*!call-stack.0!default-space))
     (trace "m" loc)
     (assert (isa v.loc 'int) "addresses must be numeric (problem in convert-names?) @loc")
     (with (n  sizeof.loc
@@ -714,9 +715,9 @@
 
 (def setm (loc val)  ; set memory, respecting metadata
   (point return
-    (when (is v.loc 'default-scope)
-      (assert (is 1 sizeof.loc) "can't store compounds in default-scope @loc")
-      (= rep.routine*!call-stack.0!default-scope val)
+    (when (is v.loc 'default-space)
+      (assert (is 1 sizeof.loc) "can't store compounds in default-space @loc")
+      (= rep.routine*!call-stack.0!default-space val)
       (return))
     (assert (isa v.loc 'int) "can't store to non-numeric address (problem in convert-names?)")
     (trace "setm" loc " <= " val)
@@ -813,7 +814,7 @@
             (raw))
           (die "routine has no globals: @operand"))
       :else
-        (iflet base rep.routine*!call-stack.0!default-scope
+        (iflet base rep.routine*!call-stack.0!default-space
           (lookup-space (rem [caris _ 'space] operand)
                         base
                         space.operand)
@@ -828,7 +829,7 @@
         (raw))
       (die "no room for var @operand in routine of size @memory*.base"))
     ; recursive case
-    (lookup-space operand (memory* (+ base 1))  ; location 0 points to parent space
+    (lookup-space operand (memory* (+ base 1))  ; location 0 points to next space
                   (- space 1))))
 
 (def space (operand)
@@ -992,7 +993,7 @@
 
 ;; convert symbolic names to raw memory locations
 
-(def add-closure-generator (instrs name)
+(def add-next-space-generator (instrs name)
 ;?   (prn "== @name")
   (each instr instrs
     (when acons.instr
@@ -1000,10 +1001,10 @@
         (each oarg oargs
           (when (and (nondummy oarg)
                      (is v.oarg 0)
-                     (iso ty.oarg '(scope-address)))
-            (assert (no closure-generator*.name) "function can have only one closure-generator environment")
-            (tr "closure-generator of @name is @(alref oarg 'names)")
-            (= closure-generator*.name (alref oarg 'names))))))))
+                     (iso ty.oarg '(space-address)))
+            (assert (no next-space-generator*.name) "function can have only one next-space-generator environment")
+            (tr "next-space-generator of @name is @(alref oarg 'names)")
+            (= next-space-generator*.name (alref oarg 'names))))))))
 
 ; just a helper for testing; in practice we unbundle assign-names-to-location
 ; and replace-names-with-location.
@@ -1018,7 +1019,7 @@
 (def assign-names-to-location (instrs name)
   (ret location (table)
     (with (isa-field  (table)
-           idx  1)  ; 0 always reserved for parent scope
+           idx  1)  ; 0 always reserved for next space
       (each instr instrs
         (point continue
         (when atom.instr
@@ -1083,7 +1084,7 @@
              (~literal? arg)
              (~location v.arg)
              (isa v.arg 'sym)
-             (~in v.arg 'nil 'default-scope)
+             (~in v.arg 'nil 'default-space)
              (~pos '(raw) metadata.arg))
     (= (location v.arg) idx)))
 
@@ -1107,7 +1108,7 @@
   (ret name default-name
     (when (~is space.arg 'global)
       (repeat space.arg
-        (zap closure-generator* name)))))
+        (zap next-space-generator* name)))))
 
 ;; literate tangling system for reordering code
 
@@ -1241,7 +1242,7 @@
 ;?     (prn "freeze " name)
     (= function-table.name (convert-labels:convert-braces:tokenize-args:insert-code body name)))
   (each (name body)  canon.function-table
-    (add-closure-generator body name))
+    (add-next-space-generator body name))
   (each (name body)  canon.function-table
     (= location*.name (assign-names-to-location body name)))
   (each (name body)  canon.function-table
@@ -1329,7 +1330,7 @@
 (section 100
 
 (init-fn maybe-coerce
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (x:tagged-value-address <- new tagged-value:literal)
   (x:tagged-value-address/deref <- next-input)
   (p:type <- next-input)
@@ -1343,7 +1344,7 @@
   (reply xvalue:location match?:boolean))
 
 (init-fn init-tagged-value
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   ; assert sizeof:arg.0 == 1
   (xtype:type <- next-input)
   (xtypesize:integer <- sizeof xtype:type)
@@ -1360,19 +1361,19 @@
   (reply result:tagged-value-address))
 
 (init-fn list-next  ; list-address -> list-address
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (base:list-address <- next-input)
   (result:list-address <- get base:list-address/deref cdr:offset)
   (reply result:list-address))
 
 (init-fn list-value-address  ; list-address -> tagged-value-address
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (base:list-address <- next-input)
   (result:tagged-value-address <- get-address base:list-address/deref car:offset)
   (reply result:tagged-value-address))
 
 (init-fn init-list
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   ; new-list = curr = new list
   (result:list-address <- new list:literal)
   (curr:list-address <- copy result:list-address)
@@ -1395,7 +1396,7 @@
   (reply result:list-address))
 
 (init-fn list-length
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (curr:list-address <- next-input)
 ;?   ; recursive
 ;?   { begin
@@ -1429,7 +1430,7 @@
   (reply result:integer))
 
 (init-fn init-channel
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   ; result = new channel
   (result:channel-address <- new channel:literal)
   ; result.first-full = 0
@@ -1446,14 +1447,14 @@
   (reply result:channel-address))
 
 (init-fn capacity
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (chan:channel <- next-input)
   (q:tagged-value-array-address <- get chan:channel circular-buffer:offset)
   (qlen:integer <- length q:tagged-value-array-address/deref)
   (reply qlen:integer))
 
 (init-fn write
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (chan:channel-address <- next-input)
   (val:tagged-value <- next-input)
   { begin
@@ -1480,7 +1481,7 @@
   (reply chan:channel-address/deref))
 
 (init-fn read
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (chan:channel-address <- next-input)
   { begin
     ; block if chan is empty
@@ -1506,7 +1507,7 @@
 
 ; An empty channel has first-empty and first-full both at the same value.
 (init-fn empty?
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   ; return arg.first-full == arg.first-free
   (chan:channel <- next-input)
   (full:integer <- get chan:channel first-full:offset)
@@ -1517,7 +1518,7 @@
 ; A full channel has first-empty just before first-full, wasting one slot.
 ; (Other alternatives: https://en.wikipedia.org/wiki/Circular_buffer#Full_.2F_Empty_Buffer_Distinction)
 (init-fn full?
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (chan:channel <- next-input)
   ; curr = chan.first-free + 1
   (curr:integer <- get chan:channel first-free:offset)
@@ -1535,7 +1536,7 @@
   (reply result:boolean))
 
 (init-fn strcat
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   ; result = new string[a.length + b.length]
   (a:string-address <- next-input)
   (a-len:integer <- length a:string-address/deref)
@@ -1580,7 +1581,7 @@
 
 ; replace underscores in first with remaining args
 (init-fn interpolate  ; string-address template, string-address a..
-  (default-scope:scope-address <- new scope:literal 60:literal)
+  (default-space:space-address <- new space:literal 60:literal)
   (template:string-address <- next-input)
   ; compute result-len, space to allocate for result
   (tem-len:integer <- length template:string-address/deref)
@@ -1703,7 +1704,7 @@
   (reply idx:integer))
 
 (init-fn split  ; string, character -> string-address-array-address
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (s:string-address <- next-input)
   (delim:character <- next-input)  ; todo: unicode chars
   ; empty string? return empty array
diff --git a/mu.arc.t b/mu.arc.t
index 0c62899e..b880ea7e 100644
--- a/mu.arc.t
+++ b/mu.arc.t
@@ -1844,21 +1844,21 @@
 ; Even though our memory locations can now have names, the names are all
 ; globals, accessible from any function. To isolate functions from their
 ; callers we need local variables, and mu provides them using a special
-; variable called default-scope. When you initialize such a variable (likely
+; variable called default-space. When you initialize such a variable (likely
 ; with a call to our just-defined memory allocator) mu interprets memory
-; locations as offsets from its value. If default-scope is set to 1000, for
+; locations as offsets from its value. If default-space is set to 1000, for
 ; example, reads and writes to memory location 1 will really go to 1001.
 ;
-; 'default-scope' is itself hard-coded to be function-local; it's nil in a new
+; 'default-space' is itself hard-coded to be function-local; it's nil in a new
 ; function, and it's restored when functions return to their callers. But the
-; actual scope allocation is independent. So you can define closures, or do
+; actual space allocation is independent. So you can define closures, or do
 ; even more funky things like share locals between two coroutines.
 
 (reset)
-(new-trace "set-default-scope")
+(new-trace "set-default-space")
 (add-code
   '((function main [
-      (default-scope:scope-address <- new scope:literal 2:literal)
+      (default-space:space-address <- new space:literal 2:literal)
       (1:integer <- copy 23:literal)
      ])))
 (let routine make-routine!main
@@ -1869,14 +1869,14 @@
 ;?     (prn memory*)
     (if (~and (~is 23 memory*.1)
               (is 23 (memory* (+ before 2))))
-      (prn "F - default-scope implicitly modifies variable locations"))))
+      (prn "F - default-space implicitly modifies variable locations"))))
 ;? (quit)
 
 (reset)
-(new-trace "set-default-scope-skips-offset")
+(new-trace "set-default-space-skips-offset")
 (add-code
   '((function main [
-      (default-scope:scope-address <- new scope:literal 2:literal)
+      (default-space:space-address <- new space:literal 2:literal)
       (1:integer <- copy 23:offset)
      ])))
 (let routine make-routine!main
@@ -1887,13 +1887,13 @@
 ;?     (prn memory*)
     (if (~and (~is 23 memory*.1)
               (is 23 (memory* (+ before 2))))
-      (prn "F - default-scope skips 'offset' types just like literals"))))
+      (prn "F - default-space skips 'offset' types just like literals"))))
 
 (reset)
-(new-trace "default-scope-bounds-check")
+(new-trace "default-space-bounds-check")
 (add-code
   '((function main [
-      (default-scope:scope-address <- new scope:literal 2:literal)
+      (default-space:space-address <- new space:literal 2:literal)
       (2:integer <- copy 23:literal)
      ])))
 ;? (set dump-trace*)
@@ -1901,13 +1901,13 @@
 ;? (prn memory*)
 (let routine (car completed-routines*)
   (if (no rep.routine!error)
-    (prn "F - default-scope checks bounds")))
+    (prn "F - default-space checks bounds")))
 
 (reset)
-(new-trace "default-scope-and-get-indirect")
+(new-trace "default-space-and-get-indirect")
 (add-code
   '((function main [
-      (default-scope:scope-address <- new scope:literal 5:literal)
+      (default-space:space-address <- new space:literal 5:literal)
       (1:integer-boolean-pair-address <- new integer-boolean-pair:literal)
       (2:integer-address <- get-address 1:integer-boolean-pair-address/deref 0:offset)
       (2:integer-address/deref <- copy 34:literal)
@@ -1920,14 +1920,14 @@
 (each routine completed-routines*
   (aif rep.routine!error (prn "error - " it)))
 (if (~is 34 memory*.3)
-  (prn "F - indirect 'get' works in the presence of default-scope"))
+  (prn "F - indirect 'get' works in the presence of default-space"))
 ;? (quit)
 
 (reset)
-(new-trace "default-scope-and-index-indirect")
+(new-trace "default-space-and-index-indirect")
 (add-code
   '((function main [
-      (default-scope:scope-address <- new scope:literal 5:literal)
+      (default-space:space-address <- new space:literal 5:literal)
       (1:integer-array-address <- new integer-array:literal 4:literal)
       (2:integer-address <- index-address 1:integer-array-address/deref 2:offset)
       (2:integer-address/deref <- copy 34:literal)
@@ -1940,27 +1940,27 @@
 (each routine completed-routines*
   (aif rep.routine!error (prn "error - " it)))
 (if (~is 34 memory*.3)
-  (prn "F - indirect 'index' works in the presence of default-scope"))
+  (prn "F - indirect 'index' works in the presence of default-space"))
 ;? (quit)
 
 (reset)
-(new-trace "convert-names-default-scope")
+(new-trace "convert-names-default-space")
 (= traces* (queue))
 (if (~iso (convert-names
             '((((x integer)) <- ((copy)) ((4 literal)))
               (((y integer)) <- ((copy)) ((2 literal)))
-              ; unsafe in general; don't write random values to 'default-scope'
-              (((default-scope integer)) <- ((add)) ((x integer)) ((y integer)))))
+              ; unsafe in general; don't write random values to 'default-space'
+              (((default-space integer)) <- ((add)) ((x integer)) ((y integer)))))
           '((((1 integer)) <- ((copy)) ((4 literal)))
             (((2 integer)) <- ((copy)) ((2 literal)))
-            (((default-scope integer)) <- ((add)) ((1 integer)) ((2 integer)))))
-  (prn "F - convert-names never renames default-scope"))
+            (((default-space integer)) <- ((add)) ((1 integer)) ((2 integer)))))
+  (prn "F - convert-names never renames default-space"))
 
 (reset)
-(new-trace "suppress-default-scope")
+(new-trace "suppress-default-space")
 (add-code
   '((function main [
-      (default-scope:scope-address <- new scope:literal 2:literal)
+      (default-space:space-address <- new space:literal 2:literal)
       (1:integer/raw <- copy 23:literal)
      ])))
 (let routine make-routine!main
@@ -1971,7 +1971,7 @@
 ;?     (prn memory*)
     (if (~and (is 23 memory*.1)
               (~is 23 (memory* (+ before 1))))
-      (prn "F - default-scope skipped for locations with metadata 'raw'"))))
+      (prn "F - default-space skipped for locations with metadata 'raw'"))))
 ;? (quit)
 
 (reset)
@@ -1979,7 +1979,7 @@
 (add-code
   '((function main [
       (10:integer <- copy 30:literal)  ; pretend allocation
-      (default-scope:scope-address <- copy 10:literal)  ; unsafe
+      (default-space:space-address <- copy 10:literal)  ; unsafe
       (1:integer <- copy 2:literal)  ; raw location 12
       (2:integer <- copy 23:literal)
       (3:boolean <- copy nil:literal)
@@ -1995,7 +1995,7 @@
 (each routine completed-routines*
   (aif rep.routine!error (prn "error - " it)))
 (if (~iso memory*.18 2)  ; variable 7
-  (prn "F - indirect array copy in the presence of 'default-scope'"))
+  (prn "F - indirect array copy in the presence of 'default-space'"))
 ;? (quit)
 
 (reset)
@@ -2003,7 +2003,7 @@
 (add-code
   '((function main [
       (10:integer <- copy 30:literal)  ; pretend allocation
-      (default-scope:scope-address <- copy 10:literal)  ; unsafe
+      (default-space:space-address <- copy 10:literal)  ; unsafe
       (1:integer <- copy 2:literal)  ; raw location 12
       (2:integer <- copy 23:literal)
       (3:boolean <- copy nil:literal)
@@ -2020,22 +2020,22 @@
 ;? (quit)
 
 (reset)
-(new-trace "default-scope-shared")
+(new-trace "default-space-shared")
 (add-code
   '((function init-counter [
-      (default-scope:scope-address <- new scope:literal 30:literal)
+      (default-space:space-address <- new space:literal 30:literal)
       (1:integer <- copy 3:literal)  ; initialize to 3
-      (reply default-scope:scope-address)
+      (reply default-space:space-address)
      ])
     (function increment-counter [
-      (default-scope:scope-address <- next-input)
+      (default-space:space-address <- next-input)
       (1:integer <- add 1:integer 1:literal)  ; increment
       (reply 1:integer)
      ])
     (function main [
-      (1:scope-address <- init-counter)
-      (2:integer <- increment-counter 1:scope-address)
-      (3:integer <- increment-counter 1:scope-address)
+      (1:space-address <- init-counter)
+      (2:integer <- increment-counter 1:space-address)
+      (3:integer <- increment-counter 1:space-address)
      ])))
 (run 'main)
 (each routine completed-routines*
@@ -2047,24 +2047,24 @@
 ;? (quit)
 
 (reset)
-(new-trace "default-scope-closure")
+(new-trace "default-space-closure")
 (add-code
   '((function init-counter [
-      (default-scope:scope-address <- new scope:literal 30:literal)
+      (default-space:space-address <- new space:literal 30:literal)
       (1:integer <- copy 3:literal)  ; initialize to 3
-      (reply default-scope:scope-address)
+      (reply default-space:space-address)
      ])
     (function increment-counter [
-      (default-scope:scope-address <- new scope:literal 30:literal)
-      (0:scope-address <- next-input)  ; share outer scope
+      (default-space:space-address <- new space:literal 30:literal)
+      (0:space-address <- next-input)  ; share outer space
       (1:integer/space:1 <- add 1:integer/space:1 1:literal)  ; increment
       (1:integer <- copy 34:literal)  ; dummy
       (reply 1:integer/space:1)
      ])
     (function main [
-      (1:scope-address <- init-counter)
-      (2:integer <- increment-counter 1:scope-address)
-      (3:integer <- increment-counter 1:scope-address)
+      (1:space-address <- init-counter)
+      (2:integer <- increment-counter 1:space-address)
+      (3:integer <- increment-counter 1:space-address)
      ])))
 ;? (set dump-trace*)
 (run 'main)
@@ -2077,25 +2077,25 @@
 ;? (quit)
 
 (reset)
-(new-trace "default-scope-closure-with-names")
+(new-trace "default-space-closure-with-names")
 (add-code
   '((function init-counter [
-      (default-scope:scope-address <- new scope:literal 30:literal)
+      (default-space:space-address <- new space:literal 30:literal)
       (x:integer <- copy 23:literal)
       (y:integer <- copy 3:literal)  ; correct copy of y
-      (reply default-scope:scope-address)
+      (reply default-space:space-address)
      ])
     (function increment-counter [
-      (default-scope:scope-address <- new scope:literal 30:literal)
-      (0:scope-address/names:init-counter <- next-input)  ; outer scope must be created by 'init-counter' above
+      (default-space:space-address <- new space:literal 30:literal)
+      (0:space-address/names:init-counter <- next-input)  ; outer space must be created by 'init-counter' above
       (y:integer/space:1 <- add y:integer/space:1 1:literal)  ; increment
       (y:integer <- copy 34:literal)  ; dummy
       (reply y:integer/space:1)
      ])
     (function main [
-      (1:scope-address/names:init-counter <- init-counter)
-      (2:integer <- increment-counter 1:scope-address/names:init-counter)
-      (3:integer <- increment-counter 1:scope-address/names:init-counter)
+      (1:space-address/names:init-counter <- init-counter)
+      (2:integer <- increment-counter 1:space-address/names:init-counter)
+      (3:integer <- increment-counter 1:space-address/names:init-counter)
      ])))
 ;? (set dump-trace*)
 (run 'main)
@@ -2124,7 +2124,7 @@
       ; doesn't matter too much how many locals you allocate space for (here 20)
       ; if it's slightly too many -- memory is plentiful
       ; if it's too few -- mu will raise an error
-      (default-scope:scope-address <- new scope:literal 20:literal)
+      (default-space:space-address <- new space:literal 20:literal)
       (first-arg-box:tagged-value-address <- next-input)
       ; if given integers, add them
       { begin
@@ -2153,7 +2153,7 @@
 ;? (set dump-trace*)
 (add-code
   '((function test1 [
-      (default-scope:scope-address <- new scope:literal 20:literal)
+      (default-space:space-address <- new space:literal 20:literal)
       (first-arg-box:tagged-value-address <- next-input)
       ; if given integers, add them
       { begin
@@ -2193,7 +2193,7 @@
 (new-trace "dispatch-multiple-calls")
 (add-code
   '((function test1 [
-      (default-scope:scope-address <- new scope:literal 20:literal)
+      (default-space:space-address <- new space:literal 20:literal)
       (first-arg-box:tagged-value-address <- next-input)
       ; if given integers, add them
       { begin
@@ -2627,7 +2627,7 @@
   '((function f1 [
       ; waits for memory location 1 to be changed, before computing its successor
       (10:integer <- copy 5:literal)  ; array of locals
-      (default-scope:scope-address <- copy 10:literal)
+      (default-space:space-address <- copy 10:literal)
       (1:integer <- copy 23:literal)  ; really location 12
       (sleep 1:integer)
       (2:integer <- add 1:integer 1:literal)
@@ -2672,7 +2672,7 @@
 (new-trace "fork-copies-args")
 (add-code
   '((function f1 [
-      (default-scope:scope-address <- new scope:literal 5:literal)
+      (default-space:space-address <- new space:literal 5:literal)
       (x:integer <- copy 4:literal)
       (fork f2:fn nil:literal x:integer)
       (x:integer <- copy 0:literal)  ; should be ignored
@@ -2691,9 +2691,9 @@
       (1:integer/raw <- copy 2:integer/space:global)
      ])
     (function main [
-      (default-scope:scope-address <- new scope:literal 5:literal)
+      (default-space:space-address <- new space:literal 5:literal)
       (2:integer <- copy 4:literal)
-      (fork f1:fn default-scope:scope-address)
+      (fork f1:fn default-space:space-address)
      ])))
 (run 'main)
 (each routine completed-routines*
@@ -3017,13 +3017,13 @@
 (new-trace "channel-handoff")
 (add-code
   '((function consumer [
-      (default-scope:scope-address <- new scope:literal 30:literal)
+      (default-space:space-address <- new space:literal 30:literal)
       (chan:channel-address <- init-channel 3:literal)  ; create a channel
       (fork producer:fn nil:literal chan:channel-address)  ; fork a routine to produce a value in it
       (1:tagged-value/raw <- read chan:channel-address)  ; wait for input on channel
      ])
     (function producer [
-      (default-scope:scope-address <- new scope:literal 30:literal)
+      (default-space:space-address <- new space:literal 30:literal)
       (n:integer-address <- new integer:literal)
       (n:integer-address/deref <- copy 24:literal)
       (ochan:channel-address <- next-input)
@@ -3045,13 +3045,13 @@
 (new-trace "channel-handoff-routine")
 (add-code
   '((function consumer [
-      (default-scope:scope-address <- new scope:literal 30:literal)
+      (default-space:space-address <- new space:literal 30:literal)
       (1:channel-address <- init-channel 3:literal)  ; create a channel
-      (fork producer:fn default-scope:address)  ; pass it as a global to another routine
+      (fork producer:fn default-space:address)  ; pass it as a global to another routine
       (1:tagged-value/raw <- read 1:channel-address)  ; wait for input on channel
      ])
     (function producer [
-      (default-scope:scope-address <- new scope:literal 30:literal)
+      (default-space:space-address <- new space:literal 30:literal)
       (n:integer-address <- new integer:literal)
       (n:integer-address/deref <- copy 24:literal)
       (x:tagged-value <- save-type n:integer-address)
@@ -3783,21 +3783,21 @@
             (tokenize-arg              'a:b/c:d))
 
 ; support labels
-(assert:iso '((((default-scope scope-address)) <- ((new)) ((scope literal)) ((30 literal)))
+(assert:iso '((((default-space space-address)) <- ((new)) ((space literal)) ((30 literal)))
               foo)
             (tokenize-args
-              '((default-scope:scope-address <- new scope:literal 30:literal)
+              '((default-space:space-address <- new space:literal 30:literal)
                 foo)))
 
 ; support braces
-(assert:iso '((((default-scope scope-address)) <- ((new)) ((scope literal)) ((30 literal)))
+(assert:iso '((((default-space space-address)) <- ((new)) ((space literal)) ((30 literal)))
               foo
               { begin
                 bar
                 (((a b)) <- ((op)) ((c d)) ((e f)))
               })
             (tokenize-args
-              '((default-scope:scope-address <- new scope:literal 30:literal)
+              '((default-space:space-address <- new space:literal 30:literal)
                 foo
                 { begin
                   bar
@@ -3821,15 +3821,15 @@
   (prn "F - 'absolutize' works without routine"))
 (= routine* make-routine!foo)
 (if (~iso '((4 integer)) (absolutize '((4 integer))))
-  (prn "F - 'absolutize' works without default-scope"))
-(= rep.routine*!call-stack.0!default-scope 10)
-(= memory*.10 5)  ; bounds check for default-scope
+  (prn "F - 'absolutize' works without default-space"))
+(= rep.routine*!call-stack.0!default-space 10)
+(= memory*.10 5)  ; bounds check for default-space
 (if (~iso '((15 integer) (raw))
           (absolutize '((4 integer))))
-  (prn "F - 'absolutize' works with default-scope"))
+  (prn "F - 'absolutize' works with default-space"))
 (absolutize '((5 integer)))
 (if (~posmatch "no room" rep.routine*!error)
-  (prn "F - 'absolutize' checks against default-scope bounds"))
+  (prn "F - 'absolutize' checks against default-space bounds"))
 (if (~iso '((_ integer)) (absolutize '((_ integer))))
   (prn "F - 'absolutize' passes dummy args right through"))
 
@@ -3899,20 +3899,20 @@
   (prn "F - 'addr' works with indirectly-addressed 'deref' inside routines"))
 
 ;? (prn 301)
-(= rep.routine*!call-stack.0!default-scope 10)
+(= rep.routine*!call-stack.0!default-space 10)
 ;? (prn 302)
-(= memory*.10 5)  ; bounds check for default-scope
+(= memory*.10 5)  ; bounds check for default-space
 ;? (prn 303)
 (if (~is 15 (addr '((4 integer))))
-  (prn "F - directly addressed operands in routines add default-scope"))
+  (prn "F - directly addressed operands in routines add default-space"))
 ;? (quit)
 (if (~is 15 (addr '((4 integer-address))))
-  (prn "F - directly addressed operands in routines add default-scope - 2"))
+  (prn "F - directly addressed operands in routines add default-space - 2"))
 (if (~is 15 (addr '((4 literal))))
   (prn "F - 'addr' doesn't understand literals"))
 (= memory*.15 23)
 (if (~is 23 (addr '((4 integer-address) (deref))))
-  (prn "F - 'addr' adds default-scope before 'deref', not after"))
+  (prn "F - 'addr' adds default-space before 'deref', not after"))
 ;? (quit)
 
 ; array-len
@@ -3969,16 +3969,16 @@
 (= routine* make-routine!foo)
 (if (~is 24 (sizeof '((4 integer-array))))
   (prn "F - 'sizeof' reads array lengths from memory inside routines"))
-(= rep.routine*!call-stack.0!default-scope 10)
-(= memory*.10 5)  ; bounds check for default-scope
+(= rep.routine*!call-stack.0!default-space 10)
+(= memory*.10 5)  ; bounds check for default-space
 (if (~is 35 (sizeof '((4 integer-array))))
-  (prn "F - 'sizeof' reads array lengths from memory using default-scope"))
+  (prn "F - 'sizeof' reads array lengths from memory using default-space"))
 (= memory*.35 4)  ; size of array
 (= memory*.15 35)
 ;? (= dump-trace* (obj whitelist '("sizeof")))
 (aif rep.routine*!error (prn "error - " it))
 (if (~is 9 (sizeof '((4 integer-boolean-pair-array-address) (deref))))
-  (prn "F - 'sizeof' works on pointers to arrays using default-scope"))
+  (prn "F - 'sizeof' works on pointers to arrays using default-space"))
 ;? (quit)
 
 ; m
diff --git a/tangle.mu b/tangle.mu
index 7580c328..b975fd2a 100644
--- a/tangle.mu
+++ b/tangle.mu
@@ -4,7 +4,7 @@
 ; possibilities.
 
 (function factorial [
-  (default-scope:scope-address <- new scope:literal 30:literal)
+  (default-space:space-address <- new space:literal 30:literal)
   (n:integer <- next-input)
   { begin
     base-case