Updates to account for FUNC_BODY(), BLANK

This syncs Ren-Cpp and Ren Garden with the master branch of Ren-C after
a somewhat long period of drift.  The main change is an improvement
surrounding the amount of information that can be "stowed" with a
customized native function.

Previously, function REBVALs (4 pointers in size) contained header bits,
a spec array pointer, a paramlist array pointer, and a native C
function pointer.  This put the burden on Ren-Cpp to find a way to
locate the C++ std::function implementing its extensions based on the
information passed in--because the raw native function pointer would
not be enough.  That led to the ugly lambda identity trick of
REN_STD_FUNCTION.

(The decision was made at a time when no assumptions were being made
about what was being passed *other* than the function pointer.  Today's
decision-making environment is much different than the one which guided
that choice.)

This gets rid of REN_STD_FUNCTION, instead taking advantage of the
ability to stow arbitrary values along with the function via FUNC_BODY()
when the instance is created.

It also does the change from NONE => BLANK, as NONE is being retaken
to mean "none of the expressions in the block are true".

examples/function-1.cpp

@@ -11,8 +11,6 @@ int main(int, char **) {
         "{Demonstration of the C++ Extension mechanism}"
         "blk [block!] {The block to print}",
 
-        REN_STD_FUNCTION,
-
         [](Block const & blk) -> Logic {
             print("blk is", blk);
             return true;

examples/workbench/evaluator.cpp

@@ -88,7 +88,7 @@ void EvaluatorWorker::doWork(
                 //
                 // https://github.com/metaeducation/ren-garden/issues/17
 
-                if (t.value() == nullopt || is<None>(t.value())) {
+                if (t.value() == nullopt || is<Blank>(t.value())) {
                     qApp->exit(0);
                 }
                 else if (is<Integer>(t.value())) {

examples/workbench/renconsole.cpp

@@ -88,8 +88,6 @@ RenConsole::RenConsole (EvaluatorWorker * worker, QWidget * parent) :
         "    {block to execute or other instruction (see documentation)}"
         "/meta {Interpret in 'meta mode' for controlling the dialect}",
 
-        REN_STD_FUNCTION,
-
         [this](AnyValue const & arg, AnyValue const & meta) -> optional<AnyValue>
         {
             if (not meta) {
@@ -174,15 +172,15 @@ RenConsole::RenConsole (EvaluatorWorker * worker, QWidget * parent) :
                     if (not bannerPrinted) {
                         printBanner();
                         bannerPrinted = true;
-                        return {none};
+                        return {blank};
                     }
                 }
 
                 // Meta protocol may query you for lit-word features you
                 // do not support, so don't raise an error if you don't
                 // know what it is... just return none.
 
-                return {none};
+                return {blank};
             }
 
             if (is<Block>(arg)) {
@@ -250,8 +248,6 @@ RenConsole::RenConsole (EvaluatorWorker * worker, QWidget * parent) :
             "{word to watch or other legal parameter, see documentation)} "
         "/dialect {Interpret as instruction to WATCH vs. raw value} ",
 
-        REN_STD_FUNCTION,
-
         [this](
             AnyValue const & argOriginal, AnyValue const & dialect
         )

examples/workbench/renshell.cpp

@@ -521,23 +521,14 @@ RenShell::RenShell (AnyContext const & helpers, QObject * parent) :
 
     shellFunction = Function::construct(
         "{SHELL dialect for interacting with an OS shell process}"
-        "'arg [word! lit-word! block! paren! string! none!]"
+        "'arg [<end> word! lit-word! block! paren! string!]"
         "    {block in dialect or other instruction (see documentation)}"
         "/meta {Interpret in 'meta mode' for controlling the dialect}",
 
-        REN_STD_FUNCTION,
-
         [this, worker](optional<AnyValue> const & arg, AnyValue const & meta)
             -> optional<AnyValue>
         {
-            if (is<None>(arg)) {
-                //
-                // Used to use the "unset quoting" trick to do variadic, but
-                // now that's been removed.  Real variadic handling has not
-                // been added to Ren-C, and would need `ren::Varargs`.
-                //
-                // For now, just signal that with NONE!
-                //
+            if (not arg) {
                 runtime("console quote", shellFunction);
                 return nullopt;
             }
@@ -583,7 +574,7 @@ RenShell::RenShell (AnyContext const & helpers, QObject * parent) :
                 // Meta protocol may ask you for things you don't know about,
                 // so gracefully ignore them.
                 if (is<LitWord>(arg))
-                    return {none};
+                    return {blank};
 
                 if (not is<Block>(arg))
                     throw Error {"Unknown meta command"};

examples/workbench/scripts/combine.reb

@@ -62,7 +62,7 @@ combine: function [
         out: make string! 10 ;; No good heuristic for string size yet
     ]
 
-    unless set? 'delimiter [delimiter: none]
+    unless set? 'delimiter [delimiter: _]
 
     unless any-function? :delimiter [
         unless block? delimiter [
@@ -91,7 +91,7 @@ combine: function [
             set/any quote temp: delimiter depth
             if all [
                 value? 'temp
-                (not none? temp) or (block? out)
+                (not blank? temp) or (block? out)
             ][
                 out: append out temp
             ]
@@ -101,7 +101,7 @@ combine: function [
     ]
 
 
-    ; Do evaluation of the block until a non-none evaluation result
+    ; Do evaluation of the block until a non-blank evaluation result
     ; is found... the limit is hit...or end of the input is reached.
 
     original: block
@@ -110,7 +110,7 @@ combine: function [
         all [
             not tail? block
             any [
-                none? part
+                blank? part
                 either integer? limit [
                     0 <= limit: limit - 1
                 ][
@@ -124,7 +124,7 @@ combine: function [
         ; in this case that is okay since block is a parameter and won't
         ; leak as a global
 
-        set/any (quote value:) either safe [
+        value: either safe [
             either any [word? block/1 path? block/1] [
                 get/any first back (block: next block)
             ][
@@ -166,14 +166,14 @@ combine: function [
         case [
             ; Ignore voids (precedent: ANY, ALL, COMPOSE)
 
-            void? :value []
+            not set? 'value []
 
 
-            ; Skip all nones.  This is suggested for COMPOSE as well:
+            ; Skip all blanks.  This is suggested for COMPOSE as well:
             ;
             ;     http://curecode.org/rebol3/ticket.rsp?id=2198
 
-            none? :value []
+            blank? :value []
 
 
             ; If a function or PAREN! are returned, then evaluate it at
@@ -193,7 +193,7 @@ combine: function [
 
             any [
                 any-function? :value
-                paren? value
+                group? value
             ][
                 if safe [
                     do make error! {

examples/workbench/scripts/helpers/autocomplete.reb

@@ -85,20 +85,20 @@ Rebol [
 ;
 
 try-get-scope-from-path: function [path [path!]] [
-    obj: none
+    obj: _
 
     for-each element path [
 
         ; only consider paths made up of words...
 
-        unless word? :element [return none]
+        unless word? :element [return _]
 
 
         ; If we have an object in progress, look up the word in it,
         ; otherwise get the word.
 
         value: either obj [
-            unless in obj element [return none]
+            unless in obj element [return _]
             select obj element
         ][
             get/any element
@@ -118,7 +118,7 @@ try-get-scope-from-path: function [path [path!]] [
         ;
         ; How did it know?
 
-        unless object? :value [return none]
+        unless object? :value [return _]
 
         obj: value
     ]
@@ -143,7 +143,7 @@ fake-context-from-function: function [fun [any-function!]] [
             append spec to-set-word word
         ]
     ]
-    append spec none
+    append spec _
     return has spec
 ]
 
@@ -175,7 +175,7 @@ autocomplete-helper: function [
     ; asking to have completed?  :-/  Leave it alone for now.
 
     if index = 1 [
-        return reduce [text index none]
+        return reduce [text index _]
     ]
 
 
@@ -270,8 +270,8 @@ autocomplete-helper: function [
     ; to the current complete "state" embodied by the selection, and want
     ; whichever one is after that instead.
 
-    first-candidate-word: none
-    first-candidate-ctx: none
+    first-candidate-word: _
+    first-candidate-ctx: _
     take-next: false
 
     for-each ctx adjusted-contexts [
@@ -374,5 +374,5 @@ autocomplete-helper: function [
 
     ; Didn't find anything, just return what we were given...
     ;
-    return reduce [text index none]
+    return reduce [text index _]
 ]

include/rencpp/atoms.hpp

@@ -84,16 +84,16 @@ class Atom : public AnyValue {
 // probably never find much of a reason to use it.
 //
 
-constexpr AnyValue::none_t none {AnyValue::none_t::init{}};
+constexpr AnyValue::blank_t blank {AnyValue::blank_t::init{}};
 
-class None : public Atom {
+class Blank : public Atom {
 protected:
     friend class AnyValue;
-    None (Dont) noexcept : Atom (Dont::Initialize) {}
+    Blank (Dont) noexcept : Atom (Dont::Initialize) {}
     static bool isValid(RenCell const & cell);
 
 public:
-    explicit None (Engine * engine = nullptr) : Atom (none, engine) {}
+    explicit Blank (Engine * engine = nullptr) : Atom (blank, engine) {}
 };