From 4965597043aca57a05760113f1851e96dad1eaf8 Mon Sep 17 00:00:00 2001
From: Eduardo Julian
Date: Mon, 14 Mar 2022 06:14:57 -0400
Subject: Leaner syntax for the "for" macro.

---
 stdlib/source/library/lux.lux | 99 ++++++++++++++++++++++---------------------
 1 file changed, 50 insertions(+), 49 deletions(-)

(limited to 'stdlib/source/library/lux.lux')

diff --git a/stdlib/source/library/lux.lux b/stdlib/source/library/lux.lux
index 09f0a9e4c..6120a52be 100644
--- a/stdlib/source/library/lux.lux
+++ b/stdlib/source/library/lux.lux
@@ -2584,6 +2584,17 @@
          {#None}
          {#Some [tokens (list)]}))
 
+(def:' .private (maybeP itP tokens)
+       (All (_ a)
+         (-> (Parser a)
+             (Parser (Maybe a))))
+       (case (itP tokens)
+         {#Some [tokens it]}
+         {#Some [tokens {#Some it}]}
+
+         {#None}
+         {#Some [tokens {#None}]}))
+
 (def:' .private (tupleP itP tokens)
        (All (_ a)
          (-> (Parser a) (Parser a)))
@@ -4882,52 +4893,41 @@
         (target_pick target options' default)))))
 
 (macro: .public (for tokens)
-  (do meta_monad
-    [target ..target]
-    (case tokens
-      (^ (list [_ {#Tuple options}]))
-      (case (pairs options)
-        {#Some options}
-        (target_pick target options {#None})
-
-        {#None}
-        (failure (..wrong_syntax_error (symbol ..for))))
-      
-      (^ (list [_ {#Tuple options}] default))
-      (case (pairs options)
-        {#Some options}
-        (target_pick target options {#Some default})
-
-        {#None}
-        (failure (..wrong_syntax_error (symbol ..for))))
+  (case (..parsed (..andP (..someP (..andP ..anyP ..anyP))
+                          (..maybeP ..anyP))
+                  tokens)
+    {.#Some [options default]}
+    (do meta_monad
+      [target ..target]
+      (target_pick target options default))
 
-      _
-      (failure (..wrong_syntax_error (symbol ..for))))))
+    {.#None}
+    (failure (..wrong_syntax_error (symbol ..for)))))
 
 ... TODO: Delete "scope_type_vars" (including the #scope_type_vars Lux state) and ":parameter" ASAP.
-(for ["{old}" (as_is (def: (scope_type_vars state)
-                       (Meta (List Nat))
-                       (case state
-                         [..#info info ..#source    source ..#current_module _   ..#modules modules
-                          ..#scopes scopes ..#type_context types    ..#host    host
-                          ..#seed seed ..#expected  expected ..#location  location ..#extensions extensions
-                          ..#scope_type_vars scope_type_vars ..#eval _eval]
-                         {#Right [state scope_type_vars]}))
-
-                     (macro: .public (:parameter tokens)
-                       (case tokens
-                         (^ (list [_ {#Nat idx}]))
-                         (do meta_monad
-                           [stvs ..scope_type_vars]
-                           (case (..item idx (list#reversed stvs))
-                             {#Some var_id}
-                             (in (list (` {.#Ex (~ (nat$ var_id))})))
-
-                             {#None}
-                             (failure (text#composite "Indexed-type does not exist: " (nat#encoded idx)))))
+(for "{old}" (as_is (def: (scope_type_vars state)
+                      (Meta (List Nat))
+                      (case state
+                        [..#info info ..#source    source ..#current_module _   ..#modules modules
+                         ..#scopes scopes ..#type_context types    ..#host    host
+                         ..#seed seed ..#expected  expected ..#location  location ..#extensions extensions
+                         ..#scope_type_vars scope_type_vars ..#eval _eval]
+                        {#Right [state scope_type_vars]}))
+
+                    (macro: .public (:parameter tokens)
+                      (case tokens
+                        (^ (list [_ {#Nat idx}]))
+                        (do meta_monad
+                          [stvs ..scope_type_vars]
+                          (case (..item idx (list#reversed stvs))
+                            {#Some var_id}
+                            (in (list (` {.#Ex (~ (nat$ var_id))})))
 
-                         _
-                         (failure (..wrong_syntax_error (symbol ..$))))))]
+                            {#None}
+                            (failure (text#composite "Indexed-type does not exist: " (nat#encoded idx)))))
+
+                        _
+                        (failure (..wrong_syntax_error (symbol ..$))))))
      (as_is))
 
 (macro: .public (using _imports)
@@ -4946,13 +4946,14 @@
            =module (` ("lux def module" (~ =imports)))]
      g!_ (..generated_symbol "")]
     (in {#Item =module
-               (for [... TODO: Remove this hack once Jython is no longer being used as the Python interpreter.
-                     ... Without it, I get this strange error
-                     ... {library/lux/tool/compiler/language/lux/generation.no_buffer_for_saving_code}
-                     ... Artifact ID: 0
-                     ... Which only ever happens for the Python compiler.
-                     "Python" (list& (` ("lux def" (~ g!_) [] #0))
-                                     =refers)]
+               (for "Python"
+                    ... TODO: Remove this hack once Jython is no longer being used as the Python interpreter.
+                    ... Without it, I get this strange error
+                    ... {library/lux/tool/compiler/language/lux/generation.no_buffer_for_saving_code}
+                    ... Artifact ID: 0
+                    ... Which only ever happens for the Python compiler.
+                    (list& (` ("lux def" (~ g!_) [] #0))
+                           =refers)
                     =refers)})))
 
 (def: (embedded_expansions code)
-- 
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