[nongnu] elpa/geiser-kawa 4ba3dc2 035/119: Add support for macroexpand

[Philip Kaludercic]

branch: elpa/geiser-kawa
commit 4ba3dc21a035a05e383f5fc191cfb6c25ceb5a23
Author: spellcard199 <spellcard199@protonmail.com>
Commit: spellcard199 <spellcard199@protonmail.com>

    Add support for macroexpand
---
 README.org                                      | 20 +++----
 elisp/geiser-kawa.el                            |  3 +-
 src/main/java/kawageiser/Geiser.java            |  1 +
 src/main/java/kawageiser/GeiserMacroexpand.java | 74 +++++++++++++++++++++++++
 4 files changed, 86 insertions(+), 12 deletions(-)

diff --git a/README.org b/README.org
index ce4b257..feb68a1 100644
--- a/README.org
+++ b/README.org
@@ -22,6 +22,7 @@ Only versions of Kawa > 3.1 are supported, mostly due to the 
fact that before th
     - load-file
     - completions
     - module-completions (very fragile atm)
+    - macroexpand
     - autodoc:
         - for scheme procedures
         - for java methods
@@ -36,16 +37,15 @@ Only versions of Kawa > 3.1 are supported, mostly due to 
the fact that before th
 
 ** Unsupported features
 
-geiser-related:
-- macroexpand
-- find-file
-- symbol-location
-- module-location
-- symbol-documentation
-- module-exports
-- callers
-- callees
-- generic-methods
+- geiser-related:
+    - find-file
+    - symbol-location
+    - module-location
+    - symbol-documentation
+    - module-exports
+    - callers
+    - callees
+    - generic-methods
 
 ** Try geiser-kawa without modifying your emacs configuration
 
diff --git a/elisp/geiser-kawa.el b/elisp/geiser-kawa.el
index f08491b..cf55eb8 100644
--- a/elisp/geiser-kawa.el
+++ b/elisp/geiser-kawa.el
@@ -362,8 +362,7 @@ Argument MOD is passed by geiser, but it's not used here."
  ;; https://github.com/cask/cask/issues/472 in projects that depend on
  ;; geiser-kawa.
  '(define-geiser-implementation kawa
-    (unsupported-procedures '(macroexpand
-                              find-file
+    (unsupported-procedures '(find-file
                               symbol-location
                               module-location
                               symbol-documentation
diff --git a/src/main/java/kawageiser/Geiser.java 
b/src/main/java/kawageiser/Geiser.java
index 40b7e18..b7f6a40 100644
--- a/src/main/java/kawageiser/Geiser.java
+++ b/src/main/java/kawageiser/Geiser.java
@@ -28,5 +28,6 @@ public class Geiser implements Runnable {
         lang.defineFunction(new GeiserAutodoc("geiser:autodoc", lang));
         lang.defineFunction(new 
kawageiser.java.Complete("geiser:complete-java"));
         lang.defineFunction(new 
ManualEpubUnzipToTmpDir("geiser:manual-epub-unzip-to-tmp-dir"));
+        lang.defineFunction(new GeiserMacroexpand("geiser:macroexpand"));
     }
 }
diff --git a/src/main/java/kawageiser/GeiserMacroexpand.java 
b/src/main/java/kawageiser/GeiserMacroexpand.java
new file mode 100644
index 0000000..32e982f
--- /dev/null
+++ b/src/main/java/kawageiser/GeiserMacroexpand.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2020 spellcard199 <spellcard199@protonmail.com>
+ * This is free software;  for terms and warranty disclaimer see ./COPYING.
+ */
+
+package kawageiser;
+
+import gnu.expr.Language;
+import gnu.kawa.functions.Format;
+import gnu.kawa.slib.syntaxutils;
+import gnu.mapping.Environment;
+import gnu.mapping.Procedure1or2;
+
+public class GeiserMacroexpand extends Procedure1or2 {
+
+    GeiserMacroexpand(String name) {
+        super(name);
+    }
+
+    @Override
+    public Object apply1(Object form) throws Throwable {
+        return apply2(form, false);
+    }
+
+    @Override
+    public Object apply2(Object form, Object all) throws Throwable {
+        // I think Kawa macro expansion can only expand to the whole tree, so:
+        // 1. There is no macroexpand-1
+        // 2. The `all' argument that geiser passes is ignored
+        return expand(form, Language.getDefaultLanguage().getEnvironment());
+    }
+
+    public Object expand(Object form, Environment env) throws Throwable {
+        // TODO: How do you invoke kawa procedures with keyword arguments from 
java?
+        //  - ignoring env and using apply1, for now
+        //  - an alternative would be to port gnu.kawa.slib.syntaxutils.expand 
from scheme to java (it's easy)
+
+        //  I keep getting Wrong arguments using 
syntaxutils.expand.apply2(form, (Object) env)
+        //  Same from scheme:
+        //  (gnu.kawa.slib.syntaxutils:expand:apply2
+        //    (quote (cond ((< 1 3) (display "hi"))))
+        //    (interaction-environment))
+        //  gnu.mapping.WrongArguments
+        //  at gnu.mapping.CallContext.matchError(CallContext.java:150)
+        //  at gnu.mapping.CallContext.checkDone(CallContext.java:228)
+        //  at gnu.kawa.slib.syntaxutils.expand$check(syntaxutils.scm:67)
+        //  at gnu.mapping.CallContext.runUntilValue(CallContext.java:656)
+        //  at gnu.mapping.Procedure.apply2(Procedure.java:160)
+        //  at kawageiser.GeiserMacroexpand.expand(GeiserMacroexpand.java:35)
+        //  at kawageiser.GeiserMacroexpand.apply2(GeiserMacroexpand.java:31)
+        //  at gnu.mapping.Procedure2.applyToObject(Procedure2.java:62)
+        //  at gnu.mapping.Procedure.applyToConsumerDefault(Procedure.java:75)
+        //  at 
gnu.kawa.functions.ApplyToArgs.applyToConsumerA2A(ApplyToArgs.java:132)
+        //  at gnu.mapping.CallContext.runUntilDone(CallContext.java:586)
+        //  at gnu.expr.ModuleExp.evalModule2(ModuleExp.java:343)
+        //  at gnu.expr.ModuleExp.evalModule(ModuleExp.java:211)
+        //  at kawa.Shell.run(Shell.java:289)
+        //  at kawa.Shell.run(Shell.java:196)
+        //  at kawa.Shell.run(Shell.java:183)
+        //  at kawa.TelnetRepl.apply0(TelnetRepl.java:25)
+        //  at gnu.mapping.RunnableClosure.run(RunnableClosure.java:75)
+        //  at java.base/java.lang.Thread.run(Thread.java:834)
+        //
+        //  This, instead, works:
+        //  (gnu.kawa.slib.syntaxutils:expand
+        //    (quote (cond ((< 1 3) (display "hi"))))
+        //    env: (interaction-environment))
+        Object expanded = syntaxutils.expand.apply1(form);
+        // Double formatting so that double quotes around strings are not lost.
+        return Format.format(
+                "~S",
+                Format.format("~S", expanded));
+    }
+}