From ec0f8fe57483e72f45fba995f3e17870e4e30bec Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Sat, 19 May 2018 14:03:32 +1000
Subject: [PATCH] Extend `try` command to support multiple catches.

If a catch command fails, and another catch is availabe following
it, that following catch gets executed.
---
 doc/pages/commands.asciidoc |  7 +++++--
 src/commands.cc             | 36 +++++++++++++++++++++---------------
 2 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/doc/pages/commands.asciidoc b/doc/pages/commands.asciidoc
index 9a86b86d..cd79d26a 100644
--- a/doc/pages/commands.asciidoc
+++ b/doc/pages/commands.asciidoc
@@ -225,10 +225,13 @@ but not really useful in that context.
     *-title* <text>:::
         set the title of the message box
 
-*try* <commands> catch <on_error_commands>::
+*try* <commands> [catch <on_error_commands>]...::
     prevent an error in *commands* from aborting the whole command
     execution, execute *on_error_commands* instead. If nothing is to be
-    done on error, the catch part can be omitted
+    done on error, the catch part can be omitted. If an error is raised
+    in the *on_error_commands*, that error is propagated, except if
+    another *catch* and *on_error_commands* parameter follows, in which
+    case those commands get executed, and so-on.
 
 *nop*::
     does nothing, but arguments will be evaluated (e.g. shell expansion)
diff --git a/src/commands.cc b/src/commands.cc
index e81528d6..7c41ba16 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -1958,31 +1958,37 @@ const CommandDesc info_cmd = {
 const CommandDesc try_catch_cmd = {
     "try",
     nullptr,
-    "try <cmds> [catch <error_cmds>]: execute <cmds> in current context.\n"
-    "if an error is raised and <error_cmds> is specified, execute it; "
-    "The error is not propagated further.",
-    ParameterDesc{{}, ParameterDesc::Flags::None, 1, 3},
+    "try <cmds> [catch <error_cmds>]...: execute <cmds> in current context.\n"
+    "if an error is raised and <error_cmds> is specified, execute it and do\n"
+    "not propagate that error. If <error_cmds> raises an error and another\n"
+    "<error_cmds> is provided, execute this one and so-on\n",
+    ParameterDesc{{}, ParameterDesc::Flags::None, 1},
     CommandFlags::None,
     CommandHelper{},
     CommandCompleter{},
     [](const ParametersParser& parser, Context& context, const ShellContext& shell_context)
     {
-        if (parser.positional_count() == 2)
+        if ((parser.positional_count() % 2) != 1)
             throw wrong_argument_count();
 
-        const bool do_catch = parser.positional_count() == 3;
-        if (do_catch and parser[1] != "catch")
-            throw runtime_error("usage: try <commands> [catch <on error commands>]");
+        for (size_t i = 1; i < parser.positional_count(); i += 2)
+        {
+            if (parser[i] != "catch")
+                throw runtime_error("usage: try <commands> [catch <on error commands>]...");
+        }
 
         CommandManager& command_manager = CommandManager::instance();
-        try
+        for (size_t i = 0; i < parser.positional_count(); i += 2)
         {
-            command_manager.execute(parser[0], context, shell_context);
-        }
-        catch (Kakoune::runtime_error& e)
-        {
-            if (do_catch)
-                command_manager.execute(parser[2], context, shell_context);
+            if (i == 0 or i < parser.positional_count() - 1)
+            {
+                try {
+                    command_manager.execute(parser[i], context, shell_context);
+                    return;
+                } catch (runtime_error&) {}
+            }
+            else
+                command_manager.execute(parser[i], context, shell_context);
         }
     }
 };