Added `tree` back as a parameter to compile actions, which helps with

better error reporting, e.g. for (fail) (no arguments). Overall better
error reporting now. Also added shorthand ("Action" tree with ...) for
(SyntaxTree {.type = "Action", .1 = ...}).

1 files changed, 23 insertions, 9 deletions

diff --git a/lib/shell/init.nom b/lib/shell/init.nom
index d58894e..13dde56 100644
--- a/lib/shell/init.nom
+++ b/lib/shell/init.nom
@@ -1,12 +1,26 @@
 #
     This file defines some actions for running shell commands.
-    
+
 external:
-    (=sh $cmd) means:
-        lua> ("
-            local result = io.popen(\$cmd)
-            local contents = result:read("*a")
-            result:close()
-            return contents
-        ")
-    $(sh> $) = $os.execute
+    (at $callsite =sh $cmd) means:
+        $f = ($io.popen $cmd)
+        $contents = ($f, read "*a")
+        [$ok, $return_type, $return] = ($f, close)
+        unless $ok:
+            if ($return_type == "exit"):
+                at $callsite fail "Command failure: Command `\$cmd` failed with exit code \$return"
+            ..else:
+                at $callsite fail "Command failure: Command `\$cmd` was terminated by signal \$return"
+        return $contents
+
+    (at $callsite sh> $cmd) means:
+        [$ok, $return_type, $return] = ($os.execute $cmd)
+        unless $ok:
+            if ($return_type == "exit"):
+                at $callsite fail "Command failure: Command `\$cmd` failed with exit code \$return"
+            ..else:
+                at $callsite fail "Command failure: Command `\$cmd` was terminated by signal \$return"
+
+    # Attach callsite information for better error reporting
+    (=sh $cmd) compiles to (\(at ("Text" tree with "\($cmd.source)") =sh $cmd) as lua)
+    (sh> $cmd) compiles to (\(at ("Text" tree with "\($cmd.source)") sh> $cmd) as lua)