Small host execution ergos

lib/arboricx-manifest.tri

@@ -243,35 +243,39 @@ getExportNames_ = y (self acc exports :
 getExportNames = (exports :
   getExportNames_ t exports)
 
--- Select an export: prefer explicit name, then "main", then single, then error.
-selectExport_ = y (self exports name nameBytes :
-  matchBool
-    -- Explicit name given
-    (matchBool
-      nothing
-      (err errMissingSection t)
-      (_ _ : nothing)
-      (findExportByName exports nameBytes))
-    -- No explicit name: try "main"
-    (matchBool
-      nothing
-      (matchBool
-        (equal? (length exports) 1)
-        (ok (head exports) t)
+mainExportName = "main"
+
+maybeExportToResult = (maybeExport :
+  triage
+    (err errMissingSection t)
+    (export : ok export t)
+    (_ _ : err errMissingSection t)
+    maybeExport)
+
+selectSingleExport = (exports :
+  matchList
+    (err errMissingSection t)
+    (export rest :
+      matchBool
+        (ok export t)
         (err errMissingSection t)
-        (bytesEq? (exportName (head exports)) nameBytes))
-      (_ _ : nothing)
-      (findExportByName exports nameBytes))
-    -- Single export: auto-select
-    (matchBool
-      (equal? (length exports) 1)
-      (ok (head exports) t)
-      (err errMissingSection t)
-      (emptyList? exports))
+        (emptyList? rest))
     exports)
 
+selectDefaultExport = (exports :
+  triage
+    (selectSingleExport exports)
+    (export : ok export t)
+    (_ _ : err errMissingSection t)
+    (findExportByName exports mainExportName))
+
+-- Select an export: explicit name if provided, otherwise "main", otherwise
+-- the sole export if the bundle has exactly one export.
 selectExport = (exports nameBytes :
-  selectExport_ exports nameBytes nameBytes)
+  matchBool
+    (selectDefaultExport exports)
+    (maybeExportToResult (findExportByName exports nameBytes))
+    (emptyList? nameBytes))
 
 selectExportOpt = (exports optNameBytes :
   selectExport exports optNameBytes)
@@ -304,7 +308,7 @@ manifestRuntimeAbi = (core : pairFirst (pairSecond (pairSecond (pairSecond (pair
 manifestCapabilities = (core : pairFirst (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond core))))))))))
 manifestClosureByte = (core : pairFirst (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond core)))))))))))
 manifestRoots = (core : pairFirst (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond core))))))))))))
-manifestExports = (core : pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond core)))))))))))
+manifestExports = (core : pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond (pairSecond core))))))))))))
 
 -- Helper: compare a manifest field against an expected byte string.
 manifestFieldMatch? = (actual expected : bytesEq? actual expected)

lib/arboricx.tri

@@ -16,3 +16,38 @@ readArboricxBundle = (bs :
                     (validCore _ : ok (pair validCore metadataWithExtensions) afterContainer))
                 parsedManifest))
         sections))
+
+-- Select an export from a validated bundle and reconstruct its root tree.
+-- Returns ok executable afterContainer, or propagates parse/selection/node errors.
+readArboricxExecutableByName = (nameBytes bs :
+  bindResult (readArboricxBundle bs)
+    (bundleResult afterBundle :
+      matchPair
+        (validCore _ :
+          bindResult (selectExport (manifestExports validCore) nameBytes)
+            (selectedExport _ :
+              readArboricxTreeFromHash (exportRoot selectedExport) bs))
+        bundleResult))
+
+readArboricxExecutable = (bs :
+  readArboricxExecutableByName [] bs)
+
+applyArgs = (f args :
+  foldl
+    (acc arg : acc arg)
+    f
+    args)
+
+runArboricxByName = (nameBytes bs arg :
+  bindResult (readArboricxExecutableByName nameBytes bs)
+    (executable rest : ok (executable arg) rest))
+
+runArboricx = (bs arg :
+  runArboricxByName [] bs arg)
+
+runArboricxArgsByName = (nameBytes bs args :
+  bindResult (readArboricxExecutableByName nameBytes bs)
+    (executable rest : ok (applyArgs executable args) rest))
+
+runArboricxArgs = (bs args :
+  runArboricxArgsByName [] bs args)