Fix redundant alpha attributes in XMIR output

Co-authored-by: yegor256 <[email protected]>

Author: Copilot

src/XMIR.hs

@@ -69,11 +69,16 @@ expression (ExDispatch expr attr) = do
 expression (ExApplication expr (BiTau attr texpr)) = do
   (base, children) <- expression expr
   (base', children') <- expression texpr
-  let as = prettyAttribute attr
-      attrs =
-        if null base'
-          then [("as", as)]
-          else [("as", as), ("base", base')]
+  let attrs = case attr of
+        AtAlpha _ -> -- For alpha attributes, omit the "as" attribute since position implies the index
+          if null base'
+            then []
+            else [("base", base')]
+        _ -> -- For non-alpha attributes, include the "as" attribute as before
+          let as = prettyAttribute attr
+          in if null base'
+               then [("as", as)]
+               else [("as", as), ("base", base')]
   pure (base, children ++ [object attrs children'])
 expression (ExApplication (ExFormation bds) tau) = throwIO (UnsupportedExpression (ExApplication (ExFormation bds) tau))
 expression expr = throwIO (UnsupportedExpression expr)

test/XMIRSpec.hs

@@ -23,3 +23,26 @@ spec = do
   it "prints valid xmir" $ do
     pending
     T.stripEnd (T.pack xmir) `shouldBe` T.stripEnd (T.pack xmir')
+  
+  it "omits redundant alpha attributes in XMIR" $ do
+    let phiCode = "Q -> [[org -> [[eolang -> [[version -> Q.org.eolang.number(α0 -> Q.org.eolang.bytes(α0 -> \"test\")), λ ⤍ Package]], λ ⤍ Package]]]]"
+    program <- parseProgramThrows phiCode
+    document <- programToXMIR program SALTY
+    let xmlOutput = printXMIR document
+    -- Check that alpha attributes are omitted - there should be no 'as="α0"' in the output
+    xmlOutput `shouldNotContain` "as=\"α0\""
+    -- Check that the structure is preserved with proper base attributes
+    xmlOutput `shouldContain` "base=\"Q.org.eolang.number\""
+    xmlOutput `shouldContain` "base=\"Q.org.eolang.bytes\""
+
+shouldNotContain :: String -> String -> IO ()
+shouldNotContain haystack needle = 
+  if T.pack needle `T.isInfixOf` T.pack haystack
+    then fail $ "Expected not to contain: " ++ needle
+    else return ()
+
+shouldContain :: String -> String -> IO ()  
+shouldContain haystack needle =
+  if T.pack needle `T.isInfixOf` T.pack haystack
+    then return ()
+    else fail $ "Expected to contain: " ++ needle