Merge #1228

1228: Add inner macro checker in mbe r=matklad a=edwin0cheng

This PR do the following things:

* Add an inner macro checker for allowing defining mbe in mbe. (It is a adhoc solution, we could eliminate it after we have a better mbe parser)
* Move all tests to an tests modules
* Filter empty tree while expanding mbe.

This is the final PR extracting from #1219 

Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 1363 insertions, 0 deletions

diff --git a/crates/ra_mbe/src/tests.rs b/crates/ra_mbe/src/tests.rs
new file mode 100644
index 000000000..cdbd4dd1c
--- /dev/null
+++ b/crates/ra_mbe/src/tests.rs
@@ -0,0 +1,1363 @@
+use ra_syntax::{ast, AstNode};
+
+use super::*;
+
+// Good first issue (although a slightly challenging one):
+//
+// * Pick a random test from here
+//   https://github.com/intellij-rust/intellij-rust/blob/c4e9feee4ad46e7953b1948c112533360b6087bb/src/test/kotlin/org/rust/lang/core/macros/RsMacroExpansionTest.kt
+// * Port the test to rust and add it to this module
+// * Make it pass :-)
+
+#[test]
+fn test_convert_tt() {
+    let macro_definition = r#"
+macro_rules! impl_froms {
+    ($e:ident: $($v:ident),*) => {
+        $(
+            impl From<$v> for $e {
+                fn from(it: $v) -> $e {
+                    $e::$v(it)
+                }
+            }
+        )*
+    }
+}
+"#;
+
+    let macro_invocation = r#"
+impl_froms!(TokenTree: Leaf, Subtree);
+"#;
+
+    let source_file = ast::SourceFile::parse(macro_definition);
+    let macro_definition =
+        source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
+
+    let source_file = ast::SourceFile::parse(macro_invocation);
+    let macro_invocation =
+        source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
+
+    let (definition_tt, _) = ast_to_token_tree(macro_definition.token_tree().unwrap()).unwrap();
+    let (invocation_tt, _) = ast_to_token_tree(macro_invocation.token_tree().unwrap()).unwrap();
+    let rules = crate::MacroRules::parse(&definition_tt).unwrap();
+    let expansion = rules.expand(&invocation_tt).unwrap();
+    assert_eq!(
+        expansion.to_string(),
+        "impl From <Leaf > for TokenTree {fn from (it : Leaf) -> TokenTree {TokenTree ::Leaf (it)}} \
+         impl From <Subtree > for TokenTree {fn from (it : Subtree) -> TokenTree {TokenTree ::Subtree (it)}}"
+    )
+}
+
+pub(crate) fn create_rules(macro_definition: &str) -> MacroRules {
+    let source_file = ast::SourceFile::parse(macro_definition);
+    let macro_definition =
+        source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
+
+    let (definition_tt, _) = ast_to_token_tree(macro_definition.token_tree().unwrap()).unwrap();
+    crate::MacroRules::parse(&definition_tt).unwrap()
+}
+
+pub(crate) fn expand(rules: &MacroRules, invocation: &str) -> tt::Subtree {
+    let source_file = ast::SourceFile::parse(invocation);
+    let macro_invocation =
+        source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
+
+    let (invocation_tt, _) = ast_to_token_tree(macro_invocation.token_tree().unwrap()).unwrap();
+
+    rules.expand(&invocation_tt).unwrap()
+}
+
+pub(crate) fn expand_to_items(
+    rules: &MacroRules,
+    invocation: &str,
+) -> ra_syntax::TreeArc<ast::MacroItems> {
+    let expanded = expand(rules, invocation);
+    token_tree_to_macro_items(&expanded).unwrap()
+}
+
+#[allow(unused)]
+pub(crate) fn expand_to_stmts(
+    rules: &MacroRules,
+    invocation: &str,
+) -> ra_syntax::TreeArc<ast::MacroStmts> {
+    let expanded = expand(rules, invocation);
+    token_tree_to_macro_stmts(&expanded).unwrap()
+}
+
+pub(crate) fn expand_to_expr(
+    rules: &MacroRules,
+    invocation: &str,
+) -> ra_syntax::TreeArc<ast::Expr> {
+    let expanded = expand(rules, invocation);
+    token_tree_to_expr(&expanded).unwrap()
+}
+
+pub(crate) fn text_to_tokentree(text: &str) -> tt::Subtree {
+    // wrap the given text to a macro call
+    let wrapped = format!("wrap_macro!( {} )", text);
+    let wrapped = ast::SourceFile::parse(&wrapped);
+    let wrapped = wrapped.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
+    let mut wrapped = ast_to_token_tree(wrapped).unwrap().0;
+    wrapped.delimiter = tt::Delimiter::None;
+
+    wrapped
+}
+
+pub(crate) enum MacroKind {
+    Items,
+    Stmts,
+}
+
+use ra_syntax::WalkEvent;
+
+pub fn debug_dump_ignore_spaces(node: &ra_syntax::SyntaxNode) -> String {
+    use std::fmt::Write;
+
+    let mut level = 0;
+    let mut buf = String::new();
+    macro_rules! indent {
+        () => {
+            for _ in 0..level {
+                buf.push_str("  ");
+            }
+        };
+    }
+
+    for event in node.preorder_with_tokens() {
+        match event {
+            WalkEvent::Enter(element) => {
+                match element {
+                    ra_syntax::SyntaxElement::Node(node) => {
+                        indent!();
+                        writeln!(buf, "{:?}", node.kind()).unwrap();
+                    }
+                    ra_syntax::SyntaxElement::Token(token) => match token.kind() {
+                        ra_syntax::SyntaxKind::WHITESPACE => {}
+                        _ => {
+                            indent!();
+                            writeln!(buf, "{:?}", token.kind()).unwrap();
+                        }
+                    },
+                }
+                level += 1;
+            }
+            WalkEvent::Leave(_) => level -= 1,
+        }
+    }
+
+    buf
+}
+
+pub(crate) fn assert_expansion(
+    kind: MacroKind,
+    rules: &MacroRules,
+    invocation: &str,
+    expected: &str,
+) -> tt::Subtree {
+    let expanded = expand(rules, invocation);
+    assert_eq!(expanded.to_string(), expected);
+
+    let expected = expected.replace("$crate", "C_C__C");
+
+    // wrap the given text to a macro call
+    let expected = text_to_tokentree(&expected);
+
+    let (expanded_tree, expected_tree) = match kind {
+        MacroKind::Items => {
+            let expanded_tree = token_tree_to_macro_items(&expanded);
+            let expected_tree = token_tree_to_macro_items(&expected);
+
+            (
+                debug_dump_ignore_spaces(expanded_tree.unwrap().syntax()).trim().to_string(),
+                debug_dump_ignore_spaces(expected_tree.unwrap().syntax()).trim().to_string(),
+            )
+        }
+
+        MacroKind::Stmts => {
+            let expanded_tree = token_tree_to_macro_stmts(&expanded);
+            let expected_tree = token_tree_to_macro_stmts(&expected);
+
+            (
+                debug_dump_ignore_spaces(expanded_tree.unwrap().syntax()).trim().to_string(),
+                debug_dump_ignore_spaces(expected_tree.unwrap().syntax()).trim().to_string(),
+            )
+        }
+    };
+
+    let expected_tree = expected_tree.replace("C_C__C", "$crate");
+    assert_eq!(
+        expanded_tree, expected_tree,
+        "left => {}\nright => {}",
+        expanded_tree, expected_tree,
+    );
+
+    expanded
+}
+
+#[test]
+fn test_fail_match_pattern_by_first_token() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:ident) => (
+                mod $ i {}
+            );
+            (= $ i:ident) => (
+                fn $ i() {}
+            );
+            (+ $ i:ident) => (
+                struct $ i;
+            )
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "mod foo {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { = bar }", "fn bar () {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { + Baz }", "struct Baz ;");
+}
+
+#[test]
+fn test_fail_match_pattern_by_last_token() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:ident) => (
+                mod $ i {}
+            );
+            ($ i:ident =) => (
+                fn $ i() {}
+            );
+            ($ i:ident +) => (
+                struct $ i;
+            )
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "mod foo {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { bar = }", "fn bar () {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { Baz + }", "struct Baz ;");
+}
+
+#[test]
+fn test_fail_match_pattern_by_word_token() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:ident) => (
+                mod $ i {}
+            );
+            (spam $ i:ident) => (
+                fn $ i() {}
+            );
+            (eggs $ i:ident) => (
+                struct $ i;
+            )
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "mod foo {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { spam bar }", "fn bar () {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { eggs Baz }", "struct Baz ;");
+}
+
+#[test]
+fn test_match_group_pattern_by_separator_token() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ ($ i:ident),*) => ($ (
+                mod $ i {}
+            )*);
+            ($ ($ i:ident)#*) => ($ (
+                fn $ i() {}
+            )*);
+            ($ i:ident ,# $ j:ident) => (
+                struct $ i;
+                struct $ j;
+            )
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo, bar }", "mod foo {} mod bar {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo# bar }", "fn foo () {} fn bar () {}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { Foo,# Bar }", "struct Foo ; struct Bar ;");
+}
+
+#[test]
+fn test_match_group_pattern_with_multiple_defs() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ ($ i:ident),*) => ( struct Bar { $ (
+                fn $ i {}
+            )*} );            
+        }
+"#,
+    );
+
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! { foo, bar }",
+        "struct Bar {fn foo {} fn bar {}}",
+    );
+}
+
+#[test]
+fn test_match_group_pattern_with_multiple_statement() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ ($ i:ident),*) => ( fn baz { $ (
+                $ i ();
+            )*} );            
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo, bar }", "fn baz {foo () ; bar () ;}");
+}
+
+#[test]
+fn test_match_group_pattern_with_multiple_statement_without_semi() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ ($ i:ident),*) => ( fn baz { $ (
+                $i()
+            );*} );            
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo, bar }", "fn baz {foo () ;bar ()}");
+}
+
+#[test]
+fn test_match_group_empty_fixed_token() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ ($ i:ident)* #abc) => ( fn baz { $ (
+                $ i ();
+            )*} );            
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! {#abc}", "fn baz {}");
+}
+
+#[test]
+fn test_match_group_in_subtree() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {            
+            (fn $name:ident {$($i:ident)*} ) => ( fn $name() { $ (
+                $ i ();
+            )*} );            
+        }"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! {fn baz {a b} }", "fn baz () {a () ; b () ;}");
+}
+
+#[test]
+fn test_match_group_with_multichar_sep() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {            
+            (fn $name:ident {$($i:literal)*} ) => ( fn $name() -> bool { $($i)&&*} );            
+        }"#,
+    );
+
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! (fn baz {true true} )",
+        "fn baz () -> bool {true &&true}",
+    );
+}
+
+#[test]
+fn test_match_group_zero_match() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {            
+            ( $($i:ident)* ) => ();            
+        }"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! ()", "");
+}
+
+#[test]
+fn test_match_group_in_group() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {            
+            { $( ( $($i:ident)* ) )* } => ( $( ( $($i)* ) )* );
+        }"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, "foo! ( (a b) )", "(a b)");
+}
+
+#[test]
+fn test_expand_to_item_list() {
+    let rules = create_rules(
+        "
+            macro_rules! structs {
+                ($($i:ident),*) => {
+                    $(struct $i { field: u32 } )*
+                }
+            }
+            ",
+    );
+    let expansion = expand(&rules, "structs!(Foo, Bar)");
+    let tree = token_tree_to_macro_items(&expansion);
+    assert_eq!(
+        tree.unwrap().syntax().debug_dump().trim(),
+        r#"
+MACRO_ITEMS@[0; 40)
+  STRUCT_DEF@[0; 20)
+    STRUCT_KW@[0; 6) "struct"
+    NAME@[6; 9)
+      IDENT@[6; 9) "Foo"
+    NAMED_FIELD_DEF_LIST@[9; 20)
+      L_CURLY@[9; 10) "{"
+      NAMED_FIELD_DEF@[10; 19)
+        NAME@[10; 15)
+          IDENT@[10; 15) "field"
+        COLON@[15; 16) ":"
+        PATH_TYPE@[16; 19)
+          PATH@[16; 19)
+            PATH_SEGMENT@[16; 19)
+              NAME_REF@[16; 19)
+                IDENT@[16; 19) "u32"
+      R_CURLY@[19; 20) "}"
+  STRUCT_DEF@[20; 40)
+    STRUCT_KW@[20; 26) "struct"
+    NAME@[26; 29)
+      IDENT@[26; 29) "Bar"
+    NAMED_FIELD_DEF_LIST@[29; 40)
+      L_CURLY@[29; 30) "{"
+      NAMED_FIELD_DEF@[30; 39)
+        NAME@[30; 35)
+          IDENT@[30; 35) "field"
+        COLON@[35; 36) ":"
+        PATH_TYPE@[36; 39)
+          PATH@[36; 39)
+            PATH_SEGMENT@[36; 39)
+              NAME_REF@[36; 39)
+                IDENT@[36; 39) "u32"
+      R_CURLY@[39; 40) "}""#
+            .trim()
+    );
+}
+
+#[test]
+fn test_expand_literals_to_token_tree() {
+    fn to_subtree(tt: &tt::TokenTree) -> &tt::Subtree {
+        if let tt::TokenTree::Subtree(subtree) = tt {
+            return &subtree;
+        }
+        unreachable!("It is not a subtree");
+    }
+
+    fn to_literal(tt: &tt::TokenTree) -> &tt::Literal {
+        if let tt::TokenTree::Leaf(tt::Leaf::Literal(lit)) = tt {
+            return lit;
+        }
+        unreachable!("It is not a literal");
+    }
+
+    let rules = create_rules(
+        r#"
+            macro_rules! literals {
+                ($i:ident) => {
+                    {
+                        let a = 'c';
+                        let c = 1000;
+                        let f = 12E+99_f64;
+                        let s = "rust1";
+                    }
+                }
+            }
+            "#,
+    );
+    let expansion = expand(&rules, "literals!(foo)");
+    let stm_tokens = &to_subtree(&expansion.token_trees[0]).token_trees;
+
+    // [let] [a] [=] ['c'] [;]
+    assert_eq!(to_literal(&stm_tokens[3]).text, "'c'");
+    // [let] [c] [=] [1000] [;]
+    assert_eq!(to_literal(&stm_tokens[5 + 3]).text, "1000");
+    // [let] [f] [=] [12E+99_f64] [;]
+    assert_eq!(to_literal(&stm_tokens[10 + 3]).text, "12E+99_f64");
+    // [let] [s] [=] ["rust1"] [;]
+    assert_eq!(to_literal(&stm_tokens[15 + 3]).text, "\"rust1\"");
+}
+
+#[test]
+fn test_two_idents() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:ident, $ j:ident) => {
+                fn foo() { let a = $ i; let b = $j; }
+            }
+        }
+"#,
+    );
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! { foo, bar }",
+        "fn foo () {let a = foo ; let b = bar ;}",
+    );
+}
+
+#[test]
+fn test_tt_to_stmts() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            () => {
+                 let a = 0;
+                 a = 10 + 1;
+                 a
+            }
+        }
+"#,
+    );
+
+    let expanded = expand(&rules, "foo!{}");
+    let stmts = token_tree_to_macro_stmts(&expanded);
+
+    assert_eq!(
+        stmts.unwrap().syntax().debug_dump().trim(),
+        r#"MACRO_STMTS@[0; 15)
+  LET_STMT@[0; 7)
+    LET_KW@[0; 3) "let"
+    BIND_PAT@[3; 4)
+      NAME@[3; 4)
+        IDENT@[3; 4) "a"
+    EQ@[4; 5) "="
+    LITERAL@[5; 6)
+      INT_NUMBER@[5; 6) "0"
+    SEMI@[6; 7) ";"
+  EXPR_STMT@[7; 14)
+    BIN_EXPR@[7; 13)
+      PATH_EXPR@[7; 8)
+        PATH@[7; 8)
+          PATH_SEGMENT@[7; 8)
+            NAME_REF@[7; 8)
+              IDENT@[7; 8) "a"
+      EQ@[8; 9) "="
+      BIN_EXPR@[9; 13)
+        LITERAL@[9; 11)
+          INT_NUMBER@[9; 11) "10"
+        PLUS@[11; 12) "+"
+        LITERAL@[12; 13)
+          INT_NUMBER@[12; 13) "1"
+    SEMI@[13; 14) ";"
+  EXPR_STMT@[14; 15)
+    PATH_EXPR@[14; 15)
+      PATH@[14; 15)
+        PATH_SEGMENT@[14; 15)
+          NAME_REF@[14; 15)
+            IDENT@[14; 15) "a""#,
+    );
+}
+
+// The following tests are port from intellij-rust directly
+// https://github.com/intellij-rust/intellij-rust/blob/c4e9feee4ad46e7953b1948c112533360b6087bb/src/test/kotlin/org/rust/lang/core/macros/RsMacroExpansionTest.kt
+
+#[test]
+fn test_path() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:path) => {
+                fn foo() { let a = $ i; }
+            }
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "fn foo () {let a = foo ;}");
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! { bar::<u8>::baz::<u8> }",
+        "fn foo () {let a = bar ::< u8 >:: baz ::< u8 > ;}",
+    );
+}
+
+#[test]
+fn test_two_paths() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:path, $ j:path) => {
+                fn foo() { let a = $ i; let b = $j; }
+            }
+        }
+"#,
+    );
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! { foo, bar }",
+        "fn foo () {let a = foo ; let b = bar ;}",
+    );
+}
+
+#[test]
+fn test_path_with_path() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:path) => {
+                fn foo() { let a = $ i :: bar; }
+            }
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "fn foo () {let a = foo :: bar ;}");
+}
+
+#[test]
+fn test_expr() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:expr) => {
+                 fn bar() { $ i; } 
+            }
+        }
+"#,
+    );
+
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! { 2 + 2 * baz(3).quux() }",
+        "fn bar () {2 + 2 * baz (3) . quux () ;}",
+    );
+}
+
+#[test]
+fn test_expr_order() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:expr) => {
+                 fn bar() { $ i * 2; } 
+            }
+        }
+"#,
+    );
+
+    assert_eq!(
+        expand_to_items(&rules, "foo! { 1 + 1  }").syntax().debug_dump().trim(),
+        r#"MACRO_ITEMS@[0; 15)
+  FN_DEF@[0; 15)
+    FN_KW@[0; 2) "fn"
+    NAME@[2; 5)
+      IDENT@[2; 5) "bar"
+    PARAM_LIST@[5; 7)
+      L_PAREN@[5; 6) "("
+      R_PAREN@[6; 7) ")"
+    BLOCK@[7; 15)
+      L_CURLY@[7; 8) "{"
+      EXPR_STMT@[8; 14)
+        BIN_EXPR@[8; 13)
+          BIN_EXPR@[8; 11)
+            LITERAL@[8; 9)
+              INT_NUMBER@[8; 9) "1"
+            PLUS@[9; 10) "+"
+            LITERAL@[10; 11)
+              INT_NUMBER@[10; 11) "1"
+          STAR@[11; 12) "*"
+          LITERAL@[12; 13)
+            INT_NUMBER@[12; 13) "2"
+        SEMI@[13; 14) ";"
+      R_CURLY@[14; 15) "}""#,
+    );
+}
+
+#[test]
+fn test_last_expr() {
+    let rules = create_rules(
+        r#"
+        macro_rules! vec {
+            ($($item:expr),*) => {
+                {
+                    let mut v = Vec::new();
+                    $(
+                        v.push($item);
+                    )*
+                    v
+                }
+            };
+        }
+"#,
+    );
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "vec!(1,2,3)",
+        "{let mut v = Vec :: new () ; v . push (1) ; v . push (2) ; v . push (3) ; v}",
+    );
+}
+
+#[test]
+fn test_ty() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:ty) => (
+                fn bar() -> $ i { unimplemented!() }
+            )
+        }
+"#,
+    );
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! { Baz<u8> }",
+        "fn bar () -> Baz < u8 > {unimplemented ! ()}",
+    );
+}
+
+#[test]
+fn test_ty_with_complex_type() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:ty) => (
+                fn bar() -> $ i { unimplemented!() }
+            )
+        }
+"#,
+    );
+
+    // Reference lifetime struct with generic type
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        "foo! { &'a Baz<u8> }",
+        "fn bar () -> & 'a Baz < u8 > {unimplemented ! ()}",
+    );
+
+    // extern "Rust" func type
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        r#"foo! { extern "Rust" fn() -> Ret }"#,
+        r#"fn bar () -> extern "Rust" fn () -> Ret {unimplemented ! ()}"#,
+    );
+}
+
+#[test]
+fn test_pat_() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:pat) => { fn foo() { let $ i; } }
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, "foo! { (a, b) }", "fn foo () {let (a , b) ;}");
+}
+
+#[test]
+fn test_stmt() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:stmt) => (
+                fn bar() { $ i; }
+            )
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, "foo! { 2 }", "fn bar () {2 ;}");
+    assert_expansion(MacroKind::Items, &rules, "foo! { let a = 0 }", "fn bar () {let a = 0 ;}");
+}
+
+#[test]
+fn test_single_item() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:item) => (
+                $ i
+            )
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, "foo! {mod c {}}", "mod c {}");
+}
+
+#[test]
+fn test_all_items() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ ($ i:item)*) => ($ (
+                $ i
+            )*)
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, r#"
+        foo! {
+            extern crate a;
+            mod b;
+            mod c {}
+            use d;
+            const E: i32 = 0;
+            static F: i32 = 0;
+            impl G {}
+            struct H;
+            enum I { Foo }
+            trait J {}
+            fn h() {}
+            extern {}
+            type T = u8;
+        }
+"#, r#"extern crate a ; mod b ; mod c {} use d ; const E : i32 = 0 ; static F : i32 = 0 ; impl G {} struct H ; enum I {Foo} trait J {} fn h () {} extern {} type T = u8 ;"#);
+}
+
+#[test]
+fn test_block() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:block) => { fn foo() $ i }
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Stmts, &rules, "foo! { { 1; } }", "fn foo () {1 ;}");
+}
+
+#[test]
+fn test_meta() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+            ($ i:meta) => (
+                #[$ i]
+                fn bar() {}
+            )
+        }
+"#,
+    );
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        r#"foo! { cfg(target_os = "windows") }"#,
+        r#"# [cfg (target_os = "windows")] fn bar () {}"#,
+    );
+}
+
+#[test]
+fn test_tt_block() {
+    let rules = create_rules(
+        r#"
+            macro_rules! foo {
+                ($ i:tt) => { fn foo() $ i }
+            }
+    "#,
+    );
+    assert_expansion(MacroKind::Items, &rules, r#"foo! { { 1; } }"#, r#"fn foo () {1 ;}"#);
+}
+
+#[test]
+fn test_tt_group() {
+    let rules = create_rules(
+        r#"
+            macro_rules! foo {
+                 ($($ i:tt)*) => { $($ i)* }
+            }
+    "#,
+    );
+    assert_expansion(MacroKind::Items, &rules, r#"foo! { fn foo() {} }"#, r#"fn foo () {}"#);
+}
+#[test]
+fn test_lifetime() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+              ($ lt:lifetime) => { struct Ref<$ lt>{ s: &$ lt str } }
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, r#"foo!{'a}"#, r#"struct Ref <'a > {s : &'a str}"#);
+}
+
+#[test]
+fn test_literal() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+              ($ type:ty $ lit:literal) => { const VALUE: $ type = $ lit;};
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, r#"foo!(u8 0)"#, r#"const VALUE : u8 = 0 ;"#);
+}
+
+#[test]
+fn test_vis() {
+    let rules = create_rules(
+        r#"
+        macro_rules! foo {
+              ($ vis:vis $ name:ident) => { $ vis fn $ name() {}};
+        }
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, r#"foo!(pub foo);"#, r#"pub fn foo () {}"#);
+
+    // test optional casse
+    assert_expansion(MacroKind::Items, &rules, r#"foo!(foo);"#, r#"fn foo () {}"#);
+}
+
+#[test]
+fn test_inner_macro_rules() {
+    let rules = create_rules(
+        r#"
+macro_rules! foo {
+    ($a:ident, $b:ident, $c:tt) => {
+
+        macro_rules! bar {
+            ($bi:ident) => {
+                fn $bi() -> u8 {$c}
+            }
+        }
+
+        bar!($a);
+        fn $b() -> u8 {$c}
+    }
+}        
+"#,
+    );
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        r#"foo!(x,y, 1);"#,
+        r#"macro_rules ! bar {($ bi : ident) => {fn $ bi () -> u8 {1}}} bar ! (x) ; fn y () -> u8 {1}"#,
+    );
+}
+
+// The following tests are based on real world situations
+#[test]
+fn test_vec() {
+    let rules = create_rules(
+        r#"
+         macro_rules! vec {
+            ($($item:expr),*) => {
+                {
+                    let mut v = Vec::new();
+                    $(
+                        v.push($item);
+                    )*
+                    v
+                }
+            };
+}
+"#,
+    );
+    assert_expansion(MacroKind::Items, &rules, r#"vec!();"#, r#"{let mut v = Vec :: new () ; v}"#);
+    assert_expansion(
+        MacroKind::Items,
+        &rules,
+        r#"vec![1u32,2]"#,
+        r#"{let mut v = Vec :: new () ; v . push (1u32) ; v . push (2) ; v}"#,
+    );
+
+    assert_eq!(
+        expand_to_expr(&rules, r#"vec![1u32,2]"#).syntax().debug_dump().trim(),
+        r#"BLOCK_EXPR@[0; 45)
+  BLOCK@[0; 45)
+    L_CURLY@[0; 1) "{"
+    LET_STMT@[1; 20)
+      LET_KW@[1; 4) "let"
+      BIND_PAT@[4; 8)
+        MUT_KW@[4; 7) "mut"
+        NAME@[7; 8)
+          IDENT@[7; 8) "v"
+      EQ@[8; 9) "="
+      CALL_EXPR@[9; 19)
+        PATH_EXPR@[9; 17)
+          PATH@[9; 17)
+            PATH@[9; 12)
+              PATH_SEGMENT@[9; 12)
+                NAME_REF@[9; 12)
+                  IDENT@[9; 12) "Vec"
+            COLONCOLON@[12; 14) "::"
+            PATH_SEGMENT@[14; 17)
+              NAME_REF@[14; 17)
+                IDENT@[14; 17) "new"
+        ARG_LIST@[17; 19)
+          L_PAREN@[17; 18) "("
+          R_PAREN@[18; 19) ")"
+      SEMI@[19; 20) ";"
+    EXPR_STMT@[20; 33)
+      METHOD_CALL_EXPR@[20; 32)
+        PATH_EXPR@[20; 21)
+          PATH@[20; 21)
+            PATH_SEGMENT@[20; 21)
+              NAME_REF@[20; 21)
+                IDENT@[20; 21) "v"
+        DOT@[21; 22) "."
+        NAME_REF@[22; 26)
+          IDENT@[22; 26) "push"
+        ARG_LIST@[26; 32)
+          L_PAREN@[26; 27) "("
+          LITERAL@[27; 31)
+            INT_NUMBER@[27; 31) "1u32"
+          R_PAREN@[31; 32) ")"
+      SEMI@[32; 33) ";"
+    EXPR_STMT@[33; 43)
+      METHOD_CALL_EXPR@[33; 42)
+        PATH_EXPR@[33; 34)
+          PATH@[33; 34)
+            PATH_SEGMENT@[33; 34)
+              NAME_REF@[33; 34)
+                IDENT@[33; 34) "v"
+        DOT@[34; 35) "."
+        NAME_REF@[35; 39)
+          IDENT@[35; 39) "push"
+        ARG_LIST@[39; 42)
+          L_PAREN@[39; 40) "("
+          LITERAL@[40; 41)
+            INT_NUMBER@[40; 41) "2"
+          R_PAREN@[41; 42) ")"
+      SEMI@[42; 43) ";"
+    PATH_EXPR@[43; 44)
+      PATH@[43; 44)
+        PATH_SEGMENT@[43; 44)
+          NAME_REF@[43; 44)
+            IDENT@[43; 44) "v"
+    R_CURLY@[44; 45) "}""#
+    );
+}
+
+#[test]
+fn test_winapi_struct() {
+    // from https://github.com/retep998/winapi-rs/blob/a7ef2bca086aae76cf6c4ce4c2552988ed9798ad/src/macros.rs#L366
+
+    let rules = create_rules(
+        r#"
+macro_rules! STRUCT {
+    ($(#[$attrs:meta])* struct $name:ident {
+        $($field:ident: $ftype:ty,)+
+    }) => (
+        #[repr(C)] #[derive(Copy)] $(#[$attrs])*
+        pub struct $name {
+            $(pub $field: $ftype,)+
+        }
+        impl Clone for $name {
+            #[inline]
+            fn clone(&self) -> $name { *self }
+        }
+        #[cfg(feature = "impl-default")]
+        impl Default for $name {
+            #[inline]
+            fn default() -> $name { unsafe { $crate::_core::mem::zeroed() } }
+        }
+    );
+}
+"#,
+    );
+    // from https://github.com/retep998/winapi-rs/blob/a7ef2bca086aae76cf6c4ce4c2552988ed9798ad/src/shared/d3d9caps.rs
+    assert_expansion(MacroKind::Items, &rules, r#"STRUCT!{struct D3DVSHADERCAPS2_0 {Caps: u8,}}"#,
+        "# [repr (C)] # [derive (Copy)] pub struct D3DVSHADERCAPS2_0 {pub Caps : u8 ,} impl Clone for D3DVSHADERCAPS2_0 {# [inline] fn clone (& self) -> D3DVSHADERCAPS2_0 {* self}} # [cfg (feature = \"impl-default\")] impl Default for D3DVSHADERCAPS2_0 {# [inline] fn default () -> D3DVSHADERCAPS2_0 {unsafe {$crate :: _core :: mem :: zeroed ()}}}");
+    assert_expansion(MacroKind::Items, &rules, r#"STRUCT!{#[cfg_attr(target_arch = "x86", repr(packed))] struct D3DCONTENTPROTECTIONCAPS {Caps : u8 ,}}"#, 
+        "# [repr (C)] # [derive (Copy)] # [cfg_attr (target_arch = \"x86\" , repr (packed))] pub struct D3DCONTENTPROTECTIONCAPS {pub Caps : u8 ,} impl Clone for D3DCONTENTPROTECTIONCAPS {# [inline] fn clone (& self) -> D3DCONTENTPROTECTIONCAPS {* self}} # [cfg (feature = \"impl-default\")] impl Default for D3DCONTENTPROTECTIONCAPS {# [inline] fn default () -> D3DCONTENTPROTECTIONCAPS {unsafe {$crate :: _core :: mem :: zeroed ()}}}");
+}
+
+#[test]
+fn test_int_base() {
+    let rules = create_rules(
+        r#"
+macro_rules! int_base {
+    ($Trait:ident for $T:ident as $U:ident -> $Radix:ident) => {
+        #[stable(feature = "rust1", since = "1.0.0")]
+        impl fmt::$Trait for $T {
+            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+                $Radix.fmt_int(*self as $U, f)
+            }
+        }
+    }
+}            
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, r#" int_base!{Binary for isize as usize -> Binary}"#, 
+        "# [stable (feature = \"rust1\" , since = \"1.0.0\")] impl fmt ::Binary for isize {fn fmt (& self , f : & mut fmt :: Formatter < \'_ >) -> fmt :: Result {Binary . fmt_int (* self as usize , f)}}"
+        );
+}
+
+#[test]
+fn test_generate_pattern_iterators() {
+    // from https://github.com/rust-lang/rust/blob/316a391dcb7d66dc25f1f9a4ec9d368ef7615005/src/libcore/str/mod.rs
+    let rules = create_rules(
+        r#"
+macro_rules! generate_pattern_iterators {        
+        { double ended; with $(#[$common_stability_attribute:meta])*,
+                           $forward_iterator:ident,
+                           $reverse_iterator:ident, $iterty:ty
+        } => {
+            fn foo(){}
+        }
+}
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, r#"generate_pattern_iterators ! ( double ended ; with # [ stable ( feature = "rust1" , since = "1.0.0" ) ] , Split , RSplit , & 'a str )"#, 
+        "fn foo () {}");
+}
+
+#[test]
+fn test_impl_fn_for_zst() {
+    // from https://github.com/rust-lang/rust/blob/5d20ff4d2718c820632b38c1e49d4de648a9810b/src/libcore/internal_macros.rs
+    let rules = create_rules(
+        r#"
+macro_rules! impl_fn_for_zst  {        
+        {  $( $( #[$attr: meta] )*
+        struct $Name: ident impl$( <$( $lifetime : lifetime ),+> )? Fn =
+            |$( $arg: ident: $ArgTy: ty ),*| -> $ReturnTy: ty
+$body: block; )+
+        } => {
+           $(
+            $( #[$attr] )*
+            struct $Name;
+
+            impl $( <$( $lifetime ),+> )? Fn<($( $ArgTy, )*)> for $Name {
+                #[inline]
+                extern "rust-call" fn call(&self, ($( $arg, )*): ($( $ArgTy, )*)) -> $ReturnTy {
+                    $body
+                }
+            }
+
+            impl $( <$( $lifetime ),+> )? FnMut<($( $ArgTy, )*)> for $Name {
+                #[inline]
+                extern "rust-call" fn call_mut(
+                    &mut self,
+                    ($( $arg, )*): ($( $ArgTy, )*)
+                ) -> $ReturnTy {
+                    Fn::call(&*self, ($( $arg, )*))
+                }
+            }
+
+            impl $( <$( $lifetime ),+> )? FnOnce<($( $ArgTy, )*)> for $Name {
+                type Output = $ReturnTy;
+
+                #[inline]
+                extern "rust-call" fn call_once(self, ($( $arg, )*): ($( $ArgTy, )*)) -> $ReturnTy {
+                    Fn::call(&self, ($( $arg, )*))
+                }
+            }
+        )+
+}
+        }
+}
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, r#"
+impl_fn_for_zst !   { 
+     # [ derive ( Clone ) ] 
+     struct   CharEscapeDebugContinue   impl   Fn   =   | c :   char |   ->   char :: EscapeDebug   { 
+         c . escape_debug_ext ( false ) 
+     } ; 
+
+     # [ derive ( Clone ) ] 
+     struct   CharEscapeUnicode   impl   Fn   =   | c :   char |   ->   char :: EscapeUnicode   { 
+         c . escape_unicode ( ) 
+     } ; 
+     # [ derive ( Clone ) ] 
+     struct   CharEscapeDefault   impl   Fn   =   | c :   char |   ->   char :: EscapeDefault   { 
+         c . escape_default ( ) 
+     } ; 
+ }
+"#, 
+        "# [derive (Clone)] struct CharEscapeDebugContinue ; impl Fn < (char ,) > for CharEscapeDebugContinue {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeDebug {{c . escape_debug_ext (false)}}} impl FnMut < (char ,) > for CharEscapeDebugContinue {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeDebug {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeDebugContinue {type Output = char :: EscapeDebug ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeDebug {Fn :: call (& self , (c ,))}} # [derive (Clone)] struct CharEscapeUnicode ; impl Fn < (char ,) > for CharEscapeUnicode {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeUnicode {{c . escape_unicode ()}}} impl FnMut < (char ,) > for CharEscapeUnicode {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeUnicode {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeUnicode {type Output = char :: EscapeUnicode ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeUnicode {Fn :: call (& self , (c ,))}} # [derive (Clone)] struct CharEscapeDefault ; impl Fn < (char ,) > for CharEscapeDefault {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeDefault {{c . escape_default ()}}} impl FnMut < (char ,) > for CharEscapeDefault {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeDefault {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeDefault {type Output = char :: EscapeDefault ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeDefault {Fn :: call (& self , (c ,))}}");
+}
+
+#[test]
+fn test_impl_nonzero_fmt() {
+    // from https://github.com/rust-lang/rust/blob/316a391dcb7d66dc25f1f9a4ec9d368ef7615005/src/libcore/num/mod.rs#L12
+    let rules = create_rules(
+        r#"
+        macro_rules! impl_nonzero_fmt {
+            ( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
+                fn foo () {}
+            }
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, r#"impl_nonzero_fmt! { # [stable(feature= "nonzero",since="1.28.0")] (Debug,Display,Binary,Octal,LowerHex,UpperHex) for NonZeroU8}"#,
+        "fn foo () {}");
+}
+
+#[test]
+fn test_cfg_if_items() {
+    // from https://github.com/rust-lang/rust/blob/33fe1131cadba69d317156847be9a402b89f11bb/src/libstd/macros.rs#L986
+    let rules = create_rules(
+        r#"
+        macro_rules! __cfg_if_items {
+            (($($not:meta,)*) ; ) => {};
+            (($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => {
+                 __cfg_if_items! { ($($not,)* $($m,)*) ; $($rest)* }
+            }
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, r#"__cfg_if_items ! { ( rustdoc , ) ; ( ( ) ( # [ cfg ( any ( target_os = "redox" , unix ) ) ] # [ stable ( feature = "rust1" , since = "1.0.0" ) ] pub use sys :: ext as unix ; # [ cfg ( windows ) ] # [ stable ( feature = "rust1" , since = "1.0.0" ) ] pub use sys :: ext as windows ; # [ cfg ( any ( target_os = "linux" , target_os = "l4re" ) ) ] pub mod linux ; ) ) , }"#,         
+        "__cfg_if_items ! {(rustdoc ,) ;}");
+}
+
+#[test]
+fn test_cfg_if_main() {
+    // from https://github.com/rust-lang/rust/blob/3d211248393686e0f73851fc7548f6605220fbe1/src/libpanic_unwind/macros.rs#L9
+    let rules = create_rules(
+        r#"
+        macro_rules! cfg_if {
+            ($(
+                if #[cfg($($meta:meta),*)] { $($it:item)* }
+            ) else * else {
+                $($it2:item)*
+            }) => {
+                __cfg_if_items! {
+                    () ;
+                    $( ( ($($meta),*) ($($it)*) ), )*
+                    ( () ($($it2)*) ),
+                }
+            }
+        }
+"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, r#"
+cfg_if !   { 
+     if   # [ cfg ( target_env   =   "msvc" ) ]   { 
+         // no extra unwinder support needed 
+     }   else   if   # [ cfg ( all ( target_arch   =   "wasm32" ,   not ( target_os   =   "emscripten" ) ) ) ]   { 
+         // no unwinder on the system! 
+     }   else   { 
+         mod   libunwind ; 
+         pub   use   libunwind :: * ; 
+     } 
+ }        
+"#,         
+        "__cfg_if_items ! {() ; ((target_env = \"msvc\") ()) , ((all (target_arch = \"wasm32\" , not (target_os = \"emscripten\"))) ()) , (() (mod libunwind ; pub use libunwind :: * ;)) ,}");
+}
+
+#[test]
+fn test_proptest_arbitrary() {
+    // from https://github.com/AltSysrq/proptest/blob/d1c4b049337d2f75dd6f49a095115f7c532e5129/proptest/src/arbitrary/macros.rs#L16
+    let rules = create_rules(
+        r#"
+macro_rules! arbitrary {
+    ([$($bounds : tt)*] $typ: ty, $strat: ty, $params: ty;
+        $args: ident => $logic: expr) => {
+        impl<$($bounds)*> $crate::arbitrary::Arbitrary for $typ {
+            type Parameters = $params;
+            type Strategy = $strat;
+            fn arbitrary_with($args: Self::Parameters) -> Self::Strategy {
+                $logic
+            }
+        }
+    };  
+   
+}"#,
+    );
+
+    assert_expansion(MacroKind::Items, &rules, r#"arbitrary !   ( [ A : Arbitrary ] 
+        Vec < A > , 
+        VecStrategy < A :: Strategy > , 
+        RangedParams1 < A :: Parameters > ; 
+        args =>   { let product_unpack !   [ range , a ] = args ; vec ( any_with :: < A >   ( a ) , range ) } 
+    ) ;"#,
+    "impl <A : Arbitrary > $crate :: arbitrary :: Arbitrary for Vec < A > {type Parameters = RangedParams1 < A :: Parameters > ; type Strategy = VecStrategy < A :: Strategy > ; fn arbitrary_with (args : Self :: Parameters) -> Self :: Strategy {{let product_unpack ! [range , a] = args ; vec (any_with :: < A > (a) , range)}}}");
+}
+
+#[test]
+fn test_old_ridl() {
+    // This is from winapi 2.8, which do not have a link from github
+    //
+    let rules = create_rules(
+        r#"
+#[macro_export]
+macro_rules! RIDL {    
+    (interface $interface:ident ($vtbl:ident) : $pinterface:ident ($pvtbl:ident)
+        {$(
+            fn $method:ident(&mut self $(,$p:ident : $t:ty)*) -> $rtr:ty
+        ),+}
+    ) => {
+        impl $interface {
+            $(pub unsafe fn $method(&mut self) -> $rtr {
+                ((*self.lpVtbl).$method)(self $(,$p)*)
+            })+
+        }        
+    };
+}"#,
+    );
+
+    let expanded = expand(&rules, r#"
+RIDL!{interface ID3D11Asynchronous(ID3D11AsynchronousVtbl): ID3D11DeviceChild(ID3D11DeviceChildVtbl) {
+    fn GetDataSize(&mut self) -> UINT
+}}"#);
+    assert_eq!(expanded.to_string(), "impl ID3D11Asynchronous {pub unsafe fn GetDataSize (& mut self) -> UINT {((* self . lpVtbl) .GetDataSize) (self)}}");
+}
+
+#[test]
+fn test_quick_error() {
+    let rules = create_rules(
+        r#"
+macro_rules! quick_error {
+
+ (SORT [enum $name:ident $( #[$meta:meta] )*]
+        items [$($( #[$imeta:meta] )*
+                  => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*]
+                                {$( $ifuncs:tt )*} )* ]
+        buf [ ]
+        queue [ ]
+    ) => {
+        quick_error!(ENUM_DEFINITION [enum $name $( #[$meta] )*]
+            body []
+            queue [$(
+                $( #[$imeta] )*                      
+                => 
+                $iitem: $imode [$( $ivar: $ityp ),*]                       
+            )*]
+        );        
+};
+
+}
+"#,
+    );
+
+    let expanded = expand(
+        &rules,
+        r#"
+quick_error ! (SORT [enum Wrapped # [derive (Debug)]] items [
+        => One : UNIT [] {} 
+        => Two : TUPLE [s :String] {display ("two: {}" , s) from ()}
+    ] buf [] queue []) ;
+"#,
+    );
+
+    assert_eq!(expanded.to_string(), "quick_error ! (ENUM_DEFINITION [enum Wrapped # [derive (Debug)]] body [] queue [=> One : UNIT [] => Two : TUPLE [s : String]]) ;");
+}