1 files changed, 290 insertions, 0 deletions

diff --git a/src/grammar/items/mod.rs b/src/grammar/items/mod.rs
new file mode 100644
index 000000000..d5f75f13d
--- /dev/null
+++ b/src/grammar/items/mod.rs
@@ -0,0 +1,290 @@
+use super::*;
+
+mod consts;
+mod structs;
+mod traits;
+mod use_item;
+
+pub(super) fn mod_contents(p: &mut Parser, stop_on_r_curly: bool) {
+    attributes::inner_attributes(p);
+    while !p.at(EOF) && !(stop_on_r_curly && p.at(R_CURLY)) {
+        item(p);
+    }
+}
+
+pub(super) const ITEM_FIRST: TokenSet =
+    token_set![EXTERN_KW, MOD_KW, USE_KW, STRUCT_KW, ENUM_KW, FN_KW, PUB_KW, POUND];
+
+pub(super) fn item(p: &mut Parser) {
+    let item = p.start();
+    attributes::outer_attributes(p);
+    visibility(p);
+    let la = p.nth(1);
+    let item_kind = match p.current() {
+        USE_KW => {
+            use_item::use_item(p);
+            USE_ITEM
+        }
+        // test extern_crate
+        // extern crate foo;
+        EXTERN_KW if la == CRATE_KW => {
+            extern_crate_item(p);
+            EXTERN_CRATE_ITEM
+        }
+        EXTERN_KW => {
+            abi(p);
+            match p.current() {
+                // test extern_fn
+                // extern fn foo() {}
+                FN_KW => {
+                    fn_item(p);
+                    FN_ITEM
+                }
+                // test extern_block
+                // extern {}
+                L_CURLY => {
+                    extern_block(p);
+                    EXTERN_BLOCK
+                }
+                // test extern_struct
+                // extern struct Foo;
+                _ => {
+                    item.abandon(p);
+                    p.error("expected `fn` or `{`");
+                    return;
+                }
+            }
+        }
+        STATIC_KW => {
+            consts::static_item(p);
+            STATIC_ITEM
+        }
+        CONST_KW => match p.nth(1) {
+            // test const_fn
+            // const fn foo() {}
+            FN_KW => {
+                p.bump();
+                fn_item(p);
+                FN_ITEM
+            }
+            // test const_unsafe_fn
+            // const unsafe fn foo() {}
+            UNSAFE_KW if p.nth(2) == FN_KW => {
+                p.bump();
+                p.bump();
+                fn_item(p);
+                FN_ITEM
+            }
+            _ => {
+                consts::const_item(p);
+                CONST_ITEM
+            }
+        },
+        UNSAFE_KW => {
+            p.bump();
+            let la = p.nth(1);
+            match p.current() {
+                // test unsafe_trait
+                // unsafe trait T {}
+                TRAIT_KW => {
+                    traits::trait_item(p);
+                    TRAIT_ITEM
+                }
+
+                // test unsafe_auto_trait
+                // unsafe auto trait T {}
+                IDENT if p.at_contextual_kw("auto") && la == TRAIT_KW => {
+                    p.bump_remap(AUTO_KW);
+                    traits::trait_item(p);
+                    TRAIT_ITEM
+                }
+
+                // test unsafe_impl
+                // unsafe impl Foo {}
+                IMPL_KW => {
+                    traits::impl_item(p);
+                    IMPL_ITEM
+                }
+
+                // test unsafe_default_impl
+                // unsafe default impl Foo {}
+                IDENT if p.at_contextual_kw("default") && la == IMPL_KW => {
+                    p.bump_remap(DEFAULT_KW);
+                    traits::impl_item(p);
+                    IMPL_ITEM
+                }
+
+                // test unsafe_extern_fn
+                // unsafe extern "C" fn foo() {}
+                EXTERN_KW => {
+                    abi(p);
+                    if !p.at(FN_KW) {
+                        item.abandon(p);
+                        p.error("expected function");
+                        return;
+                    }
+                    fn_item(p);
+                    FN_ITEM
+                }
+
+                // test unsafe_fn
+                // unsafe fn foo() {}
+                FN_KW => {
+                    fn_item(p);
+                    FN_ITEM
+                }
+
+                t => {
+                    item.abandon(p);
+                    let message = "expected `trait`, `impl` or `fn`";
+
+                    // test unsafe_block_in_mod
+                    // fn foo(){} unsafe { } fn bar(){}
+                    if t == L_CURLY {
+                        error_block(p, message);
+                    } else {
+                        p.error(message);
+                    }
+                    return;
+                }
+            }
+        }
+        TRAIT_KW => {
+            traits::trait_item(p);
+            TRAIT_ITEM
+        }
+        // test auto_trait
+        // auto trait T {}
+        IDENT if p.at_contextual_kw("auto") && la == TRAIT_KW => {
+            p.bump_remap(AUTO_KW);
+            traits::trait_item(p);
+            TRAIT_ITEM
+        }
+        IMPL_KW => {
+            traits::impl_item(p);
+            IMPL_ITEM
+        }
+        // test default_impl
+        // default impl Foo {}
+        IDENT if p.at_contextual_kw("default") && la == IMPL_KW => {
+            p.bump_remap(DEFAULT_KW);
+            traits::impl_item(p);
+            IMPL_ITEM
+        }
+
+        FN_KW => {
+            fn_item(p);
+            FN_ITEM
+        }
+        TYPE_KW => {
+            type_item(p);
+            TYPE_ITEM
+        }
+        MOD_KW => {
+            mod_item(p);
+            MOD_ITEM
+        }
+        STRUCT_KW => {
+            structs::struct_item(p);
+            STRUCT_ITEM
+        }
+        ENUM_KW => {
+            structs::enum_item(p);
+            ENUM_ITEM
+        }
+        L_CURLY => {
+            item.abandon(p);
+            error_block(p, "expected item");
+            return;
+        }
+        err_token => {
+            item.abandon(p);
+            let message = if err_token == SEMI {
+                //TODO: if the item is incomplete, this message is misleading
+                "expected item, found `;`\n\
+                 consider removing this semicolon"
+            } else {
+                "expected item"
+            };
+            p.err_and_bump(message);
+            return;
+        }
+    };
+    item.complete(p, item_kind);
+}
+
+fn extern_crate_item(p: &mut Parser) {
+    assert!(p.at(EXTERN_KW));
+    p.bump();
+    assert!(p.at(CRATE_KW));
+    p.bump();
+    name(p);
+    alias(p);
+    p.expect(SEMI);
+}
+
+fn extern_block(p: &mut Parser) {
+    assert!(p.at(L_CURLY));
+    p.bump();
+    p.expect(R_CURLY);
+}
+
+fn fn_item(p: &mut Parser) {
+    assert!(p.at(FN_KW));
+    p.bump();
+
+    name(p);
+    // test fn_item_type_params
+    // fn foo<T: Clone + Copy>(){}
+    type_params::type_param_list(p);
+
+    if p.at(L_PAREN) {
+        params::param_list(p);
+    } else {
+        p.error("expected function arguments");
+    }
+    // test fn_item_ret_type
+    // fn foo() {}
+    // fn bar() -> () {}
+    fn_ret_type(p);
+
+    // test fn_item_where_clause
+    // fn foo<T>() where T: Copy {}
+    type_params::where_clause(p);
+
+    expressions::block(p);
+}
+
+// test type_item
+// type Foo = Bar;
+fn type_item(p: &mut Parser) {
+    assert!(p.at(TYPE_KW));
+    p.bump();
+
+    name(p);
+
+    // test type_item_type_params
+    // type Result<T> = ();
+    type_params::type_param_list(p);
+
+    // test type_item_where_clause
+    // type Foo where Foo: Copy = ();
+    type_params::where_clause(p);
+
+    p.expect(EQ);
+    types::type_(p);
+    p.expect(SEMI);
+}
+
+fn mod_item(p: &mut Parser) {
+    assert!(p.at(MOD_KW));
+    p.bump();
+
+    name(p);
+    if !p.eat(SEMI) {
+        if p.expect(L_CURLY) {
+            mod_contents(p, true);
+            p.expect(R_CURLY);
+        }
+    }
+}