syntax: split deriving module into submodules for each trait

src/libsyntax/ext/base.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -153,13 +153,13 @@ pub fn syntax_expander_table() -> SyntaxEnv {
                                 ext::deriving::expand_meta_deriving)));
     syntax_expanders.insert(@~"deriving_eq",
                             @SE(ItemDecorator(
-                                ext::deriving::expand_deriving_eq)));
+                                ext::deriving::eq::expand_deriving_eq)));
     syntax_expanders.insert(@~"deriving_iter_bytes",
                             @SE(ItemDecorator(
-                                ext::deriving::expand_deriving_iter_bytes)));
+                                ext::deriving::iter_bytes::expand_deriving_iter_bytes)));
     syntax_expanders.insert(@~"deriving_clone",
                             @SE(ItemDecorator(
-                                ext::deriving::expand_deriving_clone)));
+                                ext::deriving::clone::expand_deriving_clone)));
 
     // Quasi-quoting expanders
     syntax_expanders.insert(@~"quote_tokens",

src/libsyntax/ext/deriving/clone.rs

@@ -0,0 +1,289 @@
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use core::prelude::*;
+
+use ast;
+use ast::{TraitTyParamBound, Ty, and, bind_by_ref, binop, deref, enum_def};
+use ast::{enum_variant_kind, expr, expr_match, ident, impure_fn, item, item_};
+use ast::{item_enum, item_impl, item_struct, Generics};
+use ast::{m_imm, meta_item, method};
+use ast::{named_field, or, pat, pat_ident, pat_wild, public, pure_fn};
+use ast::{stmt, struct_def, struct_variant_kind};
+use ast::{sty_by_ref, sty_region, tuple_variant_kind, ty_nil, TyParam};
+use ast::{TyParamBound, ty_path, ty_rptr, unnamed_field, variant};
+use ext::base::ext_ctxt;
+use ext::build;
+use ext::deriving::*;
+use codemap::{span, spanned};
+use ast_util;
+
+use core::uint;
+
+pub fn expand_deriving_clone(cx: @ext_ctxt,
+                             span: span,
+                             _: @meta_item,
+                             in_items: ~[@item])
+                          -> ~[@item] {
+    expand_deriving(cx,
+                    span,
+                    in_items,
+                    expand_deriving_clone_struct_def,
+                    expand_deriving_clone_enum_def)
+}
+
+fn create_derived_clone_impl(cx: @ext_ctxt,
+                             span: span,
+                             type_ident: ident,
+                             generics: &Generics,
+                             method: @method)
+                          -> @item {
+    let methods = [ method ];
+    let trait_path = [
+        cx.ident_of(~"core"),
+        cx.ident_of(~"clone"),
+        cx.ident_of(~"Clone"),
+    ];
+    create_derived_impl(cx, span, type_ident, generics, methods, trait_path)
+}
+// Creates a method from the given expression conforming to the signature of
+// the `clone` method.
+fn create_clone_method(cx: @ext_ctxt,
+                       span: span,
+                       +type_ident: ast::ident,
+                       generics: &Generics,
+                       expr: @ast::expr)
+                    -> @method {
+    // Create the type parameters of the return value.
+    let mut output_ty_params = ~[];
+    for generics.ty_params.each |ty_param| {
+        let path = build::mk_ty_path(cx, span, ~[ ty_param.ident ]);
+        output_ty_params.push(path);
+    }
+
+    // Create the type of the return value.
+    let output_type_path = build::mk_raw_path_(span,
+                                               ~[ type_ident ],
+                                               output_ty_params);
+    let output_type = ast::ty_path(output_type_path, cx.next_id());
+    let output_type = @ast::Ty {
+        id: cx.next_id(),
+        node: output_type,
+        span: span
+    };
+
+    // Create the function declaration.
+    let fn_decl = build::mk_fn_decl(~[], output_type);
+
+    // Create the body block.
+    let body_block = build::mk_simple_block(cx, span, expr);
+
+    // Create the self type and method identifier.
+    let self_ty = spanned { node: sty_region(None, m_imm), span: span };
+    let method_ident = cx.ident_of(~"clone");
+
+    // Create the method.
+    @ast::method {
+        ident: method_ident,
+        attrs: ~[],
+        generics: ast_util::empty_generics(),
+        self_ty: self_ty,
+        purity: impure_fn,
+        decl: fn_decl,
+        body: body_block,
+        id: cx.next_id(),
+        span: span,
+        self_id: cx.next_id(),
+        vis: public,
+    }
+}
+
+fn call_substructure_clone_method(cx: @ext_ctxt,
+                                  span: span,
+                                  self_field: @expr)
+                               -> @expr {
+    // Call the substructure method.
+    let clone_ident = cx.ident_of(~"clone");
+    let self_method = build::mk_access_(cx, span, self_field, clone_ident);
+    build::mk_call_(cx, span, self_method, ~[])
+}
+
+fn expand_deriving_clone_struct_def(cx: @ext_ctxt,
+                                    span: span,
+                                    struct_def: &struct_def,
+                                    type_ident: ident,
+                                    generics: &Generics)
+                                 -> @item {
+    // Create the method.
+    let method = if !is_struct_tuple(struct_def) {
+        expand_deriving_clone_struct_method(cx,
+                                            span,
+                                            struct_def,
+                                            type_ident,
+                                            generics)
+    } else {
+        expand_deriving_clone_tuple_struct_method(cx,
+                                                  span,
+                                                  struct_def,
+                                                  type_ident,
+                                                  generics)
+    };
+
+    // Create the implementation.
+    create_derived_clone_impl(cx, span, type_ident, generics, method)
+}
+
+fn expand_deriving_clone_enum_def(cx: @ext_ctxt,
+                                  span: span,
+                                  enum_definition: &enum_def,
+                                  type_ident: ident,
+                                  generics: &Generics)
+                               -> @item {
+    // Create the method.
+    let method = expand_deriving_clone_enum_method(cx,
+                                                   span,
+                                                   enum_definition,
+                                                   type_ident,
+                                                   generics);
+
+    // Create the implementation.
+    create_derived_clone_impl(cx, span, type_ident, generics, method)
+}
+
+fn expand_deriving_clone_struct_method(cx: @ext_ctxt,
+                                       span: span,
+                                       struct_def: &struct_def,
+                                       type_ident: ident,
+                                       generics: &Generics)
+                                    -> @method {
+    let self_ident = cx.ident_of(~"self");
+
+    // Create the new fields.
+    let mut fields = ~[];
+    for struct_def.fields.each |struct_field| {
+        match struct_field.node.kind {
+            named_field(ident, _, _) => {
+                // Create the accessor for this field.
+                let self_field = build::mk_access(cx,
+                                                  span,
+                                                  ~[ self_ident ],
+                                                  ident);
+
+                // Call the substructure method.
+                let call = call_substructure_clone_method(cx,
+                                                          span,
+                                                          self_field);
+
+                let field = build::Field { ident: ident, ex: call };
+                fields.push(field);
+            }
+            unnamed_field => {
+                cx.span_bug(span,
+                            ~"unnamed fields in \
+                              expand_deriving_clone_struct_method");
+            }
+        }
+    }
+
+    // Create the struct literal.
+    let struct_literal = build::mk_struct_e(cx,
+                                            span,
+                                            ~[ type_ident ],
+                                            fields);
+    create_clone_method(cx, span, type_ident, generics, struct_literal)
+}
+
+fn expand_deriving_clone_tuple_struct_method(cx: @ext_ctxt,
+                                             span: span,
+                                             struct_def: &struct_def,
+                                             type_ident: ident,
+                                             generics: &Generics)
+                                          -> @method {
+    // Create the pattern for the match.
+    let matching_path = build::mk_raw_path(span, ~[ type_ident ]);
+    let field_count = struct_def.fields.len();
+    let subpats = create_subpatterns(cx, span, ~"__self", field_count);
+    let pat = build::mk_pat_enum(cx, span, matching_path, subpats);
+
+    // Create the new fields.
+    let mut subcalls = ~[];
+    for uint::range(0, struct_def.fields.len()) |i| {
+        // Create the expression for this field.
+        let field_ident = cx.ident_of(~"__self" + i.to_str());
+        let field = build::mk_path(cx, span, ~[ field_ident ]);
+
+        // Call the substructure method.
+        let subcall = call_substructure_clone_method(cx, span, field);
+        subcalls.push(subcall);
+    }
+
+    // Create the call to the struct constructor.
+    let call = build::mk_call(cx, span, ~[ type_ident ], subcalls);
+
+    // Create the pattern body.
+    let match_body_block = build::mk_simple_block(cx, span, call);
+
+    // Create the arm.
+    let arm = ast::arm {
+        pats: ~[ pat ],
+        guard: None,
+        body: match_body_block
+    };
+
+    // Create the method body.
+    let self_match_expr = expand_enum_or_struct_match(cx, span, ~[ arm ]);
+
+    // Create the method.
+    create_clone_method(cx, span, type_ident, generics, self_match_expr)
+}
+
+fn expand_deriving_clone_enum_method(cx: @ext_ctxt,
+                                     span: span,
+                                     enum_definition: &enum_def,
+                                     type_ident: ident,
+                                     generics: &Generics)
+                                  -> @method {
+    // Create the arms of the match in the method body.
+    let arms = do enum_definition.variants.map |variant| {
+        // Create the matching pattern.
+        let pat = create_enum_variant_pattern(cx, span, variant, ~"__self");
+
+        // Iterate over the variant arguments, creating the subcalls.
+        let mut subcalls = ~[];
+        for uint::range(0, variant_arg_count(cx, span, variant)) |j| {
+            // Create the expression for this field.
+            let field_ident = cx.ident_of(~"__self" + j.to_str());
+            let field = build::mk_path(cx, span, ~[ field_ident ]);
+
+            // Call the substructure method.
+            let subcall = call_substructure_clone_method(cx, span, field);
+            subcalls.push(subcall);
+        }
+
+        // Create the call to the enum variant (if necessary).
+        let call = if subcalls.len() > 0 {
+            build::mk_call(cx, span, ~[ variant.node.name ], subcalls)
+        } else {
+            build::mk_path(cx, span, ~[ variant.node.name ])
+        };
+
+        // Create the pattern body.
+        let match_body_block = build::mk_simple_block(cx, span, call);
+
+        // Create the arm.
+        ast::arm { pats: ~[ pat ], guard: None, body: match_body_block }
+    };
+
+    // Create the method body.
+    let self_match_expr = expand_enum_or_struct_match(cx, span, arms);
+
+    // Create the method.
+    create_clone_method(cx, span, type_ident, generics, self_match_expr)
+}