feat(frontends/lean): remove 'using' expressions

Reason: we have include/omit commands

library/data/list/sort.lean

@@ -29,8 +29,12 @@ include decA
 variable {R}
 variables (to : total R) (tr : transitive R) (rf : reflexive R)
 
+section
+include to tr rf
 lemma min_core_lemma : ∀ {b l} a, b ∈ l ∨ b = a → R (min_core R l a) b
-:= using to tr rf, sorry
+:= sorry
+end
+
 /-
 | b []     a h := or.elim h
   (suppose b ∈ [], absurd this !not_mem_nil)
@@ -123,10 +127,12 @@ lemma min_mem : ∀ (l : list A) (h : l ≠ nil), min R l h ∈ l
   end
   -/
 
+section
+include to tr rf
 lemma min_map (f : B → A) {l : list B} (h : l ≠ nil) :
       all l (λ b, (R (min R (map f l) (map_ne_nil_of_ne_nil _ h))) (f b)):=
-  using to tr rf,
-  sorry
+sorry
+end
   /-
   begin
     apply all_of_forall,

src/frontends/lean/builtin_exprs.cpp

@@ -161,44 +161,6 @@ static expr parse_begin_end(parser & p, unsigned, expr const *, pos_info const &
 
 static expr parse_proof(parser & p);
 
-static expr parse_using_expr(parser & p, pos_info const & using_pos) {
-    parser::local_scope scope(p);
-    buffer<expr> locals;
-    buffer<expr> new_locals;
-    while (!p.curr_is_token(get_comma_tk())) {
-        auto id_pos = p.pos();
-        expr l      = p.parse_id();
-        if (!is_local(l))
-            throw parser_error("invalid 'using' declaration, local expected", id_pos);
-        expr new_l;
-        binder_info bi = local_info(l);
-        if (p.is_local_variable_parameter(local_pp_name(l))) {
-            expr new_type = p.save_pos(mk_as_is(mlocal_type(l)), id_pos);
-            new_l = p.save_pos(mk_local(mlocal_name(l), local_pp_name(l), new_type, bi), id_pos);
-        } else {
-            new_l = p.save_pos(update_local(l, bi), id_pos);
-        }
-        p.add_local(new_l);
-        locals.push_back(l);
-        new_locals.push_back(new_l);
-    }
-    p.next(); // consume ','
-    expr pr = p.parse_expr();
-    unsigned i = locals.size();
-    while (i > 0) {
-        --i;
-        expr l     = locals[i];
-        expr new_l = new_locals[i];
-        pr = p.save_pos(Fun(new_l, pr), using_pos);
-        pr = p.save_pos(mk_app(pr, l), using_pos);
-    }
-    return pr;
-}
-
-static expr parse_using(parser & p, unsigned, expr const *, pos_info const & pos) {
-    return parse_using_expr(p, pos);
-}
-
 static expr parse_proof(parser & p) {
     if (p.curr_is_token(get_from_tk())) {
         // parse: 'from' expr
@@ -726,7 +688,6 @@ parse_table init_nud_table() {
     r = r.add({transition("@", mk_ext_action(parse_explicit_expr))}, x0);
     r = r.add({transition("@@", mk_ext_action(parse_partial_explicit_expr))}, x0);
     r = r.add({transition("begin", mk_ext_action_core(parse_begin_end))}, x0);
-    r = r.add({transition("using", mk_ext_action(parse_using))}, x0);
     r = r.add({transition("sorry", mk_ext_action(parse_sorry))}, x0);
     r = r.add({transition("match", mk_ext_action(parse_match))}, x0);
     r = r.add({transition("do", mk_ext_action(parse_do))}, x0);

src/frontends/lean/token_table.cpp

@@ -95,7 +95,7 @@ void init_token_table(token_table & t) {
          {"[", g_max_prec}, {"]", 0}, {"⦃", g_max_prec}, {"⦄", 0}, {".{", 0}, {"Type", g_max_prec},
          {"{|", g_max_prec}, {"|}", 0}, {"(:", g_max_prec}, {":)", 0},
          {"⊢", 0}, {"⟨", g_max_prec}, {"⟩", 0}, {"^", 0}, {"↑", 0}, {"▸", 0},
-         {"using", 0}, {"|", 0}, {"!", g_max_prec}, {"?", 0},  {"with", 0}, {"...", 0}, {",", 0},
+         {"|", 0}, {"!", g_max_prec}, {"?", 0},  {"with", 0}, {"...", 0}, {",", 0},
          {".", 0}, {":", 0}, {"::", 0}, {"calc", 0}, {"as", 0}, {":=", 0}, {"--", 0}, {"#", 0},
          {"(*", 0}, {"/-", 0}, {"begin", g_max_prec}, {"abstract", g_max_prec},
          {"@@", g_max_prec}, {"@", g_max_prec},

src/frontends/lean/tokens.cpp

@@ -78,7 +78,6 @@ static name const * g_in_tk = nullptr;
 static name const * g_at_tk = nullptr;
 static name const * g_assign_tk = nullptr;
 static name const * g_from_tk = nullptr;
-static name const * g_using_tk = nullptr;
 static name const * g_then_tk = nullptr;
 static name const * g_else_tk = nullptr;
 static name const * g_by_tk = nullptr;
@@ -222,7 +221,6 @@ void initialize_tokens() {
     g_at_tk = new name{"at"};
     g_assign_tk = new name{":="};
     g_from_tk = new name{"from"};
-    g_using_tk = new name{"using"};
     g_then_tk = new name{"then"};
     g_else_tk = new name{"else"};
     g_by_tk = new name{"by"};
@@ -367,7 +365,6 @@ void finalize_tokens() {
     delete g_at_tk;
     delete g_assign_tk;
     delete g_from_tk;
-    delete g_using_tk;
     delete g_then_tk;
     delete g_else_tk;
     delete g_by_tk;
@@ -511,7 +508,6 @@ name const & get_in_tk() { return *g_in_tk; }
 name const & get_at_tk() { return *g_at_tk; }
 name const & get_assign_tk() { return *g_assign_tk; }
 name const & get_from_tk() { return *g_from_tk; }
-name const & get_using_tk() { return *g_using_tk; }
 name const & get_then_tk() { return *g_then_tk; }
 name const & get_else_tk() { return *g_else_tk; }
 name const & get_by_tk() { return *g_by_tk; }

src/frontends/lean/tokens.h

@@ -80,7 +80,6 @@ name const & get_in_tk();
 name const & get_at_tk();
 name const & get_assign_tk();
 name const & get_from_tk();
-name const & get_using_tk();
 name const & get_then_tk();
 name const & get_else_tk();
 name const & get_by_tk();

src/frontends/lean/tokens.txt

@@ -73,7 +73,6 @@ in           in
 at           at
 assign       :=
 from         from
-using        using
 then         then
 else         else
 by           by