chore(frontends/lean): add 'replace' auxiliary funcs

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/frontends/lean/parse_table.cpp

@@ -189,6 +189,23 @@ action mk_scoped_expr_action(expr const & rec, unsigned rb, bool lambda) {
 action mk_ext_action(parse_fn const & fn) { return action(new ext_action_cell(fn)); }
 action mk_ext_lua_action(char const * fn) { return action(new ext_lua_action_cell(fn)); }
 
+action replace(action const & a, std::function<expr(expr const &)> const & f) {
+    switch (a.kind()) {
+    case action_kind::Skip: case action_kind::Binder: case action_kind::Binders:
+    case action_kind::Ext:  case action_kind::LuaExt: case action_kind::Expr:
+        return a;
+    case action_kind::Exprs:
+        return mk_exprs_action(a.get_sep(), f(a.get_rec()), f(a.get_initial()), a.is_fold_right(), a.rbp());
+    case action_kind::ScopedExpr:
+        return mk_scoped_expr_action(f(a.get_rec()), a.rbp(), a.use_lambda_abstraction());
+    }
+    lean_unreachable(); // LCOV_EXCL_LINE
+}
+
+transition replace(transition const & t, std::function<expr(expr const &)> const & f) {
+    return transition(t.get_token(), replace(t.get_action(), f));
+}
+
 struct parse_table::cell {
     bool                                                         m_nud;
     list<expr>                                                   m_accept;

src/frontends/lean/parse_table.h

@@ -89,6 +89,9 @@ action mk_scoped_expr_action(expr const & rec, unsigned rbp = 0, bool lambda = t
 action mk_ext_action(parse_fn const & fn);
 action mk_ext_lua_action(char const * lua_fn);
 
+/** \brief Apply \c f to expressions embedded in the given action */
+action replace(action const & a, std::function<expr(expr const &)> const & f);
+
 class transition {
     name           m_token;
     action         m_action;
@@ -99,6 +102,9 @@ public:
     action const & get_action() const { return m_action; }
 };
 
+/** \brief Apply \c f to expressions embedded in the given transition */
+transition replace(transition const & t, std::function<expr(expr const &)> const & f);
+
 /**
    \brief Parse table "transition rules" for implementing a Pratt's parser.
    The table supports "left factoring" in the methods \c add and \c merge.

src/frontends/lean/parser_config.cpp

@@ -6,6 +6,7 @@ Author: Leonardo de Moura
 */
 #include <string>
 #include "util/sstream.h"
+#include "util/list_fn.h"
 #include "library/scoped_ext.h"
 #include "library/kernel_serializer.h"
 #include "frontends/lean/parser_config.h"
@@ -17,6 +18,13 @@ using notation::transition;
 using notation::action;
 using notation::action_kind;
 
+notation_entry replace(notation_entry const & e, std::function<expr(expr const &)> const & f) {
+    return notation_entry(e.m_is_nud,
+                          map(e.m_transitions, [&](transition const & t) { return notation::replace(t, f); }),
+                          f(e.m_expr),
+                          e.m_overload);
+}
+
 struct token_state {
     token_table m_table;
     token_state() { m_table = mk_default_token_table(); }

src/frontends/lean/parser_config.h

@@ -29,6 +29,9 @@ struct notation_entry {
         m_is_nud(is_nud), m_transitions(ts), m_expr(e), m_overload(overload) {}
 };
 
+/** \brief Apply \c f to expressions embedded in the notation entry */
+notation_entry replace(notation_entry const & e, std::function<expr(expr const &)> const & f);
+
 environment add_token(environment const & env, token_entry const & e);
 environment add_notation(environment const & env, notation_entry const & e);