refactor(*): add pushboolean inline function, and replace lua_pushboolean with it

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

src/library/kernel_bindings.cpp

@@ -26,16 +26,8 @@ static int level_tostring(lua_State * L) {
     return 1;
 }
 
-static int level_eq(lua_State * L) {
-    lua_pushboolean(L, to_level(L, 1) == to_level(L, 2));
-    return 1;
-}
-
-static int level_lt(lua_State * L) {
-    lua_pushboolean(L, is_lt(to_level(L, 1), to_level(L, 2)));
-    return 1;
-}
-
+static int level_eq(lua_State * L) { return pushboolean(L, to_level(L, 1) == to_level(L, 2)); }
+static int level_lt(lua_State * L) { return pushboolean(L, is_lt(to_level(L, 1), to_level(L, 2))); }
 static int mk_level_zero(lua_State * L) { return push_level(L, mk_level_zero()); }
 static int mk_level_one(lua_State * L)  { return push_level(L, mk_level_one());  }
 static int mk_level_succ(lua_State * L) { return push_level(L, mk_succ(to_level(L, 1))); }

src/util/exception.cpp

@@ -79,8 +79,7 @@ static int exception_rethrow(lua_State * L) {
 }
 
 static int exception_pred(lua_State * L) {
-    lua_pushboolean(L, is_exception(L, 1));
-    return 1;
+    return pushboolean(L, is_exception(L, 1));
 }
 
 static const struct luaL_Reg exception_m[] = {

src/util/lua.h

@@ -128,4 +128,11 @@ void set_migrate_fn_field(lua_State * src, int i, lua_migrate_fn fn);
    for the userdata at position \c i.
 */
 lua_migrate_fn get_migrate_fn(lua_State * src, int i);
+// =======================================
+
+// =======================================
+// Useful macros
+inline int pushboolean(lua_State * L, bool b) { lua_pushboolean(L, b); return 1; }
+// =======================================
+
 }

src/util/name.cpp

@@ -478,13 +478,11 @@ static int name_tostring(lua_State * L) {
 }
 
 static int name_eq(lua_State * L) {
-    lua_pushboolean(L, to_name(L, 1) == to_name(L, 2));
-    return 1;
+    return pushboolean(L, to_name(L, 1) == to_name(L, 2));
 }
 
 static int name_lt(lua_State * L) {
-    lua_pushboolean(L, to_name(L, 1) < to_name(L, 2));
-    return 1;
+    return pushboolean(L, to_name(L, 1) < to_name(L, 2));
 }
 
 static int name_hash(lua_State * L) {
@@ -492,11 +490,7 @@ static int name_hash(lua_State * L) {
     return 1;
 }
 
-#define NAME_PRED(P)                            \
-static int name_ ## P(lua_State * L) {          \
-    lua_pushboolean(L, to_name(L, 1).P());      \
-    return 1;                                   \
-}
+#define NAME_PRED(P) static int name_ ## P(lua_State * L) { return pushboolean(L, to_name(L, 1).P()); }
 
 NAME_PRED(is_atomic)
 NAME_PRED(is_anonymous)

src/util/numerics/mpq.cpp

@@ -178,13 +178,11 @@ static int mpq_tostring(lua_State * L) {
 }
 
 static int mpq_eq(lua_State * L) {
-    lua_pushboolean(L, to_mpq<1>(L) == to_mpq<2>(L));
-    return 1;
+    return pushboolean(L, to_mpq<1>(L) == to_mpq<2>(L));
 }
 
 static int mpq_lt(lua_State * L) {
-    lua_pushboolean(L, to_mpq<1>(L) < to_mpq<2>(L));
-    return 1;
+    return pushboolean(L, to_mpq<1>(L) < to_mpq<2>(L));
 }
 
 static int mpq_add(lua_State * L) {

src/util/numerics/mpz.cpp

@@ -126,13 +126,11 @@ static int mpz_tostring(lua_State * L) {
 }
 
 static int mpz_eq(lua_State * L) {
-    lua_pushboolean(L, to_mpz<1>(L) == to_mpz<2>(L));
-    return 1;
+    return pushboolean(L, to_mpz<1>(L) == to_mpz<2>(L));
 }
 
 static int mpz_lt(lua_State * L) {
-    lua_pushboolean(L, to_mpz<1>(L) < to_mpz<2>(L));
-    return 1;
+    return pushboolean(L, to_mpz<1>(L) < to_mpz<2>(L));
 }
 
 static int mpz_add(lua_State * L) {

src/util/rb_map.cpp

@@ -23,13 +23,11 @@ static int lua_rb_map_size(lua_State * L) {
 }
 
 static int lua_rb_map_contains(lua_State * L) {
-    lua_pushboolean(L, to_lua_rb_map(L, 1).contains(luaref(L, 2)));
-    return 1;
+    return pushboolean(L, to_lua_rb_map(L, 1).contains(luaref(L, 2)));
 }
 
 static int lua_rb_map_empty(lua_State * L) {
-    lua_pushboolean(L, to_lua_rb_map(L, 1).empty());
-    return 1;
+    return pushboolean(L, to_lua_rb_map(L, 1).empty());
 }
 
 static int lua_rb_map_insert(lua_State * L) {

src/util/script_state.cpp

@@ -298,8 +298,7 @@ int state_set_global(lua_State * L) {
 }
 
 static int state_pred(lua_State * L) {
-    lua_pushboolean(L, is_state(L, 1));
-    return 1;
+    return pushboolean(L, is_state(L, 1));
 }
 
 static const struct luaL_Reg state_m[] = {
@@ -535,8 +534,7 @@ static int thread_gc(lua_State * L) {
 }
 
 static int thread_pred(lua_State * L) {
-    lua_pushboolean(L, is_thread(L, 1));
-    return 1;
+    return pushboolean(L, is_thread(L, 1));
 }
 
 static int thread_write(lua_State * L) {

src/util/sexpr/options.cpp

@@ -241,20 +241,17 @@ static int options_size(lua_State * L) {
 }
 
 static int options_contains(lua_State * L) {
-    lua_pushboolean(L, to_options(L, 1).contains(to_name_ext(L, 2)));
-    return 1;
+    return pushboolean(L, to_options(L, 1).contains(to_name_ext(L, 2)));
 }
 
 static int options_empty(lua_State * L) {
-    lua_pushboolean(L, to_options(L, 1).empty());
-    return 1;
+    return pushboolean(L, to_options(L, 1).empty());
 }
 
 static int options_get_bool(lua_State * L) {
     int nargs = lua_gettop(L);
     bool defval = nargs < 3 ? false : lua_toboolean(L, 3);
-    lua_pushboolean(L, to_options(L, 1).get_bool(to_name_ext(L, 2), defval));
-    return 1;
+    return pushboolean(L, to_options(L, 1).get_bool(to_name_ext(L, 2), defval));
 }
 
 static int options_get_int(lua_State * L) {

src/util/sexpr/sexpr.cpp

@@ -406,14 +406,10 @@ static int mk_sexpr(lua_State * L) {
     return push_sexpr(L, r);
 }
 
-static int sexpr_eq(lua_State * L)        { lua_pushboolean(L, to_sexpr(L, 1) == to_sexpr(L, 2));  return 1; }
-static int sexpr_lt(lua_State * L)        { lua_pushboolean(L, to_sexpr(L, 1) < to_sexpr(L, 2));   return 1; }
+static int sexpr_eq(lua_State * L)        { return pushboolean(L, to_sexpr(L, 1) == to_sexpr(L, 2)); }
+static int sexpr_lt(lua_State * L)        { return pushboolean(L, to_sexpr(L, 1) < to_sexpr(L, 2)); }
 
-#define SEXPR_PRED(P)                           \
-static int sexpr_ ## P(lua_State * L)    {      \
-    lua_pushboolean(L, P(to_sexpr(L, 1)));      \
-    return 1;                                   \
-}
+#define SEXPR_PRED(P) static int sexpr_ ## P(lua_State * L) { return pushboolean(L, P(to_sexpr(L, 1))); }
 
 SEXPR_PRED(is_nil)
 SEXPR_PRED(is_cons)
@@ -453,8 +449,7 @@ static int sexpr_to_bool(lua_State * L) {
     sexpr const & e = to_sexpr(L, 1);
     if (!is_bool(e))
         throw exception("s-expression is not a Boolean");
-    lua_pushboolean(L, to_bool(e));
-    return 1;
+    return pushboolean(L, to_bool(e));
 }
 
 static int sexpr_to_string(lua_State * L) {