refactor(kernel): move printer and formatter objects to the kernel

The printer and formatter objects are not trusted code.
We moved them to the kernel to be able to provide them as an argument to the trace objects.
Another motivation is to eliminate the kernel_exception_formatter hack.
With the formatter in the kernel, we can implement the pretty printer for kernel exceptions as a virtual method.

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

src/frontends/lean/elaborator.cpp

@@ -17,7 +17,7 @@ Author: Leonardo de Moura
 #include "kernel/replace.h"
 #include "kernel/instantiate.h"
 #include "kernel/metavar.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "library/placeholder.h"
 #include "library/reduce.h"
 #include "library/update_expr.h"

src/frontends/lean/elaborator.h

@@ -7,7 +7,7 @@ Author: Leonardo de Moura
 #pragma once
 #include <memory>
 #include "kernel/environment.h"
-#include "library/formatter.h"
+#include "kernel/formatter.h"
 
 namespace lean {
 class frontend;

src/frontends/lean/parser.cpp

@@ -25,8 +25,8 @@ Author: Leonardo de Moura
 #include "kernel/builtin.h"
 #include "kernel/kernel_exception.h"
 #include "kernel/expr_maps.h"
+#include "kernel/printer.h"
 #include "library/arith/arith.h"
-#include "library/printer.h"
 #include "library/state.h"
 #include "library/kernel_exception_formatter.h"
 #include "library/placeholder.h"

src/frontends/lean/pp.h

@@ -7,7 +7,7 @@ Author: Leonardo de Moura
 #pragma once
 #include "util/sexpr/options.h"
 #include "kernel/context.h"
-#include "library/formatter.h"
+#include "kernel/formatter.h"
 
 namespace lean {
 class frontend;

src/kernel/CMakeLists.txt

@@ -1,6 +1,6 @@
 add_library(kernel expr.cpp free_vars.cpp abstract.cpp instantiate.cpp
   normalizer.cpp context.cpp level.cpp object.cpp environment.cpp
   type_checker.cpp builtin.cpp occurs.cpp metavar.cpp trace.cpp
-  unification_constraint.cpp)
+  unification_constraint.cpp printer.cpp formatter.cpp)
 
 target_link_libraries(kernel ${LEAN_LIBS})

src/kernel/context.h

@@ -60,7 +60,5 @@ inline context extend(context const & c, name const & n, expr const & d, expr co
 inline context extend(context const & c, name const & n, expr const & d) { return context(c, n, d); }
 inline bool empty(context const & c) { return c.empty(); }
 
-// Remark: the implementation is at library/printer.cpp
-// We add the definition here to prevent the compiler from using the coercion to bool.
 std::ostream & operator<<(std::ostream & out, context const & ctx);
 }

src/kernel/expr.h

@@ -625,7 +625,5 @@ inline expr update_metavar(expr const & e, local_context const & lctx) {
 }
 // =======================================
 
-// Remark: the implementation is at library/printer.cpp
-// We add the definition here to prevent the compiler from using the coercion to bool.
 std::ostream & operator<<(std::ostream & out, expr const & e);
 }

src/kernel/formatter.cpp

@@ -6,8 +6,8 @@ Author: Leonardo de Moura
 */
 #include <sstream>
 #include "kernel/kernel_exception.h"
-#include "library/printer.h"
-#include "library/formatter.h"
+#include "kernel/printer.h"
+#include "kernel/formatter.h"
 
 namespace lean {
 class simple_formatter_cell : public formatter_cell {

src/kernel/printer.cpp

@@ -7,7 +7,7 @@ Author: Leonardo de Moura
 #include <algorithm>
 #include <utility>
 #include "util/exception.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "kernel/environment.h"
 
 namespace lean {

src/library/CMakeLists.txt

@@ -1,6 +1,6 @@
 add_library(library basic_thms.cpp deep_copy.cpp max_sharing.cpp
-  printer.cpp formatter.cpp context_to_lambda.cpp
-  state.cpp update_expr.cpp kernel_exception_formatter.cpp
-  reduce.cpp light_checker.cpp placeholder.cpp ho_unifier.cpp
-  expr_lt.cpp)
+  context_to_lambda.cpp state.cpp update_expr.cpp
+  kernel_exception_formatter.cpp reduce.cpp light_checker.cpp
+  placeholder.cpp ho_unifier.cpp expr_lt.cpp)
+
 target_link_libraries(library ${LEAN_LIBS})

src/library/ho_unifier.cpp

@@ -13,11 +13,11 @@ Author: Leonardo de Moura
 #include "kernel/free_vars.h"
 #include "kernel/instantiate.h"
 #include "kernel/normalizer.h"
+#include "kernel/printer.h"
 #include "library/light_checker.h"
 #include "library/reduce.h"
 #include "library/update_expr.h"
 #include "library/ho_unifier.h"
-#include "library/printer.h"
 
 #ifndef LEAN_LIBRARY_HO_UNIFIER_MAX_SOLUTIONS
 #define LEAN_LIBRARY_HO_UNIFIER_MAX_SOLUTIONS std::numeric_limits<unsigned>::max()

src/library/kernel_exception_formatter.h

@@ -6,7 +6,7 @@ Author: Leonardo de Moura
 */
 #pragma once
 #include "kernel/kernel_exception.h"
-#include "library/formatter.h"
+#include "kernel/formatter.h"
 #include "library/state.h"
 
 namespace lean {

src/library/rewriter/fo_match.cpp

@@ -7,12 +7,12 @@ Author: Soonho Kong
 #include <utility>
 #include "util/trace.h"
 #include "kernel/expr.h"
+#include "kernel/printer.h"
 #include "library/all/all.h"
 #include "library/arith/nat.h"
 #include "library/arith/arith.h"
 #include "library/rewriter/fo_match.h"
 #include "library/rewriter/rewriter.h"
-#include "library/printer.h"
 
 using std::cout;
 using std::endl;

src/library/rewriter/fo_match.h

@@ -5,7 +5,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Soonho Kong
 */
 #pragma once
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "util/scoped_map.h"
 #include "kernel/expr.h"
 #include "kernel/context.h"

src/library/rewriter/rewriter.cpp

@@ -10,9 +10,9 @@
 #include "kernel/environment.h"
 #include "kernel/expr.h"
 #include "kernel/replace.h"
+#include "kernel/printer.h"
 #include "library/basic_thms.h"
 #include "library/light_checker.h"
-#include "library/printer.h"
 #include "library/rewriter/fo_match.h"
 #include "library/rewriter/rewriter.h"
 #include "util/buffer.h"

src/library/state.h

@@ -7,7 +7,7 @@ Author: Leonardo de Moura
 #pragma once
 #include "util/output_channel.h"
 #include "util/sexpr/options.h"
-#include "library/formatter.h"
+#include "kernel/formatter.h"
 
 namespace lean {
 /**

src/shell/lean.cpp

@@ -8,7 +8,7 @@ Author: Leonardo de Moura
 #include <fstream>
 #include <signal.h>
 #include "util/interruptable_ptr.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "frontends/lean/parser.h"
 #include "version.h"
 

src/tests/frontends/lean/frontend.cpp

@@ -10,7 +10,7 @@ Author: Leonardo de Moura
 #include "kernel/kernel_exception.h"
 #include "kernel/builtin.h"
 #include "kernel/abstract.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "frontends/lean/frontend.h"
 #include "frontends/lean/operator_info.h"
 #include "frontends/lean/pp.h"

src/tests/frontends/lean/implicit_args.cpp

@@ -10,8 +10,8 @@ Author: Leonardo de Moura
 #include "kernel/occurs.h"
 #include "kernel/abstract.h"
 #include "kernel/free_vars.h"
+#include "kernel/printer.h"
 #include "library/placeholder.h"
-#include "library/printer.h"
 #include "library/basic_thms.h"
 #include "library/all/all.h"
 #include "frontends/lean/frontend.h"

src/tests/frontends/lean/parser.cpp

@@ -9,7 +9,7 @@ Author: Leonardo de Moura
 #include "util/exception.h"
 #include "util/numerics/mpq.h"
 #include "kernel/builtin.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "library/arith/arith.h"
 #include "frontends/lean/parser.h"
 #include "frontends/lean/pp.h"

src/tests/frontends/lean/pp.cpp

@@ -7,7 +7,7 @@ Author: Leonardo de Moura
 #include "util/test.h"
 #include "kernel/abstract.h"
 #include "kernel/builtin.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "frontends/lean/frontend.h"
 #include "frontends/lean/pp.h"
 using namespace lean;

src/tests/kernel/arith.cpp

@@ -11,7 +11,7 @@ Author: Leonardo de Moura
 #include "kernel/builtin.h"
 #include "kernel/normalizer.h"
 #include "kernel/abstract.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "library/arith/arith.h"
 #include "library/all/all.h"
 using namespace lean;

src/tests/kernel/environment.cpp

@@ -13,7 +13,7 @@ Author: Leonardo de Moura
 #include "kernel/builtin.h"
 #include "kernel/normalizer.h"
 #include "kernel/abstract.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "library/arith/arith.h"
 #include "library/all/all.h"
 using namespace lean;

src/tests/kernel/expr.cpp

@@ -14,8 +14,8 @@ Author: Leonardo de Moura
 #include "kernel/free_vars.h"
 #include "kernel/abstract.h"
 #include "kernel/instantiate.h"
+#include "kernel/printer.h"
 #include "library/max_sharing.h"
-#include "library/printer.h"
 #include "library/arith/arith.h"
 using namespace lean;
 

src/tests/kernel/level.cpp

@@ -8,7 +8,7 @@ Author: Leonardo de Moura
 #include "util/test.h"
 #include "util/exception.h"
 #include "kernel/environment.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 using namespace lean;
 
 static void tst0() {

src/tests/kernel/metavar.cpp

@@ -16,7 +16,7 @@ Author: Leonardo de Moura
 #include "kernel/normalizer.h"
 #include "kernel/environment.h"
 #include "kernel/type_checker.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "library/placeholder.h"
 #include "library/arith/arith.h"
 #include "library/all/all.h"

src/tests/kernel/normalizer.cpp

@@ -15,7 +15,7 @@ Author: Leonardo de Moura
 #include "kernel/expr_sets.h"
 #include "kernel/abstract.h"
 #include "kernel/kernel_exception.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "library/all/all.h"
 using namespace lean;
 

src/tests/kernel/occurs.cpp

@@ -7,7 +7,7 @@ Author: Leonardo de Moura
 #include "util/test.h"
 #include "kernel/occurs.h"
 #include "kernel/abstract.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 using namespace lean;
 
 static void tst1() {

src/tests/kernel/replace.cpp

@@ -11,8 +11,8 @@ Author: Leonardo de Moura
 #include "kernel/instantiate.h"
 #include "kernel/expr_maps.h"
 #include "kernel/replace.h"
+#include "kernel/printer.h"
 #include "library/deep_copy.h"
-#include "library/printer.h"
 using namespace lean;
 
 expr mk_big(expr f, unsigned depth, unsigned val) {

src/tests/kernel/type_checker.cpp

@@ -15,7 +15,7 @@ Author: Leonardo de Moura
 #include "kernel/abstract.h"
 #include "kernel/builtin.h"
 #include "kernel/normalizer.h"
-#include "library/printer.h"
+#include "kernel/printer.h"
 #include "library/basic_thms.h"
 #include "library/arith/arith.h"
 #include "library/all/all.h"

src/tests/library/formatter.cpp

@@ -9,7 +9,7 @@ Author: Leonardo de Moura
 #include "util/test.h"
 #include "kernel/environment.h"
 #include "kernel/abstract.h"
-#include "library/formatter.h"
+#include "kernel/formatter.h"
 using namespace lean;
 
 static void check(format const & f, char const * expected) {

src/tests/library/ho_unifier.cpp

@@ -8,8 +8,8 @@ Author: Leonardo de Moura
 #include "kernel/environment.h"
 #include "kernel/builtin.h"
 #include "kernel/abstract.h"
+#include "kernel/printer.h"
 #include "library/ho_unifier.h"
-#include "library/printer.h"
 #include "library/reduce.h"
 #include "library/arith/arith.h"
 using namespace lean;

src/tests/library/light_checker.cpp

@@ -9,8 +9,8 @@ Author: Leonardo de Moura
 #include "kernel/type_checker.h"
 #include "kernel/environment.h"
 #include "kernel/abstract.h"
+#include "kernel/printer.h"
 #include "library/light_checker.h"
-#include "library/printer.h"
 #include "library/arith/arith.h"
 #include "library/all/all.h"
 using namespace lean;

src/tests/library/max_sharing.cpp

@@ -7,8 +7,8 @@ Author: Leonardo de Moura
 #include <iostream>
 #include "util/test.h"
 #include "kernel/abstract.h"
+#include "kernel/printer.h"
 #include "library/max_sharing.h"
-#include "library/printer.h"
 using namespace lean;
 
 static void tst1() {

src/tests/library/rewriter/fo_match.cpp

@@ -9,13 +9,13 @@ Author: Soonho Kong
 #include "kernel/abstract.h"
 #include "kernel/expr.h"
 #include "kernel/metavar.h"
+#include "kernel/printer.h"
 #include "library/all/all.h"
 #include "library/arith/arith.h"
 #include "library/arith/nat.h"
 #include "library/rewriter/fo_match.h"
 #include "library/rewriter/rewriter.h"
 #include "library/basic_thms.h"
-#include "library/printer.h"
 using namespace lean;
 
 using std::cout;

src/tests/library/rewriter/rewriter.cpp

@@ -8,14 +8,13 @@ Author: Soonho Kong
 #include "kernel/abstract.h"
 #include "kernel/context.h"
 #include "kernel/expr.h"
+#include "kernel/printer.h"
 #include "library/all/all.h"
 #include "library/arith/arith.h"
 #include "library/arith/nat.h"
 #include "library/rewriter/fo_match.h"
 #include "library/rewriter/rewriter.h"
 #include "library/basic_thms.h"
-#include "library/printer.h"
-#include "library/kernel_exception_formatter.h"
 using namespace lean;
 
 using std::cout;