new evaluator, y'all

* libguile/eval.c: So, ladies & gents, a new evaluator. It's similar to
  the old one, in that we memoize and then evaluate, but in this
  incarnation, memoization of an expression happens before evaluation,
  not lazily as the expression is evaluated. This makes the evaluation
  itself much cleaner, in addition to being threadsafe. In addition,
  since this C evaluator will in the future just serve to bootstrap the
  Scheme evaluator, we don't have to pay much concern for debugging
  conveniences. So the environment is just a list of values, and the
  memoizer pre-computes where it's going to find each individual value
  in the environment.

  Interface changes are commented below, with eval.h.

  (scm_evaluator_traps): No need to reset the debug mode after rnning te
  traps thing. But really, the whole traps system needs some love.

* libguile/memoize.h:
* libguile/memoize.c: New memoizer, which runs before evaluation,
  checking all syntax before evaluation begins. Significantly, no
  debugging information is left for lexical variables, which is not so
  great for interactive debugging; perhaps we should change this to have
  a var list in the future as per the classic interpreters. But it's
  quite fast, and the resulting code is quite good. Also note that it
  doesn't produce ilocs, memoized code is a smob whose type is in the
  first word of the smob itself.

* libguile/eval.h (scm_sym_and, scm_sym_begin, scm_sym_case)
  (scm_sym_cond, scm_sym_define, scm_sym_do, scm_sym_if, scm_sym_lambda)
  (scm_sym_let, scm_sym_letstar, scm_sym_letrec, scm_sym_quote)
  (scm_sym_quasiquote, scm_sym_unquote, scm_sym_uq_splicing, scm_sym_at)
  (scm_sym_atat, scm_sym_atapply, scm_sym_atcall_cc)
  (scm_sym_at_call_with_values, scm_sym_delay, scm_sym_eval_when)
  (scm_sym_arrow, scm_sym_else, scm_sym_apply, scm_sym_set_x)
  (scm_sym_args): Remove public declaration of these symbols.
  (scm_ilookup, scm_lookupcar, scm_eval_car, scm_eval_body)
  (scm_eval_args, scm_i_eval_x, scm_i_eval): Remove public declaration
  of these functions.
  (scm_ceval, scm_deval, scm_ceval_ptr): Remove declarations of these
  deprecated functions.
  (scm_i_print_iloc, scm_i_print_isym, scm_i_unmemocopy_expr)
  (scm_i_unmemocopy_body): Remove declarations of these internal
  functions.
  (scm_primitive_eval_x, scm_eval_x): Redefine as macros for their less
  destructive siblings.

* libguile/Makefile.am: Add memoize.[ch] to the build.

* libguile/debug.h (scm_debug_mode_p, scm_check_entry_p)
  (scm_check_apply_p, scm_check_exit_p, scm_check_memoize_p)
  (scm_debug_eframe_size): Remove these vars that were tied to the old
  evaluator's execution model.
  (SCM_RESET_DEBUG_MODE): Remove, no more need for this.
  (SCM_MEMOIZEDP, SCM_MEMOIZED_EXP, SCM_MEMOIZED_ENV): Remove macros
  referring to old memoized code representation.
  (scm_local_eval, scm_procedure_environment, scm_memoized_environment)
  (scm_make_memoized, scm_memoized_p): Remove functions operating on old
  memoized code representation.
  (scm_memcons, scm_mem_to_proc, scm_proc_to_mem): Remove debug-only
  code for old evaluator.

* libguile/debug.c: Remove code to correspond with debug.h removals.
  (scm_debug_options): No need to set the debug mode or frame limit
  here, as we don't have C stack limits any more. Perhaps this is a bug,
  but as long as we can compile eval.scm, we should be fine.

* libguile/init.c (scm_i_init_guile): Init memoize.c.

* libguile/modules.c (scm_top_level_env, scm_env_top_level)
  (scm_env_module, scm_system_module_env_p): Remove these functions.

* libguile/print.c (iprin1): No more need to handle isyms. Adapt to new
  form of interpreted procedures.

* libguile/procprop.c (scm_i_procedure_arity): Adapt to new form of
  interpreted procedures.

* libguile/procs.c (scm_thunk_p): Adapt to new form of interpreted
  procedures.
* libguile/procs.h (SCM_CLOSURE_FORMALS): Removed, this exists no more.
  (SCM_CLOSURE_NUM_REQUIRED_ARGS, SCM_CLOSURE_HAS_REST_ARGS): New
  accessors.

* libguile/srcprop.c (scm_source_properties, scm_source_property)
  (scm_set_source_property_x): Remove special cases for memoized code.

* libguile/stacks.c (read_frame): Remove a source-property case for
  interpreted code.
  (NEXT_FRAME): Remove a case that I don't fully understand, that seems
  to be designed to skip over apply frames. Will be obsolete in the
  futures.
  (read_frames): Default source value for interpreted frames to #f.
  (narrow_stack): Don't pay attention to the system_module thing.

* libguile/tags.h: Remove isyms and ilocs. Whee!

* libguile/validate.h (SCM_VALIDATE_MEMOIZED): Fix to use the new
  MEMOIZED_P formulation.

* module/ice-9/psyntax-pp.scm (do, quasiquote, case): Adapt for these no
  longer being primitive macros.
* module/ice-9/boot-9.scm: Whitespace change, but just a poke to force a
  rebuild due to and/or/cond/... not being primitives any more.

* module/ice-9/deprecated.scm (unmemoize-expr): Deprecate, it's
  unmemoize-expression now.

* test-suite/tests/eval.test ("define set procedure-name"): XFAIL a
  couple of tests here; I don't know what to do about them. I reckon the
  expander should ensure that defined values are named.

* test-suite/tests/chars.test ("basic char handling"): Fix expected
  exception when trying to apply a char.

1 files changed, 106 insertions, 0 deletions

diff --git a/libguile/memoize.h b/libguile/memoize.h
new file mode 100644
index 000000000..5a96ef6bf
--- /dev/null
+++ b/libguile/memoize.h
@@ -0,0 +1,106 @@
+/* classes: h_files */
+
+#ifndef SCM_MEMOIZE_H
+#define SCM_MEMOIZE_H
+
+/* Copyright (C) 1995,1996,1998,1999,2000,2001,2002,2004,2008,2009
+ * Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+
+
+#include "libguile/__scm.h"
+
+
+
+
+SCM_API SCM scm_sym_and;
+SCM_API SCM scm_sym_begin;
+SCM_API SCM scm_sym_case;
+SCM_API SCM scm_sym_cond;
+SCM_API SCM scm_sym_define;
+SCM_API SCM scm_sym_do;
+SCM_API SCM scm_sym_if;
+SCM_API SCM scm_sym_lambda;
+SCM_API SCM scm_sym_let;
+SCM_API SCM scm_sym_letstar;
+SCM_API SCM scm_sym_letrec;
+SCM_API SCM scm_sym_quote;
+SCM_API SCM scm_sym_quasiquote;
+SCM_API SCM scm_sym_unquote;
+SCM_API SCM scm_sym_uq_splicing;
+
+SCM_API SCM scm_sym_at;
+SCM_API SCM scm_sym_atat;
+SCM_API SCM scm_sym_atapply;
+SCM_API SCM scm_sym_atcall_cc;
+SCM_API SCM scm_sym_at_call_with_values;
+SCM_API SCM scm_sym_delay;
+SCM_API SCM scm_sym_eval_when;
+SCM_API SCM scm_sym_arrow;
+SCM_API SCM scm_sym_else;
+SCM_API SCM scm_sym_apply;
+SCM_API SCM scm_sym_set_x;
+SCM_API SCM scm_sym_args;
+
+/* {Memoized Source}
+ */
+
+SCM_INTERNAL scm_t_bits scm_tc16_memoized;
+
+#define SCM_MEMOIZED_P(x) 	(SCM_SMOB_PREDICATE (scm_tc16_memoized, (x)))
+#define SCM_MEMOIZED_TAG(x) 	(SCM_SMOB_FLAGS (x))
+#define SCM_MEMOIZED_ARGS(x) 	(SCM_SMOB_OBJECT (x))
+
+enum
+  {
+    SCM_M_BEGIN,
+    SCM_M_IF,
+    SCM_M_LAMBDA,
+    SCM_M_LET,
+    SCM_M_QUOTE,
+    SCM_M_DEFINE,
+    SCM_M_APPLY,
+    SCM_M_CONT,
+    SCM_M_CALL_WITH_VALUES,
+    SCM_M_CALL,
+    SCM_M_LEXICAL_REF,
+    SCM_M_LEXICAL_SET,
+    SCM_M_TOPLEVEL_REF,
+    SCM_M_TOPLEVEL_SET,
+    SCM_M_MODULE_REF,
+    SCM_M_MODULE_SET
+  };
+
+
+
+
+SCM_INTERNAL SCM scm_memoize_expression (SCM exp);
+SCM_INTERNAL SCM scm_unmemoize_expression (SCM memoized);
+SCM_API SCM scm_memoized_p (SCM obj);
+
+SCM_INTERNAL void scm_init_memoize (void);
+
+
+#endif  /* SCM_MEMOIZE_H */
+
+/*
+  Local Variables:
+  c-file-style: "gnu"
+  End:
+*/