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Diffstat (limited to 'lib/syntax_tools/examples/merl/basicc.erl')
-rw-r--r-- | lib/syntax_tools/examples/merl/basicc.erl | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/lib/syntax_tools/examples/merl/basicc.erl b/lib/syntax_tools/examples/merl/basicc.erl new file mode 100644 index 0000000000..531ac51538 --- /dev/null +++ b/lib/syntax_tools/examples/merl/basicc.erl @@ -0,0 +1,149 @@ +%% --------------------------------------------------------------------- +%% Licensed under the Apache License, Version 2.0 (the "License"); you may +%% not use this file except in compliance with the License. You may obtain +%% a copy of the License at <http://www.apache.org/licenses/LICENSE-2.0> +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% @author Richard Carlsson <[email protected]> +%% @copyright 2012 Richard Carlsson +%% @doc Basic compiler in Erlang. + +-module(basicc). + +-export([run/2, make_lines/1, bool/1]). + +-include_lib("eunit/include/eunit.hrl"). + +-define(INTERPRETED, true). +-include("basic_test.erl"). + +-include("merl.hrl"). + +run(N, Prog) -> + compile(Prog, tmp), + tmp:run(N, Prog). + +make_lines(Prog) -> + ets:new(line, [private, named_table, ordered_set]), + lists:foreach(fun ({L,_}) -> ets:insert(line, {L,label(L)}) end, Prog). + +compile(Prog, ModName) -> + make_lines(Prog), + Fs0 = lists:map(fun ({L, X}) -> + {true, label(L), + case stmt(X) of + {Stmt, false} -> + [?Q("() -> _@Stmt")]; + {Stmt, true} -> + Next = case ets:next(line, L) of + '$end_of_table' -> + ?Q("stop(0)"); + L1 -> + Label = label(L1), + ?Q("_@Label@()") + end, + [?Q("() -> _@Stmt, _@Next")] + end} + end, Prog), + ets:delete(line), + Run = ?Q(["(N, Prog) ->", + " ets:new(var, [private, named_table]),", + " basicc:make_lines(Prog),", + " goto(N)" + ]), + Stop = ?Q(["(R) ->", + " ets:delete(var),", + " ets:delete(line),", + " R" + ]), + Goto = ?Q(["(L) ->", + " case ets:lookup(line, L) of", + " [{_, X}] -> apply(tmp, X, []);", + " _ ->", + " case ets:next(line, L) of", + " '$end_of_table' -> stop(0);", + " L1 -> goto(L1)", + " end", + " end"]), + Fs = [{true, run, [Run]}, + {false, stop, [Stop]}, + {true, goto, [Goto]} + | Fs0], + Forms = merl_build:module_forms( + lists:foldl(fun ({X, Name, Cs}, S) -> + merl_build:add_function(X, Name, Cs, S) + end, + merl_build:init_module(ModName), + Fs)), + %% %% Write source to file for debugging + %% file:write_file(lists:concat([ModName, "_gen.erl"]), + %% erl_prettypr:format(erl_syntax:form_list(Forms), + %% [{paper,160},{ribbon,80}])), + merl:compile_and_load(Forms, [verbose]). + +label(L) -> + list_to_atom("label_" ++ integer_to_list(L)). + +stmt({print, S, As}) -> + Exprs = [expr(A) || A <- As], + {[?Q(["io:format(_@S@, [_@Exprs])"])], true}; +stmt({set, V, X}) -> + Expr = expr(X), + {[?Q(["ets:insert(var, {_@V@, _@Expr})"])], true}; +stmt({goto, X}) -> + {[jump(X)], false}; +stmt({stop, X}) -> + Expr = expr(X), + {[?Q(["stop(_@Expr)"])], false}; +stmt({iff, X, A, B}) -> + Cond = expr(X), + True = jump(A), + False = jump(B), + {?Q(["case _@Cond of", + " 0 -> _@False;", + " _ -> _@True", + "end"]), + false}. + +jump(X) -> + case ets:lookup(line, X) of + [{_, F}] -> + ?Q(["_@F@()"]); + true -> + Expr = expr(X), + [?Q(["goto(_@Expr)"])] + end. + +expr(X) when is_number(X) ; is_list(X) -> + ?Q("_@X@"); +expr(X) when is_atom(X) -> + ?Q(["case ets:lookup(var, _@X@) of", + " [] -> 0;", + " [{_,V}] -> V", + "end"]); +expr({plus, X, Y}) -> + ExprX = expr(X), + ExprY = expr(Y), + ?Q("_@ExprX + _@ExprY"); +expr({equal, X, Y}) -> + ExprX = expr(X), + ExprY = expr(Y), + ?Q("basicc:bool(_@ExprX == _@ExprY)"); +expr({gt, X, Y}) -> + ExprX = expr(X), + ExprY = expr(Y), + ?Q("basicc:bool(_@ExprX > _@ExprY)"); +expr({knot, X}) -> + Expr = expr(X), + ?Q(["case _@Expr of", + " 0 -> 1;", + " _ -> 0", + "end"]). + +bool(true) -> 1; +bool(false) -> 0. |