[translation] Move TDOP spec to a different module.

Start plugging a C++ version in.

Down to 6 errors.

cpp/arith_spec.h

@@ -0,0 +1,16 @@
+// Replacement for osh/arith_spec
+
+#ifndef ARITH_SPEC_H
+#define ARITH_SPEC_H
+
+namespace tdop {  // forward declare
+  class ParserSpec;
+}
+
+namespace arith_spec {
+
+tdop::ParserSpec* Spec();
+
+}  // arith_spec
+
+#endif  // ARITH_SPEC_H

frontend/parse_lib.py

@@ -22,7 +22,7 @@
 
 from oil_lang import expr_parse
 from oil_lang import expr_to_ast
-from osh import arith_parse
+from osh import arith_spec
 from osh import cmd_parse
 from osh import word_parse
 from mycpp import mylib
@@ -309,7 +309,7 @@ def MakeArithParser(self, code_str):
     lx = self._MakeLexer(line_reader)
     w_parser = word_parse.WordParser(self, lx, line_reader)
     w_parser.Init(lex_mode_e.Arith)  # Special initialization
-    a_parser = tdop.TdopParser(arith_parse.SPEC, w_parser)
+    a_parser = tdop.TdopParser(arith_spec.Spec(), w_parser)
     return a_parser
 
   def MakeParserForCommandSub(self, line_reader, lexer, eof_id):

mycpp/examples.sh

@@ -245,6 +245,7 @@ using id_kind_asdl::Kind_t;
 // oil/cpp
 #include "pretty.h"
 #include "match.h"
+#include "arith_spec.h"
 
 
 // Hack for now.  Every sum type should have repr()?

osh/arith_parse.py

@@ -175,5 +175,3 @@ def MakeShellSpec():
     spec.Left(1, tdop.LeftBinaryOp, [Id.Arith_Comma])
 
     return spec
-
-  SPEC = MakeShellSpec()

osh/arith_spec.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python2
+"""
+arith_spec.py
+"""
+from __future__ import print_function
+
+from osh import arith_parse
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+  from frontend.tdop import ParserSpec
+
+_SPEC = arith_parse.MakeShellSpec()
+
+def Spec():
+  # type: () -> ParserSpec
+  return _SPEC

osh/word_parse.py

@@ -72,7 +72,7 @@
 from frontend import lookup
 from frontend import reader
 from frontend import tdop
-from osh import arith_parse
+from osh import arith_spec
 from osh import braces
 from osh import word_
 from mycpp.mylib import NewStr
@@ -932,7 +932,7 @@ def _ReadArithExpr(self):
     See the assertion in ArithParser.Parse() -- unexpected extra input.
     """
     # calls self.ReadWord(lex_mode_e.Arith)
-    a_parser = tdop.TdopParser(arith_parse.SPEC, self)
+    a_parser = tdop.TdopParser(arith_spec.Spec(), self)
     anode = a_parser.Parse()
     return anode