Remove support for backticks from the grammar and compiler.

Still need to remove traces of the UNARY_CONVERT opcode.

Author: brettcannon

Doc/ref/ref5.tex

@@ -268,49 +268,6 @@ \subsection{Dictionary displays\label{dict}}
 \indexii{immutable}{object}
 
 
-\subsection{String conversions\label{string-conversions}}
-\indexii{string}{conversion}
-\indexii{reverse}{quotes}
-\indexii{backward}{quotes}
-\index{back-quotes}
-
-A string conversion is an expression list enclosed in reverse (a.k.a.
-backward) quotes:
-
-\begin{productionlist}
-  \production{string_conversion}
-             {"`" \token{expression_list} "`"}
-\end{productionlist}
-
-A string conversion evaluates the contained expression list and
-converts the resulting object into a string according to rules
-specific to its type.
-
-If the object is a string, a number, \code{None}, or a tuple, list or
-dictionary containing only objects whose type is one of these, the
-resulting string is a valid Python expression which can be passed to
-the built-in function \function{eval()} to yield an expression with the
-same value (or an approximation, if floating point numbers are
-involved).
-
-(In particular, converting a string adds quotes around it and converts
-``funny'' characters to escape sequences that are safe to print.)
-
-Recursive objects (for example, lists or dictionaries that contain a
-reference to themselves, directly or indirectly) use \samp{...} to
-indicate a recursive reference, and the result cannot be passed to
-\function{eval()} to get an equal value (\exception{SyntaxError} will
-be raised instead).
-\obindex{recursive}
-
-The built-in function \function{repr()} performs exactly the same
-conversion in its argument as enclosing it in parentheses and reverse
-quotes does.  The built-in function \function{str()} performs a
-similar but more user-friendly conversion.
-\bifuncindex{repr}
-\bifuncindex{str}
-
-
 \section{Primaries\label{primaries}}
 \index{primary}
 

Grammar/Grammar

@@ -102,7 +102,6 @@ power: atom trailer* ['**' factor]
 atom: ('(' [yield_expr|testlist_gexp] ')' |
        '[' [listmaker] ']' |
        '{' [dictmaker] '}' |
-       '`' testlist1 '`' |
        NAME | NUMBER | STRING+)
 listmaker: test ( list_for | (',' test)* [','] )
 testlist_gexp: test ( gen_for | (',' test)* [','] )

Lib/tokenize.py

@@ -83,7 +83,7 @@ def maybe(*choices): return group(*choices) + '?'
                  r"~")
 
 Bracket = '[][(){}]'
-Special = group(r'\r?\n', r'[:;.,`@]')
+Special = group(r'\r?\n', r'[:;.,@]')
 Funny = group(Operator, Bracket, Special)
 
 PlainToken = group(Number, Funny, String, Name)

Parser/tokenizer.c

@@ -67,7 +67,6 @@ char *_PyParser_TokenNames[] = {
 	"EQUAL",
 	"DOT",
 	"PERCENT",
-	"BACKQUOTE",
 	"LBRACE",
 	"RBRACE",
 	"EQEQUAL",
@@ -955,7 +954,6 @@ PyToken_OneChar(int c)
 	case '=':	return EQUAL;
 	case '.':	return DOT;
 	case '%':	return PERCENT;
-	case '`':	return BACKQUOTE;
 	case '{':	return LBRACE;
 	case '}':	return RBRACE;
 	case '^':	return CIRCUMFLEX;

Python/ast.c

@@ -1190,7 +1190,7 @@ static expr_ty
 ast_for_atom(struct compiling *c, const node *n)
 {
     /* atom: '(' [yield_expr|testlist_gexp] ')' | '[' [listmaker] ']'
-       | '{' [dictmaker] '}' | '`' testlist '`' | NAME | NUMBER | STRING+
+       | '{' [dictmaker] '}' | NAME | NUMBER | STRING+
     */
     node *ch = CHILD(n, 0);
 
@@ -1276,13 +1276,6 @@ ast_for_atom(struct compiling *c, const node *n)
 	}
 	return Dict(keys, values, LINENO(n), n->n_col_offset, c->c_arena);
     }
-    case BACKQUOTE: { /* repr */
-	expr_ty expression = ast_for_testlist(c, CHILD(n, 1));
-	if (!expression)
-	    return NULL;
-
-	return Repr(expression, LINENO(n), n->n_col_offset, c->c_arena);
-    }
     default:
 	PyErr_Format(PyExc_SystemError, "unhandled atom %d", TYPE(ch));
 	return NULL;

Python/compile.c

@@ -721,7 +721,6 @@ opcode_stack_effect(int opcode, int oparg)
 		case UNARY_POSITIVE:
 		case UNARY_NEGATIVE:
 		case UNARY_NOT:
-		case UNARY_CONVERT:
 		case UNARY_INVERT:
 			return 0;
 
@@ -2983,10 +2982,6 @@ compiler_visit_expr(struct compiler *c, expr_ty e)
 		return compiler_compare(c, e);
 	case Call_kind:
 		return compiler_call(c, e);
-	case Repr_kind:
-		VISIT(c, expr, e->v.Repr.value);
-		ADDOP(c, UNARY_CONVERT);
-		break;
 	case Num_kind:
 		ADDOP_O(c, LOAD_CONST, e->v.Num.n, consts);
 		break;