bpo-40334: PEP 617 implementation: New PEG parser for CPython (GH-19503)
Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
diff --git a/Parser/pegen/parse_string.h b/Parser/pegen/parse_string.h
new file mode 100644
index 0000000..4f2aa94
--- /dev/null
+++ b/Parser/pegen/parse_string.h
@@ -0,0 +1,46 @@
+#ifndef STRINGS_H
+#define STRINGS_H
+
+#include <Python.h>
+#include <Python-ast.h>
+#include "pegen.h"
+
+#define EXPRLIST_N_CACHED 64
+
+typedef struct {
+ /* Incrementally build an array of expr_ty, so be used in an
+ asdl_seq. Cache some small but reasonably sized number of
+ expr_ty's, and then after that start dynamically allocating,
+ doubling the number allocated each time. Note that the f-string
+ f'{0}a{1}' contains 3 expr_ty's: 2 FormattedValue's, and one
+ Constant for the literal 'a'. So you add expr_ty's about twice as
+ fast as you add expressions in an f-string. */
+
+ Py_ssize_t allocated; /* Number we've allocated. */
+ Py_ssize_t size; /* Number we've used. */
+ expr_ty *p; /* Pointer to the memory we're actually
+ using. Will point to 'data' until we
+ start dynamically allocating. */
+ expr_ty data[EXPRLIST_N_CACHED];
+} ExprList;
+
+/* The FstringParser is designed to add a mix of strings and
+ f-strings, and concat them together as needed. Ultimately, it
+ generates an expr_ty. */
+typedef struct {
+ PyObject *last_str;
+ ExprList expr_list;
+ int fmode;
+} FstringParser;
+
+void _PyPegen_FstringParser_Init(FstringParser *);
+int _PyPegen_parsestr(Parser *, const char *, int *, int *, PyObject **,
+ const char **, Py_ssize_t *);
+int _PyPegen_FstringParser_ConcatFstring(Parser *, FstringParser *, const char **,
+ const char *, int, int, Token *, Token *,
+ Token *);
+int _PyPegen_FstringParser_ConcatAndDel(FstringParser *, PyObject *);
+expr_ty _PyPegen_FstringParser_Finish(Parser *, FstringParser *, Token *, Token *);
+void _PyPegen_FstringParser_Dealloc(FstringParser *);
+
+#endif