add circuitpython code

1 files changed, 71 insertions, 0 deletions

diff --git a/circuitpython/py/parsenumbase.c b/circuitpython/py/parsenumbase.c
new file mode 100644
index 0000000..0802b43
--- /dev/null
+++ b/circuitpython/py/parsenumbase.c
@@ -0,0 +1,71 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2013, 2014 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/mpconfig.h"
+#include "py/misc.h"
+#include "py/parsenumbase.h"
+
+// find real radix base, and strip preceding '0x', '0o' and '0b'
+// puts base in *base, and returns number of bytes to skip the prefix
+size_t mp_parse_num_base(const char *str, size_t len, int *base) {
+    const byte *p = (const byte *)str;
+    if (len <= 1) {
+        goto no_prefix;
+    }
+    unichar c = *(p++);
+    if ((*base == 0 || *base == 16) && c == '0') {
+        c = *(p++);
+        if ((c | 32) == 'x') {
+            *base = 16;
+        } else if (*base == 0 && (c | 32) == 'o') {
+            *base = 8;
+        } else if (*base == 0 && (c | 32) == 'b') {
+            *base = 2;
+        } else {
+            if (*base == 0) {
+                *base = 10;
+            }
+            p -= 2;
+        }
+    } else if (*base == 8 && c == '0') {
+        c = *(p++);
+        if ((c | 32) != 'o') {
+            p -= 2;
+        }
+    } else if (*base == 2 && c == '0') {
+        c = *(p++);
+        if ((c | 32) != 'b') {
+            p -= 2;
+        }
+    } else {
+        p--;
+    no_prefix:
+        if (*base == 0) {
+            *base = 10;
+        }
+    }
+    return p - (const byte *)str;
+}