add float support to settings.toml and supervisor.get_setting()

docs/rstjinja.py

@@ -5,7 +5,7 @@
 
 
 def render_with_jinja(docname, source):
-    if re.search("^\s*.. jinja$", source[0], re.M):
+    if re.search(r"^\s*.. jinja$", source[0], re.M):
         return True
     return False
 

docs/shared_bindings_matrix.py

@@ -200,6 +200,8 @@ def get_settings_from_makefile(port_dir, board_name):
     contents = subprocess.run(
         [
             "make",
+            # Don't let make run in parallel; it can mix up the output from the various "print-" targets.
+            "-j1",
             "-C",
             port_dir,
             "-f",

shared-bindings/supervisor/__init__.c

@@ -364,13 +364,13 @@ static mp_obj_t supervisor_set_usb_identification(size_t n_args, const mp_obj_t
 }
 MP_DEFINE_CONST_FUN_OBJ_KW(supervisor_set_usb_identification_obj, 0, supervisor_set_usb_identification);
 
-//| def get_setting(key: str, default: object=None) -> int | str | bool:
+//| def get_setting(key: str, default: object=None) -> int | float | str | bool:
 //|     """
 //|     Get and parse the value for the given ``key`` from the ``/settings.toml`` file.
 //|     If ``key`` is not found or ``settings.toml`` is not present, return the ``default`` value.
 //|
 //|     :param str key: The setting key to retrieve
-//|     :return: The setting value as an ``int``, ``str``, or ``bool`` depending on the value in the file
+//|     :return: The setting value as an ``int``, ``float``, ``str``, or ``bool`` depending on the value in the file
 //|
 //|     :raises ValueError: If the value cannot be parsed as a valid TOML value.
 //|
@@ -379,21 +379,24 @@ MP_DEFINE_CONST_FUN_OBJ_KW(supervisor_set_usb_identification_obj, 0, supervisor_
 //|     - ``str``: Double-quoted string.
 //|       The string may include Unicode characters, and ``\\u`` Unicode escapes. Backslash-escaped characters
 //|       ``\\b``, ``\\r``, ``\\n``, ``\\t``, ``\\v``, ``\\v`` are also allowed.
-//|     - ``int``: signed or unsigned integer
-//|     - lower-case boolean words ``true`` and ``false``.
+//|     - ``int``: signed or unsigned integer.
+//|     - ``bool``: lower-case ``true`` or ``false``.
 //|       The values are returned as Python ``True`` or ``False`` values.
+//|     - ``float``: signed or unsigned decimal number with a ``.`` or exponent, or ``inf``, ``inf``, ``nan``.
 //|
 //|     Example::
 //|
 //|         # settings.toml:
 //|         WIDTH = 42
 //|         color = "red"
 //|         DEBUG = true
+//|         RATIO = 1.5
 //|
 //|         import supervisor
 //|         print(supervisor.get_setting("WIDTH")) # prints 42
 //|         print(supervisor.get_setting("color")) # prints 'red'
 //|         print(supervisor.get_setting("DEBUG")) # prints True
+//|         print(supervisor.get_setting("RATIO")) # prints 1.5
 //|     """
 //|     ...
 //|

supervisor/shared/settings.c

@@ -5,6 +5,7 @@
 //
 // SPDX-License-Identifier: MIT
 
+#include <math.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
@@ -419,6 +420,57 @@ settings_err_t settings_get_bool(const char *key, bool *value) {
     return result;
 }
 
+#if MICROPY_PY_BUILTINS_FLOAT
+static settings_err_t get_float(const char *key, mp_float_t *value) {
+    char buf[48];
+    bool quoted;
+    settings_err_t result = settings_get_buf_terminated(key, buf, sizeof(buf), &quoted);
+    if (result != SETTINGS_OK) {
+        return result;
+    }
+    if (quoted) {
+        return SETTINGS_ERR_BAD_VALUE;
+    }
+
+    const char *str = buf;
+    const char *end = buf + strlen(buf);
+    bool neg = false;
+
+    if (str < end && (*str == '+' || *str == '-')) {
+        neg = (*str == '-');
+        str++;
+    }
+
+    mp_float_t val;
+    if (end - str >= 3 && str[0] == 'i' && str[1] == 'n' && str[2] == 'f') {
+        str += 3;
+        val = (mp_float_t)INFINITY;
+    } else if (end - str >= 3 && str[0] == 'n' && str[1] == 'a' && str[2] == 'n') {
+        str += 3;
+        val = MICROPY_FLOAT_C_FUN(nan)("");
+    } else {
+        const char *num_start = str;
+        str = mp_parse_float_internal(str, end - str, &val);
+        if (str == NULL || str == num_start) {
+            return SETTINGS_ERR_BAD_VALUE;
+        }
+    }
+
+    if (str != end) {
+        return SETTINGS_ERR_BAD_VALUE;
+    }
+
+    *value = neg ? -val : val;
+    return SETTINGS_OK;
+}
+
+settings_err_t settings_get_float(const char *key, mp_float_t *value) {
+    settings_err_t result = get_float(key, value);
+    print_error(key, result);
+    return result;
+}
+#endif
+
 // Get the raw value as a vstr, whether quoted or bare. Value may be an invalid TOML value.
 settings_err_t settings_get_raw_vstr(const char *key, vstr_t *vstr) {
     bool quoted;
@@ -457,6 +509,16 @@ settings_err_t settings_get_obj(const char *key, mp_obj_t *value) {
         return SETTINGS_OK;
     }
 
+    // Not an integer, try float
+    #if MICROPY_PY_BUILTINS_FLOAT
+    mp_float_t float_val;
+    result = get_float(key, &float_val);
+    if (result == SETTINGS_OK) {
+        *value = mp_obj_new_float(float_val);
+        return SETTINGS_OK;
+    }
+    #endif
+
     return SETTINGS_ERR_BAD_VALUE;
 }
 

supervisor/shared/settings.h

@@ -10,6 +10,7 @@
 
 typedef enum {
     SETTINGS_OK = 0,
+    // The settings file could not be opened.
     SETTINGS_ERR_OPEN,
     SETTINGS_ERR_UNICODE,
     SETTINGS_ERR_LENGTH,
@@ -20,7 +21,7 @@ typedef enum {
 // Read a string value from the settings file.
 // If it fits, the return value is 0-terminated. The passed-in buffer
 // may be modified even if an error is returned. Allocation free.
-// An error that is not 'open' or 'not found' is printed on the repl.
+// An error that is not SETTINGS_ERR_OPEN or SETTINGS_ERR_NOT_FOUND is printed on the repl.
 // Returns an error if the value is not a quoted string.
 settings_err_t settings_get_str(const char *key, char *value, size_t value_len);
 
@@ -38,13 +39,23 @@ settings_err_t settings_get_int(const char *key, mp_int_t *value);
 // An error that is not 'open' or 'not found' is printed on the repl.
 settings_err_t settings_get_bool(const char *key, bool *value);
 
+#if MICROPY_PY_BUILTINS_FLOAT
+// Read a float value from the settings file.
+// Returns SETTINGS_OK and sets value to the read value. Returns
+// SETTINGS_ERR_... if the value was not a float. allocation-free.
+// If any error code is returned, value is guaranteed not modified.
+// An error that is not SETTINGS_ERR_OPEN or SETTINGS_ERR_NOT_FOUND is printed on the repl.
+settings_err_t settings_get_float(const char *key, mp_float_t *value);
+#endif
+
 // Read a value from the settings file and return as parsed Python object.
 // Returns SETTINGS_OK and sets value to a parsed Python object from the RHS value:
 // - Quoted strings return as str
 // - Bare "true" or "false" return as bool
 // - Valid integers return as int
+// - Valid floats (containing '.' or 'e'/'E') return as float
 // Returns SETTINGS_ERR_... if the value is not parseable as one of these types.
-// An error that is not 'open' or 'not found' is printed on the repl.
+// An error that is not SETTINGS_ERR_OPEN or SETTINGS_ERR_NOT_FOUND is printed on the repl.
 settings_err_t settings_get_obj(const char *key, mp_obj_t *value);
 
 // Read the raw value as a string, whether quoted or bare.

tests/circuitpython-manual/settings/code.py

@@ -0,0 +1,66 @@
+# Test supervisor.get_setting() parsing of settings.toml values.
+# Copy settings.toml to the root of the board, then run this script.
+# All lines should print PASS.
+
+import math
+import supervisor
+
+
+def check(key, expected):
+    got = supervisor.get_setting(key)
+    if type(got) is not type(expected):
+        print(
+            f"FAIL {key}: expected type {type(expected).__name__}, got {type(got).__name__} ({got!r})"
+        )
+        return
+    if isinstance(expected, float) and math.isnan(expected):
+        ok = math.isnan(got)
+    else:
+        ok = got == expected
+    if ok:
+        print(f"PASS {key}")
+    else:
+        print(f"FAIL {key}: expected {expected!r}, got {got!r}")
+
+
+check("str_val", "hello")
+check("int_val", 42)
+check("neg_int_val", -7)
+check("hex_int_val", 31)
+check("bool_true", True)
+check("bool_false", False)
+check("float_val", 3.14)
+check("neg_float_val", -1.5)
+check("sci_float_val", 6.626e-34)
+# math.nan and math.inf are not always available
+check("pos_inf", float("inf"))
+check("neg_inf", -float("inf"))
+check("pos_nan", float("nan"))
+
+
+def check_bad(key):
+    try:
+        got = supervisor.get_setting(key)
+        print(f"FAIL {key}: expected ValueError, got {got!r}")
+    except ValueError:
+        print(f"PASS {key} raises ValueError")
+
+
+check_bad("bad_word")  # unquoted non-boolean word
+check_bad("bad_float_junk")  # float with trailing garbage
+check_bad("bad_inf_junk")  # inf with trailing characters
+check_bad("bad_lone_sign")  # bare + with nothing after it
+
+# Missing key returns default
+got = supervisor.get_setting("no_such_key", "default")
+if got == "default":
+    print("PASS missing key default")
+else:
+    print(f"FAIL missing key default: got {got!r}")
+
+# Invalid value raises ValueError
+try:
+    supervisor.get_setting("str_val")  # quoted string is valid
+    print("PASS str via get_setting")
+except ValueError:
+    print("FAIL str via get_setting raised ValueError unexpectedly")

tests/circuitpython-manual/settings/settings.toml

@@ -0,0 +1,16 @@
+str_val = "hello"
+bad_word = hello
+bad_float_junk = 1.2abc
+bad_inf_junk = infoo
+bad_lone_sign = +
+int_val = 42
+neg_int_val = -7
+hex_int_val = 0x1F
+bool_true = true
+bool_false = false
+float_val = 3.14
+neg_float_val = -1.5
+sci_float_val = 6.626e-34
+pos_inf = inf
+neg_inf = -inf
+pos_nan = nan