diff --git a/msgspec/_core.c b/msgspec/_core.c
index 1f5d5230..59a08d08 100644
--- a/msgspec/_core.c
+++ b/msgspec/_core.c
@@ -11092,6 +11092,22 @@ parse_number_nonfinite(
return ms_post_decode_float(val, type, path, strict, true);
}
+static MS_NOINLINE PyObject *
+json_float_hook(
+ const char *buf, Py_ssize_t size, PathNode *path, PyObject *float_hook
+) {
+ PyObject *str = PyUnicode_New(size, 127);
+ if (str == NULL) return NULL;
+ memcpy(ascii_get_buffer(str), buf, size);
+ PyObject *out = CALL_ONE_ARG(float_hook, str);
+ Py_DECREF(str);
+ if (out == NULL) {
+ ms_maybe_wrap_validation_error(path);
+ return NULL;
+ }
+ return out;
+}
+
static MS_INLINE PyObject *
parse_number_inline(
const unsigned char *p,
@@ -11101,6 +11117,7 @@ parse_number_inline(
TypeNode *type,
PathNode *path,
bool strict,
+ PyObject *float_hook,
bool from_str
) {
uint64_t mantissa = 0;
@@ -11286,6 +11303,9 @@ parse_number_inline(
(char *)start, p - start, true, path, NULL
);
}
+ else if (MS_UNLIKELY(float_hook != NULL && type->types & MS_TYPE_ANY)) {
+ return json_float_hook((char *)start, p - start, path, float_hook);
+ }
else {
if (MS_UNLIKELY(exponent > 288 || exponent < -307)) {
/* Exponent is out of bounds */
@@ -11363,6 +11383,7 @@ maybe_parse_number(
type,
path,
strict,
+ NULL,
true
);
return (*out != NULL || errmsg == NULL);
@@ -15403,6 +15424,7 @@ typedef struct JSONDecoderState {
/* Configuration */
TypeNode *type;
PyObject *dec_hook;
+ PyObject *float_hook;
bool strict;
/* Temporary scratch space */
@@ -15425,10 +15447,11 @@ typedef struct JSONDecoder {
TypeNode *type;
char strict;
PyObject *dec_hook;
+ PyObject *float_hook;
} JSONDecoder;
PyDoc_STRVAR(JSONDecoder__doc__,
-"Decoder(type='Any', *, strict=True, dec_hook=None)\n"
+"Decoder(type='Any', *, strict=True, dec_hook=None, float_hook=None)\n"
"--\n"
"\n"
"A JSON decoder.\n"
@@ -15449,19 +15472,28 @@ PyDoc_STRVAR(JSONDecoder__doc__,
" signature ``dec_hook(type: Type, obj: Any) -> Any``, where ``type`` is the\n"
" expected message type, and ``obj`` is the decoded representation composed\n"
" of only basic JSON types. This hook should transform ``obj`` into type\n"
-" ``type``, or raise a ``NotImplementedError`` if unsupported."
+" ``type``, or raise a ``NotImplementedError`` if unsupported.\n"
+"float_hook : callable, optional\n"
+" An optional callback for handling decoding untyped float literals. Should\n"
+" have the signature ``float_hook(val: str) -> Any``, where ``val`` is the\n"
+" raw string value of the JSON float. This hook is called to decode any\n"
+" \"untyped\" float value (e.g. ``typing.Any`` typed). The default is\n"
+" equivalent to ``float_hook=float``, where all untyped JSON floats are\n"
+" decoded as python floats. Specifying ``float_hook=decimal.Decimal``\n"
+" will decode all untyped JSON floats as decimals instead."
);
static int
JSONDecoder_init(JSONDecoder *self, PyObject *args, PyObject *kwds)
{
- char *kwlist[] = {"type", "strict", "dec_hook", NULL};
+ char *kwlist[] = {"type", "strict", "dec_hook", "float_hook", NULL};
MsgspecState *st = msgspec_get_global_state();
PyObject *type = st->typing_any;
PyObject *dec_hook = NULL;
+ PyObject *float_hook = NULL;
int strict = 1;
if (!PyArg_ParseTupleAndKeywords(
- args, kwds, "|O$pO", kwlist, &type, &strict, &dec_hook)
+ args, kwds, "|O$pOO", kwlist, &type, &strict, &dec_hook, &float_hook)
) {
return -1;
}
@@ -15479,6 +15511,19 @@ JSONDecoder_init(JSONDecoder *self, PyObject *args, PyObject *kwds)
}
self->dec_hook = dec_hook;
+ /* Handle float_hook */
+ if (float_hook == Py_None) {
+ float_hook = NULL;
+ }
+ if (float_hook != NULL) {
+ if (!PyCallable_Check(float_hook)) {
+ PyErr_SetString(PyExc_TypeError, "float_hook must be callable");
+ return -1;
+ }
+ Py_INCREF(float_hook);
+ }
+ self->float_hook = float_hook;
+
/* Handle strict */
self->strict = strict;
@@ -15498,6 +15543,7 @@ JSONDecoder_traverse(JSONDecoder *self, visitproc visit, void *arg)
if (out != 0) return out;
Py_VISIT(self->orig_type);
Py_VISIT(self->dec_hook);
+ Py_VISIT(self->float_hook);
return 0;
}
@@ -15508,6 +15554,7 @@ JSONDecoder_dealloc(JSONDecoder *self)
TypeNode_Free(self->type);
Py_XDECREF(self->orig_type);
Py_XDECREF(self->dec_hook);
+ Py_XDECREF(self->float_hook);
Py_TYPE(self)->tp_free((PyObject *)self);
}
@@ -17551,7 +17598,7 @@ json_maybe_decode_number(JSONDecoderState *self, TypeNode *type, PathNode *path)
PyObject *out = parse_number_inline(
self->input_pos, self->input_end,
&pout, &errmsg,
- type, path, self->strict, false
+ type, path, self->strict, self->float_hook, false
);
self->input_pos = (unsigned char *)pout;
@@ -18014,6 +18061,7 @@ msgspec_json_format(PyObject *self, PyObject *args, PyObject *kwargs)
/* Init decoder */
dec.dec_hook = NULL;
+ dec.float_hook = NULL;
dec.type = NULL;
dec.scratch = NULL;
dec.scratch_capacity = 0;
@@ -18095,6 +18143,7 @@ JSONDecoder_decode(JSONDecoder *self, PyObject *const *args, Py_ssize_t nargs)
.type = self->type,
.strict = self->strict,
.dec_hook = self->dec_hook,
+ .float_hook = self->float_hook,
.scratch = NULL,
.scratch_capacity = 0,
.scratch_len = 0
@@ -18161,6 +18210,7 @@ JSONDecoder_decode_lines(JSONDecoder *self, PyObject *const *args, Py_ssize_t na
.type = self->type,
.strict = self->strict,
.dec_hook = self->dec_hook,
+ .float_hook = self->float_hook,
.scratch = NULL,
.scratch_capacity = 0,
.scratch_len = 0
@@ -18237,6 +18287,7 @@ static PyMemberDef JSONDecoder_members[] = {
{"type", T_OBJECT_EX, offsetof(JSONDecoder, orig_type), READONLY, "The Decoder type"},
{"strict", T_BOOL, offsetof(JSONDecoder, strict), READONLY, "The Decoder strict setting"},
{"dec_hook", T_OBJECT, offsetof(JSONDecoder, dec_hook), READONLY, "The Decoder dec_hook"},
+ {"float_hook", T_OBJECT, offsetof(JSONDecoder, float_hook), READONLY, "The Decoder float_hook"},
{NULL},
};
@@ -18334,6 +18385,7 @@ msgspec_json_decode(PyObject *self, PyObject *const *args, Py_ssize_t nargs, PyO
JSONDecoderState state = {
.strict = strict,
.dec_hook = dec_hook,
+ .float_hook = NULL,
.scratch = NULL,
.scratch_capacity = 0,
.scratch_len = 0
diff --git a/msgspec/json.pyi b/msgspec/json.pyi
index 53f9253a..30e87a92 100644
--- a/msgspec/json.pyi
+++ b/msgspec/json.pyi
@@ -18,6 +18,7 @@ T = TypeVar("T")
enc_hook_sig = Optional[Callable[[Any], Any]]
dec_hook_sig = Optional[Callable[[type, Any], Any]]
+float_hook_sig = Optional[Callable[[str], Any]]
class Encoder:
enc_hook: enc_hook_sig
@@ -41,6 +42,7 @@ class Decoder(Generic[T]):
type: Type[T]
strict: bool
dec_hook: dec_hook_sig
+ float_hook: float_hook_sig
@overload
def __init__(
@@ -48,6 +50,7 @@ class Decoder(Generic[T]):
*,
strict: bool = True,
dec_hook: dec_hook_sig = None,
+ float_hook: float_hook_sig = None,
) -> None: ...
@overload
def __init__(
@@ -56,6 +59,7 @@ class Decoder(Generic[T]):
*,
strict: bool = True,
dec_hook: dec_hook_sig = None,
+ float_hook: float_hook_sig = None,
) -> None: ...
@overload
def __init__(
@@ -64,6 +68,7 @@ class Decoder(Generic[T]):
*,
strict: bool = True,
dec_hook: dec_hook_sig = None,
+ float_hook: float_hook_sig = None,
) -> None: ...
def decode(self, data: Union[bytes, str]) -> T: ...
def decode_lines(self, data: Union[bytes, str]) -> list[T]: ...
diff --git a/tests/basic_typing_examples.py b/tests/basic_typing_examples.py
index f560ec8d..21cd3fa4 100644
--- a/tests/basic_typing_examples.py
+++ b/tests/basic_typing_examples.py
@@ -2,6 +2,7 @@
from __future__ import annotations
import datetime
+import decimal
import pickle
from typing import Any, Dict, Final, List, Type, Union
@@ -826,6 +827,14 @@ def dec_hook(typ: Type, obj: Any) -> Any:
msgspec.json.Decoder(dec_hook=dec_hook)
+def check_json_Decoder_float_hook() -> None:
+ msgspec.json.Decoder(float_hook=None)
+ msgspec.json.Decoder(float_hook=float)
+ dec = msgspec.json.Decoder(float_hook=decimal.Decimal)
+ if dec.float_hook is not None:
+ dec.float_hook("1.5")
+
+
def check_json_Decoder_strict() -> None:
dec = msgspec.json.Decoder(List[int], strict=False)
reveal_type(dec.strict) # assert "bool" in typ
diff --git a/tests/test_json.py b/tests/test_json.py
index 7ffa0b03..898c455b 100644
--- a/tests/test_json.py
+++ b/tests/test_json.py
@@ -2,6 +2,7 @@
import base64
import datetime
+import decimal
import enum
import gc
import itertools
@@ -524,6 +525,19 @@ def test_decode_lines_bad_call(self):
with pytest.raises(TypeError):
dec.decode(1)
+ def test_decoder_init_float_hook(self):
+ dec = msgspec.json.Decoder()
+ assert dec.float_hook is None
+
+ dec = msgspec.json.Decoder(float_hook=None)
+ assert dec.float_hook is None
+
+ dec = msgspec.json.Decoder(float_hook=decimal.Decimal)
+ assert dec.float_hook is decimal.Decimal
+
+ with pytest.raises(TypeError):
+ dec = msgspec.json.Decoder(float_hook=1)
+
class TestBoolAndNone:
def test_encode_none(self):
@@ -1567,6 +1581,42 @@ def test_decode_float_err_expected_int(self, s):
):
msgspec.json.decode(s, type=int)
+ def test_float_hook_untyped(self):
+ dec = msgspec.json.Decoder(float_hook=decimal.Decimal)
+ res = dec.decode(b"1.33")
+ assert res == decimal.Decimal("1.33")
+ assert type(res) is decimal.Decimal
+
+ def test_float_hook_typed(self):
+ class Ex(msgspec.Struct):
+ a: float
+ b: decimal.Decimal
+ c: Any
+ d: Any
+
+ class MyFloat(NamedTuple):
+ x: str
+
+ dec = msgspec.json.Decoder(Ex, float_hook=MyFloat)
+ res = dec.decode(b'{"a": 1.5, "b": 1.3, "c": 1.3, "d": 123}')
+ sol = Ex(1.5, decimal.Decimal("1.3"), MyFloat("1.3"), 123)
+ assert res == sol
+
+ def test_float_hook_error(self):
+ def float_hook(val):
+ raise ValueError("Oh no!")
+
+ class Ex(msgspec.Struct):
+ a: float
+ b: Any
+
+ dec = msgspec.json.Decoder(Ex, float_hook=float_hook)
+ assert dec.decode(b'{"a": 1.5, "b": 2}') == Ex(a=1.5, b=2)
+ with pytest.raises(msgspec.ValidationError) as rec:
+ dec.decode(b'{"a": 1.5, "b": 2.5}')
+ assert "Oh no!" in str(rec.value)
+ assert "at `$.b`" in str(rec.value)
+
class TestDecimal:
"""Most decimal tests are in test_common.py, the ones here are for json