| 1 | /* |
| 2 | * QNum Module |
| 3 | * |
| 4 | * Copyright (C) 2009 Red Hat Inc. |
| 5 | * |
| 6 | * Authors: |
| 7 | * Luiz Capitulino <lcapitulino@redhat.com> |
| 8 | * Anthony Liguori <aliguori@us.ibm.com> |
| 9 | * Marc-André Lureau <marcandre.lureau@redhat.com> |
| 10 | * |
| 11 | * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. |
| 12 | * See the COPYING.LIB file in the top-level directory. |
| 13 | */ |
| 14 | |
| 15 | #ifndef QNUM_H |
| 16 | #define QNUM_H |
| 17 | |
| 18 | #include "qobject/qobject.h" |
| 19 | |
| 20 | typedef enum { |
| 21 | QNUM_I64, |
| 22 | QNUM_U64, |
| 23 | QNUM_DOUBLE |
| 24 | } QNumKind; |
| 25 | |
| 26 | /* |
| 27 | * QNum encapsulates how our dialect of JSON fills in the blanks left |
| 28 | * by the JSON specification (RFC 8259) regarding numbers. |
| 29 | * |
| 30 | * Conceptually, we treat number as an abstract type with three |
| 31 | * concrete subtypes: floating-point, signed integer, unsigned |
| 32 | * integer. QNum implements this as a discriminated union of double, |
| 33 | * int64_t, uint64_t. |
| 34 | * |
| 35 | * The JSON parser picks the subtype as follows. If the number has a |
| 36 | * decimal point or an exponent, it is floating-point. Else if it |
| 37 | * fits into int64_t, it's signed integer. Else if it fits into |
| 38 | * uint64_t, it's unsigned integer. Else it's floating-point. |
| 39 | * |
| 40 | * Any number can serve as double: qnum_get_double() converts under |
| 41 | * the hood. |
| 42 | * |
| 43 | * An integer can serve as signed / unsigned integer as long as it is |
| 44 | * in range: qnum_get_try_int() / qnum_get_try_uint() check range and |
| 45 | * convert under the hood. |
| 46 | */ |
| 47 | struct QNum { |
| 48 | struct QObjectBase_ base; |
| 49 | QNumKind kind; |
| 50 | union { |
| 51 | int64_t i64; |
| 52 | uint64_t u64; |
| 53 | double dbl; |
| 54 | } u; |
| 55 | }; |
| 56 | |
| 57 | void qnum_unref(QNum *q); |
| 58 | |
| 59 | G_DEFINE_AUTOPTR_CLEANUP_FUNC(QNum, qnum_unref) |
| 60 | |
| 61 | QNum *qnum_from_int(int64_t value); |
| 62 | QNum *qnum_from_uint(uint64_t value); |
| 63 | QNum *qnum_from_double(double value); |
| 64 | |
| 65 | bool qnum_get_try_int(const QNum *qn, int64_t *val); |
| 66 | int64_t qnum_get_int(const QNum *qn); |
| 67 | |
| 68 | bool qnum_get_try_uint(const QNum *qn, uint64_t *val); |
| 69 | uint64_t qnum_get_uint(const QNum *qn); |
| 70 | |
| 71 | double qnum_get_double(QNum *qn); |
| 72 | |
| 73 | char *qnum_to_string(QNum *qn); |
| 74 | |
| 75 | #endif /* QNUM_H */ |