[Qemu-devel] [PATCH] qobject: Explain how QNum works, and why

[Qemu-devel] [PATCH] qobject: Explain how QNum works, and why

[Markus Armbruster]

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 include/qapi/qmp/qnum.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/include/qapi/qmp/qnum.h b/include/qapi/qmp/qnum.h
index 09d745c..9182129 100644
--- a/include/qapi/qmp/qnum.h
+++ b/include/qapi/qmp/qnum.h
@@ -23,6 +23,27 @@ typedef enum {
     QNUM_DOUBLE
 } QNumKind;
 
+/*
+ * QNum encapsulates how our dialect of JSON fills in the blanks left
+ * by the JSON specification (RFC 7159) regarding numbers.
+ *
+ * Conceptually, we treat number as an abstract type with three
+ * concrete subtypes: floating-point, signed integer, unsigned
+ * integer.  QNum implements this a discriminated union of double,
+ * int64_t, uint64_t.
+ *
+ * The JSON parser picks the subtype as follows.  If the number has a
+ * decimal point or an exponent, it is floating-point.  Else if it
+ * fits into int64_t, it's signed integer.  Else if it first into
+ * uint64_t, it's unsigned integer.  Else it's floating-point.
+ *
+ * Any number can serve as double: qnum_get_double() converts under
+ * the hood.
+ *
+ * An integer can serve as signed / unsigned integer as long as it is
+ * in range: qnum_get_try_int() / qnum_get_try_uint() check range and
+ * convert under the hood.
+ */
 typedef struct QNum {
     QObject base;
     QNumKind kind;
-- 
2.7.5

Re: [Qemu-devel] [PATCH] qobject: Explain how QNum works, and why

[Marc-André Lureau]

----- Original Message -----
> Suggested-by: Max Reitz <mreitz@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>


> ---
>  include/qapi/qmp/qnum.h | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/include/qapi/qmp/qnum.h b/include/qapi/qmp/qnum.h
> index 09d745c..9182129 100644
> --- a/include/qapi/qmp/qnum.h
> +++ b/include/qapi/qmp/qnum.h
> @@ -23,6 +23,27 @@ typedef enum {
>      QNUM_DOUBLE
>  } QNumKind;
>  
> +/*
> + * QNum encapsulates how our dialect of JSON fills in the blanks left
> + * by the JSON specification (RFC 7159) regarding numbers.
> + *
> + * Conceptually, we treat number as an abstract type with three
> + * concrete subtypes: floating-point, signed integer, unsigned
> + * integer.  QNum implements this a discriminated union of double,
> + * int64_t, uint64_t.
> + *
> + * The JSON parser picks the subtype as follows.  If the number has a
> + * decimal point or an exponent, it is floating-point.  Else if it
> + * fits into int64_t, it's signed integer.  Else if it first into
> + * uint64_t, it's unsigned integer.  Else it's floating-point.
> + *
> + * Any number can serve as double: qnum_get_double() converts under
> + * the hood.
> + *
> + * An integer can serve as signed / unsigned integer as long as it is
> + * in range: qnum_get_try_int() / qnum_get_try_uint() check range and
> + * convert under the hood.
> + */
>  typedef struct QNum {
>      QObject base;
>      QNumKind kind;
> --
> 2.7.5
> 
> 

Re: [Qemu-devel] [PATCH] qobject: Explain how QNum works, and why

[Max Reitz]

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On 2017-08-22 08:52, Markus Armbruster wrote:
> Suggested-by: Max Reitz <mreitz@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  include/qapi/qmp/qnum.h | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)

Thanks again!

Reviewed-by: Max Reitz <mreitz@redhat.com>


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Re: [Qemu-devel] [PATCH] qobject: Explain how QNum works, and why

[Eric Blake]

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On 08/22/2017 01:52 AM, Markus Armbruster wrote:
> Suggested-by: Max Reitz <mreitz@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  include/qapi/qmp/qnum.h | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/include/qapi/qmp/qnum.h b/include/qapi/qmp/qnum.h
> index 09d745c..9182129 100644
> --- a/include/qapi/qmp/qnum.h
> +++ b/include/qapi/qmp/qnum.h
> @@ -23,6 +23,27 @@ typedef enum {
>      QNUM_DOUBLE
>  } QNumKind;
>  
> +/*
> + * QNum encapsulates how our dialect of JSON fills in the blanks left
> + * by the JSON specification (RFC 7159) regarding numbers.
> + *
> + * Conceptually, we treat number as an abstract type with three
> + * concrete subtypes: floating-point, signed integer, unsigned
> + * integer.  QNum implements this a discriminated union of double,

s/this/this as/

> + * int64_t, uint64_t.
> + *
> + * The JSON parser picks the subtype as follows.  If the number has a
> + * decimal point or an exponent, it is floating-point.  Else if it
> + * fits into int64_t, it's signed integer.  Else if it first into

s/first/fits/

> + * uint64_t, it's unsigned integer.  Else it's floating-point.
> + *
> + * Any number can serve as double: qnum_get_double() converts under
> + * the hood.
> + *
> + * An integer can serve as signed / unsigned integer as long as it is
> + * in range: qnum_get_try_int() / qnum_get_try_uint() check range and
> + * convert under the hood.
> + */
>  typedef struct QNum {
>      QObject base;
>      QNumKind kind;
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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Re: [Qemu-devel] [PATCH] qobject: Explain how QNum works, and why

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> On 08/22/2017 01:52 AM, Markus Armbruster wrote:
>> Suggested-by: Max Reitz <mreitz@redhat.com>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>  include/qapi/qmp/qnum.h | 21 +++++++++++++++++++++
>>  1 file changed, 21 insertions(+)
>> 
>> diff --git a/include/qapi/qmp/qnum.h b/include/qapi/qmp/qnum.h
>> index 09d745c..9182129 100644
>> --- a/include/qapi/qmp/qnum.h
>> +++ b/include/qapi/qmp/qnum.h
>> @@ -23,6 +23,27 @@ typedef enum {
>>      QNUM_DOUBLE
>>  } QNumKind;
>>  
>> +/*
>> + * QNum encapsulates how our dialect of JSON fills in the blanks left
>> + * by the JSON specification (RFC 7159) regarding numbers.
>> + *
>> + * Conceptually, we treat number as an abstract type with three
>> + * concrete subtypes: floating-point, signed integer, unsigned
>> + * integer.  QNum implements this a discriminated union of double,
>
> s/this/this as/
>
>> + * int64_t, uint64_t.
>> + *
>> + * The JSON parser picks the subtype as follows.  If the number has a
>> + * decimal point or an exponent, it is floating-point.  Else if it
>> + * fits into int64_t, it's signed integer.  Else if it first into
>
> s/first/fits/
>
>> + * uint64_t, it's unsigned integer.  Else it's floating-point.
>> + *
>> + * Any number can serve as double: qnum_get_double() converts under
>> + * the hood.
>> + *
>> + * An integer can serve as signed / unsigned integer as long as it is
>> + * in range: qnum_get_try_int() / qnum_get_try_uint() check range and
>> + * convert under the hood.
>> + */
>>  typedef struct QNum {
>>      QObject base;
>>      QNumKind kind;
>> 

Fixed.  Thanks!