Docs: move type conversion functions to source (2/3) #87046
Conversation
|
Workflow [PR], commit [37e4e6c] Summary: ❌
|
…o type_conversion_functions_2
| factory.registerFunction<FunctionReinterpret>(); | ||
| FunctionDocumentation::Description description_reinterpretAsUInt8 = R"( | ||
| Performs byte reinterpretation by treating the input value as a value of type UInt8. | ||
| Unlike [`CAST`](#cast), the function does not attempt to preserve the original value - if the target type is not able to represent the input type, the output is meaningless. |
|
|
||
| factory.registerFunction<FunctionReinterpret>(); | ||
| FunctionDocumentation::Description description_reinterpretAsUInt8 = R"( | ||
| Performs byte reinterpretation by treating the input value as a value of type UInt8. |
There was a problem hiding this comment.
Simpler: Reinterprets the input value as a value of type UInt8.
In l. 544: Value to reinterpret as UInt8.
Please apply the same kind of changes also for the other functions in this file.
| "Usage example", | ||
| R"( | ||
| SELECT | ||
| toInt8(257) AS x, |
There was a problem hiding this comment.
Strange example. toInt8(257) produces an internal overflow.
Can we do this (basically the same example as in docs of function CAST):
SELECT
toInt8(-1) AS val,
toTypeName(val),
reinterpretAsUInt8(val) AS res,
toTypeName(res);?
There will still be an overflow but during re-interpretation as UInt8 ... which is what the description above warns about.
| factory.registerFunction<FunctionReinterpretAsFloat64>(documentation_reinterpretAsFloat64); | ||
|
|
||
| FunctionDocumentation::Description description_reinterpretAsDate = R"( | ||
| Accepts a string, fixed string or numeric value and interprets the bytes as a number in host order (little endian). It returns a date from the interpreted number as the number of days since the beginning of the Unix Epoch. |
There was a problem hiding this comment.
Just: Reinterprets the input value as a Date value (assuming little endian order) which is the number of days since the beginning of the Unix epoch 1970-01-01.
| factory.registerFunction<FunctionReinterpretAsDate>(documentation_reinterpretAsDate); | ||
|
|
||
| FunctionDocumentation::Description description_reinterpretAsDateTime = R"( | ||
| These functions accept a string and interpret the bytes placed at the beginning of the string as a number in host order (little endian). Returns a date with time interpreted as the number of seconds since the beginning of the Unix Epoch. |
| factory.registerFunction<FunctionReinterpretAsUUID>(documentation_reinterpretAsUUID); | ||
|
|
||
| FunctionDocumentation::Description description_reinterpretAsString = R"( | ||
| This function accepts a number, date or date with time and returns a string containing bytes representing the corresponding value in host order (little endian). Null bytes are dropped from the end. For example, a UInt32 type value of 255 is a string that is one byte long. |
There was a problem hiding this comment.
Reinterprets the input value as a string (assuming little endian order). Null bytes at the end are ignored, for example, the function returns for UInt32 value 255 a string with a single character.
Splits #86839.
Moves type conversion functions docs into the source code. Part 2/3.
Changelog category (leave one):
Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):
...
Documentation entry for user-facing changes