WriteFormat functionv0.1.0
pub func WriteFormat(
writer: &var TextWriter,
#Format() format: char8[..],
...
) -> ! FormatError
A placeholder is {}, or {:spec} carrying fill, alignment, sign, width, precision and style — see
ParseFormatSpec for the grammar. {{ and }} stand for a literal brace, and are the only way to write one.
The pattern is checked before any of it is written, so a pattern that is wrong produces no output rather than a
prefix of one. What is checked is the pattern and the argument count, both of which are known at the call site;
a value's own rendering can still fail partway, and what it managed to write stays written. format is marked
#Format(), so when it is a string literal the compiler counts its placeholders against the arguments and a
mismatch is reported while compiling rather than as ArgumentCountMismatch.
Reports InvalidSpecification with the byte offset into format for a specification that does not parse, a
brace the grammar does not allow, or a placeholder with no closing brace; ArgumentCountMismatch with the
placeholders counted and the arguments supplied when the two differ; and otherwise whatever the destination or
a value's own renderer reported, stopping at the first refusal. The first two are found before anything is
written.
Parameters
| Name | Type | Description |
|---|---|---|
writer | &var TextWriter | the destination |
#Format() format | char8[..] | |
... |
Returns: success when the whole pattern and every argument were accepted