Skip to main content

/

Docs

Nightly
v24.5
Log in

Mojo struct

Formatter

A Formatter is used by types implementing the Formattable trait to write bytes to the underlying formatter output buffer or stream.

Implemented traits​

AnyType

Methods​

__init__​

__init__[F: ToFormatter](inout self: Self, inout output: F)

Construct a new Formatter from a value implementing ToFormatter.

Parameters:

  • ​F (ToFormatter): The type that supports being used to back a Formatter.

Args:

  • ​output (F): Value to accumulate or process output streamed to the Formatter.

__init__(inout self: Self, *, fd: FileDescriptor)

Constructs a Formatter that writes to the given file descriptor.

Args:

  • ​fd (FileDescriptor): The file descriptor to write to.

__init__(inout self: Self, func: fn(UnsafePointer[NoneType, 0, 0, alignof[::AnyType,__mlir_type.!kgen.target]() if triple_is_nvidia_cuda() else 1], StringRef) -> None, arg: UnsafePointer[NoneType, 0, 0, alignof[::AnyType,__mlir_type.!kgen.target]() if triple_is_nvidia_cuda() else 1])

Constructs a formatter from any closure that accepts StringRefs.

This function should only be used by low-level types that wish to accept streamed formatted data.

Args:

  • ​func (fn(UnsafePointer[NoneType, 0, 0, alignof[::AnyType,__mlir_type.!kgen.target]() if triple_is_nvidia_cuda() else 1], StringRef) -> None): Raw closure function pointer.
  • ​arg (UnsafePointer[NoneType, 0, 0, alignof[::AnyType,__mlir_type.!kgen.target]() if triple_is_nvidia_cuda() else 1]): Opaque user data argument that is passed to the closure function pointer.

__moveinit__​

__moveinit__(inout self: Self, owned other: Self)

Move this value.

Args:

  • ​other (Self): The value to move.

write_str​

write_str(inout self: Self, str_slice: StringSlice[is_mutable, lifetime])

Write a string slice to this formatter.

Args:

  • ​str_slice (StringSlice[is_mutable, lifetime]): The string slice to write to this formatter. Must NOT be null terminated.

write​

write[*Ts: Formattable](inout self: Self, *args: *Ts)

Write a sequence of formattable arguments to the provided formatter.

Parameters:

  • ​*Ts (Formattable): Types of the provided argument sequence.

Args:

  • ​*args (*Ts): Sequence of arguments to write to this formatter.

stdout​

static stdout() -> Self

Constructs a formatter that writes directly to stdout.

Returns:

A formatter that writes provided data to the operating system standard output stream.