double_buffer

Builtin index · Collections & strings

result = double_buffer(initial)

Input: initial · Output: result

What it is

initial is any value.

Overloads

One call shape — this function is not overloaded.

Code	Input	Output	Description
`result = double_buffer(initial)`	`initial` —not documented yet	`result` —	Returns a `double_buffer` handle; front AND back both start equal to `initial`.

Examples

From the documentation, and run by the build -- the output and the figure below are what the engine actually produced. Simplest first.

b = double_buffer(1)
b.write(2)
print(b.read())     # 1 -- the write above is not visible yet

b.swap()
print(b.read())     # 2 -- now it is

output

1
2

from collections-strings

How it works

double_buffer(initial) (§ data structures pass, 2026-09-01, primitive. "write" on a Value::DoubleBuffer is a guarded arm further up this match (next to Value::File/ Value::Serial's own "write" arms); "double_buffer"/ "read"/"swap" have no competing meaning anywhere else.

From the note above this builtin in the interpreter, where the reasoning was written down as it was built.