Module rustfmt_nightly::chains

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Expand description

Formatting of chained expressions, i.e., expressions that are chained by dots: struct and enum field access, method calls, and try shorthand (?).

Instead of walking these subexpressions one-by-one, as is our usual strategy for expression formatting, we collect maximal sequences of these expressions and handle them simultaneously.

Whenever possible, the entire chain is put on a single line. If that fails, we put each subexpression on a separate, much like the (default) function argument function argument strategy.

Depends on config options: chain_indent is the indent to use for blocks in the parent/root/base of the chain (and the rest of the chain’s alignment). E.g., let foo = { aaaa; bbb; ccc }.bar.baz();, we would layout for the following values of chain_indent: Block:

let foo = {
    aaaa;
    bbb;
    ccc
}.bar
    .baz();

Visual:

let foo = {
              aaaa;
              bbb;
              ccc
          }
          .bar
          .baz();

If the first item in the chain is a block expression, we align the dots with the braces. Block:

let a = foo.bar
    .baz()
    .qux

Visual:

let a = foo.bar
           .baz()
           .qux

Structs

Enums

Traits

Functions