Alignment vs Hanging Indent

Two indentation styles when wrapping:

Aligned (column-based):

result = some_function(arg1,
                       arg2,
                       arg3)

After (: indent to column 23. All wrapped lines align there.

Hanging (block-based):

result = some_function(
    arg1,
    arg2,
    arg3,
)

Open ( at end of line; body indented one block; close ) on its own line.

Trade-offs:

• Aligned: visually clean. But editing function name shifts alignment → noisy diff.
• Hanging: less aligned but stable across edits.

Modern formatters favor hanging. Black, prettier, rustfmt all use hanging by default.

In Doc algebra:

• align(d): indent contents to current column.
• nest(i, d): indent contents by i more than parent.

Aligned wraps:

Hanging wraps:

The group decides: try one-line; if not, break + use the nested layout.

Which to use? Per-language style guide:

• Python (PEP 8): allows either; black picks hanging.
• Go: gofmt's choice (different per construct).
• C++: clang-format configurable.
• Lisp: aligned (parens are sacred).

Reformatting from aligned to hanging or vice versa is mechanical; AST-based formatters handle it trivially.