Module completion 

Implements programmable command completion support.

There are two ways in:

• Shell::complete completes a line at a cursor, as interactive completion does.
• Spec::generate generates a spec’s candidates for a word on its own, as the compgen builtin does.

Completing a line follows bash and readline:

1. The word to complete (the text candidates replace, and a completion function’s $2) and the words of COMP_WORDS are found separately, and needn’t agree: after --opt=, the word to complete is empty, while COMP_WORDS ends with =.
2. The spec to use is looked up: complete -E if there’s nothing before the cursor (and it isn’t at the start of a word), -I for the initial word, else the command’s, else -D. It’s looked up again each time a completion function asks for completion to restart, so specs it registered are used.
3. The spec generates candidates with a completion in progress on the shell, so compopt can change its options. With no spec, basic completion completes variables, file names, and commands.

Structs

CompleteActionIter

An iterator over the variants of CompleteAction

CompleteOptionIter

An iterator over the variants of CompleteOption

Completions

Represents a set of generated command completions.

Config

Encapsulates the shell’s programmable command completion configuration.

FallbackOptions

Options for fallback completions.

GenerationOptions

Options for generating completions: which CompleteOptions are enabled.

ProcessingOptions

Options governing how command completion candidates are processed after being generated.

Spec

Encapsulates a command completion specification; provides policy for how to generate completions for a given input.

SpecialSpecIter

An iterator over the variants of SpecialSpec

Enums

CompleteAction

Type of action to take to generate completion candidates. Each one’s name (e.g. arrayvar) is what complete -A takes.

CompleteOption

Options influencing how command completions are generated. Each one’s name (e.g. nospace) is what complete -o takes; they’re declared in the order bash lists them.

SpecName

Names a completion spec in a Config.

SpecialSpec

A completion spec used in place of a command’s.