fix-getters-rules 0.3.0

Fix get functions name by removing the get prefix when applicable
Documentation

fix-getters-rules

This package contains rules definitions for the fix-getters tools.

See the workspace documentation for more details on fix-getters.

Rules

The rules apply to:

  • file system directory entries to decide if a file should be processed or if a directory branch should be skipped. This requires feature dir-entry (enabled by default).
  • functions name.

Features

  • dir-entry — directory entry filtering rules. This features is enabled by default. Use default-features = false if your use case differs.

Function name rules

The initial intent is to comply with Rust naming conventions for getter methods:

A method foo(&self) -> &T for getting the current value of the field.

General rules

These rules are based on the function name and knowledge of the return type. See next chapter for get functions returning exactly one bool.

A get function is considered eligible for get prefix removal if:

  • The function starts with get_.

  • The suffix is not a Rust keyword, which would result in invalid code.

    E.g.: get_as, get_false, ... are kept as is.

  • The method would result inconsistent with other similar methods.

    E.g.: a struct Value with a get_mut method to get the underlying value as a mutable reference, get_optional to get the underlying value of a type in the form Option<T> and get_some to get the underlying value of a type for which the value is always defined.

See RESERVED in function.rs.

  • The suffix is not part of a subsitution list. This includes some Rust keywords.

    E.g.: get_type is replaced with type_.

See EXACT_SUFFIX_SUBSTITUTES in function.rs.

Another rule is applied to homogenize functions names in the form get_something_mut. This rule renames both get_something_mut and get_mut_something as something_mut.

The fix-getters tools also apply selective rules based on on the function signature. See the dedicated chapter in this README.

Functions returning exactly one bool

Get functions returning bool should usually use the form is_suffix, which when used in a condition reads natural: if event.is_serialized().

The following addtional rules are implemented.

First token substitutions

When the suffix starts with a verb, it's common to conjugate. E.g. for get_emit_eos: if element.emits_eos().

BOOL_FIRST_TOKEN_SUBSTITUTES in function.rs lists a set of verbs and the matching substitutions and also includes other cases such as:

  • get_always_... -> must_always_....
  • get_focus -> gets_focus.

Special first tokens

Modal verbs should be kept unchanged and no is prefix should be used. E.g.:

  • get_can_focus -> can_focus.
  • get_must_... -> must_....

This is also the case for already conjugated verbs. E.g.:

  • get_has_... -> has_....

See BOOL_FIRST_TOKEN_NO_PREFIX in function.rs.

Exact suffix substitutions

In some cases, the semantic requires substitutions only if the whole suffix matches a value. E.g.:

  • get_result -> result. Neither if a.is_result() nor if a.results() would be suitable.
  • get_visibility -> is_visible Neither if a.is_visibility() nor if a.visibility()) would be suitable.

See BOOL_EXACT_SUBSTITUTES in function.rs.

get_is prefix

Finally, the is prefix shouldn't be repeated when already present:

  • get_is_active -> is_active.

Detecting functions returning exactly one bool

The return type of Rust functions is usually not explicit. When renaming the get functions call sites (see fix-getters-calls), the returned type must be inferred. The rules described in previous chapter are reversed when possible and an additional heuristic is used: when the first token of the get function suffix ends in able, the function is considered as returning a bool. E.g.:

  • get_seekable -> is_seekable.

ReturnsBool is used to indicate the renaming functions current knowledge about whether the name corresponds to a function which returns exactly one bool. If this is unknown (e.g. when renaming get functions call sites), the user can pass ReturnsBool::Maybe.

LICENSE

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