struct Ameba::Rule::Performance::FirstLastAfterFilter

Overview

This rule is used to identify usage of first/last/first?/last? calls that follow filters.

For example, this is considered inefficient:

[-1, 0, 1, 2].select { |e| e > 0 }.first?
[-1, 0, 1, 2].select { |e| e > 0 }.last?

And can be written as this:

[-1, 0, 1, 2].find { |e| e > 0 }
[-1, 0, 1, 2].reverse_each.find { |e| e > 0 }

YAML configuration example:

Performance/FirstLastAfterFilter
  Enabled: true
  FilterNames:
    - select

Defined in:

ameba/rule/performance/first_last_after_filter.cr

Constant Summary

CALL_NAMES = ["first", "last", "first?", "last?"] of ::String
MSG = "Use `find {...}` instead of `%s {...}.%s`"
MSG_REVERSE = "Use `reverse_each.find {...}` instead of `%s {...}.%s`"

Constructors

Instance Method Summary

Instance methods inherited from struct Ameba::Rule::Base

==(other) ==, catch(source : Source) catch, excluded?(source) excluded?, group group, hash hash, initialize initialize, name name, special? special?, test(source : Source, node : Crystal::ASTNode, *opts)
test(source : Source) test

Constructor methods inherited from struct Ameba::Rule::Base

new new

Class methods inherited from struct Ameba::Rule::Base

parsed_doc parsed_doc

Macros inherited from struct Ameba::Rule::Base

issue_for(*args) issue_for

Macros inherited from module Ameba::Config::RuleConfig

properties(&block) properties

Constructor Detail

def self.new(config = nil) #

This rule is used to identify usage of first/last/first?/last? calls that follow filters.

For example, this is considered inefficient:

[-1, 0, 1, 2].select { |e| e > 0 }.first?
[-1, 0, 1, 2].select { |e| e > 0 }.last?

And can be written as this:

[-1, 0, 1, 2].find { |e| e > 0 }
[-1, 0, 1, 2].reverse_each.find { |e| e > 0 }

YAML configuration example:

Performance/FirstLastAfterFilter
  Enabled: true
  FilterNames:
    - select

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Instance Method Detail

def test(source, node : Crystal::Call) #

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def test(source) #

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