class

Ameba::Rule::Performance::FlattenAfterMap

Inherits Ameba::AST::Util < YAML::Serializable < Ameba::Rule::Performance::Base < YAML::Serializable < Ameba::Rule::Base < Ameba::Config::RuleConfig < Reference < Object

This rule is used to identify usage of flatten calls that follow map.

For example, this is considered inefficient:

%w[Alice Bob].map(&.chars).flatten

And can be written as this:

%w[Alice Bob].flat_map(&.chars)

YAML configuration example:

Performance/FlattenAfterMap:
  Enabled: true

Constants

MSG = "Use `flat_map {...}` instead of `map {...}.flatten`"

Constructors

new(ctx : YAML::ParseContext, node : YAML::Nodes::Node)

This rule is used to identify usage of flatten calls that follow map.

For example, this is considered inefficient:

%w[Alice Bob].map(&.chars).flatten

And can be written as this:

%w[Alice Bob].flat_map(&.chars)

YAML configuration example:

Performance/FlattenAfterMap:
  Enabled: true

new(config = nil)

This rule is used to identify usage of flatten calls that follow map.

For example, this is considered inefficient:

%w[Alice Bob].map(&.chars).flatten

And can be written as this:

%w[Alice Bob].flat_map(&.chars)

YAML configuration example:

Performance/FlattenAfterMap:
  Enabled: true

Source

new(*, __context_for_yaml_serializable ctx : YAML::ParseContext, __node_for_yaml_serializable node : YAML::Nodes::Node)

Class methods

deprecated?

Returns true if this rule is deprecated, false otherwise.

deprecation_reason

Returns the deprecation reason for this rule, if there is any.

documentation_url

Returns the documentation URL for this rule.

Ameba::Rule::Lint::Syntax.documentation_url
# => "https://crystal-ameba.org/api/master/Ameba/Rule/Lint/Syntax.html"

parsed_doc

Returns the documentation for this rule, if there is any.

module Ameba
  # This is a test rule.
  # Does nothing.
  class Rule::MyRule < Rule::Base
    def test(source)
    end
  end
end

Ameba::Rule::MyRule.parsed_doc # => "This is a test rule.\nDoes nothing."

to_json_schema(builder : JSON::Builder) : Nil

Source

Instance methods

description

description=(description : String)

enabled=(enabled : Bool)

enabled?

excluded

excluded=(excluded : Set(String) | Nil)

severity

severity=(severity : Ameba::Severity)

since_version

Source

since_version=(since_version : String)

test(source, node : Crystal::Call)

Source

test(source)

Source