class Ameba::Rule::Performance::ExcessiveAllocations

Overview

This rule is used to identify excessive collection allocations, that can be avoided by using each_<member> instead of <collection>.each.

For example, this is considered inefficient:

"Alice".chars.each { |c| puts c }
"Alice\nBob".lines.each { |l| puts l }

And can be written as this:

"Alice".each_char { |c| puts c }
"Alice\nBob".each_line { |l| puts l }

YAML configuration example:

Performance/ExcessiveAllocations:
  Enabled: true
  CallNames:
    codepoints: each_codepoint
    graphemes: each_grapheme
    chars: each_char
    lines: each_line

Included Modules

Defined in:

ameba/rule/performance/excessive_allocations.cr

Constant Summary

MSG = "Use `%s {...}` instead of `%s.each {...}` to avoid excessive allocation"

Constructors

Class Method Summary

Instance Method Summary

Instance methods inherited from module Ameba::AST::Util

abort?(node) abort?, control_exp_code(node : Crystal::ControlExpression, code_lines) control_exp_code, dynamic_literal?(node) : Bool dynamic_literal?, each_inline_directive(source, &block : Crystal::Token, String, Array(String) -> _) each_inline_directive, exit?(node) exit?, flow_command?(node, in_loop) flow_command?, flow_expression?(node, in_loop = false) flow_expression?, has_arguments?(node) : Bool has_arguments?, has_block?(node) : Bool has_block?, has_short_block?(node, code_lines) has_short_block?, heredoc?(node : Crystal::ASTNode, source : Source) heredoc?, literal?(node) : Bool literal?, loop?(node) loop?, name_end_location(node) name_end_location, name_location(node) name_location, name_location_or(token : Crystal::Token, name, *, adjust_location_column_number = nil)
name_location_or(node : Crystal::ASTNode, *, adjust_location_column_number = nil) name_location_or, name_size(node) name_size, node_source(node, code_lines) node_source, nodoc?(node) nodoc?, operator_method?(node) operator_method?, operator_method_name?(name : String) operator_method_name?, path_name(node : Crystal::Path, *, include_global = true) : String path_name, path_named?(node, *names : String) : Bool path_named?, raise?(node) raise?, setter_method?(node) setter_method?, setter_method_name?(name : String) setter_method_name?, short_block?(node, code_lines) short_block?, source_between(loc, end_loc, code_lines) : String | Nil source_between, static_literal?(node) : Bool static_literal?, suffix?(node) suffix?, takes_arguments?(node) : Bool takes_arguments?

Instance methods inherited from class Ameba::Rule::Performance::Base

catch(source : Source) catch

Constructor methods inherited from class Ameba::Rule::Performance::Base

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

Class methods inherited from class Ameba::Rule::Performance::Base

deprecated? deprecated?, deprecation_reason : String | Nil deprecation_reason, documentation_url : String documentation_url, parsed_doc : String | Nil parsed_doc

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

==(other : self) ==, catch(source : Source) catch, excluded?(source, root = Dir.current) excluded?, group group, hash(hasher) hash, name name, special? special?, test(source : Source, node : Crystal::ASTNode, *opts)
test(source : Source) test

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

default_severity : Ameba::Severity default_severity, group_name group_name, rule_name rule_name

Macros inherited from class Ameba::Rule::Base

issue_for(*args, **kwargs, &block) issue_for

Macros inherited from module Ameba::Config::RuleConfig

properties(&block) properties

Constructor Detail

def self.new(ctx : YAML::ParseContext, node : YAML::Nodes::Node) #

This rule is used to identify excessive collection allocations, that can be avoided by using each_<member> instead of <collection>.each.

For example, this is considered inefficient:

"Alice".chars.each { |c| puts c }
"Alice\nBob".lines.each { |l| puts l }

And can be written as this:

"Alice".each_char { |c| puts c }
"Alice\nBob".each_line { |l| puts l }

YAML configuration example:

Performance/ExcessiveAllocations:
  Enabled: true
  CallNames:
    codepoints: each_codepoint
    graphemes: each_grapheme
    chars: each_char
    lines: each_line

def self.new(config = nil) #

This rule is used to identify excessive collection allocations, that can be avoided by using each_<member> instead of <collection>.each.

For example, this is considered inefficient:

"Alice".chars.each { |c| puts c }
"Alice\nBob".lines.each { |l| puts l }

And can be written as this:

"Alice".each_char { |c| puts c }
"Alice\nBob".each_line { |l| puts l }

YAML configuration example:

Performance/ExcessiveAllocations:
  Enabled: true
  CallNames:
    codepoints: each_codepoint
    graphemes: each_grapheme
    chars: each_char
    lines: each_line

def self.new(*, __context_for_yaml_serializable ctx : YAML::ParseContext, __node_for_yaml_serializable node : YAML::Nodes::Node) #

Class Method Detail

def self.deprecated? #

Returns true if this rule is deprecated, false otherwise.


def self.deprecation_reason : String | Nil #

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


def self.documentation_url : String #

Returns the documentation URL for this rule.

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

def self.parsed_doc : String | Nil #

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."

def self.to_json_schema(builder : JSON::Builder) : Nil #

Instance Method Detail

def call_names : Hash(String, String) #

def call_names=(call_names : Hash(String, String)) #

def description : String #

def description=(description : String) #

def enabled=(enabled : Bool) #

def enabled? : Bool #

def excluded : Set(String) | Nil #

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

def severity : Ameba::Severity #

def severity=(severity : Ameba::Severity) #

def since_version : SemanticVersion | Nil #

def since_version=(since_version : String) #

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

def test(source) #