Packages
credo
0.9.0
1.7.19
1.7.18
1.7.17
1.7.16
1.7.15
1.7.14
1.7.13
1.7.12
1.7.11
1.7.10
1.7.9
1.7.8
1.7.7
1.7.7-rc.0
1.7.6
1.7.5
1.7.4
1.7.3
1.7.2
1.7.2-rc.4
1.7.2-rc.3
1.7.2-rc.2
1.7.2-rc.1
1.7.2-rc.0
1.7.1
1.7.0
1.7.0-rc.2
1.7.0-rc.1
1.6.7
1.6.6
1.6.5
1.6.4
1.6.3
1.6.2
1.6.1
1.6.0
1.6.0-rc.1
1.6.0-rc.0
1.5.6
1.5.5
1.5.4
1.5.3
1.5.2
1.5.1
1.5.0
1.5.0-rc.5
1.5.0-rc.4
1.5.0-rc.3
1.5.0-rc.2
1.5.0-rc.1
1.4.1
1.4.0
1.4.0-rc.2
1.4.0-rc.1
1.3.2
1.3.1
1.3.0
1.3.0-rc3
1.3.0-rc2
1.3.0-rc1
1.2.3
1.2.2
1.2.1
1.2.0
1.2.0-rc4
1.2.0-rc3
1.2.0-rc2
1.2.0-rc1
1.1.5
1.1.4
1.1.3
1.1.2
1.1.1
1.1.0
1.1.0-rc3
1.1.0-rc2
1.1.0-rc1
1.0.5
1.0.4
1.0.3
1.0.2
1.0.1
1.0.1-rc1
1.0.0
1.0.0-rc1
0.10.2
0.10.1
0.10.0
0.9.3
0.9.2
0.9.1
0.9.0
0.9.0-rc8
0.9.0-rc7
0.9.0-rc6
0.9.0-rc5
0.9.0-rc4
0.9.0-rc3
0.9.0-rc2
0.9.0-rc1
0.8.10
0.8.9
0.8.8
0.8.7
0.8.6
0.8.5
0.8.4
0.8.3
0.8.2
0.8.1
0.8.0
0.8.0-rc7
0.8.0-rc6
0.8.0-rc5
0.8.0-rc4
0.8.0-rc3
0.8.0-rc2
0.8.0-rc1
0.7.4
0.7.3
0.7.2
0.7.1
0.7.0
0.6.1
0.6.0
0.6.0-rc2
0.6.0-rc1
0.5.3
0.5.2
0.5.1
0.5.0
0.4.14
0.4.13
0.4.12
0.4.11
0.4.10
0.4.10-dev
0.4.9
0.4.8
0.4.7
0.4.6
0.4.5
0.4.4
0.4.3
0.4.2
0.4.1
0.4.0
0.4.0-beta5
0.4.0-beta4
0.4.0-beta3
0.4.0-beta2
0.4.0-beta1
0.3.13
0.3.12
0.3.11
0.3.10
0.3.9
0.3.8
0.3.7
0.3.6
0.3.5
0.3.4
0.3.3
0.3.2
0.3.1
0.3.0
0.3.0-dev2
0.3.0-dev
0.2.6
0.2.5
0.2.4
0.2.3
0.2.2
0.2.1
0.2.0
0.1.10
0.1.9
0.1.8
0.1.7
0.1.6
0.1.5
0.1.4
0.1.3
0.1.2
0.1.1
0.1.0
0.0.1-dev
A static code analysis tool with a focus on code consistency and teaching.
Current section
Files
Jump to
Current section
Files
lib/credo/check/readability/large_numbers.ex
defmodule Credo.Check.Readability.LargeNumbers do
@moduledoc """
Numbers can contain underscores for readability purposes.
These do not affect the value of the number, but can help read large numbers
more easily.
141592654 # how large is this number?
141_592_654 # ah, it's in the hundreds of millions!
Like all `Readability` issues, this one is not a technical concern.
But you can improve the odds of others reading and liking your code by making
it easier to follow.
"""
@explanation [
check: @moduledoc,
params: [
only_greater_than: "The check only reports numbers greater than this."
]
]
@default_params [
only_greater_than: 9_999
]
use Credo.Check, base_priority: :high
@doc false
def run(source_file, params \\ []) do
issue_meta = IssueMeta.for(source_file, params)
min_number = Params.get(params, :only_greater_than, @default_params)
source_file
|> Credo.Code.to_tokens()
|> collect_number_tokens([], min_number)
|> find_issues([], issue_meta)
end
defp collect_number_tokens([], acc, _), do: acc
defp collect_number_tokens([head | t], acc, min_number) do
acc =
case number_token(head, min_number) do
nil -> acc
false -> acc
token -> acc ++ [token]
end
collect_number_tokens(t, acc, min_number)
end
# tuple for Elixir >= 1.6.0
defp number_token({:int, {_, _, number}, _} = tuple, min_number)
when min_number < number do
tuple
end
defp number_token({:float, {_, _, number}, _} = tuple, min_number)
when min_number < number do
tuple
end
# tuple for Elixir <= 1.5.x
defp number_token({:number, _, number} = tuple, min_number)
when min_number < number do
tuple
end
defp number_token(_, _), do: nil
defp find_issues([], acc, _issue_meta) do
acc
end
# tuple for Elixir >= 1.6.0
defp find_issues(
[{:int, {line_no, column1, number} = location, _} | t],
acc,
issue_meta
) do
acc = acc ++ find_issue(line_no, column1, location, number, issue_meta)
find_issues(t, acc, issue_meta)
end
defp find_issues(
[{:float, {line_no, column1, number} = location, _} | t],
acc,
issue_meta
) do
acc = acc ++ find_issue(line_no, column1, location, number, issue_meta)
find_issues(t, acc, issue_meta)
end
# tuple for Elixir <= 1.5.x
defp find_issues(
[{:number, {line_no, column1, _column2} = location, number} | t],
acc,
issue_meta
) do
acc = acc ++ find_issue(line_no, column1, location, number, issue_meta)
find_issues(t, acc, issue_meta)
end
defp find_issue(line_no, column1, location, number, issue_meta) do
source = source_fragment(location, issue_meta)
underscored_number = number_with_underscores(number, source)
if decimal_in_source?(source) && source != underscored_number do
[
issue_for(
issue_meta,
line_no,
column1,
source,
underscored_number
)
]
else
[]
end
end
defp number_with_underscores(number, _) when is_integer(number) do
number
|> to_string
|> add_underscores_to_number_string
end
defp number_with_underscores(number, source_fragment)
when is_number(number) do
case String.split(source_fragment, ".", parts: 2) do
[num, decimal] ->
Enum.join([add_underscores_to_number_string(num), decimal], ".")
[num] ->
add_underscores_to_number_string(num)
end
end
defp add_underscores_to_number_string(string) do
string
|> String.reverse()
|> String.replace(~r/(\d{3})(?=\d)/, "\\1_")
|> String.reverse()
end
def issue_for(issue_meta, line_no, column, trigger, expected) do
format_issue(
issue_meta,
message: "Large numbers should be written with underscores: #{expected}",
line_no: line_no,
column: column,
trigger: trigger
)
end
defp decimal_in_source?(source) do
case String.slice(source, 0, 2) do
"0b" -> false
"0o" -> false
"0x" -> false
"" -> false
_ -> true
end
end
defp source_fragment({line_no, column1, _}, issue_meta) do
line =
issue_meta
|> IssueMeta.source_file()
|> SourceFile.line_at(line_no)
beginning_of_number =
Regex.run(~r/[^0-9_oxb]*([0-9_oxb]+$)/, String.slice(line, 1..column1))
|> List.wrap()
|> List.last()
|> to_string()
ending_of_number =
Regex.run(~r/^([0-9_\.]+)/, String.slice(line, (column1 + 1)..-1))
|> List.wrap()
|> List.last()
|> to_string()
|> String.replace(~r/\.\..+/, "")
beginning_of_number <> ending_of_number
end
end