# Max source line length
**URL:** https://discourse.julialang.org/t/max-source-line-length/4883
**Category:** General Usage
**Tags:** question
**Created:** [July 16, 2017, 2:49pm UTC](https://discourse.julialang.org/t/max-source-line-length/4883 "2017-07-16T14:49:01Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [July 16, 2017, 2:49pm UTC](https://discourse.julialang.org/t/max-source-line-length/4883/1 "2017-07-16T14:49:01Z")
Is there a recommended max line length for source code in Julia? I know it is up to personal preference to a large extent, but I am wondering if there is a reasonable default.
The [page on documentation](https://docs.julialang.org/en/latest/manual/documentation/#Documentation-1) recommends 92, but that’s for docstrings.
[JuliaPraxis/Spacing](https://github.com/JuliaPraxis/Spacing) does not give a specific number, just recommends
> Prefer to split a long line after =, , ||, &&. or (.
This page by John Myles White [recommends 80](https://github.com/johnmyleswhite/Style.jl).
[CONTRIBUTING.md](https://github.com/JuliaLang/julia/blob/master/CONTRIBUTING.md#general-formatting-guidelines-for-julia-code-contributions) recommends 92.
Running the following snippet
```julia
## count line lengths
dir = "$JULIA_HOME/$(Base.DATAROOTDIR)/julia/base"
dict = Dict{Int,Int}()
for (root, _, files) = walkdir(dir)
for file in files
filename = joinpath(root, file)
_, ext = splitext(filename)
if ext == ".jl"
for line in readlines(filename)
len = length(line)
dict[len] = get(dict, len, 0) + 1
end
end
end
end
sort(collect(filter((l, _) -> 80 ≤ l ≤ 120, dict)), by = first)
```
suggests that 92 is not that strictly adhered to: after 92, the frequency drops to about 2/3, something like
```julia
88=>473
89=>541
90=>494
91=>450
92=>416
93=>274
94=>241
95=>240
96=>231
97=>185
98=>186
99=>148
100=>188
```
---
### Author:  [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)
#### Post date: [July 16, 2017, 3:07pm UTC](https://discourse.julialang.org/t/max-source-line-length/4883/2 "2017-07-16T15:07:24Z")
Since CONTRIBUTION says 92 I would go with that. However, until there is a well made julia source code formatter, things like line length will always be a best effort endeavor.
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [July 17, 2017, 8:32am UTC](https://discourse.julialang.org/t/max-source-line-length/4883/3 "2017-07-17T08:32:53Z")
Some further stats on line length distributions (just for fun, `(lower,upper)=>percentage`)):
```julia
# Base
(0, 19)=>40.6
(20, 39)=>24.9
(40, 59)=>15.0
(60, 79)=>11.4
(80, 99)=>5.9
(100, 119)=>1.4
# packages on my system
(0, 19)=>38.2
(20, 39)=>28.7
(40, 59)=>16.1
(60, 79)=>10.1
(80, 99)=>4.6
(100, 119)=>1.2
# base > 80
(80, 89)=>46.2
(90, 99)=>25.8
(100, 109)=>11.4
(110, 119)=>6.4
(120, 129)=>3.6
(130, 139)=>2.4
(140, 149)=>1.5
# packages > 80
(80, 89)=>47.4
(90, 99)=>18.1
(100, 109)=>10.9
(110, 119)=>6.6
(120, 129)=>4.3
(130, 139)=>2.5
(140, 149)=>2.2
(150, 159)=>1.5
(160, 169)=>1.3
```
Only frequencies above 1% are shown, so the above don’t sum to 100%. As expected, packages have more outliers.
I think that trying to break up lines above 80 chars, at most 92, is a reasonable style guide. Readability will be heavily affected by 160 character monster expressions.
---
### Author:  [@lobingera](https://discourse.julialang.org/u/lobingera)
#### Post date: [July 17, 2017, 8:53am UTC](https://discourse.julialang.org/t/max-source-line-length/4883/4 "2017-07-17T08:53:35Z")
btw: a side question: is there something in (any)/a style gide how to split/format expressions that are one line, but needs to be within the 92 limit? (btw2: as old-school terminal user (80x72) i’d actually see 80 as the defining limit).
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [July 17, 2017, 10:45am UTC](https://discourse.julialang.org/t/max-source-line-length/4883/5 "2017-07-17T10:45:33Z")
See [JuliaPraxis/Spacing/Splitting lines](https://github.com/JuliaPraxis/Spacing/blob/master/guides/VerticalSpacing.md#splitting-lines), which I linked above.
---
### Author:  [@lobingera](https://discourse.julialang.org/u/lobingera)
#### Post date: [July 17, 2017, 10:53am UTC](https://discourse.julialang.org/t/max-source-line-length/4883/6 "2017-07-17T10:53:54Z")
yes, i wasn’t clear enough: Is there something else than at this link? It’s stating the obvious but leaves away how deep to indent.