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| author | Brujo Benavides <[email protected]> | 2018-08-08 12:51:59 -0300 |
|---|---|---|
| committer | GitHub <[email protected]> | 2018-08-08 12:51:59 -0300 |
| commit | 629ad2e0971efcf58934c76ea1306b0ff0629339 (patch) | |
| tree | e5f8260aee4862040d29b1feed25593611ac5d65 /system/doc/reference_manual/expressions.xml | |
| parent | 783172ca6d0453e115e038edbb46f892c0d35241 (diff) | |
| download | otp-629ad2e0971efcf58934c76ea1306b0ff0629339.tar.gz otp-629ad2e0971efcf58934c76ea1306b0ff0629339.tar.bz2 otp-629ad2e0971efcf58934c76ea1306b0ff0629339.zip | |
Add clarification on nil type
As explained by @psyeugenic on Slack:
> empty list `[]` is regarded as a separate type from `list()`, `[]` < `list()`
> i.e. nil is `[]`
Diffstat (limited to 'system/doc/reference_manual/expressions.xml')
| -rw-r--r-- | system/doc/reference_manual/expressions.xml | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/system/doc/reference_manual/expressions.xml b/system/doc/reference_manual/expressions.xml index 94e40dd077..684a1191d0 100644 --- a/system/doc/reference_manual/expressions.xml +++ b/system/doc/reference_manual/expressions.xml @@ -567,6 +567,10 @@ Expr1 <input>op</input> Expr2</pre> order is defined:</p> <pre> number < atom < reference < fun < port < pid < tuple < map < nil < list < bit string</pre> + <p><c>nil</c> in the previous expression represents the empty list + (i.e. <c>[]</c>), which is regarded as a separate type from + <c>list/0</c>. That's why <c>nil < list</c>. + </p> <p>Lists are compared element by element. Tuples are ordered by size, two tuples with the same size are compared element by element.</p> |