diff options
Diffstat (limited to 'dhall/src/syntax/text/dhall.abnf')
| -rw-r--r-- | dhall/src/syntax/text/dhall.abnf | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/dhall/src/syntax/text/dhall.abnf b/dhall/src/syntax/text/dhall.abnf index 05d76e6..362a436 100644 --- a/dhall/src/syntax/text/dhall.abnf +++ b/dhall/src/syntax/text/dhall.abnf @@ -896,11 +896,9 @@ primitive-expression = record-type-or-literal =
empty-record-literal
- / non-empty-record-type-or-literal
- / empty-record-type
+ / [non-empty-record-type-or-literal]
empty-record-literal = "="
-empty-record-type = ""
non-empty-record-type-or-literal =
(non-empty-record-type / non-empty-record-literal)
@@ -913,22 +911,18 @@ record-type-entry = any-label-or-some whsp ":" whsp1 expression non-empty-record-literal =
record-literal-entry *(whsp "," whsp record-literal-entry)
+; If the `record-literal-normal-entry` is absent, that represents a punned
+; record entry, such as in `{ x }`, which is a short-hand for `{ x = x }`
record-literal-entry =
- any-label-or-some (record-literal-normal-entry / record-literal-punned-entry)
+ any-label-or-some [record-literal-normal-entry]
record-literal-normal-entry =
*(whsp "." whsp any-label-or-some) whsp "=" whsp expression
-record-literal-punned-entry = ""
-
+; If the `union-type-entry` is absent, that represents an empty union
+; alternative, such as in `< Heads | Tails >`
union-type =
- non-empty-union-type
- / empty-union-type
-
-empty-union-type = ""
-
-non-empty-union-type =
- union-type-entry *(whsp "|" whsp union-type-entry)
+ [union-type-entry *(whsp "|" whsp union-type-entry)]
; x : Natural
; x
|