diff options
| author | Nadrieril | 2019-04-04 18:48:42 +0200 |
|---|---|---|
| committer | Nadrieril | 2019-04-04 18:48:42 +0200 |
| commit | a342f45f820e28638e4a73a7b3a577ebf2396b0d (patch) | |
| tree | 06a72d2fd8a6862e62dbcf4044c364aaaae17354 /dhall_parser/src | |
| parent | 04c6cd248aff1cbce68ae2fb997705e921d21809 (diff) | |
Factor back in some rule branches
Diffstat (limited to 'dhall_parser/src')
| -rw-r--r-- | dhall_parser/src/dhall.abnf | 64 | ||||
| -rw-r--r-- | dhall_parser/src/dhall.pest.visibility | 22 |
2 files changed, 36 insertions, 50 deletions
diff --git a/dhall_parser/src/dhall.abnf b/dhall_parser/src/dhall.abnf index 8964f44..2fad4d4 100644 --- a/dhall_parser/src/dhall.abnf +++ b/dhall_parser/src/dhall.abnf @@ -529,52 +529,46 @@ import = import-hashed [ whsp as whsp1 Text ] ; This is important to avoid the need for sequential backtracking in application-expression.
expression =
- lambda-expression
- / ifthenelse-expression
- / let-expression
- / forall-expression
+ ; "\(x : a) -> b"
+ lambda whsp "(" whsp nonreserved-label whsp ":" whsp1 expression whsp ")" whsp arrow whsp expression
+
+ ; "if a then b else c"
+ / if whsp1 expression whsp then whsp1 expression whsp else whsp1 expression
+
+ ; "let x : t = e1 in e2"
+ ; "let x = e1 in e2"
+ ; "let x = e1 let y = e2 in e3"
+ / 1*let-binding in whsp1 expression
+
+ ; "forall (x : a) -> b"
+ / forall whsp "(" whsp nonreserved-label whsp ":" whsp1 expression whsp ")" whsp arrow whsp expression
+
+ ; "a -> b"
; NOTE: Backtrack if parsing this alternative fails
- / arrow-expression
- / merge-expression
+ / operator-expression whsp arrow whsp expression
+
+ ; "merge e1 e2 : t"
+ ; "merge e1 e2"
+ / merge whsp1 import-expression whsp import-expression [ whsp ":" whsp1 application-expression ]
+
+ ; "[] : List t"
+ ; "[] : Optional t"
+ ; "[x] : Optional t"
; NOTE: Backtrack if parsing this alternative fails since we can't tell
; from the opening bracket whether or not this will be an empty list or
; a non-empty list
- / empty-list-or-optional
+ / "[" whsp (empty-collection / non-empty-optional)
+
+ ; "x : t"
/ annotated-expression
-; "\(x : a) -> b"
-lambda-expression = lambda whsp "(" whsp nonreserved-label whsp ":" whsp1 expression whsp ")" whsp arrow whsp expression
-
-; "if a then b else c"
-ifthenelse-expression = if whsp1 expression whsp then whsp1 expression whsp else whsp1 expression
+; "x : t"
+annotated-expression = operator-expression [ whsp ":" whsp1 expression ]
-; "let x : t = e1 in e2"
-; "let x = e1 in e2"
-; "let x = e1 let y = e2 in e3"
-let-expression = 1*let-binding in whsp1 expression
let-binding = let whsp1 nonreserved-label whsp [ ":" whsp1 expression whsp ] "=" whsp expression whsp
-
-; "forall (x : a) -> b"
-forall-expression = forall whsp "(" whsp nonreserved-label whsp ":" whsp1 expression whsp ")" whsp arrow whsp expression
-
-; "a -> b"
-arrow-expression = operator-expression whsp arrow whsp expression
-
-; "merge e1 e2 : t"
-; "merge e1 e2"
-merge-expression = merge whsp1 import-expression whsp import-expression [ whsp ":" whsp1 application-expression ]
-
-; "[] : List t"
-; "[] : Optional t"
-; "[x] : Optional t"
-empty-list-or-optional = "[" whsp (empty-collection / non-empty-optional)
empty-collection = "]" whsp ":" whsp1 (List / Optional) whsp import-expression
non-empty-optional = expression whsp "]" whsp ":" whsp1 Optional whsp import-expression
-; "x : t"
-annotated-expression = operator-expression [ whsp ":" whsp1 expression ]
-
-
operator-expression = import-alt-expression
; Nonempty-whitespace to disambiguate `http://a/a?a`
diff --git a/dhall_parser/src/dhall.pest.visibility b/dhall_parser/src/dhall.pest.visibility index e95cd32..ac3ea30 100644 --- a/dhall_parser/src/dhall.pest.visibility +++ b/dhall_parser/src/dhall.pest.visibility @@ -34,16 +34,15 @@ single_quote_literal # in # as # using -# merge missing -# if_ +if_ # then # else_ # let_ -# in_ +in_ # as_ # using -# merge +merge # Infinity Optional Text @@ -78,9 +77,9 @@ List # combine # combine_types # prefer -# lambda -# forall -# arrow +lambda +forall +arrow # exponent double_literal natural_literal @@ -120,14 +119,7 @@ import_type hash import_hashed import -# expression -lambda_expression -ifthenelse_expression -let_expression -forall_expression -arrow_expression -merge_expression -# empty_list_or_optional +expression empty_collection non_empty_optional annotated_expression |