diff options
Diffstat (limited to '')
| -rw-r--r-- | dhall_parser/src/dhall.abnf | 66 |
1 files changed, 34 insertions, 32 deletions
diff --git a/dhall_parser/src/dhall.abnf b/dhall_parser/src/dhall.abnf index 025f53a..640a422 100644 --- a/dhall_parser/src/dhall.abnf +++ b/dhall_parser/src/dhall.abnf @@ -543,58 +543,60 @@ expression = / annotated-expression
; "\(x : a) -> b"
-lambda-expression = lambda whsp "(" whsp unreserved-label whsp ":" whsp1 expression ")" whsp arrow whsp expression
+lambda-expression = lambda whsp "(" whsp unreserved-label whsp ":" whsp1 expression whsp ")" whsp arrow whsp expression
; "if a then b else c"
-ifthenelse-expression = if whsp1 expression then whsp1 expression else whsp1 expression
+ifthenelse-expression = 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"
let-expression = 1*let-binding in whsp1 expression
-let-binding = let whsp1 unreserved-label whsp [ ":" whsp1 expression ] "=" whsp expression
+let-binding = let whsp1 unreserved-label whsp [ ":" whsp1 expression whsp ] "=" whsp expression whsp
; "forall (x : a) -> b"
-forall-expression = forall whsp "(" whsp unreserved-label whsp ":" whsp1 expression ")" whsp arrow whsp expression
+forall-expression = forall whsp "(" whsp unreserved-label whsp ":" whsp1 expression whsp ")" whsp arrow whsp expression
; "a -> b"
-arrow-expression = operator-expression arrow whsp expression
+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 ]
+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 whsp / Optional whsp) import-expression whsp
-non-empty-optional = expression "]" whsp ":" whsp1 Optional whsp import-expression whsp
+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 [ ":" whsp1 expression ]
+annotated-expression = operator-expression [ whsp ":" whsp1 expression ]
operator-expression = import-alt-expression
-import-alt-expression = or-expression *("?" whsp1 or-expression)
-or-expression = plus-expression *("||" whsp plus-expression )
-plus-expression = text-append-expression *("+" whsp1 text-append-expression )
-text-append-expression = list-append-expression *("++" whsp list-append-expression )
-list-append-expression = and-expression *("#" whsp and-expression )
-and-expression = combine-expression *("&&" whsp combine-expression )
-combine-expression = prefer-expression *(combine whsp prefer-expression )
-prefer-expression = combine-types-expression *(prefer whsp combine-types-expression)
-combine-types-expression = times-expression *(combine-types whsp times-expression )
-times-expression = equal-expression *("*" whsp equal-expression )
-equal-expression = not-equal-expression *("==" whsp not-equal-expression )
-not-equal-expression = application-expression *("!=" whsp application-expression )
+; Nonempty-whitespace to disambiguate `http://a/a?a`
+import-alt-expression = or-expression *(whsp "?" whsp1 or-expression)
+or-expression = plus-expression *(whsp "||" whsp plus-expression)
+; Nonempty-whitespace to disambiguate `f +2`
+plus-expression = text-append-expression *(whsp "+" whsp1 text-append-expression)
+text-append-expression = list-append-expression *(whsp "++" whsp list-append-expression)
+list-append-expression = and-expression *(whsp "#" whsp and-expression)
+and-expression = combine-expression *(whsp "&&" whsp combine-expression)
+combine-expression = prefer-expression *(whsp combine whsp prefer-expression)
+prefer-expression = combine-types-expression *(whsp prefer whsp combine-types-expression)
+combine-types-expression = times-expression *(whsp combine-types whsp times-expression)
+times-expression = equal-expression *(whsp "*" whsp equal-expression)
+equal-expression = not-equal-expression *(whsp "==" whsp not-equal-expression)
+not-equal-expression = application-expression *(whsp "!=" whsp application-expression)
; Import expressions need to be separated by some whitespace, otherwise there
; would be ambiguity: `./ab` could be interpreted as "import the file `./ab`",
; or "apply the import `./a` to label `b`"
application-expression =
- import-expression *(whsp1 import-expression) whsp
+ import-expression *(whsp1 import-expression)
import-expression =
import
@@ -660,10 +662,10 @@ empty-record-literal = "=" whsp empty-record-type = ""
non-empty-record-type-or-literal =
any-label whsp (non-empty-record-literal / non-empty-record-type)
-non-empty-record-type = ":" whsp1 expression *("," whsp record-type-entry)
-record-type-entry = any-label whsp ":" whsp1 expression
-non-empty-record-literal = "=" whsp expression *("," whsp record-literal-entry)
-record-literal-entry = any-label whsp "=" whsp expression
+non-empty-record-type = ":" whsp1 expression whsp *("," whsp record-type-entry)
+record-type-entry = any-label whsp ":" whsp1 expression whsp
+non-empty-record-literal = "=" whsp expression whsp *("," whsp record-literal-entry)
+record-literal-entry = any-label whsp "=" whsp expression whsp
; "< Foo : Integer | Bar : Bool >"
; "< Foo : Integer | Bar = True >"
@@ -673,20 +675,20 @@ union-type-or-literal = empty-union-type = ""
non-empty-union-type-or-literal =
any-label whsp
- ( "=" whsp expression union-type-entries
- / ":" whsp1 expression [ "|" whsp non-empty-union-type-or-literal ]
+ ( "=" whsp expression whsp union-type-entries
+ / ":" whsp1 expression whsp [ "|" whsp non-empty-union-type-or-literal ]
)
union-type-entries = *("|" whsp union-type-entry)
-union-type-entry = any-label whsp ":" whsp1 expression
+union-type-entry = any-label whsp ":" whsp1 expression whsp
; "[1, 2, 3]"
; `empty-list-or-optional` handles empty lists
-non-empty-list-literal = "[" whsp expression *("," whsp expression) "]"
+non-empty-list-literal = "[" whsp expression whsp *("," whsp expression whsp) "]"
; "( e )"
-parenthesized-expression = "(" whsp expression ")"
+parenthesized-expression = "(" whsp expression whsp ")"
; All expressions end with trailing whitespace. This just adds a final
; whitespace prefix for the top-level of the program
-complete-expression = whsp expression
+complete-expression = whsp expression whsp
|