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author | Nadrieril | 2019-03-01 17:28:19 +0100 |
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committer | Nadrieril | 2019-03-01 17:28:19 +0100 |
commit | e5d9aee00b0c775df1d8e2d8819aeb80dffa73c2 (patch) | |
tree | e763a24a0d635048232e72e167ca37eafec69369 /dhall/src/errors/IfBranchMustBeTerm.txt | |
parent | 8a2b7536902831079eddd7b00291b718f5dd7186 (diff) |
Split abnf_to_pest and dhall into their own crates
Diffstat (limited to 'dhall/src/errors/IfBranchMustBeTerm.txt')
-rw-r--r-- | dhall/src/errors/IfBranchMustBeTerm.txt | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/dhall/src/errors/IfBranchMustBeTerm.txt b/dhall/src/errors/IfBranchMustBeTerm.txt new file mode 100644 index 0000000..4c15881 --- /dev/null +++ b/dhall/src/errors/IfBranchMustBeTerm.txt @@ -0,0 +1,51 @@ +Explanation: Every ❰if❱ expression begins with a predicate which must have type +❰Bool❱ + +For example, these are valid ❰if❱ expressions: + + + ┌──────────────────────────────┐ + │ if True then "Yes" else "No" │ + └──────────────────────────────┘ + ⇧ + Predicate + + + ┌─────────────────────────────────────────┐ + │ λ(x : Bool) → if x then False else True │ + └─────────────────────────────────────────┘ + ⇧ + Predicate + + +... but these are $_NOT valid ❰if❱ expressions: + + + ┌───────────────────────────┐ + │ if 0 then "Yes" else "No" │ ❰0❱ does not have type ❰Bool❱ + └───────────────────────────┘ + + + ┌────────────────────────────┐ + │ if "" then False else True │ ❰""❱ does not have type ❰Bool❱ + └────────────────────────────┘ + + +Your ❰if❱ expression begins with the following predicate: + +↳ $txt0 + +... that has type: + +↳ $txt1 + +... but the predicate must instead have type ❰Bool❱ + +Some common reasons why you might get this error: + +● You might be used to other programming languages that accept predicates other + than ❰Bool❱ + + For example, some languages permit ❰0❱ or ❰""❱ as valid predicates and treat + them as equivalent to ❰False❱. However, the Dhall language does not permit + this |