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author | Nadrieril | 2019-05-07 18:12:04 +0200 |
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committer | Nadrieril | 2019-05-07 18:12:04 +0200 |
commit | 3da450aa3fae23214aa982643b9bc4dd0ea4eaa6 (patch) | |
tree | 02e00cd008d2e7dc899b9211379596fe792f41c8 /dhall/src/error/text/FieldCollision.txt | |
parent | d8a3e831fb67f86269c4baa99f9f0798a73a7247 (diff) | |
parent | 14dfeb8e7d2aa87a361a711a485243449426b144 (diff) |
Merge branch 'reorganize'
Diffstat (limited to 'dhall/src/error/text/FieldCollision.txt')
-rw-r--r-- | dhall/src/error/text/FieldCollision.txt | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/dhall/src/error/text/FieldCollision.txt b/dhall/src/error/text/FieldCollision.txt new file mode 100644 index 0000000..2b2d260 --- /dev/null +++ b/dhall/src/error/text/FieldCollision.txt @@ -0,0 +1,43 @@ +Explanation: You can combine records if they don't share any fields in common, +like this: + + + ┌───────────────────────────────────────────┐ + │ { foo = 1, bar = "ABC" } ∧ { baz = True } │ + └───────────────────────────────────────────┘ + + + ┌────────────────────────────────────────┐ + │ λ(r : { baz : Bool}) → { foo = 1 } ∧ r │ + └────────────────────────────────────────┘ + + +... but you cannot merge two records that share the same field + +For example, the following expression is $_NOT valid: + + + ┌───────────────────────────────────────────┐ + │ { foo = 1, bar = "ABC" } ∧ { foo = True } │ Invalid: Colliding ❰foo❱ fields + └───────────────────────────────────────────┘ + + +You combined two records that share the following field: + +↳ $txt0 + +... which is not allowed + +Some common reasons why you might get this error: + +● You tried to use ❰∧❱ to update a field's value, like this: + + + ┌────────────────────────────────────────┐ + │ { foo = 1, bar = "ABC" } ∧ { foo = 2 } │ + └────────────────────────────────────────┘ + ⇧ + Invalid attempt to update ❰foo❱'s value to ❰2❱ + + Field updates are intentionally not allowed as the Dhall language discourages + patch-oriented programming |