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Diffstat (limited to 'doc/fill.md')
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diff --git a/doc/fill.md b/doc/fill.md index 45d98487..ed93b02c 100644 --- a/doc/fill.md +++ b/doc/fill.md @@ -4,7 +4,7 @@ A few array operations need an array element to use when no existing element applies. BQN tries to maintain a "default" element for every array, known as a fill element, for this purpose. If it's known, the fill element is a nested array structure where each atom is either `0` or `' '`. If no fill is known, a function that requests it results in an error. -Fills are used by [Take](take.md) (`↑`) when a value in `𝕨` is larger than the corresponding length in `𝕩`, by the two [Nudge](shift.md) functions (`»«`) when `𝕩` is non-empty, and by [First](pick.md) (`⊑`) and [Reshape](reshape.md) (`⥊`) when `𝕩` is empty. Except for these specific cases, the fill value an array has can't affect the program. The result of [Match](match.md) (`≡`) doesn't depend on fills, and any attempt to compute a fill can't cause side effects. +Fills are used by [Take](take.md) (`↑`) when a value in `𝕨` is larger than the corresponding length in `𝕩`, by the two [Nudge](shift.md) functions (`»«`) when `𝕩` is non-empty, and by [Reshape](reshape.md) (`⥊`) when `𝕨` contains `↑`. Except for these specific cases, the fill value an array has can't affect the program. The result of [Match](match.md) (`≡`) doesn't depend on fills, and any attempt to compute a fill can't cause side effects. ## Using fills @@ -24,17 +24,13 @@ Nudge Left or Right shifts the array over and places a fill in the vacated space »⟨⟩ # Fill not needed -[First](pick.md) (`⊑`) and [Reshape](reshape.md) (`⥊`) use the fill when `𝕩` is empty, and in the case of Reshape only when the result needs to be non-empty. +[Reshape](reshape.md#computed-lengths) (`⥊`) uses the fill when `𝕨` contains `↑` and the product of the rest of `𝕨` doesn't evenly divide the number of elements in `𝕩`. - ⊑ "" + ↑‿8 ⥊ "completepart" - 4 ⥊¨ ⟨↕0, ""⟩ +If for some reason you need to find an array's fill element, the easiest general way is probably `⊑»1↑⥊a`. - 0‿3 ⥊ ⟨⟩ # Fill not needed - -If for some reason you need to find an array's fill element, the easiest way is `⊑0⥊a`. - - ⊑0⥊"string" + ⊑»1↑⥊"string" ## How fills are computed |