Migration level: Difference between revisions

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{{Built-ins|Migration level|⎕ML|⎕EL}} or '''Evolution level''' is a number that, in [[Dyalog APL]] and [[APL+Win]] respectively, determines exact where the original [[NARS]] specification and the current [[APL2]] implementation differ. A lower value represents a behaviour closer to NARS, while a higher the value represents a behaviour closer to APL2.
{{Built-ins3|Migration level|⎕ML|⎕EL|⎕CS}}, '''Evolution level''', or '''Compatibility setting''' is a number that, in [[Dyalog APL]], [[APL+Win]], and [[APLX]] respectively, specifies exact behaviour relative to [[APL2]]. In Dyalog APL and APL+Win, a lower value represents a behaviour closer to the original [[NARS]] specification, while a higher the value represents a behaviour closer to APL2. In APLX, a lower value matches APL2 while a higher value indicates higher [[backwards compatibility]] with [[APL.68000]].


== APL+Win settings ==
== APL+Win settings ==
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|}
|}
Alternatively, the definitions can be used directly inside the text substitutions, whereby one avoids polluting existing code with these cover names.
Alternatively, the definitions can be used directly inside the text substitutions, whereby one avoids polluting existing code with these cover names.
== APLX settings ==
APLX treats the value as a collection of individual bits, thus allowing the combination of an exact set of behaviours:
{|class=wikitable
| <source lang=apl inline>⎕CS←1</source> || [[Strand notation|Stranding]] is done before [[bracket indexing]]
|-
| <source lang=apl inline>⎕CS←2</source> || The [[name class]] of an invalid name is 4 rather than ¯1.
|-
| <source lang=apl inline>⎕CS←4</source> || Format (<source lang=apl inline>⍕</source>) and default output uses the same width for all columns, rather than determining  the  width separately for  each column.
|}


== External links ==
== External links ==
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* [https://help.dyalog.com/latest/#Language/System%20Functions/ml.htm Dyalog]
* [https://help.dyalog.com/latest/#Language/System%20Functions/ml.htm Dyalog]
* [http://microapl.com/apl_help/ch_020_070_140.htm APLX]


{{APL built-ins}}[[Category:System constants]]
{{APL built-ins}}[[Category:System constants]]

Revision as of 08:43, 8 February 2021

⎕ML ⎕EL ⎕CS

Migration level (⎕ML, ⎕EL, ⎕CS), Evolution level, or Compatibility setting is a number that, in Dyalog APL, APL+Win, and APLX respectively, specifies exact behaviour relative to APL2. In Dyalog APL and APL+Win, a lower value represents a behaviour closer to the original NARS specification, while a higher the value represents a behaviour closer to APL2. In APLX, a lower value matches APL2 while a higher value indicates higher backwards compatibility with APL.68000.

APL+Win settings

[TBD]

Dyalog settings

Dyalog APL currently offers the following settings:

⎕ML=0 Z←∊R Monadic is interpreted as Type rather than Enlist.
⎕ML=1 Default behaviour
⎕ML≤2 Z←↑R Monadic is interpreted as First rather than Mix.
Z←⊃R Monadic is interpreted as Mix rather than First.
Z←≡R Monadic returns a positive rather than a negative value, if its argument has non-uniform depth.
⎕ML=3 R←X⊂[K]Y Dyadic is interpreted as Partition () rather than Partitioned Enclose.
⎕TC The order of the elements of ⎕TC is the same as in APL2.

Work-arounds

When migrating to Dyalog APL, the below drop-ins for the affected built-ins allow setting ⎕ML←1 while preserving code behaviour. It is then safe to programmatically (as shown in the rightmost column) change all occurrences of the affected built-ins with their respective covers.

Migrating from Define Then run this on all code
⎕ML=0
Epsilon←{×⎕NC'⍺':⍺∊⍵ ⋄ ⊃0⍴⊂⍵}
'''[^'']+''' '∊'⎕R'&' 'Epsilon'
⎕ML=2
UpArrow←{×⎕NC'⍺':⍺↑⍵ ⋄ ⊃⍵}
RightShoe←{×⎕NC'⍺':⍺↑⍵ ⋄ ↑⍵}
EqualUnderbar←|≡
'''[^'']+''' '↑' '⊃' '≡'⎕R'&' 'UpArrow' 'RightShoe' 'EqualUnderbar'
⎕ML=3
UpArrow←{×⎕NC'⍺':⍺↑⍵ ⋄ ⊃⍵}
RightShoe←{×⎕NC'⍺':⍺↑⍵ ⋄ ↑⍵}
EqualUnderbar←(|≡)
LeftShoe←{×⎕NC'⍺':⍺⊆⍵ ⋄ ⊂⍵}
quadTC←(⎕UCS 8 13 10)
'''[^'']+''' '↑' '⊃' '≡' '⊂' '⎕TC'⎕R'&' 'UpArrow' 'RightShoe' 'EqualUnderbar' 'LeftShoe' ' quadTC'

Alternatively, the definitions can be used directly inside the text substitutions, whereby one avoids polluting existing code with these cover names.

APLX settings

APLX treats the value as a collection of individual bits, thus allowing the combination of an exact set of behaviours:

⎕CS←1 Stranding is done before bracket indexing
⎕CS←2 The name class of an invalid name is 4 rather than ¯1.
⎕CS←4 Format () and default output uses the same width for all columns, rather than determining the width separately for each column.

External links

Documentation


APL built-ins [edit]
Primitives (Timeline) Functions
Scalar
Monadic ConjugateNegateSignumReciprocalMagnitudeExponentialNatural LogarithmFloorCeilingFactorialNotPi TimesRollTypeImaginarySquare Root
Dyadic AddSubtractTimesDivideResiduePowerLogarithmMinimumMaximumBinomialComparison functionsBoolean functions (And, Or, Nand, Nor) ∙ GCDLCMCircularComplexRoot
Non-Scalar
Structural ShapeReshapeTallyDepthRavelEnlistTableCatenateReverseRotateTransposeRazeMixSplitEncloseNestCut (K)PairLinkPartitioned EnclosePartition
Selection FirstPickTakeDropUniqueIdentityStopSelectReplicateExpandSet functions (IntersectionUnionWithout) ∙ Bracket indexingIndexCartesian ProductSort
Selector Index generatorGradeIndex OfInterval IndexIndicesDealPrefix and suffix vectors
Computational MatchNot MatchMembershipFindNub SieveEncodeDecodeMatrix InverseMatrix DivideFormatExecuteMaterialiseRange
Operators Monadic EachCommuteConstantReplicateExpandReduceWindowed ReduceScanOuter ProductKeyI-BeamSpawnFunction axis
Dyadic BindCompositions (Compose, Reverse Compose, Beside, Withe, Atop, Over) ∙ Inner ProductDeterminantPowerAtUnderRankDepthVariantStencilCutDirect definition (operator)
Quad names Index originComparison toleranceMigration levelAtomic vector