Implementation Comparisons

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Features Missing in NARS2000

  • Selective Assignment: The syntax of (...)←... where the code inside of the parens selects elements of a named array is missing from NARS2000. It may be emulated by using Indexed Assignment:
    Dyalog: ((⊂ L)⌷R)←...
    NARS2000: R[L]←...

Differences With Dyalog APL

Different designers make different choices. Neither should be considered Good or Bad, just different. Here are a few of the differences between Dyalog APL and NARS2000:

  • Multi-name assignment in Dyalog does not require parens, whereas NARS2000 does
    Dyalog: i j ←⍺
    NARS2000: (i j)←⍺
  • A Train assigned to a name does not require parens in Dyalog, but are required in NARS2000
    Dyalog: e← -phi grad
    NARS2000: e←(-phi grad)
  • Dyalog's definition of the monadic function depends upon the value of ⎕ML (⎕ML<2 is Mix, ⎕ML≥2 is First), whereas NARS2000 uses the monadic function for Mix and for First
    Dyalog: csc←{sign↑⍳n⍴n←⍴⍵}
    NARS2000: csc←{sign⊃⍳n⍴n←⍴⍵}
  • I'm not sure about Dyalog, but I know that NARS2000 does not have the concept of Rank well-integrated into its implementation.
  • The Binding Strength Rules are different. In NARS2000, a numeric strand as the right operand to an operator must be enclosed in parens
    Dyalog: ⍤ 0 1
    NARS2000: ⍤(0 1)