Requires Python ≥3.10.
pip install miniapl
This installs the miniapl command and Python package.
Run miniapl to open the REPL. Type an expression and press Enter. ⍝ introduces a comment; examples here use it to show the result.
APL evaluates right-to-left. Parentheses change grouping.
2×3+4 ⍝ 14
(2×3)+4 ⍝ 10
Spaces form vectors. Functions work on every element.
10+1 2 3 ⍝ 11 12 13
⍳ generates indices, ← assigns a name, and +/ sums.
v←⍳5 ⋄ v ⍝ 1 2 3 4 5
+/⍳5 ⍝ 15
To enter ⍳5, type backtick, iota, then 5. The digit accepts the glyph and enters the argument. Symbol entry also supports abbreviations and Tab completion.
Bare numbers are approximate. Use x for exact integers and r for fractions.
1÷3 ⍝ 0.3333333333333333
1x÷3x ⍝ 1r3
j separates real and imaginary parts.
1j2×1j¯2 ⍝ 5
⍴ reshapes a vector; +/ sums each row.
+/2 3⍴⍳6 ⍝ 6 15
Indices start at 1. Comparisons use tolerance 1E¯14; 0.3=0.1+0.2 is true. See language rules and the glyph index.