indexing

indexing

Angle offers

• zero based indexing (a b c)[1] == b

• one based indexing {a b c}#2 == b

• map field object accessors:

• {a:1 b:2}[a] == 1

• {a:1 b:2}.a == 1

• a in {a:1 b:2} == 1

• a of {a:1 b:2} == 1

The bracket version allows complex expression, whereas '#' 'in' and 'of' bind tightly, so

1 + 1 in {1:2} == 1 + {1:2}['1'] == 1+2 TODO: REALLY ? 1 + 1 in {1:3} == (1+1) in {1:3} == false Solution: compiler error: mixing evalutations needs grouping

{a:1 b:2}[a] is related to pattern matching and evaluation {a:1 b:2}(a)