The Crow Programming Language
SpecGitHub

Maps

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m = map[b = 2, a = 1]
log[keys[m]]
log[values[m]]
log['a' in m]
m2 = set[m, 'c', 3]
log[len[m2]]
log[del[m2, 'b']]
log[m2['c']]

expected output — from the book, verified by crow test --book

['a', 'b']
[1, 2]
true
3
[a = 1, c = 3]
3

Reference: spec section 8 (Maps) and section 11 (Map Operations).

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words = ['the', 'cat', 'sat']
at = map[words, range[len[words]]]
log[at['cat']]
log['dog' in at]

expected output — from the book, verified by crow test --book

1
false
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scores = map[[7, 3], [0.5, 0.25]]
log[scores[3]]
log[keys[scores]]
log[3 in scores]
by_id = map[1 = 'a', 2 = 'b']
log[by_id[2]]
counts = map[]
for n in [3, 1, 3]
    if n in counts
        counts = set[counts, n, counts[n] + 1]
    else
        counts = set[counts, n, 1]
log[counts]

expected output — from the book, verified by crow test --book

0.25
[3, 7]
true
b
[1 = 1, 3 = 2]