A jq clone implemented in MoonBit.
moon install mizchi/jq/cmd/moonjqThis installs moonjq to ~/.moon/bin/moonjq.
echo '{"name":"alice","age":30}' | moonjq '.name'
# "alice"
echo '[1,2,3,4,5]' | moonjq 'map(. * 2) | add'
# 30
echo '[{"a":1},{"a":2},{"a":3}]' | moonjq '[.[] | select(.a > 1)]'
# [{"a":2},{"a":3}]moon add mizchi/jqlet results = @jq.run(".foo", @json.parse("{\"foo\":42}"))
// results = [Number(42)]
// Pre-compile for repeated use
let filter = @jq.compile("map(. + 1)")
let r1 = @jq.run_compiled(filter, @json.parse("[1,2,3]"))
// r1 = [Array([Number(2), Number(3), Number(4)])]See README.mbt.md for full doc-tested API examples.
96.2% compatible with jq 1.8.1 (252/262 verified tests).
429 of 514 jq.test cases ported. 496 MoonBit tests total, all passing.
| Category | Features |
|---|---|
| Basic | ., .foo, .[n], .[], .., .[m:n] |
| Operators | |, ,, + - * / %, == != < > <= >=, and or not, // |
| Assignment | =, |=, +=, -=, *=, /=, %=, //= |
| Construction | [expr], {k: v}, {foo} (shorthand), (expr), "\(.expr)" |
| Control | if-then-elif-else-end, try-catch, .foo?, foreach, while, until, label/break |
| Binding | as $x, as [$a,$b], as {a:$x}, ?//, reduce, def |
| Path | path(), setpath(), getpath(), delpaths(), del(), pick() |
| Builtins | length, keys, values, type, select, map, map_values, empty, add, sort, sort_by, group_by, unique, unique_by, reverse, flatten, min, max, min_by, max_by, first, last, limit, range, has, contains, inside, any, all, tostring, tonumber, toboolean, tojson, fromjson, ascii_downcase, ascii_upcase, split, join, startswith, endswith, ltrimstr, rtrimstr, trim, ltrim, rtrim, trimstr, abs, fabs, floor, ceil, round, explode, implode, to_entries, from_entries, with_entries, walk, transpose, bsearch, indices, index, rindex, not, recurse, debug, IN, INDEX, error, paths, isempty, nth, skip, builtins, utf8bytelength, $__loc__ |
| Math | sqrt, sin, cos, atan, atan2, log, log2, exp, exp2, pow, infinite, nan, isnan, isinfinite, isfinite, isnormal |
| Formats | @base64, @base64d, @json, @text, @html, @uri |
| Types | numbers, strings, booleans, nulls, arrays, objects, iterables, scalars |
| Feature | Tests | Notes |
|---|---|---|
import/include |
10 | Module system (out of scope) |
input |
1 | Multi-input I/O |
All caused by platform constraints (IEEE 754 double / JS string handling):
| Issue | Tests | Detail |
|---|---|---|
| Large integers > 2^53 | 4 | Overflow to Infinity instead of exact representation |
-0 handling |
1 | abs on -0.0 outputs 0 instead of -0 |
NUL byte (\u0000) in strings |
2 | contains and toboolean misbehave with embedded NUL |
path() error message |
1 | Missing result value in error message |
pick(last) negative index |
1 | Different error from jq |
fromjson error message |
1 | MoonBit JSON parser produces different error text |
just # check + test
just fmt # format code
just check # type check
just test # run tests
just moonjq FILTER # run CLIApache-2.0
