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December 30, 2020 11:18
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| const λ = ({raw: [raw]}, ...subs) => { | |
| if (subs.length > 0) { | |
| console.error('Interpolation is unnecessary, just use x instead of ${x}') | |
| return | |
| } | |
| const indices = [] | |
| const expr = raw.replace(/#(\d+)/g, (_, n) => { | |
| indices.push(n) | |
| return '(vars[' + n + '])' | |
| }) | |
| const f = eval('(function (vars) { return (' + expr + '); })') | |
| return (...args) => { | |
| const vars = {} | |
| indices.forEach(i => { vars[i] = args[i] }) | |
| return f(vars) | |
| } | |
| } | |
| /* | |
| > λ`(#0 + #2) * #1`(4, 7, 2) | |
| 42 | |
| > [{x: 'foo'}, {x: true}, {x: 3}].map(λ`#0.x`) | |
| ["foo", true, 3] | |
| > const field = 'x', n = 4 | |
| > [{x: 8}, {x: 3}, {x: 9}].map(λ`#0[field] * (#1 + n)`) | |
| [32,15,54] | |
| */ |
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can we make this safer by making it type-safe with typescript?