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| const λ = ({raw}, ...subs) => (...args) => { | |
| const buf = [], | |
| table = {} | |
| function addVar(name, value) { | |
| table[name] = value | |
| return name | |
| } | |
| for (let i = 0; i < raw.length; i++) { | |
| buf.push(raw[i].replace(/#(\d+)/g, (_, n) => addVar('___' + n, args[n]))) | |
| if (i < raw.length - 1) | |
| buf.push(addVar('____' + i, subs[i])) | |
| } | |
| const expr = buf.join('') | |
| const keys = Object.keys(table) | |
| const values = keys.map(k => table[k]) | |
| return (new (Function.prototype.bind.apply(Function, [null, keys, `return ${expr}`]))).apply(null, values) | |
| } | |
| /* | |
| > λ`(#0 + #1) * #2`(4, 2, 7) | |
| 42 | |
| > [{x: 'foo'}, {x: true}, {x: 3}].map(λ`#0.x`) | |
| ["foo", true, 3] | |
| > const field = 'x', n = 4 | |
| > [{x: 8}, {x: 3}, {x: 9}].map(λ`#0[${field}] * (#1 + ${n})`) | |
| [32,15,54] | |
| */ |
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can we make this safer by making it type-safe with typescript?