30 lines
723 B
JavaScript
30 lines
723 B
JavaScript
export default function extent(values, valueof) {
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let min;
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let max;
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if (valueof === undefined) {
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for (const value of values) {
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if (value != null) {
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if (min === undefined) {
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if (value >= value) min = max = value;
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} else {
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if (min > value) min = value;
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if (max < value) max = value;
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}
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}
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}
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} else {
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let index = -1;
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for (let value of values) {
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if ((value = valueof(value, ++index, values)) != null) {
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if (min === undefined) {
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if (value >= value) min = max = value;
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} else {
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if (min > value) min = value;
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if (max < value) max = value;
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}
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}
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}
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}
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return [min, max];
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}
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