44 lines
1.9 KiB
JavaScript
44 lines
1.9 KiB
JavaScript
'use strict';
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const { getBooleanOption, cppdb } = require('../util');
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module.exports = function defineAggregate(name, options) {
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// Validate arguments
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if (typeof name !== 'string') throw new TypeError('Expected first argument to be a string');
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if (typeof options !== 'object' || options === null) throw new TypeError('Expected second argument to be an options object');
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if (!name) throw new TypeError('User-defined function name cannot be an empty string');
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// Interpret options
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const start = 'start' in options ? options.start : null;
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const step = getFunctionOption(options, 'step', true);
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const inverse = getFunctionOption(options, 'inverse', false);
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const result = getFunctionOption(options, 'result', false);
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const safeIntegers = 'safeIntegers' in options ? +getBooleanOption(options, 'safeIntegers') : 2;
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const deterministic = getBooleanOption(options, 'deterministic');
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const directOnly = getBooleanOption(options, 'directOnly');
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const varargs = getBooleanOption(options, 'varargs');
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let argCount = -1;
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// Determine argument count
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if (!varargs) {
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argCount = Math.max(getLength(step), inverse ? getLength(inverse) : 0);
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if (argCount > 0) argCount -= 1;
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if (argCount > 100) throw new RangeError('User-defined functions cannot have more than 100 arguments');
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}
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this[cppdb].aggregate(start, step, inverse, result, name, argCount, safeIntegers, deterministic, directOnly);
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return this;
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};
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const getFunctionOption = (options, key, required) => {
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const value = key in options ? options[key] : null;
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if (typeof value === 'function') return value;
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if (value != null) throw new TypeError(`Expected the "${key}" option to be a function`);
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if (required) throw new TypeError(`Missing required option "${key}"`);
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return null;
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};
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const getLength = ({ length }) => {
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if (Number.isInteger(length) && length >= 0) return length;
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throw new TypeError('Expected function.length to be a positive integer');
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};
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