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ruleset.js — parse style-attribute-like strings.
import {Schema, string, bool, number, listOf, optional, cssUnit4} from './ruleset.js';
const parse = Schema({
title: string,
isHidden: optional(bool, false),
numbers: listOf(number)
});
parse("title: 8 Beautiful Notes; numbers: 1, 2, 3, 4, 5, 6, 7, 8")
// > {title: "8 Beautiful Notes", numbers: [1, 2, 3...], isHidden: false}
const parseNumberList = listOf(number);
parseNumberList('1, 2, 3');
// > [1, 2, 3]
const parseCSSUnits = cssUnit4('10px 10%');
// > [{value: 10, unit: 'px'}, {value: 10, unit: 'px'}, {value: 10, unit: '%'}, {value: 10, unit: '%'}]
// Tools for parsing style-attribute-like strings.
//
// The MIT License
//
// Copyright (c) 2018 Gordon Brander
//
// Permission is hereby granted, free of charge,
// to any person obtaining a copy of this software and
// associated documentation files (the "Software"), to
// deal in the Software without restriction, including
// without limitation the rights to use, copy, modify,
// merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom
// the Software is furnished to do so,
// subject to the following conditions:
//
// The above copyright notice and this permission notice
// shall be included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
// ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
const notEmpty = x => x !== '';
const trim = s => s.trim();
const fromEntries = entries => {
const object = {}
for (let [key, value] of entries) {
object[key] = value;
}
return object
}
export const parseRule = rule => {
const [key, value] = rule.split(':').map(trim);
return [key, value];
}
export const parseRuleset= ruleset => fromEntries(
ruleset
.split(';')
.filter(notEmpty)
.map(parseRule)
);
export const throughSchema = (schema, raw) => {
const parsed = {};
for (let [key, parser] of Object.entries(schema)) {
parsed[key] = parser(raw[key]);
}
return parsed;
}
export const Schema = schema => ruleset =>
throughSchema(schema, parseRuleset(ruleset));
export const number = x => parseFloat(x, 10);
export const deg = x => parseFloat(x.replace('deg', ''), 10) % 360;
export const percent = x => parseFloat(x.replace('%', ''), 10);
export const string = (x='') => x + '';
export const selector = (x='*') => x + '';
export const bool = x => !!x;
const find = (s, regexp, flags) => {
const match = s.match(regexp, flags);
return match != null ? match[0] : null;
}
export const optional = (coerce, fallback) => (value=fallback) => coerce(value);
export const listOf = (coerce, sep=',') => x => {
const s = x + '';
return s.split(sep).map(trim).filter(notEmpty).map(coerce);
}
export const cssUnit = x => {
const s = x + '';
const raw = find(s, /^[0-9\.]+/);
const unit = find(s, /[a-zA-Z%]+$/, 'm');
if (raw == null) {
return {
value: null,
unit: 'undefined'
};
} else if (unit == null) {
return {
value: parseFloat(raw, 10),
unit: 'none'
};
} else {
return {
value: parseFloat(raw, 10),
unit
};
}
}
export const cssUnitList = listOf(cssUnit, ' ');
// Extrapolate a space-separated list of 1 to 3 CSS units.
// Returns an array of 3 cssValues.
export const cssUnit3 = x => {
const units = cssUnitList(x);
if (units.length == 1) {
const [a] = units;
return [a, a, a];
} else if (units.length == 2) {
const [a, b] = units;
return [a, b, b];
} else if (units.length == 3) {
const [a, b, c] = units;
return [a, b, c];
}
}
// Extrapolate a space-separated list of up to 4 CSS units.
// Uses typical CSS unit extrapolation rules
// (e.g. same behavior as `padding: 1px;`).
// Returns an array of 4 cssValues.
export const cssUnit4 = x => {
const units = cssUnitList(x);
if (units.length == 1) {
const [a] = units;
return [a, a, a, a];
} else if (units.length == 2) {
const [a, b] = units;
return [a, a, b, b];
} else if (units.length == 3) {
const [a, b, c] = units;
return [a, b, b, c];
} else if (units.length > 3) {
const [a, b, c, d] = units;
return [a, b, c, d];
}
}
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