fentastic
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Validate and parse Forsyth-Edwards Notation (FEN) used to describe a chess game board position.
58 lines (57 loc) • 1.79 kB
JavaScript
import { tokenIs } from './token.js';
import { ParseError } from './ParseError.js';
const isPositive = tokenIs(/[1-9]/);
const isNonNegative = tokenIs(/[\d]/);
const validate = (tokens, fieldName) => {
for (const token of tokens) {
if (!isNonNegative(token)) {
throw new ParseError(fieldName, token.value, token.index, '0-9');
}
}
return tokens;
};
const halfMoveName = 'Halfmove clock';
export const validateHalfMoveClock = (field) => {
try {
if (!field.tokens.length) {
throw new ParseError(halfMoveName, '', field.delimiter.index, '0-9');
}
const tokens = validate(field.tokens, halfMoveName);
const fieldValue = Number(field.value);
if (fieldValue > 100) {
throw new ParseError(halfMoveName, field.value, tokens[0].index, '100', 'field to not exceed');
}
}
catch (e) {
if (e instanceof ParseError) {
field.error = e;
}
else {
throw e;
}
}
return field;
};
export const parseHalfMoveClock = (field) => Number(field.value);
const fullMoveName = 'Fullmove number';
export const validateFullMoveNumber = (field) => {
try {
if (!field.tokens.length) {
throw new ParseError(fullMoveName, '', field.delimiter.index, '1-9');
}
if (!isPositive(field.tokens[0])) {
throw new ParseError(fullMoveName, field.tokens[0].value, field.tokens[0].index, '1-9');
}
validate(field.tokens.slice(1), fullMoveName);
}
catch (e) {
if (e instanceof ParseError) {
field.error = e;
}
else {
throw e;
}
}
return field;
};
export const parseFullMoveNumber = (field) => Number(field.value);