src/vs/editor/contrib/snippet/snippetParser.ts/FormatString/resolve
class FormatString:	resolve(value?: string): string {
		if (this.shorthandName === 'upcase') {
			return !value ? '' : value.toLocaleUpperCase();
		} else if (this.shorthandName === 'downcase') {
			return !value ? '' : value.toLocaleLowerCase();
		} else if (this.shorthandName === 'capitalize') {
			return !value ? '' : (value[0].toLocaleUpperCase() + value.substr(1));
		} else if (this.shorthandName === 'pascalcase') {
			return !value ? '' : this._toPascalCase(value);
		} else if (this.shorthandName === 'camelcase') {
			return !value ? '' : this._toCamelCase(value);
		} else if (Boolean(value) && typeof this.ifValue === 'string') {
			return this.ifValue;
		} else if (!Boolean(value) && typeof this.elseValue === 'string') {
			return this.elseValue;
		} else {
			return value || '';
		}
	}