three.js/examples/jsm/nodes/core/StructNode.js

import { TempNode } from './TempNode.js';

var declarationRegexp = /^struct\s*([a-z_0-9]+)\s*{\s*((.|\n)*?)}/img,
	propertiesRegexp = /\s*(\w*?)\s*(\w*?)(\=|\;)/img;

function StructNode( src ) {

	TempNode.call( this );

	this.parse( src );

}

StructNode.prototype = Object.create( TempNode.prototype );
StructNode.prototype.constructor = StructNode;
StructNode.prototype.nodeType = 'Struct';

StructNode.prototype.getType = function ( builder ) {

	return builder.getTypeByFormat( this.name );

};

StructNode.prototype.getInputByName = function ( name ) {

	var i = this.inputs.length;

	while ( i -- ) {

		if ( this.inputs[ i ].name === name ) {

			return this.inputs[ i ];

		}

	}

};

StructNode.prototype.generate = function ( builder, output ) {

	if ( output === 'source' ) {

		return this.src + ';';

	} else {

		return builder.format( '( ' + this.src + ' )', this.getType( builder ), output );

	}

};

StructNode.prototype.parse = function ( src ) {

	this.src = src || '';

	this.inputs = [];

	var declaration = declarationRegexp.exec( this.src );

	if ( declaration ) {

		var properties = declaration[ 2 ], match;

		while ( match = propertiesRegexp.exec( properties ) ) {

			this.inputs.push( {
				type: match[ 1 ],
				name: match[ 2 ]
			} );

		}

		this.name = declaration[ 1 ];

	} else {

		this.name = '';

	}

	this.type = this.name;

};

StructNode.prototype.toJSON = function ( meta ) {

	var data = this.getJSONNode( meta );

	if ( ! data ) {

		data = this.createJSONNode( meta );

		data.src = this.src;

	}

	return data;

};

export { StructNode };