1. A device for interpreting XML documents, comprising: an acquiring unit that acquires an XML document, wherein the XML document includes a plurality of elements that form a predetermined tree structure; an arranging unit that arranges the elements in the XML document acquired in a row according to the tree structure in an order of appearance in the XML document of the elements; an extracting unit that extracts character-string data from each of the elements arranged, wherein the character-string data include character string in a start tag and an end tag, and character string within the start tag and the end tag in the elements; an identifying unit that identifies a node-type of each of the elements arranged, wherein the node-type indicates a kind in the tree structure for each of the elements; a generating unit that generates link data that associates character-string data extracted with a node-type identified for each of the elements arranged.