Abstract: A system and computer-implemented method of indexing source code where the source code is processed into abstract syntax trees, the abstract syntax trees are linearized, and the linearizations are used to build an index structure. The index structure enables the look up of the pattern tree in time linear in its length. Further, the index structure can be used to identify code clones. Two alternate variants of the index structure can be used. One is based on a trie which builds a plain index structure, and the other index structure is based on a compressed trie which builds a compressed index structure.

Abstract: A computer-implemented method of indexing source code is disclosed. Source code is processed to abstract syntax trees, the abstract syntax trees are linearized and the linearizations are used to build an index structure. The index structure enables one to look up the pattern tree in time linear in its length. In addition, the index structure can be used to identify code clones. Two variants of the index structure are claimed: one based on the trie, which is referred to as the plain index structure or simply the plain index, and one based on the compressed trie, which is referred to as the compressed index structure or simply the compressed index.