Lexical analyzer in java

The program need to read any text file that contains (what is intended to be) a string in the category ⟨fun def list⟩. It will then construct an explicit parse tree and display it in linearly indented form: each syntactic category name labeling a node is displayed on a separate line, prefixed with the integer i representing the node's depth and indented by i blanks. This is a basic form of syntax profiler.