1. A method of generating program source code to perform a mapping task in which enterprise system nested array object fields and legacy system nested array object fields are mapped to one another, said method comprising: performing a depth-first traversal of a logical tree having a root node, a leaf node for each desired mapping connection, and intermediate nodes between said root node and said leaf nodes, each intermediate node being associated with an array, the depth-first traversal comprising: (i) for each intermediate node visited when traversing away from said root node, generating program source code to open a loop; (ii) for each visited leaf node, generating program source code to create the mapping connection represented by said visited leaf node; and (iii) for each intermediate node having no unvisited children that is visited when traversing towards said root node, generating program source code to close said loop.