Source code structural inference based on indentation

Inferring source code structure based on indentation. A portion of source code comprising a plurality of lines is identified, and a corresponding indentation level for each line is determined. A plurality of nodes, each representing a different line in the plurality of lines are generated. The nodes are arranged into an ordered tree based on the corresponding indentation level for each line. Based on an identified line in the plurality of lines, a subset of the plurality of lines are identified from the ordered tree, based on identifying a subtree that comprises a node representing the identified line. A source code action is initiated based on the subset of the plurality of lines.