> viewing the source of a program as a linear page of text doesn't make much sense. I don’t think we really view a file of source code as a linear page of text

> viewing the source of a program as a linear page of text doesn't make much sense. I don’t think we really view a file of source code as a linear page of text though, right? It’s a tree. Sibling nodes are often laid out either horizontally or vertically, and children are often wrapped in some type of brace and/or indented, maybe delimited. I think the fact that editors usually a) align the textual boundaries of tree nodes, and b) allow syntactically/semantically-invalid states, sometimes gets people thinking about editing a character stream instead of a semantic tree.