function edit.check_locs(State)
-- if State is inconsistent (i.e. file changed by some other program),
-- throw away all cursor state entirely
if edit.invalid1(State, State.screen_top1)
or edit.invalid1(State, State.cursor1)
or not edit.cursor_on_text(State)
or not Text.le1(State.screen_top1, State.cursor1) then
State.screen_top1 = {line=1, pos=1}
edit.put_cursor_on_first_text_line(State)
end
end
function edit.invalid1(State, loc1)
return loc1.line > #State.lines
or loc1.pos > #State.lines[loc1.line].data
end
function edit.cursor_on_text(State)
return State.cursor1.line <= #State.lines
and State.lines[State.cursor1.line].mode == 'text'
end
function edit.put_cursor_on_first_text_line(State)