Element Selection Syntax

[ax3l]

5hr vibe pair coded in Cursor. Maybe should have just done it manually instead of holding its hand xD

I guided/instructed, reviewed and adjusted the logic throughout. If you like to review this PR, please just look at the user-facing logic and if you like the test, to safe time.

# Filter by element type
drift_elements = lattice.select(kind="Drift")
quad_elements = lattice.select(kind=elements.Quad)

# Filter by regex pattern
all_quads = lattice.select(kind=r".*Quad")  # matches Quad, ChrQuad, ExactQuad

# Filter by name
specific_elements = lattice.select(name="quad1")

# Chain filters (AND logic)
drift_named_d1 = lattice.select(kind="Drift").select(name="drift1")

# Modify original elements through references
drift_elements[0].ds = 2.0  # modifies original lattice

• implement most important functions for Element Selection Syntax #1088 Python: Element Groups & Lattice Manipulation #884: name & kind filters (modifiable results)
• docs

Follow-Up Ideas

• filter by position / position range in s Element Selection Syntax: Position #1183
• return boolean masks and filter by them, too
• filter by provided element attributes: give me all elements that have a k property, are thin/thick, etc.
• scale an attribute of selection result elements (e.g., multiply/add the .k property of every element in the selection): can be done in a simple 2-liner loop already

[cemitch99]

Great feature, which will no doubt be widely used. Works for me on some local tests.