allow chained commands for less verbose way to add Strands to DNADesign #85
Description
codenano allows "chained commands" for a less verbose way to create strands. For example see here: https://docs.rs/codenano/0.5.1/codenano/
design.strand(0, 0).to(31)
.cross(1).to(10)
.cross(2).to(21);
// Now its reverse complement:
design.strand(2, 21).to(10)
.cross(1).to(31)
.cross(0).to(0);This is equivalent to the more verbose Python code:
domain_11 = sc.Domain(0, True, 0, 31)
domain_12 = sc.Domain(1, False, 10, 31)
domain_13 = sc.Domain(2, True, 10, 21)
strand1 = sc.Strand([domain_11, domain_12, domain_13])
domain_21 = sc.Domain(2, False, 10, 21)
domain_22 = sc.Domain(1, True, 10, 31)
domain_23 = sc.Domain(0, False, 0, 31)
strand1 = sc.Strand([domain_11, domain_12, domain_13])or the slightly less verbose
strand1 = sc.Strand([
sc.Domain(0, True, 0, 31),
sc.Domain(1, False, 10, 31),
sc.Domain(2, True, 10, 21),
])
strand1 = sc.Strand([
sc.Domain(2, False, 10, 21),
sc.Domain(1, True, 10, 31),
sc.Domain(0, False, 0, 31),
])Note that this requires crossovers to be "vertical", i.e., they have the same offset on the from Helix and the to Helix. Perhaps that can be overridden with an optional second parameter to cross. But since the most common crossover is vertical, the less verbose method is superior, since it reduces the amount of redundant information that needs to be specified.