Syntax Section

[rapodaca]

LL(1) formal grammar is the centerpiece. It could be a challenge to strike the right balance between background info on that and describing the syntax itself.

• UTF-8 string
  • "dstrings" ?
• encodes a depth-first traversal
  • branches
  • closures (C1CC1), "closure digit" = rnum (blech)
  • disconnections (C.C)
  • allows multiple components
• formal grammar
  • LL(1)
  • listing
  • changes from before
    • --, ++ charge disallowed
    • only @ and @@ configuration
    • closure, disconnection
• data types
  • Integer(n)
  • -n -> +n, inclusive
  • PositiveInteger(n)
  • 0 -> n, inclusive
  • Boolean
  • AtomicSymbol
  • list published by IUPAC
  • LowercaseSymbol
  • Star
  • Configuration
  • None
• atoms
  • bare
  • "organic subset"
  • bracketed [ ... ]
  • virtual hydrogens
    • default values
    • isotope: None
    • hcount: 0
    • charge: 0
    • configuration: none
    • extension: none
  • lowercase
  • eligibility
  • may occur inside or outside brackets
• bonds
  • single -, double =, triple # quadruple $
  • elided
  • none `,:`
  • always two-electron
  • up /, down /
  • two-electron
• closures
  • closure digits: 1..99
  • balancing not easily expressable in syntax
  • it could be done, but with a lot of effort
    • explain
  • re-use digits
  • interaction with up/down bonds
  • errors
  • loops (C11)
  • up/down mismatch
• disconnection .
  • "no bond"
  • not "zero order bond", but no bond
  • explicitly allows zob extension (link)
  • to enable disconnected components
  • other uses
    • example
  • may occur within cycle
  • examples
  • may not occur immediately before ring junction
• using the formal grammar
  • reading
  • recursive descent parser
  • scanner-driven parser development
  • parser generator
  • parentheses vs. ring closure digits
  • writing
  • no counterpart to scanner-driven parser development

[rapodaca]

Resources on including BNF in LaTex:

• Which package can be used to write BNF grammars?
• The backnaur package
• How to set indentation within grammar environment?

When a suitable LaTeX package is found, it will need to be activated. This can (hopefully) be done by adding the appropriate entry in the header-includes section of the manuscript front matter.

Installing CTAN packages:

• How do I install CTAN packages on Mac OS with TexShop? . Third option (tlmgr) appears to be installed.