IR Constants

Due to the mathematical foundation of ASMs, all constants with a type (Type) can have besides the type-specified (domain) content, an undefined value (undef). All type-specific content together with the undef value is represented in the following Extended Backus–Naur Form (EBNF) definition as Value.

Constant ::= "@" identifier "=" Type Value

Furthermore, we directly include in the CASM-IR the notion of symbolic (sym) values that enable a clear definition of numeric as well as symbolic execution, whereas the symbolic values are its own domain. The Listing given below depicts three constant examples – an integer, a string, and a rule reference constant:

;; integer constant of value ’123’
@c0 = i 123
;; string constant of value ’foobar’
@c1 = s "foobar"
;; rule reference constant of value ’undef’
@c2 = r < -> v > undef