The Fortress Language Specification - CiteSeerX

Values, evaluation contexts, and redexes
v ::= O −→ τ ( −→ v ) value
E ::= □ evaluation context
| O −→ τ ( −→ e E −→ e )
| E.x
| E.f −→ τ ( −→ e )
| e.f −→ τ ( −→ e E −→ e )
| f −→ τ ( −→ e E −→ e )
R ::= v.x redex
| v.f −→ τ ( −→ v )
| f −→ τ ( −→ v )
Evaluation rules: p ⊢ E[R] −→ E[e]
[R-FIELD]
[R-METHOD]
[R-FUNCTION]
object O ( −−→ x: ) end ∈ p
p ⊢ E[O −→ τ ( −→ v ).x i ] −→ E[v i ]
object O −−−−−−−−−→ αextends N( −−→ x: ) end ∈ p
−−−−−→
type(v ′ ) = −→ τ ′′
mostspecific p;∅ (applicable p;∅ (f −→ τ ′ ( −→ τ ′′ ),visible p (O −→ τ ))) = f −−−−−−−−−−→ α ′ extends N ′ ( −−→ x ′ : ):
p ⊢ E[O −→ τ ( −→ v ).f −→ τ ′ ( −→ v ′ )] −→ E[[ −→ v / −→ x ][O −→ τ ( −→ v )/self][ −→ v ′ / −→ x ′ ]e]
−−−−→
type(v) = −→ τ ′
mostspecific p;∅ (applicable p;∅ (f −→ τ ( −→ τ ′ ), {(fd,Object) | fd ∈ p})) = f −−−−−−−−−→ αextends N( −−→ x: ): = e
p ⊢ E[f −→ τ ( −→ v )] −→ E[[ −→ v / −→ x ]e]
= e
Types of values: type(v) = τ
type(O −→ τ ( −→ v )) = O −→ τ
Figure A.14: Dynamic Semantics of Core Fortress with Overloading
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