Symbolic

Code Organization

This package implements symbolic evaluation and typechecking. This package does not implement a type system in the traditional sense.

• eval.go: main evaluation logic
• eval_call.go: function call evaluation logic
• state.go: symbolic evaluation state
• data.go: symbolic evaluation and type checking data (e.g. typechecking errors, warnings)
• narrowing_widening.go: type narrowing and widening
• multivalue.go: symbolic representation of value unions
• intersection.go: type intersection
• readonly.go: interfaces and helpers related to readonly values (unrelated to immutable values)
• pattern.go: symbolic representation of Inox patterns (e.g object pattens)
• error.go: error message constants and formatting

The other files contain the symbolic representations of Inox values: most of the files in the core package have a counterpart in this package.

Implementation Details

Representation

Symbolic values are immutable. They are replaced when a mutation happens in analyzed code. In the following example the symbolic representation of {a: 1} (an *Object) is immutable. When obj is mutated the scope is updated with a new *Object of value {a: 2} assigned to obj.

obj = {a: 1}
obj.a = 2