Adds:
- analyzer/LocalVariableScope: tracks local variables created within a given scope.
- Instantiated on the stack during semantic analysis, this registers itself with LocalVariableScopes during construction and deregisters itself during destruction.
- Detects unused variables during deregistration
- analyzer/LocalVariableScopes: this is what LocalVariableScope registers with.
- keeps track of the stack of local scopes.
- can provide the current local scope, for var statements.
Other notes:
"Shadowed" variables: this is when a variable in one scope hides a variable in another, like so:
var a := 2;
if (a)
var a := 3;
a := 4;
endif
print(a); // still 2
"debug_variables": We'll use these later when writing debug files.
Adds support for var statements at the global level.
Adds:
- analyzer/Variables: keeps track of the variables in scope (either local or global).
- ast/Identifier: AST node for an identifier.
- The optimizer will replace constant identifiers with their constant value (in a later commit).
- The semantic analyzer will set the variable field for local or global variable identifiers.
- ast/VarStatement: AST node for a var statement.
- A single var statement will generate one VarStatement per variable declared.
- model/Variable: Describes a variable, including its index within its scope.
