refactor how repl works

internal/compiler/symbol_table.go

@@ -20,7 +20,7 @@ type SymbolTable struct {
 	Outer *SymbolTable
 
 	Store          map[string]Symbol
-	numDefinitions int
+	NumDefinitions int
 
 	FreeSymbols []Symbol
 }
@@ -38,7 +38,7 @@ func NewSymbolTable() *SymbolTable {
 }
 
 func (s *SymbolTable) Define(name string) Symbol {
-	symbol := Symbol{Name: name, Index: s.numDefinitions}
+	symbol := Symbol{Name: name, Index: s.NumDefinitions}
 	if s.Outer == nil {
 		symbol.Scope = GlobalScope
 	} else {
@@ -46,7 +46,7 @@ func (s *SymbolTable) Define(name string) Symbol {
 	}
 
 	s.Store[name] = symbol
-	s.numDefinitions++
+	s.NumDefinitions++
 	return symbol
 }