Linted symbol_table.rb

lib/n65/symbol_table.rb

@@ -1,128 +1,108 @@
+# frozen_string_literal: true
 
 module N65
-
   class SymbolTable
     attr_accessor :scope_stack
 
-    #####  Custom Exceptions
+    # Custom Exceptions
     class InvalidScope < StandardError; end
     class UndefinedSymbol < StandardError; end
     class CantExitScope < StandardError; end
 
-
+    # Initialize a symbol table that begins in global scope
-    ####
-    ##  Initialize a symbol table that begins in global scope
     def initialize
       @symbols = {
-        :global => {}
+        global: {}
       }
       @anonymous_scope_number = 0
       @scope_stack = [:global]
       @subroutine_cycles = {}
     end
 
-
+    # Add a running cycle count to current top level scopes (ie subroutines)
-    ####
-    ##  Add a running cycle count to current top level scopes (ie subroutines)
     def add_cycles(cycles)
       cycles ||= 0
       top_level_subroutine = @scope_stack[1]
-      unless top_level_subroutine.nil?
+      return if top_level_subroutine.nil?
-        @subroutine_cycles[top_level_subroutine] ||= 0
+
-        @subroutine_cycles[top_level_subroutine] += cycles
+      @subroutine_cycles[top_level_subroutine] ||= 0
-      end
+      @subroutine_cycles[top_level_subroutine] += cycles
     end
 
-
+    # Define a new scope, which can be anonymous or named
-    ####
+    # and switch into that scope
-    ##  Define a new scope, which can be anonymous or named
-    ##  and switch into that scope
     def enter_scope(name = nil)
       name = generate_name if name.nil?
       name = name.to_sym
       scope = current_scope
-      if scope.has_key?(name)
+      raise(InvalidScope, "Scope: #{name} already exists") if scope.key?(name)
-        fail(InvalidScope, "Scope: #{name} already exists")
+
-      end
       scope[name] = {}
       @scope_stack.push(name)
     end
 
-
+    # Exit the current scope
-    ####
-    ##  Exit the current scope
     def exit_scope
-      if @scope_stack.size == 1
+      raise(CantExitScope, 'You cannot exit global scope') if @scope_stack.size == 1
-        fail(CantExitScope, "You cannot exit global scope")
+
-      end
       @scope_stack.pop
     end
 
-
+    # Define a symbol in the current scope
-    ####
-    ##  Define a symbol in the current scope
     def define_symbol(symbol, value)
       scope = current_scope
       scope[symbol.to_sym] = value
     end
 
-
+    # Separate arithmetic from scope name
-    ####
-    ##  Separate arithmetic from scope name
     def find_arithmetic(name)
       last_name = name.split('.').last
-      md = last_name.match(/([\+\-\*\/])(\d+)$/)
+      md = last_name.match(%r{([+\-*/])(\d+)$})
-      f = lambda{|v| v}
+      f = ->(v) { v }
 
       unless md.nil?
         full_match, operator, argument = md.to_a
         name.gsub!(full_match, '')
-        f = lambda {|value| value.send(operator.to_sym, argument.to_i) }
+        f = ->(value) { value.send(operator.to_sym, argument.to_i) }
       end
 
       [name, f]
     end
 
-
+    # Resolve a symbol to its value
-    ####
-    ##  Resolve a symbol to its value
     def resolve_symbol(name)
       name, arithmetic = find_arithmetic(name)
 
       method = name.include?('.') ? :resolve_symbol_dot_syntax : :resolve_symbol_scoped
-      value = self.send(method, name)
+      value = send(method, name)
       value = arithmetic.call(value)
+      raise(UndefinedSymbol, name) if value.nil?
 
-      fail(UndefinedSymbol, name) if value.nil?
       value
     end
 
-
+    # Resolve symbol by working backwards through each
-    ####
+    # containing scope.  Similarly named scopes shadow outer scopes
-    ##  Resolve symbol by working backwards through each
-    ##  containing scope.  Similarly named scopes shadow outer scopes
     def resolve_symbol_scoped(name)
       root = "-#{name}".to_sym
       stack = @scope_stack.dup
       loop do
         scope = retreive_scope(stack)
 
-        ##  We see if there is a key either under this name, or root
+        # We see if there is a key either under this name, or root
         v = scope[name.to_sym] || scope[root]
-        v = v.kind_of?(Hash) ? v[root] : v
+        v = v.is_a?(Hash) ? v[root] : v
 
         return v unless v.nil?
 
-        ##  Pop the stack so we can decend to the parent scope, if any
+        # Pop the stack so we can decend to the parent scope, if any
         stack.pop
         return nil if stack.empty?
       end
     end
 
-
+    # Dot syntax means to check an absolute path to the symbol
-    ####
+    # :global is ignored if it is provided as part of the path
-    ##  Dot syntax means to check an absolute path to the symbol
-    ##  :global is ignored if it is provided as part of the path
     def resolve_symbol_dot_syntax(name)
       path_ary = name.split('.').map(&:to_sym)
       symbol = path_ary.pop
@@ -131,40 +111,32 @@ module N65
 
       scope = retreive_scope(path_ary)
 
-      ##  We see if there is a key either under this name, or root
+      # We see if there is a key either under this name, or root
       v = scope[symbol]
-      v.kind_of?(Hash) ? v[root] : v
+      v.is_a?(Hash) ? v[root] : v
     end
 
-
+    # Export the symbol table as YAML
-    ####
-    ##  Export the symbol table as YAML
     def export_to_yaml
       @symbols.to_yaml.gsub(/(\d+)$/) do |match|
         integer = match.to_i
-        sprintf("0x%.4X", integer)
+        format('0x%.4X', integer)
       end
     end
 
-
+    # Export a cycle count for top level subroutines
-    ####
-    ##  Export a cycle count for top level subroutines
     def export_cycle_count_yaml
       @subroutine_cycles.to_yaml
     end
 
-
     private
 
-    ####
+    # A bit more clearly states to get the current scope
-    ##  A bit more clearly states to get the current scope
     def current_scope
       retreive_scope
     end
 
-
+    # Retrieve a reference to a scope, current scope by default
-    ####
-    ##  Retrieve a reference to a scope, current scope by default
     def retreive_scope(path_ary = @scope_stack)
       path_ary = path_ary.dup
       path_ary.unshift(:global) unless path_ary.first == :global
@@ -175,28 +147,22 @@ module N65
         if new_scope.nil?
           path_string = generate_scope_path(path_ary)
           message = "Resolving scope: #{path_string} failed at #{path_component}"
-          fail(InvalidScope, message) if new_scope.nil?
+          raise(InvalidScope, message) if new_scope.nil?
         end
 
         new_scope
       end
     end
 
-
+    # Generate a scope path from an array
-    ####
-    ##  Generate a scope path from an array
     def generate_scope_path(path_ary)
       path_ary.join('.')
     end
 
-
+    # Generate an anonymous scope name
-    ####
-    ##  Generate an anonymous scope name
     def generate_name
       @anonymous_scope_number += 1
       "anonymous_#{@anonymous_scope_number}"
     end
-
   end
-
 end