Refactored Property List methods

Author: JoshTheLion

expression.cpp

@@ -153,6 +153,16 @@ Expression::String Expression::asString() const noexcept{
 /***********************************************************************
 Property List and Graphic Primitive Methods
 **********************************************************************/
+void Expression::setProperty(const String key, Expression value)
+{
+  // Add/reset (key, value) to this Expression's property list
+  if(this->m_props.find(key) != this->m_props.end()){
+    std::swap(this->m_props.at(key), value);
+  }
+  else{
+		this->m_props.emplace(key, value);
+  }
+}
 
 Expression Expression::getProperty(const String key) const noexcept{
 
@@ -487,16 +497,12 @@ Expression Expression::set_property(Environment & env)
   // Evaluate main Expression and copy result (including m_props)
   Expression result = m_tail[2].eval(env);
 
-  // Add/reset (key, value) to property list of copied Expression
-  if(result.m_props.find(key) != result.m_props.end()){
-    std::swap(result.m_props.at(key), value);
-  }
-  else{
-    result.m_props.emplace(key, value);
-  }
+	// Add to property List
+	result.setProperty(key, value);
+
   // Return copied Expression with modified property list
   return result;
-};
+}
 
 /*
  * (get-property <String> <Expression>)
@@ -522,13 +528,7 @@ Expression Expression::get_property(Environment & env)
   // tail[1] can be any valid Expression
   Expression exp = m_tail[1].eval(env);
 
-  // Search property list of tail[1] copy for key
-  auto result = exp.m_props.find(key);
-  if(result != exp.m_props.end()){
-    return result->second;
-  }
-
-  return Expression();
+  return exp.getProperty(key);
 }
 
 // this is a simple recursive version. the iterative version is more

expression.hpp

@@ -100,8 +100,11 @@ class Expression {
   // Convenience member for external checks
   String asString() const noexcept;
 
-  // Temporary accessor method until I fix built-in methods later
-  Expression getProperty(String key) const noexcept;
+  // Convenient helper method for special-form equivalent
+  void setProperty(const String key, Expression value);
+
+	// Convenient helper method for special-form equivalent
+	Expression getProperty(const String key) const noexcept;
 
   /// convienience member to determine if Expression is a Graphic Primitive Point
   bool isPointG() const noexcept;

startup.pls

@@ -1,20 +1,22 @@
 (begin
-  (define make-point (lambda (x y) (begin
-									  (define point{x,y} (list x y))
-									  (define point{x,y} (set-property "object-name" "point" point{x,y}))
-									  ;(define point{x,y} (set-property "size" 0 point{x,y}))
-									)))
-  
-  (define make-line (lambda (p1 p2)(begin
-									  (define line{p1,p2} (list p1 p2))
-									  (define line{p1,p2} (set-property "object-name" "line" line{p1,p2}))
-									  ;(define line{p1,p2} (set-property "thickness" 1 line{p1,p2}))
-									)))
-  
-  (define make-text (lambda (str)  (begin
-									  (define text{str}  (str))
-									  (define text{str}  (set-property "object-name" "text" text{str}))
-									  ;(define point{x,y} (make-point 0 0))
-									  ;(define text{str}  (set-property "position" point{x,y} text{str}))
-									)))
+	(define make-point
+		(lambda (x y) (begin
+			(define point{x,y} (list x y))
+			(define point{x,y} (set-property "object-name" "point" point{x,y})) )
+		)
+	)
+	
+	(define make-line
+		(lambda (p1 p2) (begin
+			(define line{p1,p2} (list p1 p2))
+			(define line{p1,p2} (set-property "object-name" "line" line{p1,p2})) )
+		)
+	)
+	
+	(define make-text
+		(lambda (str) (begin
+			(define text{str} (str))
+			(define text{str} (set-property "object-name" "text" text{str})) )
+		)
+	)
 )