refactor: FieldForms.hx

src/kiss/FieldForms.hx

@@ -0,0 +1,102 @@
+package kiss;
+
+import haxe.macro.Expr;
+import haxe.macro.Context;
+import kiss.Reader;
+
+using StringTools;
+
+// Fields usually are set to expressions, so a ReaderExp conversion function
+// needs to be passed to field forms
+typedef ExprConversion = (ReaderExp) -> Expr;
+
+// Field forms convert Kiss reader expressions into Haxe macro class fields
+typedef FieldFormFunction = (position:String, args:Array<ReaderExp>, convert:ExprConversion) -> Field;
+
+class FieldForms {
+	public static function builtins() {
+		var map:Map<String, FieldFormFunction> = [];
+
+		map["defvar"] = varOrProperty.bind("defvar");
+		map["defprop"] = varOrProperty.bind("defprop");
+
+		map["defun"] = funcOrMethod.bind("defun");
+		map["defmethod"] = funcOrMethod.bind("defmethod");
+
+		return map;
+	}
+
+	static function fieldAccess(formName:String, fieldName:String) {
+		var access = [];
+		if (formName == "defvar" || formName == "defun") {
+			access.push(AStatic);
+		}
+		access.push(if (fieldName.startsWith("_")) APrivate else APublic);
+		return access;
+	}
+
+	static function fieldName(formName:String, position:String, nameExp:ReaderExp) {
+		return switch (nameExp) {
+			case Symbol(name):
+				name;
+			default:
+				throw 'The first argument to $formName at $position should be a variable name';
+		};
+	}
+
+	static function varOrProperty(formName:String, position:String, args:Array<ReaderExp>, convert:ExprConversion):Field {
+		if (args.length != 2) {
+			throw '$formName with $args at $position is not a valid field definition';
+		}
+
+		var name = fieldName(formName, position, args[0]);
+		var access = fieldAccess(formName, name);
+
+		return {
+			name: name,
+			access: access,
+			kind: FVar(null, // TODO allow type anotations
+				convert(args[1])),
+			pos: Context.currentPos()
+		};
+	}
+
+	static function funcOrMethod(formName:String, position:String, args:Array<ReaderExp>, convert:ExprConversion):Field {
+		if (args.length <= 2) {
+			throw '$formName with $args is not a valid function/method definition';
+		}
+
+		var name = fieldName(formName, position, args[0]);
+		var access = fieldAccess(formName, name);
+
+		return {
+			name: name,
+			access: access,
+			kind: FFun({
+				args: switch (args[1]) {
+					case List(funcArgs):
+						[
+							for (funcArg in funcArgs)
+								{
+									name: switch (funcArg) {
+										case Symbol(name):
+											name;
+										default:
+											throw '$funcArg should be a symbol for a function argument';
+									},
+									type: null
+								}
+						];
+					default:
+						throw '$args[1] should be an argument list';
+				},
+				ret: null,
+				expr: {
+					pos: Context.currentPos(),
+					expr: EReturn(convert(Call(Symbol("begin"), args.slice(2))))
+				}
+			}),
+			pos: Context.currentPos()
+		};
+	}
+}

src/kiss/Kiss.hx

@@ -4,6 +4,7 @@ import haxe.macro.Context;
 import haxe.macro.Expr;
 import kiss.Stream;
 import kiss.Reader;
+import kiss.FieldForms;
 
 class Kiss {
 	/**
@@ -14,6 +15,9 @@ class Kiss {
 
 		var stream = new Stream(kissFile);
 		var reader = new Reader();
+
+		var fieldForms = FieldForms.builtins();
+
 		while (true) {
 			stream.dropWhitespace();
 			if (stream.isEmpty())
@@ -26,7 +30,7 @@ class Kiss {
 			// The last expression might be a comment, in which case None will be returned
 			switch (nextExp) {
 				case Some(nextExp):
-					classFields.push(readerExpToField(nextExp, position));
+					classFields.push(readerExpToField(nextExp, position, fieldForms));
 				case None:
 					stream.dropWhitespace(); // If there was a comment, drop whitespace that comes after
 			}
@@ -35,58 +39,12 @@ class Kiss {
 		return classFields;
 	}
 
-	static function readerExpToField(exp:ReaderExp, position:String):Field {
+	static function readerExpToField(exp:ReaderExp, position:String, fieldForms:Map<String, FieldFormFunction>):Field {
 		return switch (exp) {
-			case Call(Symbol("defvar"), args) if (args.length == 2):
-				{
-					name: switch (args[0]) {
-						case Symbol(name):
-							name;
-						default:
-							throw 'The first argument to defvar at $position should be a variable name';
-					},
-					access: [APublic, AStatic],
-					kind: FVar(null, // TODO allow type anotations
-						readerExpToHaxeExpr(args[1])),
-					pos: Context.currentPos()
-				};
-			case Call(Symbol("defun"), args) if (args.length > 2):
-				{
-					name: switch (args[0]) {
-						case Symbol(name):
-							name;
-						default:
-							throw 'The first argument to defun at $position should be a function name';
-					},
-					access: [APublic, AStatic],
-					kind: FFun({
-						args: switch (args[1]) {
-							case List(funcArgs):
-								[
-									for (funcArg in funcArgs)
-										{
-											name: switch (funcArg) {
-												case Symbol(name):
-													name;
-												default:
-													throw '$funcArg should be a symbol for a function argument';
-											},
-											type: null
-										}
-								];
-							default:
-								throw '$args[1] should be an argument list';
-						},
-						ret: null,
-						expr: {
-							pos: Context.currentPos(),
-							expr: EReturn(readerExpToHaxeExpr(Call(Symbol("begin"), args.slice(2))))
-						}
-					}),
-					pos: Context.currentPos()
-				};
+			case Call(Symbol(formName), args) if (fieldForms.exists(formName)):
+				fieldForms[formName](position, args, readerExpToHaxeExpr);
 			default:
-				throw '$exp at $position is not a valid defvar or defun expression';
+				throw '$exp at $position is not a valid field form';
 		};
 	}
 

src/test/cases/BasicTestCase.hx

@@ -20,4 +20,12 @@ class BasicTestCase extends Test {
 	function testFuncall() {
 		Assert.equals(7, BasicTestCase.funResult);
 	}
+
+	function testField() {
+		Assert.equals(5, new BasicTestCase().myField);
+	}
+
+	function testMethod() {
+		Assert.equals(5, new BasicTestCase().myMethod());
+	}
 }

src/test/cases/BasicTestCase.kiss

@@ -7,4 +7,10 @@
     // funcalls can use dot access
     (Math.floor num))
 // functions are resolved in the macro context
-(defvar funResult (myFloor 7.5))
+(defvar funResult (myFloor 7.5))
+
+// (defprop) declares instance variables
+(defprop myField 5)
+
+// (defmethod) declares instance methods
+(defmethod myMethod [] this.myField)