'and' and 'or' operators are now evaluated using logic shortcut (this behaviour can be changed setting system var '_bool_shortcut' to false

operator-bool.go

@@ -4,6 +4,8 @@
 // operator-bool.go
 package expr
 
+import "fmt"
+
 //-------- NOT term
 
 func newNotTerm(tk *Token) (inst *term) {
@@ -48,6 +50,15 @@ func newAndTerm(tk *Token) (inst *term) {
 }
 
 func evalAnd(ctx exprContext, self *term) (v any, err error) {
+	if isEnabled(ctx, preset_bool_shortcut) {
+		v, err = evalAndWithShortcut(ctx, self)
+	} else {
+		v, err = evalAndWithoutShortcut(ctx, self)
+	}
+	return
+}
+
+func evalAndWithoutShortcut(ctx exprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 	var leftBool, rightBool bool
 	var lok, rok bool
@@ -67,6 +78,32 @@ func evalAnd(ctx exprContext, self *term) (v any, err error) {
 	return
 }
 
+func evalAndWithShortcut(ctx exprContext, self *term) (v any, err error) {
+	var leftValue, rightValue any
+
+	if err = self.checkOperands(); err != nil {
+		return
+	}
+
+	if leftValue, err = self.children[0].compute(ctx); err != nil {
+		return
+	}
+
+	if leftBool, lok := toBool(leftValue); !lok {
+		err = fmt.Errorf("got %T as left operand type of 'and' operator, it must be bool", leftBool)
+		return
+	} else if !leftBool {
+		v = false
+	} else if rightValue, err = self.children[1].compute(ctx); err == nil {
+		if rightBool, rok := toBool(rightValue); rok {
+			v = rightBool
+		} else {
+			err = self.errIncompatibleTypes(leftValue, rightValue)
+		}
+	}
+	return
+}
+
 //-------- OR term
 
 func newOrTerm(tk *Token) (inst *term) {
@@ -82,6 +119,15 @@ func newOrTerm(tk *Token) (inst *term) {
 }
 
 func evalOr(ctx exprContext, self *term) (v any, err error) {
+	if isEnabled(ctx, preset_bool_shortcut) {
+		v, err = evalOrWithShortcut(ctx, self)
+	} else {
+		v, err = evalOrWithoutShortcut(ctx, self)
+	}
+	return
+}
+
+func evalOrWithoutShortcut(ctx exprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 	var leftBool, rightBool bool
 	var lok, rok bool
@@ -101,6 +147,32 @@ func evalOr(ctx exprContext, self *term) (v any, err error) {
 	return
 }
 
+func evalOrWithShortcut(ctx exprContext, self *term) (v any, err error) {
+	var leftValue, rightValue any
+
+	if err = self.checkOperands(); err != nil {
+		return
+	}
+
+	if leftValue, err = self.children[0].compute(ctx); err != nil {
+		return
+	}
+
+	if leftBool, lok := toBool(leftValue); !lok {
+		err = fmt.Errorf("got %T as left operand type of 'or' operator, it must be bool", leftBool)
+		return
+	} else if leftBool {
+		v = true
+	} else if rightValue, err = self.children[1].compute(ctx); err == nil {
+		if rightBool, rok := toBool(rightValue); rok {
+			v = rightBool
+		} else {
+			err = self.errIncompatibleTypes(leftValue, rightValue)
+		}
+	}
+	return
+}
+
 // init
 func init() {
 	registerTermConstructor(SymNot, newNotTerm)