Expressions now support function definition

operand-expr.go

@@ -0,0 +1,36 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// operand-expr.go
+package expr
+
+import "errors"
+
+// -------- expr term
+func newExprTerm(tk *Token) *term {
+	return &term{
+		tk:       *tk,
+		class:    classVar,
+		kind:     kindUnknown,
+		parent:   nil,
+		children: nil,
+		position: posLeaf,
+		priority: priValue,
+		evalFunc: evalExpr,
+	}
+}
+
+// -------- eval expr
+func evalExpr(ctx exprContext, self *term) (v any, err error) {
+	if expr, ok := self.value().(Expr); ok {
+		v, err = expr.Eval(ctx, false)
+	} else {
+		err = errors.New("invalid body of function definition")
+	}
+	return
+}
+
+// init
+// func init() {
+// 	registerTermConstructor(SymExpression, newExprTerm)
+// }