Add 'xo-expression/' from commit '5ac3c03a0c'

git-subtree-dir: xo-expression
git-subtree-mainline: d0f5ccc1ce
git-subtree-split: 5ac3c03a0c

xo-expression/src/expression/DefineExpr.cpp

@@ -0,0 +1,99 @@
+/* file DefineExpr.cpp
+ *
+ * author: Roland Conybeare
+ */
+
+#include "DefineExpr.hpp"
+
+namespace xo {
+    namespace ast {
+        rp<DefineExpr>
+        DefineExpr::make(std::string lhs_name,
+                         rp<Expression> rhs)
+        {
+            TypeDescr rhs_valuetype = nullptr;
+
+            if (rhs)
+                rhs_valuetype = rhs->valuetype();
+
+            return new DefineExpr(rhs_valuetype,
+                                  std::move(lhs_name),
+                                  std::move(rhs));
+        } /*make*/
+
+        DefineExpr::DefineExpr(TypeDescr rhs_valuetype,
+                               std::string lhs_name,
+                               rp<Expression> rhs)
+            : Expression(exprtype::define, rhs_valuetype),
+              lhs_name_{std::move(lhs_name)},
+              rhs_{std::move(rhs)}
+        {
+            this->free_var_set_ = this->calc_free_variables();
+        }
+
+        std::set<std::string>
+        DefineExpr::calc_free_variables() const
+        {
+            std::set<std::string> retval;
+
+            if (rhs_)
+                retval = rhs_->get_free_variables();
+
+            /* but remove this variable */
+            if (!this->lhs_name().empty())
+                retval.erase(this->lhs_name());
+
+            return retval;
+        } /*calc_free_variables*/
+
+        void
+        DefineExpr::display(std::ostream & os) const {
+            os << "<Define"
+               << xtag("name", lhs_name_)
+               << xtag("rhs", rhs_)
+               << ">";
+        } /*display*/
+
+        // ----- DefineExprAccess -----
+
+        rp<DefineExprAccess>
+        DefineExprAccess::make(std::string lhs_name,
+                               rp<Expression> rhs)
+        {
+            TypeDescr rhs_valuetype = nullptr;
+
+            if (rhs)
+                rhs_valuetype = rhs->valuetype();
+
+            return new DefineExprAccess(rhs_valuetype,
+                                        std::move(lhs_name),
+                                        std::move(rhs));
+        }
+
+        rp<DefineExprAccess>
+        DefineExprAccess::make_empty()
+        {
+            return new DefineExprAccess(nullptr /*rhs_valuetype*/,
+                                        "" /*lhs_name*/,
+                                        nullptr /*rhs*/);
+        }
+
+        void
+        DefineExprAccess::assign_rhs(const rp<Expression> & x)
+        {
+            assert(x);
+
+            this->rhs_ = x;
+
+            if (x) {
+                this->assign_valuetype(x->valuetype());
+            }
+
+            this->free_var_set_ = this->calc_free_variables();
+        }
+
+    } /*namespace ast*/
+} /*namespace xo*/
+
+
+/* end DefineExpr.cpp */