From 5df79c53745fde5d6c3340a2979b1429cd5892c1 Mon Sep 17 00:00:00 2001
From: Henrik Rydberg <rydberg@euromail.se>
Date: Sat, 8 Oct 2011 20:30:28 +0200
Subject: Initial import of htcd system 1.0

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
---
 src/ops/express.cc | 173 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 173 insertions(+)
 create mode 100644 src/ops/express.cc

(limited to 'src/ops/express.cc')

diff --git a/src/ops/express.cc b/src/ops/express.cc
new file mode 100644
index 0000000..2cd3114
--- /dev/null
+++ b/src/ops/express.cc
@@ -0,0 +1,173 @@
+/*************************************************************************
+ *
+ * HTCd - Copyright (C) 1998-2006 Henrik Rydberg
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <ops/express.h>
+
+const mstring sp_tag="SP";
+
+////////////////////////////////////////////////////////////////
+
+uniheap<sizeof(expr_t)> expr_t::tree;
+void* expr_t::operator new(size_t n) { return tree.push(); }
+void expr_t::operator delete(void* p) { tree.pop(p); }
+
+////////////////////////////////////////////////////////////////
+
+inline int precedence(const expr_t* root,const op_t* op)
+{
+  if(!root->op) return 1;
+  else if(!op) return 0;
+  else if(root->left) {
+    if(root->right) return op->pre2&&root->op->pre2>=op->pre2;
+    else return root->op->pre2>=op->pre1;
+  }
+  else {
+    if(root->right) return op->pre2&&root->op->pre1>=op->pre2;
+    else return root->op->pre1>=op->pre1;
+  }
+}
+
+static int ins_node_sp(expr_t*& root,op_env& env,
+                       const sref& in,const op_t* op) throw(merror_t)
+{
+  if(root==0) { root=new expr_t(in,op); root->expand(env); return 1; }
+  else if(precedence(root,op)) {
+    if(op) { root=new expr_t(in,op,root); return 1; } else return 0;
+  }
+  else return ins_node_sp(root->right,env,in,op);
+}
+
+static void ins_node(expr_t*& root,op_env& env,const sref& in) throw(merror_t)
+{
+  const op_t* op=env.ops->get(in);
+  if(!ins_node_sp(root,env,in,op)) {
+    if(!ins_node_sp(root,env,sp_tag,env.ops->get(sp_tag)))
+      THROW("ops: ("<<root->expr<<" ["<<in<<"]): operator expected");
+    ins_node_sp(root,env,in,op);
+  }
+}
+
+///////////////////////////////////////////////////////////////
+
+void expr_t::clear()
+{
+  expr.clear();
+  op=0;
+  status=OP_ALL;
+  result.clear();
+  delete left; left=0;
+  delete right; right=0;
+}
+
+void expr_t::copy(const expr_t& x)
+{
+  expr=x.expr;
+  op=x.op;
+  if(x.left) left=new expr_t(*x.left);
+  if(x.right) right=new expr_t(*x.right);
+}
+
+void expr_t::trav(mstream& out,int n)
+{
+  if(n&&left) left->trav(out,n-1);
+  for(int i=0;i<3*n;i++) out.put(' ');
+  out<<"["<<expr<<"]("<<status<<") -> "<<result<<"\n";
+  if(n&&right) right->trav(out,n-1);
+}
+
+void expr_t::expand(op_env& env) throw(merror_t)
+{
+  if(!op) {
+    sref first,rest=expr;
+    env.split(first,rest);
+    if(first!=expr) {
+      do ins_node(right,env,first);
+      while(env.split(first,rest));
+    }
+  }
+}
+
+///////////////////////////////////////////////////////////////
+
+void expr_t::eval(mstream& out,op_env& env,int opt) throw(merror_t)
+{
+  if(op) {
+    if(left) {
+      if(op->left>1) {
+        if(left->status&opt) {
+          swrite sw(left->result);
+          left->eval(sw,env,opt);
+        }
+      }
+      else if(!op->left)
+        THROW("ops: ("<<left->expr<<" ["<<expr<<"]): not an L operator")
+      else if(left->op)
+        THROW("ops: (["<<left->expr<<"] "<<expr<<"): Lvalue required")
+      else {
+        left->status=OP_LOCAL;
+        left->result=left->expr;
+      }
+    }
+    if(right) {
+      if(op->right>1) {
+        if(right->status&opt) {
+          swrite sw(right->result);
+          right->eval(sw,env,opt);
+        }
+      }
+      else if(!op->right)
+        THROW("ops: ("<<right->expr<<" ["<<expr<<"]): not an R operator")
+      else if(right->op)
+        THROW("ops: (["<<right->expr<<"] "<<expr<<"): Lvalue required")
+      else {
+        right->status=OP_LOCAL;
+        right->result=right->expr;
+      }
+    }
+    if(left) {
+      if(right) {
+        status=left->status|right->status;
+        if((status&OP_NINIT)==0) op->f2(out,env,left->result,right->result);
+      }
+      else if(!op->f1)
+        THROW("ops: ("<<left->expr<<" "<<expr<<" [R]): missing R argument")
+      else {
+        status=left->status;
+        if((status&OP_NINIT)==0) op->f1(out,env,left->result);
+      }
+    }
+    else if(right) {
+      if(!op->f1)
+        THROW("ops: ([L] "<<expr<<" "<<right->expr<<"): missing L argument")
+      else {
+        status=right->status;
+        if((status&OP_NINIT)==0) op->f1(out,env,right->result);
+      }
+    }
+    else THROW("ops: ["<<expr<<"]: operator not expected");
+  }
+  else {
+    if(right) {
+      right->eval(out,env,opt);
+      status=right->status;
+    }
+    else env.term(out,this);
+  }
+  if(status&OP_NINIT) THROW("ops: unfinished expression ["<<expr<<"]");
+}
-- 
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