MADARA  3.1.8
SystemCallExpandStatement.cpp
Go to the documentation of this file.
1 
2 #ifndef _MADARA_NO_KARL_
3 
4 
9 
10 
13  const ComponentNodes & nodes)
14  : SystemCallNode (context, nodes)
15 {
16 
17 }
18 
19 // Dtor
21 {
22 }
23 
26 {
28 }
29 
35 {
36  // user can always change a function, and we have no control over
37  // what it does. Consequently, a function node cannot be pruned out
38  // under any situation
39  can_change = true;
40 
42 
43  if (nodes_.size () == 1)
44  {
45  bool arg_can_change = false;
46  result = nodes_[0]->prune (arg_can_change);
47 
48  if (!arg_can_change && dynamic_cast <LeafNode *> (nodes_[0]) == 0)
49  {
50  delete nodes_[0];
51  nodes_[0] = new LeafNode (*(this->logger_), result);
52  }
53  }
54  else
55  {
57  "KARL COMPILE ERROR: System call expand_statement requires 1 argument,"
58  "e.g., #expand_statement ('var{.i}')\n");
59  }
60 
61 
62  return result;
63 }
64 
70 {
71  knowledge::KnowledgeRecord return_value;
72 
73  if (nodes_.size () == 1)
74  {
75  std::string statement (nodes_[0]->evaluate (settings).to_string ());
76 
78  "System call expand_statement is returning the expansion "
79  "of %s.\n", statement.c_str ());
80 
82  }
83  else
84  {
86  "KARL COMPILE ERROR: System call expand_statement requires 1 argument,"
87  "e.g., #expand_statement ('var{.i}').\n");
88  }
89 
90  return return_value;
91 }
92 
93 // accept a visitor
94 void
96  madara::expression::Visitor &visitor) const
97 {
98  visitor.visit (*this);
99 }
100 
101 #endif // _MADARA_NO_KARL_
This class encapsulates an entry in a KnowledgeBase.
virtual madara::knowledge::KnowledgeRecord item(void) const
Returns the value of the node.
madara::knowledge::KnowledgeRecord KnowledgeRecord
std::deque< ComponentNode * > ComponentNodes
a vector of Component Nodes
logger::Logger * logger_
handle the context
Definition: ComponentNode.h:96
This class stores variables and their values for use by any entity needing state information in a thr...
virtual madara::knowledge::KnowledgeRecord evaluate(const madara::knowledge::KnowledgeUpdateSettings &settings)
Evaluates the expression tree.
Defines a node that contains a madara::knowledge::KnowledgeRecord::Integer value. ...
Definition: LeafNode.h:23
virtual void accept(Visitor &visitor) const
Accepts a visitor subclassed from the Visitor class.
#define madara_logger_ptr_log(logger, level,...)
Fast version of the madara::logger::log method for Logger pointers.
Definition: Logger.h:32
Abstract base class for all visitors to all classes that derive from ComponentNode.
Definition: Visitor.h:90
madara::knowledge::ThreadSafeContext & context_
static constexpr struct madara::knowledge::tags::string_t string
Interface for a MADARA system call.
std::string expand_statement(const std::string &statement) const
Expands a string with variable expansion.
SystemCallExpandStatement(madara::knowledge::ThreadSafeContext &context, const ComponentNodes &nodes)
Constructor.
virtual madara::knowledge::KnowledgeRecord prune(bool &can_change)
Prunes the expression tree of unnecessary nodes.
Settings for applying knowledge updates.
virtual void visit(const LeafNode &node)=0
Visit a LeafNode.