Unigine.Expression Class
This class allows you to execute a given code fragment at run-time. There can be up to 4 arguments of any type passed to the Expression. The setVariable() function sets values of such arguments. For example:
Source code (C#)
Expression e0 = new Expression(Engine.get().getWorldInterpreter(), "133.0 * 133.0");
if (e0.isCompiled() == 1)
{
Log.Message("{0}\n", e0.run().getFloat());
}
Expression e1 = new Expression(Engine.get().getWorldInterpreter(), @"
{
int a,b,c,d;
return a + b + c + d;
}
");
e1.setVariable("a", new Variable(1));
e1.setVariable("b", new Variable(2));
e1.setVariable("c", new Variable(3));
e1.setVariable("d", new Variable(4));
if(e1.isCompiled() == 1) {
Log.Message("{0}\n",e1.run().getInt());
}
Expression e2 = new Expression(Engine.get().getWorldInterpreter(), @"
{
string name;
File file = new File(name," + "\"rb\"" + @");
int size = file.getSize();
file.close();
delete file;
return size;
}
");
e2.setVariable("name", new Variable("test.cpp"));
if(e2.isCompiled() == 1) {
Log.Message("{0}\n", e2.run().getInt());
}
Output
double: 17689
int: 10
int: 1302Expression Class
Members
Expression ( IntPtr interpreter, string src, int scope = 0 ) #
Constructor. Creates the expression from the specified source buffer.Arguments
- IntPtr interpreter - Interpreter pointer.
- string src - Source buffer. Source buffer is a string containing expression's source code.
- int scope - 1 to treat the expression namespace as the global; otherwise, 0 (by default).
variable run ( ) #
Runs the given expression.Return value
Argument value.bool saveState ( Stream stream ) #
Saves the expression data (all its parameters) to the specified binary stream.Example using saveState() and restoreState() methods:
Source code (C#)
// initialize an expression and set its state
//...//
// save state
Blob blob_state = new Blob();
expression1.SaveState(blob_state);
// change the node state
//...//
// restore state
blob_state.SeekSet(0); // returning the carriage to the start of the blob
expression1.RestoreState(blob_state);Arguments
- Stream stream - Stream to which the expression data will be saved.
Return value
true if the expression data is saved successfully; otherwise, false.bool restoreState ( Stream stream ) #
Restores the data of the expression (all its parameters) from the specified binary stream.Example using saveState() and restoreState() methods:
Source code (C#)
// initialize an expression and set its state
//...//
// save state
Blob blob_state = new Blob();
expression1.SaveState(blob_state);
// change the node state
//...//
// restore state
blob_state.SeekSet(0); // returning the carriage to the start of the blob
expression1.RestoreState(blob_state);Arguments
- Stream stream - Stream in which the saved expression data is stored.
Return value
true if the expression data is restored successfully; otherwise, false.Last update:
2021-02-03
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