Fetch the string value from a KB value object.
returnedString = getstrval(aValue);
returnedString - type: str
aValue - type: val
A string, returnedString, representing the name of the input value, aValue.
Concepts can have zero or more attributes. Each attribute can have zero or more values. This function takes a value as argument and returns the string associated with aValue. Writes an error message to the output log if aValue is a number, rather than a string. If passed a bad argument value, the function writes an error message to the output log.
To demonstrate getstrval, we first need to build a KB:
@CODE
# if you find apples in the concept hierarchy
if (findconcept(findroot(),"apple"))
# kill them (to start fresh)
rmconcept(findconcept(findroot(),"apple"));
# Create the apple concept
G("apple") = makeconcept(findroot(),"apple");
# Apples have color
addstrval(G("apple"),"have","color");
# Apple's color is red
addstrval(G("apple"),"color","red");
# Apple's color is also green and yellow
addstrval(G("apple"),"color","green and yellow");
The code creates a KB like this:
The following code accesses the KB's attributes and values:
# Find apple's attribute list
G("attrList") = findattrs(G("apple"));
# Find the list of values of the first attribute
G("valList") = attrvals(G("attrList"));
# print out the first attribute's name and value
if(attrname(G("attrList"))){
"output.txt" << "1) first attribute of apple is: "
<< attrname(G("attrList")) << "\n";
"output.txt" << "2) first value of that attribute is: "
<< getstrval(G("valList")) << "\n";}
# get the next attribute
G("nextAttr") = nextattr(G("attrList"));
if(attrname(nextattr(G("attrList"))))
"output.txt" << "3) next attribute of apple is: "
<< attrname(G("nextAttr")) << "\n";
# get the list of values of the second attribute
G("valList") = attrvals(G("nextAttr"));
# print the first value's name
"output.txt" << "4) first value of that attribute is: "
<< getstrval(G("valList")) << "\n";
# print the second value of the second attribute
"output.txt" << "5) second value of that attribute is: "
<< getstrval(nextval(G("valList"))) << "\n";
The output looks like this:
