/**
* Set a named constant (constants names are not case-sensitive). Constants are like variables but
* are not cleared by clear(). Variables of the same name have precedence over constants.
*/
public MathEval setConstant(String nam, Double val) {
if (constants.get(nam) != null) {
throw new IllegalArgumentException("Constants may not be redefined");
}
validateName(nam);
constants.put(nam, val);
return this;
}
private double doNamedVal(int beg, int end) {
while (beg < end && Character.isWhitespace(expression.charAt(end))) {
end--;
} // since a letter triggers a named value, this can never reduce to beg==end
String nam = expression.substring(beg, (end + 1));
Double val;
if ((val = constants.get(nam)) != null) {
return val.doubleValue();
} else if ((val = variables.get(nam)) != null) {
isConstant = false;
return val.doubleValue();
} else if (relaxed) {
isConstant = false;
return 0.0;
}
throw exception(beg, "Unrecognized constant or variable \"" + nam + "\"");
}
private double doFunction(int beg, int end) {
int argbeg;
for (argbeg = beg; argbeg <= end && expression.charAt(argbeg) != '('; argbeg++) {;
}
String fncnam = expression.substring(beg, argbeg).trim();
ArgParser fncargs = new ArgParser(argbeg, end);
FunctionHandler fnchdl = null;
try {
if ((fnchdl = pureFunctions.get(fncnam)) != null) {
return fnchdl.evaluateFunction(fncnam, fncargs);
} else if ((fnchdl = impureFunctions.get(fncnam)) != null) {
isConstant = false; // impure functions cannot be guaranteed to be constant
return fnchdl.evaluateFunction(fncnam, fncargs);
}
fncargs = null; // suppress check for too many fncargs
} catch (ArithmeticException thr) {
fncargs = null;
throw thr;
} catch (NoSuchMethodError thr) {
fncargs = null;
throw exception(beg, "Function not supported in this JVM: \"" + fncnam + "\"");
} catch (UnsupportedOperationException thr) {
fncargs = null;
throw exception(beg, thr.getMessage());
} catch (Throwable thr) {
fncargs = null;
throw exception(beg, "Unexpected exception parsing function arguments", thr);
} finally {
if (fncargs != null) {
if (fncargs.hasNext()) {
throw exception(fncargs.getIndex(), "Function has too many arguments");
}
offset = fncargs.getIndex();
}
}
throw exception(beg, "Function \"" + fncnam + "\" not recognized");
}
/** Set a named variable (variables names are not case-sensitive). */
public double getVariable(String nam) {
Double val = variables.get(nam);
return (val == null ? 0 : val.doubleValue());
}
/**
* Set a named constant (constant names are not case-sensitive). Constants are like variables but
* are not cleared by clear(). Variables of the same name have precedence over constants.
*/
public double getConstant(String nam) {
Double val = constants.get(nam);
return (val == null ? 0 : val.doubleValue());
}