// protected
-#if 0
-void basic::copy(const basic & other)
-{
- flags=other.flags & ~ status_flags::dynallocated;
- hashvalue=other.hashvalue;
- tinfo_key=other.tinfo_key;
-}
-#endif
+// none (all inlined)
//////////
// other constructors
/** Number of operands/members. */
unsigned basic::nops() const
{
+ // iterating from 0 to nops() on atomic objects should be an empty loop,
+ // and accessing their elements is a range error. Container objects should
+ // override this.
return 0;
}
ex basic::operator[](const ex & index) const
{
- if (is_exactly_of_type(*index.bp,numeric)) {
+ if (is_exactly_of_type(*index.bp,numeric))
return op(static_cast<const numeric &>(*index.bp).to_int());
- }
+
throw(std::invalid_argument("non-numeric indices not supported by this type"));
}
return op(i);
}
+/** Search ocurrences. An object 'has' an expression if it is the expression
+ * itself or one of the children 'has' it. */
bool basic::has(const ex & other) const
{
GINAC_ASSERT(other.bp!=0);
return false;
}
+/** Return degree of highest power in symbol s. */
int basic::degree(const symbol & s) const
{
return 0;
}
+/** Return degree of lowest power in symbol s. */
int basic::ldegree(const symbol & s) const
{
return 0;
}
+/** Return coefficient of degree n in symbol s. */
ex basic::coeff(const symbol & s, int n) const
{
return n==0 ? *this : _ex0();
}
+/** Sort expression in terms of powers of some symbol.
+ * @param s symbol to sort in. */
ex basic::collect(const symbol & s) const
{
ex x;
- int ldeg=ldegree(s);
- int deg=degree(s);
+ int ldeg = this->ldegree(s);
+ int deg = this->degree(s);
for (int n=ldeg; n<=deg; n++) {
- x += coeff(s,n)*power(s,n);
+ x += this->coeff(s,n)*power(s,n);
}
return x;
}
+/* Perform automatic symbolic evaluations on expression. */
ex basic::eval(int level) const
{
+ // There is nothing to do for basic objects:
return this->hold();
}
+/** Evaluate object numerically. */
ex basic::evalf(int level) const
{
+ // There is nothing to do for basic objects:
return *this;
}
+/* Substitute a set of symbols. */
ex basic::subs(const lst & ls, const lst & lr) const
{
return *this;
}
+/** Default interface of nth derivative ex::diff(s, n). It should be called
+ * instead of ::derivative(s) for first derivatives and for nth derivatives it
+ * just recurses down.
+ *
+ * @param s symbol to differentiate in
+ * @param nth order of differentiation
+ * @see ex::diff */
+ex basic::diff(const symbol & s, unsigned nth) const
+{
+ // trivial: zeroth derivative
+ if (!nth)
+ return ex(*this);
+
+ // evaluate unevaluated *this before differentiating
+ if (!(flags & status_flags::evaluated))
+ return ex(*this).diff(s, nth);
+
+ ex ndiff = derivative(s);
+ while (!ndiff.is_zero() && // stop differentiating zeros
+ nth>1) {
+ ndiff = ndiff.diff(s);
+ --nth;
+ }
+ return ndiff;
+}
+
exvector basic::get_indices(void) const
{
return exvector(); // return an empty exvector
// protected
+/** Default implementation of ex::diff(). It simply throws an error message.
+ *
+ * @exception logic_error (differentiation not supported by this type)
+ * @see ex::diff */
+ex basic::derivative(const symbol & s) const
+{
+ throw(std::logic_error("differentiation not supported by this type"));
+}
+
+/** Returns order relation between two objects of same type. Needs to be
+ * implemented by each class. */
int basic::compare_same_type(const basic & other) const
{
return compare_pointers(this, &other);
}
+/** Returns true if two objects of same type are equal. Normally needs
+ * not be reimplemented as long as it wasn't overwritten by some parent
+ * class, since it just calls complare_same_type(). */
bool basic::is_equal_same_type(const basic & other) const
{
return compare_same_type(other)==0;
return v;
}
+/** Expand expression, i.e. multiply it out and return the result as a new
+ * expression. */
ex basic::expand(unsigned options) const
{
return this->setflag(status_flags::expanded);
}
+
//////////
// non-virtual functions in this class
//////////
// public
+/** Substitute symbols in expression and return the result as a new expression.
+ * There are two valid types of replacement arguments: 1) a relational like
+ * symbol==ex and 2) a list of relationals lst(symbol1==ex1,symbol2==ex2,...),
+ * which is converted to subs(lst(symbol1,symbol2,...),lst(ex1,ex2,...)).
+ * In addition, an object of class idx can be used instead of a symbol. */
ex basic::subs(const ex & e) const
{
- // accept 2 types of replacement expressions:
- // - symbol==ex
- // - lst(symbol1==ex1,symbol2==ex2,...)
- // convert to subs(lst(symbol1,symbol2,...),lst(ex1,ex2,...))
- // additionally, idx can be used instead of symbol
if (e.info(info_flags::relation_equal)) {
return subs(lst(e));
}
return cmpval;
}
+/** Test for equality. */
bool basic::is_equal(const basic & other) const
{
unsigned hash_this = gethash();
// protected
+/** Stop further evaluation.
+ * @see basic::eval */
const basic & basic::hold(void) const
{
return setflag(status_flags::evaluated);
// protected
-unsigned basic::precedence=70;
-unsigned basic::delta_indent=4;
+unsigned basic::precedence = 70;
+unsigned basic::delta_indent = 4;
//////////
// global constants
git://www.ginac.de / ginac.git / blobdiff