eq: generic comparisons

value prefix = : 'a -> 'a -> bool

e1 = e2 tests for structural equality of e1 and e2. Mutable structures (e.g. references and arrays) are equal if and only if their current contents are structurally equal, even if the two mutable objects are not the same physical object. Equality between functional values raises Invalid_argument. Equality between cyclic data structures may not terminate.

value prefix <> : 'a -> 'a -> bool

Negation of prefix =.

value prefix < : 'a -> 'a -> bool
value prefix <= : 'a -> 'a -> bool
value prefix > : 'a -> 'a -> bool
value prefix >= : 'a -> 'a -> bool

Structural ordering functions. These functions coincide with the usual orderings over integer, string and floating-point numbers, and extend them to a total ordering over all types. The ordering is compatible with prefix =. As in the case of prefix =, mutable structures are compared by contents. Comparison between functional values raises Invalid_argument. Comparison between cyclic structures may not terminate.

value compare: 'a -> 'a -> int

compare x y returns 0 if x=y, a negative integer if x<y, and a positive integer if x>y. The same restrictions as for = apply. compare can be used as the comparison function required by the set and map modules.

value min: 'a -> 'a -> 'a

Return the smaller of the two arguments.

value max: 'a -> 'a -> 'a

Return the greater of the two arguments.

value prefix == : 'a -> 'a -> bool

e1 == e2 tests for physical equality of e1 and e2. On integers and characters, it is the same as structural equality. On mutable structures, e1 == e2 is true if and only if physical modification of e1 also affects e2. On non-mutable structures, the behavior of prefix == is implementation-dependent, except that e1 == e2 implies e1 = e2.

value prefix != : 'a -> 'a -> bool

Negation of prefix ==.