ML: Built-in Functions

Functions on Int and Real
name	type(s)	action
~	int -> int or real -> real	negates its argument
min, max	int*int -> int	obvious
abs	int -> int or real -> real	absolute value
real	int -> real	convert integer into real of same value
floor, ceiling, trunc	real -> int	conversions
sin, cos, arctan	real -> real	angles in radians
sqrt,exp,ln	real -> real	obvious
chr	int -> string	ASCII code
makestring	int -> string or real -> string	produces text digits
print	int -> unit or real -> unit	side effect is output

Functions on String
name type(s) action
explode string -> string list makes list of single characters
implode string list -> string ...
size string -> int ...
substring string*int*int -> string first int is starting position (from 0), second int is # if characters to include; will generate exception is # characters runs off end of string
ord string -> int convert first character of string to ASCII code
ordof string*int -> int convert character at position in a string
print string -> unit overloaded...

Functions on Boolean
name type(s) action
andalso, orelse bool*bool -> bool logical operations
not bool -> bool logical negation
makestring bool -> string turn boolean value into its name
print bool -> unit overloaded ...

Functions on Lists
name type(s) action
hd 'a list -> 'a head of a list
tl 'a list -> 'a list tail of a list
nth 'a list * int -> 'a list element selector (start from 0)
nthtail 'a list * int -> 'a list produce tail of a list starting from the indicated element
null 'a list -> bool is the list empty?
length 'a list -> int number of elements in a list
rev 'a list -> 'a list reverse a list
map ('a -> 'b) -> 'a list -> 'b list apply a function to all elements in a list
app, revapp ('a -> 'b) -> 'a list -> unit like map but return "unit" instead of the list... however, the function is applied to elements in the list; useful for side effects like printing each list element
fold,revfold (('a * 'b) -> 'b) -> 'a list -> 'b -> 'b composes a list of functions
exists ('a -> bool) -> 'a list -> bool takes a predicate P and a list of type-matching elements, returns true if at least one of the list elements satisfies P.

ML: Built-in Exceptions

name	description
Io	an error has occurred during input or output
Bind	a pattern has failed to match the expression to which it must be bound ex: val x::xs = nil
Match	a match has no pattern that matches the expression to which it is applied
Div	a division by zero
Overflow	The result of arithmetic op on int or real does not fit storage for that type
Sqrt	arg to sqrt is negative
Exp	arg to exp is invalid
Ln	arg to ln is invalid
Chr	chr was given an integer out of range
Ord	ord was given the empty string
Substring	substring was given a range not fully in the string argument ex: substring("abc",2,4)
Range	raised with type "bytearray"
Hd, Tl	using hd or tl on empty list
Nth, NthTail	functions applied to list without the desired position in it ex: nth([10,20,30],5)
Subscript	array reference out of range

Functions on String
name	type(s)	action
explode	string -> string list	makes list of single characters
implode	string list -> string	...
size	string -> int	...
substring	stringintint -> string	first int is starting position (from 0), second int is # if characters to include; will generate exception is # characters runs off end of string
ord	string -> int	convert first character of string to ASCII code
ordof	string*int -> int	convert character at position in a string
print	string -> unit	overloaded...

Functions on Boolean
name	type(s)	action
andalso, orelse	bool*bool -> bool	logical operations
not	bool -> bool	logical negation
makestring	bool -> string	turn boolean value into its name
print	bool -> unit	overloaded ...

Functions on Lists
name	type(s)	action
hd	'a list -> 'a	head of a list
tl	'a list -> 'a list	tail of a list
nth	'a list * int -> 'a	list element selector (start from 0)
nthtail	'a list * int -> 'a list	produce tail of a list starting from the indicated element
null	'a list -> bool	is the list empty?
length	'a list -> int	number of elements in a list
rev	'a list -> 'a list	reverse a list
map	('a -> 'b) -> 'a list -> 'b list	apply a function to all elements in a list
app, revapp	('a -> 'b) -> 'a list -> unit	like map but return "unit" instead of the list... however, the function is applied to elements in the list; useful for side effects like printing each list element
fold,revfold	(('a * 'b) -> 'b) -> 'a list -> 'b -> 'b	composes a list of functions
exists	('a -> bool) -> 'a list -> bool	takes a predicate P and a list of type-matching elements, returns true if at least one of the list elements satisfies P.