Appendix B: Builtins by identifier

Note: we have interpreted the term "builtin" very broadly in this appendix and included many things that are properly speaking special forms; but we have excluded for loops, with and without, and the various piping operators, except by giving links to extended articles here and in the appropriate places below rather than attempting a precis. For the conditional : and ; operators so the article on Functions and commands, which also introduces conditionals.

Builtins with symbols

Note: these are arranged in alphabetic order of how someone might describe them in words, e.g. addition comes before division because "a" comes before "d".

(x float) + (y float) Returns the sum of two floating-point numbers.

(x int) + (y int) Returns the sum of two integers.

(x list) + (y list) Returns the concatenation of two lists.

(x rune) + (y rune) Returns the concatenation of two runes as a string.

(x rune) + (y string) Returns the result of prepending a rune to a string.

(x set) + (y set) Returns the union of the given sets.

(x string) + (y rune) Returns the result of appending the rune y to a string x.

(x string) + (y string) Returns the concatenation of two strings.

(x float) / (y float) Returns the quotient of two floating-point numbers, or an error if the divisor is zero.

(x int) / (y int) Returns the quotient of two integers, or an error if the divisor is zero.

(x list) ?> <expression> A filter operator. For further information we direct the reader to the entire article on piping.

(x float) > (y float) Returns true if x is strictly greater than y, or false otherwise.

(x float) >= (y float) Returns true if x is greater than or equal to y, or false otherwise.

(x int) > (y int) Returns true if x is strictly greater than y, or false otherwise.

(x int) >= (y int) Returns true if x is greater than or equal to y, or false otherwise.

(x <any enum type>)[(y int)] Returns the y-indexed element of the type, counting as usual from 0, or an error if this element does not exist.

(x list)[(y int)] Returns the y-indexed element of the list, counting as usual from 0, or an error if this element does not exist.

(x list)[(y::z pair)] Returns the elements of the list from and including y up to and excluding z, or an error if some or all of those elements do not exist.

(x map)[(y single?)] Returns the value in the map indexed by the key y, or an error if the key does not exist.

(x pair)[(y int)] Returns the y-indexed element of the pair, where y must be 0 or 1, and an error if it isn't.

(x <any struct type>)[(y label)] Returns the value in the struct indexed by the label y, or an error if the key does not exist.

(x string)[(y int)] Returns the y-indexed rune of the string, counting as usual from 0, or an error if this rune does not exist.

(x string)[(y::z pair)] Returns the substring of the list from and including y up to and excluding z, or an error if some or all of those elements do not exist.

(x tuple)[(y int)] Returns the y-indexed element of the tuple, counting as usual from 0, or an error if this element does not exist.

(x tuple)[(y::z pair)] Returns the elements of the list from and including y up to and excluding z, or an error if some or all of those elements do not exist.

(x float) < (y float) Returns true if x is strictly less than y, or false otherwise.

(x float) <= (y float) Returns true if x is less than or equal to y, or false otherwise.

(x int) < (y int) Returns true if x is strictly less than y, or false otherwise.

(x int) <= (y int) Returns true if x is less than or equal to y, or false otherwise.

(x float) * (y float) Returns the product of two floating-point numbers.

(x int) * (y int) Returns the product of two integers.

(x list) >> <expression> A mapping operator. For further information we direct the reader to the entire article on piping.

(x int) % (y int) Returns the modulus of two integers, or an error if the divisor is zero. The result is negative if the dividend is negative.

(x any) -> <expression> A piping operator. For further information we direct the reader to the entire article on piping.

(x float) - (y float) Returns the difference between two floating-point numbers.

(x int) - (y int) Returns the difference between two integers.

(x single?) :: (y single?) Returns a pair of which x is the 0-indexed element and y is the 1-indexed element.

(x type) / (y type) Returns the union of the two types.

Builtins with names

(x bool) and (y bool) Returns true if both x and yare true, otherwisefalse. It doesn't bother to compute y` if x is false.

cast(x single, y type) Returns a cast of a value to a given type; or an error if y is not a clone of the type of x. Note that this can be overloaded, like most builtins, to allow other casts where they are desirable.

codepoint(x rune) Returns the Unicode value of the rune.

error(x string) Returns an error with the given error text.

for <and various forms of expression following it> For this we direct the reader to the entire article on for loops.

float(x floatlike) Casts any value in a clone of float to a float, but returns an error if passed any other type.

float(x int) Converts any integer to a float.

float(x string) Converts a string to a float if the string is indeed a valid representation of a float, and returns an error otherwise.

(x single?) in (y list) Returns true if the list contains the given element and false otherwise.

(x single?) in (y set) Returns true if the list contains the given element and false otherwise.

(x single?) in (y tuple) Returns true if the tuple contains the given element and false otherwise.

(x single?) in (y type) Returns true if the type contains the given value and false otherwise.

first(x tuple) Returns the first element of a tuple.

int(x intlike) Casts any value in a clone of int (or int itself) to an integer, but returns an error if passed a value of any other type.

int(x string) Converts a string to a float if the string is indeed a valid representation of a float, and returns an error otherwise.

int(x float) Converts a float to an integer

keys(x maplike) Returns the keys of a map or a clone of a map.

keys(x struct) Returns the keys of a struct, which will belong to the type label.

label(x string) Converts the given string to the label, if the label exists.

last(x tuple) Returns the last element of a tuple.

len(x listlike) Returns the length of a list or a clone of list.

len(x maplike) Returns the length of a map or a clone of map, where the length is the number of key-value pairs.

len(x setlike) Returns the length of a set or a clone of set.

len(x stringlike) Returns the length of a string or a clone of string.

len(x tuple) Returns the length of a tuple.

list(x listlike) Casts any value in a clone of list (or list itself) to an list, but returns an error if passed a value of any other type.

literal(x single?) Returns a Pipefish string literal representing the given value, e.g. literal 2 * 2 returns "4"

literal(x tuple) Returns a Pipefish string literal representing the given value.

map(x maplike) Casts any value in a clone of map (or map itself) to an map, but returns an error if passed a value of any other type.

(x list) ?> <expression> A filter operator. For further information we direct the reader to the entire article on piping.

map(x ... pair) Converts a tuple of pairs into a map, so long as the keys are hashable, and returns an error otherwise.

not(x bool) Returns the opposite of x.

(x bool) or (y bool) Returns true if either x or y are true, otherwise true. It doesn't bother to compute y if x is true.

pair(x pairlike) Casts any value in a clone of pair (or pair itself) to a pair, but returns an error if passed a value of any other type.

rune(x int) Returns a rune corresponding to the given codepoint.

set(x setlike) Casts any value in a clone of set (or set itself) to a pair, but returns an error if passed a value of any other type.

set(x ... single?) Converts a tuple to a set containing the same elements.

string(x single?)` Converts a value to a string representation which is prettier than a literal but therefore is not in fact a literal. Can be recursively overloaded.

tuple(x ... single?) Coverts a sequence of values to a tuple. Useful for constructing tuples of one element.

tuple(x tuple) Converts a tuple to the same tuple.

type(x single?) Returns the type of the given value.

type(x tuple) Returns tuple.

unwrap(x error) Returns a value of type Error having fields errorCode and errorMessage if it is passed an error, and returns an error otherwise.

valid(x single?/tuple/error) Returns true if the value is not a error; false if it is.

varchar(x int) Returns the type varchar(x).

• (x list) with (y ... pair)
• (x map) with (y ... single?)
• (x type) with (y ... single?)
• (x map) without (y ... single?) For these we refer the reader to the entire page on these operators, as they cannot be briefly summarized.