Haskell Cheat Sheet printable pdf download

Haskell Cheat Sheet

Strings

Enumerations

– List of numbers –

. . .

– Unicode string.

This cheat sheet lays out the fundamental elements

– Inﬁnite list of numbers –

– Single character.

of the Haskell language: syntax, keywords and

. . . .

other elements.

It is presented as both an ex-

Multi-line Strings

Normally, it is syntax error if

– Empty list; ranges only go forwards.

ecutable Haskell ﬁle and a printable document.

a string has any actual new line characters. That is,

– Negative integers.

Load the source into your favorite interpreter to

this is a syntax error:

– Syntax error; need

play with code samples shown.

for negatives.

– List from 1 to 100 by

2, -1 to 100 by 4.

Syntax

However, backslashes (‘ ’) can be used to “escape”

In fact, any value which is in the

class can be

around the new line:

Below the most basic syntax for Haskell is given.

used. E.g.,:

– List of characters –

. . .

–

Comments

– List of

A single line comment starts with ‘ ’ and extends

values (from

The area between the backslashes is ignored. An

to the end of the line. Multi-line comments start

important note is that new lines in the string must

with ’ ’ and extend to ’ ’. Comments can be

still be represented explicitly:

Lists & Tuples

nested.

– Empty list.

Comments above function deﬁnitions should

– List of three numbers.

start with ‘

’ and those next to parameter types

– Alternate way to write lists us-

with ‘

’ for compatibility with Haddock, a sys-

That is,

evaluates to:

ing “cons” ( ) and “nil” ( ).

tem for documenting Haskell code.

– List of three characters (strings are lists).

– List of characters (same

Reserved Words

While

evaluates to:

– 2-element tuple of a number and a string.

The following lists the reserved words deﬁned by

– 4-element tuple of two

Haskell. It is a syntax error to give a variable or

functions, a number and a character.

function one of these names.

“Layout” rule, braces and semi-colons.

Numbers

Haskell can be written using braces and semi-

- Integer

colons, just like C. However, no one does. Instead,

- Floating point

the “layout” rule is used, where spaces represent

c 2008 Justin Bailey.

Haskell Cheat Sheet

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