Top Qs
Timeline
Chat
Perspective
Whitespace (programming language)
Esoteric programming language From Wikipedia, the free encyclopedia
Remove ads
Remove ads
Whitespace is an esoteric programming language with syntax where only whitespace characters (space, tab and linefeed) have meaning – contrasting typical languages that largely ignore whitespace characters. [1][2]

tabs
spaces
As a consequence of its syntax, Whitespace source code can be contained within the whitespace of code written in a language that ignores whitespace – making the text a polyglot.[2]
Whitespace is an imperative, stack-based language. The programmer can push arbitrary-width integer values onto a stack and access a heap to store data.
An interpreter, along with its Haskell source code, is provided by the Whitespace creators.
Remove ads
History
Edwin Brady and Chris Morris, who also developed the Kaya and Idris languages, created Whitespace in 2002 at the University of Durham. Slashdot published a review on April Fool's Day 2003.[3]
The idea of using whitespace characters as operators for the C++ language had been facetiously suggested five years earlier by Bjarne Stroustrup.[4]
Syntax
Summarize
Perspective
Whitespace defines a command as a sequences of whitespace characters. For example, [Tab][Space][Space][Space]
performs arithmetic addition of the top two elements on the stack.
A command is written as an instruction modification parameter (IMP) followed by an operation and then any parameters. [1]
IMP sequences include:
Operator sequences, organized by IMP, include:[1]
*Due to Haskell being lazily evaluated, the effect of the stack being too small may only show when, for example, invoking the outputting a number side-effect.
**The copy and slide operations were added in Whitespace 0.3.[1]
Comments
Characters other than space
, tab
and linefeed
are ignored and thus can be used for comments.
Numbers
A numeric value is represented as a sequence of space
and tab
characters that represent 0 and 1 respectively and terminated by a linefeed
. The first character represents the sign of the value – space
for positive and tab
for negative. Subsequent characters before the terminator represent the binary digits of a value.
For example:
- [space][tab][space][space][tab][space][tab][tab][linefeed] (STSSTSTTL) is positive since it starts with
space
and represents 1001011 in binary, which is 75 in decimal. - [tab][tab][tab][space][space][tab][space][linefeed] (TTTSSTSL) is negative since it starts with
tab
and represents -110010 in binary which is −50 in decimal.
Labels
A label is used for control flow. It is a linefeed
-terminated sequence of space
and tab
characters. As there is only one namespace, all labels must be unique.
[1]
Remove ads
Sample code
The following source code is for a Whitespace "Hello, world!" program. For clarity, it is annotated with S
, T
and L
before each
space
,
tab
, and linefeed
.
S S S T S S T S S S L:Push_+1001000=72='H'_onto_the_stack T L S S :Output_'H';_S S S T T S S T S T L:Push_+1100101=101='e'_onto_the_stack T L S S :Output_'e';_S S S T T S T T S S L:+1101100=108='l' T L S S S S S T T S T T S S L:+1101100=108='l' T L S S S S S T T S T T T T L:+1101111=111='o' T L S S S S S T S T T S S L:+101100=44=',' T L S S S S S T S S S S S L:+100000=32=Space T L S S S S S T T T S T T T L:+1110111=119='w' T L S S S S S T T S T T T T L:+1101111=111='o' T L S S S S S T T T S S T S L:+1110010=114='r' T L S S S S S T T S T T S S L:+1101100=108='l' T L S S S S S T T S S T S S L=+1100100=100='d' T L S S S S S T S S S S T L:+100001=33='!' T L S S :Output_'!';_L L L:End_the_program
When Whitespace source code is displayed in some browsers, the horizontal spacing produced by a tab character is not fixed, but depends on its location in the text relative to the next horizontal tab stop. Depending on the software, tab characters may also get replaced by the corresponding variable number of space characters.
References
External links
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads