The Concepts and Confusions of Prefix, Infix, Postfix and Fully Functional Notations

Discussion in 'Python' started by Xah Lee, May 23, 2007.

  1. Xah Lee

    Xah Lee Guest

    The Concepts and Confusions of Prefix, Infix, Postfix and Fully
    Functional Notations

    Xah Lee, 2006-03-15

    [This articles explains away the confusion of common terms for
    notation systems used in computer languages: prefix, infix, postfix,
    algebraic, functional. These notation's relation to the concept of
    operators. These are explained using examples from LISP, Mathematica,
    and imperative languages. Then, it discuss some problems of purely
    nested notation.]

    In LISP languages, they use a notation like “(+ 1 2)†to mean “1+2â€.
    Likewise, they write “(if test this that)†to mean “if (test) {this}
    else {that}â€. LISP codes are all of the form “(a b c ...)â€, where the
    a b c themselves may also be of that form. There is a wide
    misunderstanding that this notation being “prefix notationâ€.. In this
    article, i'll give some general overview of the meanings of Algebraic
    Notation and prefix, infix, postfix notations, and explain how LISP
    notation is a Functional Notation and is not a so-called prefix
    notation or algebraic notation.

    The math notation we encounter in school, such as “1+2â€, is called
    Infix Algebraic Notation. Algebraic notations have the concept of
    operators, meaning, symbols placed around arguments. In algebraic
    infix notation, different symbols have different stickiness levels
    defined for them. e.g. “3+2*5>7†means “(3+(2*5))>7â€. The stickiness
    of operator symbols is normally called “Operator Precedenceâ€. It is
    done by giving a order specification for the symbols, or equivalently,
    give each symbol a integer index, so that for example if we have
    “a⊗b⊙câ€, we can unambiguously understand it to mean one of “(a⊗b)⊙câ€
    or “a⊗(b⊙c)â€.

    In a algebraic postfix notation known as Polish Notation, there needs
    not to have the concept of Operator Precedence. For example, the infix
    notation “(3+(2*5))>7†is written as “3 2 5 * + 7 >â€, where the
    operation simply evaluates from left to right. Similarly, for a prefix
    notation syntax, the evaluation goes from right to left, as in “> 7 +
    * 5 2 3â€.

    While functional notations, do not employ the concept of Operators,
    because there is no operators. Everything is a syntactically a
    “functionâ€, written as f(a,b,c...). For example, the same expression
    above is written as “>( +(3, *(2,5)), 7)†or “greaterThan( plus(3,
    times(2,5)), 7)â€.

    For lisps in particular, their fully functional notation is
    historically termed sexp (short for S-Expression, where S stands for
    Symbolic). It is sometimes known as Fully Parenthesized Notation. For
    example, in lisp it would be (f a b c ...). In the above example it
    is: “(> (+ 3 (* 2 5)) 7)â€.

    The common concepts of “prefix, postfix, infix†are notions in
    algebraic notations only. Because in Full Functional Notation, there
    are no operators, therefore no positioning to talk about. A Function's
    arguments are simply explicitly written out inside a pair of enclosing
    delimiters.

    Another way to see that lisp notation are not “pre†anything, is by
    realizing that the “head†f in (f a b c) can be defined to be placed
    anywhere. e.g. (a b c f) or even (a f b c), and its syntax syntactical
    remains the same. In the language Mathematica, f(a b c) would be
    written as f[a,b,c] where the argument enclosure symbols is the square
    bracket instead of parenthesis, and argument separator is comma
    instead of space, and the function symbol (aka “headâ€) is placed in
    outside and in front of the argument enclosure symbols.

    The reason for the misconception that lisp notations are “prefix†is
    because the “head†appears as the first element in the enclosed
    parenthesis. Such use of the term “prefix†is a confusion engenderer
    because the significance of the term lies in algebraic notation
    systems that involves the concept of operators.

    A side note: the terminology “Algebraic†Notation is a misnomer. It
    seems to imply that such notations have something to do with the
    branch of math called algebra while other notation systems do not. The
    reason the name Algebraic Notation is used because when the science of
    algebra was young, around 1700s mathematicians are dealing with
    equations using symbols like “+ × =†written out similar to the way we
    use them today. This is before the activities of systematic
    investigation into notation systems as necessitated in the studies of
    logic in 1800s or computer languages in 1900s. So, when notation
    systems are actually invented, the conventional way of infixing “+ ×
    =†became known as algebraic because that's what people think of when
    seeing them.

    --------
    This post is part of a 3-part exposition:
    “The Concepts and Confusions of Prefix, Infix, Postfix and Fully
    Functional Notationsâ€,
    “Prefix, Infix, Postfix notations in Mathematicaâ€,
    “How Purely Nested Notation Limits The Language's Utilityâ€,
    available at:
    http://xahlee.org/UnixResource_dir/writ/notations.html

    Xah

    ∑ http://xahlee.org/
    Xah Lee, May 23, 2007
    #1
    1. Advertising

  2. Xah Lee

    Larry Clapp Guest

    ["Followup-To:" header set to comp.lang.lisp.]

    On 2007-05-23, Xah Lee <> wrote:
    > The Concepts and Confusions of Prefix, Infix, Postfix and Fully
    > Functional Notations
    >
    > Xah Lee, 2006-03-15


    Xah, why do you post year-old essays to newsgroups that couldn't care
    less about them?
    Larry Clapp, May 23, 2007
    #2
    1. Advertising

  3. Re: The Concepts and Confusions of Prefix, Infix, Postfix and FullyFunctional Notations


    > On 2007-05-23, Xah Lee <> wrote:
    >> The Concepts and Confusions of Prefix, Infix, Postfix and Fully
    >> Functional Notations
    >>
    >> Xah Lee, 2006-03-15

    >
    > Xah, why do you post year-old essays to newsgroups that couldn't care
    > less about them?



    And even more to the point -- why does he post now again the same
    drivel he already posted on the 9th of May 2007? And will we now
    treated to repeats of his garbage every 2 weeks?

    The answer to your question is very simple: Xah Lee is a troll.

    Regards -- Markus
    Markus E Leypold, May 23, 2007
    #3
  4. Xah Lee

    Jon Harrop Guest

    Markus E Leypold wrote:
    > The answer to your question is very simple: Xah Lee is a troll.


    In this context, I believe he is marketing/advertising himself as a
    consultant and some kind of vampiric man-whore according to this page:

    http://xahlee.org/PageTwo_dir/Personal_dir/xah.html

    "... I'm technically American. Love me and I can make you American."

    Xah is perhaps the world's first person to claim to be both a Lisp
    programmer and "strong at siring". :)

    Anyway, are there any libraries to do hardware accelerated vector graphics
    in Perl, Python, Lisp, Java or any functional language (except OCaml and F#
    and excluding WPF and Silverlight)?

    --
    Dr Jon D Harrop, Flying Frog Consultancy
    The F#.NET Journal
    http://www.ffconsultancy.com/products/fsharp_journal/?u7
    Jon Harrop, May 29, 2007
    #4
  5. 3D libraries (was The Concepts and Confusions of Prefix, Infix,Postfix and Fully Functional Notations)

    On Tue, 29 May 2007, Jon Harrop wrote:

    > Anyway, are there any libraries to do hardware accelerated vector graphics
    > in Perl, Python, Lisp, Java or any functional language (except OCaml and F#
    > and excluding WPF and Silverlight)?


    I believe there are OpenGL bindings for quite many languages, here are two
    for java:

    https://jogl.dev.java.net/
    http://www.lwjgl.org/

    - Ville Oikarinen
    Ville Oikarinen, May 29, 2007
    #5
  6. Xah Lee

    Ulf Wiger Guest

    >>>>> "Jon" == Jon Harrop <> writes:

    Jon> Anyway, are there any libraries to do hardware accelerated
    Jon> vector graphics in Perl, Python, Lisp, Java or any functional
    Jon> language (except OCaml and F# and excluding WPF and
    Jon> Silverlight)?

    I guess the OpenGL binding for Erlang qualifies. The best
    exhibit of this would be Wings3D, an Open Source 3D
    graphics modeller, written in Erlang, and with quite a
    large user base.

    http://www.wings3d.com

    BR,
    Ulf W

    --
    Ulf Wiger, Senior Specialist,
    / / / Architecture & Design of Carrier-Class Software
    / / / Team Leader, Software Characteristics
    / / / Ericsson AB, IMS Gateways
    Ulf Wiger, May 29, 2007
    #6
  7. Xah Lee

    Tony Finch Guest

    vector graphics bindings, was Re: The Concepts and Confusions of Prefix, Infix, Postfix and Fully Functional Notations

    Jon Harrop <> wrote:
    >
    >Anyway, are there any libraries to do hardware accelerated vector graphics
    >in Perl, Python, Lisp, Java or any functional language (except OCaml and F#
    >and excluding WPF and Silverlight)?


    http://www.cairographics.org/bindings/
    That covers all the languages you named, plus O'Caml and Haskell.

    Tony.
    --
    f.a.n.finch <> http://dotat.at/
    GERMAN BIGHT: NORTH BECOMING CYCLONIC 4 OR 5, THEN WEST 5 OR 6. MODERATE OR
    ROUGH. RAIN OR DRIZZLE. MODERATE OR GOOD, OCCASIONALLY POOR.
    Tony Finch, May 29, 2007
    #7
  8. Xah Lee

    Xah Lee Guest

    Prefix, Infix, Postfix notations in Mathematica

    2000-02-21, 2007-05

    [In the following essay, I discuss prefix, infix, postfix notations
    and Mathematica's syntax for them. The full HTML formatted article is
    available at:
    http://xahlee.org/UnixResource_dir/writ/notations.html
    ]

    THE HEAD OF EXPRESSIONS

    Lisp's nested parenthesis syntax is a Functional Notation. It has the
    general form of “(f a b ...)†where any of the symbols inside the
    matching parenthesis may again be that form. For example, here's a
    typical code from Emacs Lisp.

    ; Recursively apply (f x i), where i is the ith element in the list
    li.
    ; For example, (fold f x '(1 2)) computes (f (f x 1) 2)
    (defun fold (f x li)
    (let ((li2 li) (ele) (x2 x))
    (while (setq ele (pop li2))
    (setq x2 (funcall f x2 ele))
    )
    x2
    )
    )

    Vast majority of computer languages, interpret source code in a one-
    dimensional, linear nature. Namely, from left to right, line by line,
    as in written text. (Examples of computer languages's source code that
    are not linear in nature, are spread sheets, cellular automata,
    graphical programing languages) For languages that interprets source
    code linearly, the logics of their syntax necessarily have a
    hierarchical structure (i.e. tree). The lisp's notation, is the most
    effective in visually showing the logics of the syntax. This is
    because, a function and its arguments, are simply laid out inside a
    parenthesis. The level of nesting corresponds to the “precedence†in
    evaluating the expression.

    The first element inside the matching parenthesis, is called the
    “head†of the expression. For example, in “(f a b)â€, the “f†is the
    head. The head is a function, and the rest of the symbols inside the
    matching parenthesis are its arguments.

    The head of lisp's notation needs not to be defined as the first
    element inside the parenthesis. For example, we can define the “headâ€
    to be the last element inside the parenthesis. So, we write “(arg1
    arg2 ... f)†instead of the usual “(f arg1 arg2 ...)†and its
    syntactical analysis remains unchanged. Like wise, you can move the
    head outside of the parenthesis.

    In Mathematica, the head is placed in front of the parenthesis, and
    square brackets are used instead of parenthesis for the enclosing
    delimiter. For example, lisp's “(f a b c)†is syntactically equivalent
    to Mathematica's “f[a,b,c]â€. Other examples: “(sin θ)†vs “Sin[θ]â€,
    “(map f list)†vs “Map[f,list]â€. Placing the head in front of the
    matching bracket makes the notation more familiar, because it is a
    conventional math notation.

    However, there is a disadvantage in moving the head of a expression
    from inside the matching bracket to outside. Namely: The nesting of
    the matching delimiters, no longer corresponds to the logics of the
    syntax, when the head is itself a compound expression.

    For example, suppose Reflection(vectorV,pointP) is function that
    returns a function f, such that f(graphicsData) will reflect the
    graphicsData along a line passing pointP and parallel to vectorV. In
    lisp, we would write “((Reflection vectorV pointP) graphicsData)â€. In
    Mathematica, we would write “Reflection[vectorV,pointP]
    [graphicsData]â€. In lisp's version, the nesting corresponds to the
    logics of the evaluation. In the Mathematica's form, that is no longer
    so.

    For another example, suppose Deriv is a function that takes a function
    f and returns a function g (the derivative of f), and we want to apply
    g to a variable x. In lisp, we would write “((Deriv f) x)â€. In
    Mathematica, we would write “Deriv[f][x]â€. In lisp's version, the
    nesting corresponds to the logics of the evaluation. In the
    Mathematica's form, the logics of the evaluation no longer corresponds
    to the nesting level, because now the head is outside of the enclosing
    delimiters, so the head of expressions no longer nests.

    PREFIX, POSTFIX, INFIX

    A prefix notation in Mathematica is represented as “f@argâ€.
    Essentially, a prefix notation in this context limits it to uses for
    functions on only one argument. For example: “f@a@b@c†is equivalent
    to “f[a[b[c]]]†or in lispy “(f (a (b c)))â€.. Mathematica also offers a
    postfix notation using the operator “//â€. For example, “c//b//a//f†is
    syntactically equivalent to “f[a[b[c]]]â€. (unix's pipe “|†syntax, is
    a form of postfix notation. e.g. “c | b | a | fâ€).

    For example, “Sin[List[1,2,3]]†can be written in postfix as
    “List[1,2,3]//Sinâ€, or prefix “Sin@List[1,2,3]â€. (by the way, they are
    semantically equivalent to “Map[Sin, List[1,2,3]]†in Mathematica) For
    infix notation, the function symbol is placed between its arguments.
    In Mathematica, the generic form for infix notation is by sandwiching
    the tilde symbol around the function name. e.g.
    “Join[List[1,2],List[3,4]]†is syntactically equivalent to “List[1,2]
    ~Join~ List[3,4]â€.

    In Mathematica, there is quite a lot syntax variations beside the
    above mentioned systematic constructs. For example, Plus[a,b,c] can be
    written as “a+b+câ€, “Plus[a+b,c]â€, “Plus[Plus[a,b],c]â€, or “(a
    +b)~Plus~câ€. “List[a,b,c]†can be written as “{a,b,c}â€, and
    “Map[f,List[a,b,c]]†can be written as “f /@ {a,b,c}â€.

    The gist being that certain functions are given a special syntactical
    construct to emulate the irregular and inefficient but nevertheless
    well-understood conventional notations. Also, it reduces the use of
    deep nesting that is difficult to type and manage. For example, the
    “Plus†function is given a operator “+â€, so that Plus[3,4] can be
    written with the more familiar “3+4â€. The “List†function is given a
    syntax construct of “{}â€, so that, List[3,4] can be more easily
    written as “{3,4}â€. The boolean “And†function is given the operator
    “&&â€, so that And[a,b] can be written with the more familiar and
    convenient “a && bâ€. Combining all these types of syntax variations,
    it can make the source code easier to read than a purely nested
    structure. For example, common math expressions such as “3+2*5>7â€
    don't have to be written as “Greater[Plus[3,Times[2,5]],7]†or the
    lispy “(> (+ 3 (* 2 5)) 7)â€.
    C and Perl

    When we say that C is a infix notation language, the term “infix
    notation†is used loosely for convenience of description. C and other
    language's syntaxes derived from it (e.g. C++, Java, Perl,
    Javascript...) are not based on a notation system, but takes the
    approach of a ad hoc syntax soup. Things like “i++â€, “++iâ€, “for(;;)
    {}â€, “while(){}â€, 0x123, “sprint(...%s...,....)â€, ... are syntax
    whimsies.

    As a side note, the Perl mongers are proud of their slogan of “There
    Are More Than One Way To Do It†in their gazillion ad hoc syntax
    sugars but unaware that in functional languages (such as Mathematica,
    Haskell, Lisp) that there are consistent and generalized constructs
    that can generate far more syntax variations than the ad hoc
    inflexible Perl both in theory AND in practice. (in lisp, its power of
    syntax variation comes in the guise of macros.) And, more importantly,
    Perlers clamor about Perl's “expressiveness†more or less on the
    syntax level but don't realize that semantic expressibility is far
    more important.

    Xah

    ∑ http://xahlee.org/
    Xah Lee, May 30, 2007
    #8
  9. Xah Lee

    Guest

    How Purely Nested Notation Limits The Language's Utility

    [The full HTML formatted article is available at:
    http://xahlee.org/UnixResource_dir/writ/notations.html
    ]

    2007-05-03

    There is a common complain by programers about lisp's notation, of
    nested parenthesis, being unnatural or difficult to read. Long time
    lisp programers, often counter, that it is a matter of conditioning,
    and or blaming the use of “inferior†text editors that are not
    designed to display nested notations. In the following, i describe how
    lisp notation is actually a problem, in several levels.

    (1) Some 99% of programers are not used to the nested parenthesis
    syntax. This is a practical problem. On this aspect along, lisp's
    syntax can be considered a problem.

    (2) Arguably, the pure nested syntax is not natural for human to read.
    Long time lispers may disagree on this point.

    (3) Most importantly, a pure nested syntax discourages frequent or
    advanced use of function sequencing or compositions. This aspect is
    the most devastating.

    The first issue, that most programers are not comfortable with nested
    notation, is well known. It is not a technical issue. Whether it is
    considered a problem of the lisp language is a matter of philosophical
    disposition.

    The second issue, about nested parenthesis not being natural for human
    to read, may be debatable. I do think, that deep nesting is a problem
    to the programer. Here's a example of 2 blocks of code that are
    syntactically equivalent in the Mathematica language:

    vectorAngle[{a1_, a2_}] := Module[{x, y},
    {x, y} = {a1, a2}/Sqrt[a1^2 + a2^2] // N;
    If[x == 0, If[Sign@y === 1, π/2, -π/2],
    If[y == 0, If[Sign@x === 1, 0, π],
    If[Sign@y === 1, ArcCos@x, 2 π - ArcCos@x]
    ]
    ]
    ]

    SetDelayed[vectorAngle[List[Pattern[a1,Blank[]],Pattern[a2,Blank[]]]],
    Module[List[x,y],
    CompoundExpression[
    Set[List[x,y],
    N[Times[List[a1,a2],
    Power[Sqrt[Plus[Power[a1,2],Power[a2,2]]],-1]]]],
    If[Equal[x,0],
    If[SameQ[Sign[y],1],Times[Ï€,Power[2,-1]],
    Times[Times[-1,Ï€],Power[2,-1]]],
    If[Equal[y,0],If[SameQ[Sign[x],1],0,Ï€],
    If[SameQ[Sign[y],1],ArcCos[x],
    Plus[Times[2,Ï€],Times[-1,ArcCos[x]]]]]]]]]


    In the latter, it uses a full nested form (called FullForm in
    Mathematica). This form is isomorphic to lisp's nested parenthesis
    syntax, token for token (i.e. lisp's “(f a b)†is Mathematica's
    “f[a,b]â€). As you can see, this form, by the sheer number of nested
    brackets, is in practice problematic to read and type. In Mathematica,
    nobody really program using this syntax. (The FullForm syntax is
    there, for the same reason of language design principle shared with
    lisp of “consistency and simplicityâ€, or the commonly touted lisp
    advantage of “data is program; program is dataâ€.)

    The third issue, about how nested syntax seriously discourages
    frequent or advanced use of inline function sequencing on the fly, is
    the most important and I'll give further explanation below.

    One practical way to see how this is so, is by considering unix's
    shell syntax. You all know, how convenient and powerful is the unix's
    pipes. Here are some practical example: “ls -al | grep xyzâ€, or “cat a
    b c | grep xyz | sort | uniqâ€.

    Now suppose, we get rid of the unix's pipe notation, instead, replace
    it with a pure functional notation: e.g. (uniq (sort (grep xyz (cat a
    b c)))), or enrich it with a composition function and a pure function
    construct (λ), so this example can be written as: ((composition uniq
    sort (lambda (x) (grep xyz x))) (cat a b c)).

    You see, how this change, although syntactically equivalent to the
    pipe “|†(or semantically equivalent in the example using function
    compositions), but due to the cumbersome nested syntax, will force a
    change in the nature of the language by the code programer produces.
    Namely, the frequency of inline sequencing of functions on the fly
    will probably be reduced, instead, there will be more code that define
    functions with temp variables and apply it just once as with
    traditional languages.

    A language's syntax or notation system, has major impact on what kind
    of code or style or thinking pattern on the language's users. This is
    a well-known fact for those acquainted with the history of math
    notations.

    The sequential notation “f@g@h@xâ€, or “x//h//g//fâ€, or unixy “x|h|g|
    fâ€, are far more convenient and easier to decipher, than “(f (g (h
    x)))†or “((composition f g h) x)â€. In actual code, any of the f, g, h
    might be a complex pure function (aka lambda constructs, full of
    parenthesis themselves).

    Lisp, by sticking with a almost uniform nested parenthesis notation,
    it immediately reduces the pattern of sequencing functions, simply
    because the syntax does not readily lend the programer to it as in the
    unix's “x|h|g|fâ€. For programers who are aware of the coding pattern
    of sequencing functions, now either need to think in terms of a
    separate “composition†construct, and or subject to the much
    problematic typing and deciphering of nested parenthesis.

    (Note: Lisp's sexp is actually not that pure. It has ad hoc syntax
    equivalents such as the “quote†construct “ '(a b c) â€, and also “`â€,
    “#â€, “,@†constructs, precisely for the purpose of reducing
    parenthesis and increasing readability. Scheme's coming standard the
    R6RS ↗, even proposes the introduction of [] and {} and few other
    syntax sugars to break the uniformity of nested parenthesis for
    legibility. Mathematica's FullForm, is actually a version of
    unadulterated nested notation as can be.)

    Xah

    ∑ http://xahlee.org/
    , Jun 8, 2007
    #9
  10. wrote:
    [nothing relevant to Perl]

    Oh no, it is back.
    Did your ISP finally cancel your old account or why are you switching to a
    new address?
    Don't try to disguise yourself. Your 'contributions' can easily be
    identified no matter what pseudonym you are using.

    ***PLONK AGAIN***

    jue
    Jürgen Exner, Jun 9, 2007
    #10
  11. Xah Lee

    Twisted Guest

    On Jun 8, 7:30 pm, "Jürgen Exner" <> wrote:
    > wrote:
    >
    > [nothing relevant to Perl]


    Perl?? Perl is even less relevant to Java than the original post,
    which admittedly has some connection to pretty much all programming
    languages. (Perl, on the other hand, has no connection to any known
    programming language. ;) In particular, Perl code looks more like line
    noise than like code from any known programming language. ;))
    Twisted, Jun 9, 2007
    #11
  12. Xah Lee

    Lew Guest

    Re: The Concepts and Confusions of Prefix, Infix, Postfix and FullyFunctional Notations

    Twisted wrote:
    > On Jun 8, 7:30 pm, "Jürgen Exner" <> wrote:
    >> wrote:
    >>
    >> [nothing relevant to Perl]

    >
    > Perl?? Perl is even less relevant to Java than the original post,
    > which admittedly has some connection to pretty much all programming
    > languages. (Perl, on the other hand, has no connection to any known
    > programming language. ;) In particular, Perl code looks more like line
    > noise than like code from any known programming language. ;))


    Hmm - I know of APL and SNOBOL.

    --
    Lew
    Lew, Jun 9, 2007
    #12
  13. Xah Lee

    Paul McGuire Guest

    On Jun 9, 6:49 am, Lew <> wrote:
    > > In particular, Perl code looks more like line
    > > noise than like code from any known programming language. ;))

    >
    > Hmm - I know of APL and SNOBOL.
    >
    > --
    > Lew


    TECO editor commands. I don't have direct experience with TECO, but
    I've heard that a common diversion was to type random characters on
    the command line, and see what the editor would do.

    -- Paul
    Paul McGuire, Jun 9, 2007
    #13
  14. Xah Lee

    BCB Guest

    "Paul McGuire" <> wrote in message
    news:...
    > On Jun 9, 6:49 am, Lew <> wrote:
    >> > In particular, Perl code looks more like line
    >> > noise than like code from any known programming language. ;))

    >>
    >> Hmm - I know of APL and SNOBOL.
    >>
    >> --
    >> Lew

    >
    > TECO editor commands. I don't have direct experience with TECO, but
    > I've heard that a common diversion was to type random characters on
    > the command line, and see what the editor would do.
    >
    > -- Paul
    >


    J

    http://www.jsoftware.com/
    BCB, Jun 10, 2007
    #14
  15. Xah Lee

    Twisted Guest

    On Jun 9, 8:21 pm, "BCB" <> wrote:
    > "Paul McGuire" <> wrote in message
    >
    > news:...
    >
    > > On Jun 9, 6:49 am, Lew <> wrote:
    > >> > In particular, Perl code looks more like line
    > >> > noise than like code from any known programming language. ;))

    >
    > >> Hmm - I know of APL and SNOBOL.

    >
    > >> --
    > >> Lew

    >
    > > TECO editor commands. I don't have direct experience with TECO, but
    > > I've heard that a common diversion was to type random characters on
    > > the command line, and see what the editor would do.

    >
    > > -- Paul

    >
    > J
    >
    > http://www.jsoftware.com/


    Oh come on! Toy languages (such as any set of editor commands) and
    joke languages (ala Intercal) don't count, even if they are
    technically Turing-complete. ;)

    Nor does anything that was designed for the every-character-at-a-
    premium punch-card era, particularly if it is, or rhymes with,
    "COBOL".

    Those have excuses, like it's a joke or it's a constrained
    environment. Perl, unfortunately, has no such excuses. If there were
    such a thing as "embedded Perl", I'd have to hesitate here, but since
    there isn't...
    Twisted, Jun 10, 2007
    #15
  16. Xah Lee

    Larry Elmore Guest

    Re: The Concepts and Confusions of Prefix, Infix, Postfix and FullyFunctional Notations

    Twisted wrote:
    > On Jun 9, 8:21 pm, "BCB" <> wrote:
    >> "Paul McGuire" <> wrote in message
    >>
    >> news:...
    >>
    >>> On Jun 9, 6:49 am, Lew <> wrote:
    >>>>> In particular, Perl code looks more like line
    >>>>> noise than like code from any known programming language. ;))
    >>>> Hmm - I know of APL and SNOBOL.
    >>>> --
    >>>> Lew
    >>> TECO editor commands. I don't have direct experience with TECO, but
    >>> I've heard that a common diversion was to type random characters on
    >>> the command line, and see what the editor would do.
    >>> -- Paul

    >> J
    >>
    >> http://www.jsoftware.com/

    >
    > Oh come on! Toy languages (such as any set of editor commands) and
    > joke languages (ala Intercal) don't count, even if they are
    > technically Turing-complete. ;)
    >
    > Nor does anything that was designed for the every-character-at-a-
    > premium punch-card era, particularly if it is, or rhymes with,
    > "COBOL".
    >
    > Those have excuses, like it's a joke or it's a constrained
    > environment. Perl, unfortunately, has no such excuses. If there were
    > such a thing as "embedded Perl", I'd have to hesitate here, but since
    > there isn't...


    Neither APL nor Snobol nor J are toy or joke languages.
    Larry Elmore, Jun 10, 2007
    #16
  17. Xah Lee

    Lew Guest

    Re: The Concepts and Confusions of Prefix, Infix, Postfix and FullyFunctional Notations

    Twisted wrote:
    >> Oh come on! Toy languages (such as any set of editor commands) and
    >> joke languages (ala Intercal) don't count, even if they are
    >> technically Turing-complete. ;)
    >>
    >> Nor does anything that was designed for the every-character-at-a-
    >> premium punch-card era, particularly if it is, or rhymes with,
    >> "COBOL".
    >>
    >> Those have excuses, like it's a joke or it's a constrained
    >> environment. Perl, unfortunately, has no such excuses. If there were
    >> such a thing as "embedded Perl", I'd have to hesitate here, but since
    >> there isn't...


    Larry Elmore wrote:
    > Neither APL nor Snobol nor J are toy or joke languages.


    Indeed. One wonders where Perl would be if Snobol hadn't preceded it.

    --
    Lew
    Lew, Jun 10, 2007
    #17
  18. Xah Lee

    Reilly Guest

    On Jun 10, 3:11 pm, Larry Elmore <>
    wrote:
    > Twisted wrote:
    > > On Jun 9, 8:21 pm, "BCB" <> wrote:
    > >> "Paul McGuire" <> wrote in message

    >
    > >>news:...

    >
    > >>> On Jun 9, 6:49 am, Lew <> wrote:
    > >>>>> In particular, Perl code looks more like line
    > >>>>> noise than like code from any known programming language. ;))
    > >>>> Hmm - I know of APL and SNOBOL.
    > >>>> --
    > >>>> Lew
    > >>> TECO editor commands. I don't have direct experience with TECO, but
    > >>> I've heard that a common diversion was to type random characters on
    > >>> the command line, and see what the editor would do.
    > >>> -- Paul
    > >> J

    >
    > >>http://www.jsoftware.com/

    >
    > > Oh come on! Toy languages (such as any set of editor commands) and
    > > joke languages (ala Intercal) don't count, even if they are
    > > technically Turing-complete. ;)

    >
    > > Nor does anything that was designed for the every-character-at-a-
    > > premium punch-card era, particularly if it is, or rhymes with,
    > > "COBOL".

    >
    > > Those have excuses, like it's a joke or it's a constrained
    > > environment. Perl, unfortunately, has no such excuses. If there were
    > > such a thing as "embedded Perl", I'd have to hesitate here, but since
    > > there isn't...

    >
    > Neither APL nor Snobol nor J are toy or joke languages.


    I'd like register my agreement. SNOBOL was a very sophisticated
    language and way ahead of its time in many ways. While it's not
    really used anymore, SNOBOL's legacy does live on in languages that
    are in wide use.

    APL and it's successors (including J & K) are neither toys nor extinct
    relics. APL is still used in a variety of applications. The price of
    the last airline ticket you bought was probably determined by a yield
    management application written in APL. K was created in 1993 and Kx
    systems has built an incredibly valuable company on top of it.

    APL's terseness has more to do with the Iverson's notational goals
    than economy with characters related to punchcards. In fact, the
    dominant languages of the punchcard era (COBOL & FORTRAN) are both
    pretty verbose.

    Lastly, ITS Teco wasn't a joke or toy language either.. It was
    psychotically terse and virtually impenetrable to later review. But
    it wasn't a toy. When I learned to use EMACS, it was still
    implemented in ITS Teco.
    Reilly, Jun 11, 2007
    #18
  19. Xah Lee

    BCB Guest

    <snip>

    >
    > Neither APL nor Snobol nor J are toy or joke languages


    I wholeheartedly agree, and did not mean to imply as much in my original
    post, in which my intent was to emphasize the fact that, until you learn the
    language, a J program /does/ resemble line noise! :)
    BCB, Jun 11, 2007
    #19
  20. Xah Lee

    Twisted Guest

    On Jun 10, 8:50 pm, "BCB" <> wrote:
    > I wholeheartedly agree, and did not mean to imply as much in my original
    > post, in which my intent was to emphasize the fact that, until you learn the
    > language, a J program /does/ resemble line noise! :)


    Eh. This isn't right. The whole discussion was supposed to have died
    after the original Perl joke, certainly after the subsequent exclusion
    of joke and toy languages. I think I made it clear also that an
    editor's command set, Turing-complete though it may be, constitutes a
    toy language. Anyway I amend the original claim to cover joke
    languages, toy languages, and any write-only languages that
    mysteriously aren't considered to fall into either of the former two
    categories. After all, you can't really take a language seriously if
    it's either impossible to write unmaintainable code in it OR
    impossible to write maintainable code in it. The one is necessarily
    trivial, and the other unsuitable for anything serious, except as a
    machine-compiled intermediate format or a mechanism for assuring job
    security.
    Twisted, Jun 11, 2007
    #20
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