% Reference Card for Asymptote

% Copyright (c) 2011 John C. Bowman. May be freely distributed.
% Thanks to Stephen Gildea for the multicolumn macro package
% and Joseph H. Silverman for the C Reference card.

%**start of header
\newcount\columnsperpage

\overfullrule=0pt

% This file can be printed with 1, 2, or 3 columns per page (see below).
% [For 2 or 3 columns, you'll need 6 and 8 point fonts.]
% Specify how many you want here.  Nothing else needs to be changed.

\columnsperpage=2

% This reference card is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

% This file is intended to be processed by plain TeX (TeX82).
%
% The final reference card has six columns, three on each side.
% This file can be used to produce it in any of three ways:
% 1 column per page
%    produces six separate pages, each of which needs to be reduced to 80%.
%    This gives the best resolution.
% 2 columns per page
%    produces three already-reduced pages.
%    You will still need to cut and paste.
% 3 columns per page
%    produces two pages which must be printed sideways to make a
%    ready-to-use 8.5 x 11 inch reference card.
%    For this you need a dvi device driver that can print sideways.
% Which mode to use is controlled by setting \columnsperpage above.
%
%  (reference card macros due to Stephen Gildea)
%

\def\versionnumber{1.1}  % Version of this reference card
\def\year{2014}
\def\month{May}
\def\version{\month\ \year\ v\versionnumber}

\def\shortcopyrightnotice{\vskip .5ex plus 2 fill
  \centerline{\small \copyright\ \year\ John C. Bowman
  Permissions on back.  v\versionnumber}}

\def\copyrightnotice{
\vskip 1ex plus 100 fill\begingroup\small
\centerline{\version. Copyright \copyright\ \year\ John C. Bowman}

Permission is granted to make and distribute copies of this card, with
or without modifications, provided the copyright notice and this
permission notice are preserved on all copies.
\endgroup}

% make \bye not \outer so that the \def\bye in the \else clause below
% can be scanned without complaint.
\def\bye{\par\vfill\supereject\end}

\newdimen\intercolumnskip
\newbox\columna
\newbox\columnb

\def\ncolumns{\the\columnsperpage}

\message{[\ncolumns\space 
  column\if 1\ncolumns\else s\fi\space per page]}

\def\scaledmag#1{ scaled \magstep #1}

% This multi-way format was designed by Stephen Gildea
% October 1986.
\if 1\ncolumns
  \hsize 4in
  \vsize 10in
  \voffset -.7in
  \font\titlefont=\fontname\tenbf \scaledmag3
  \font\headingfont=\fontname\tenbf \scaledmag2
		\font\headingfonttt=\fontname\tentt \scaledmag2
  \font\smallfont=\fontname\sevenrm
  \font\smallsy=\fontname\sevensy

  \footline{\hss\folio}
  \def\makefootline{\baselineskip10pt\hsize6.5in\line{\the\footline}}
\else
  \hsize 3.2in
  \vsize 7.95in
  \hoffset -.75in
  \voffset -.745in
  \font\titlefont=cmbx10 \scaledmag2
  \font\headingfont=cmbx10 \scaledmag1
		\font\headingfonttt=cmtt10 \scaledmag1
  \font\smallfont=cmr6
  \font\smallsy=cmsy6
  \font\eightrm=cmr8
  \font\eightbf=cmbx8
  \font\eightit=cmti8
  \font\eighttt=cmtt8
  \font\eightsy=cmsy8
  \font\eightsl=cmsl8
  \font\eighti=cmmi8
  \font\eightex=cmex10 at 8pt
  \textfont0=\eightrm  
  \textfont1=\eighti
  \textfont2=\eightsy
  \textfont3=\eightex
  \def\rm{\fam0 \eightrm}
  \def\bf{\eightbf}
  \def\it{\eightit}
  \def\tt{\eighttt}
  \def\sl{\eightsl}
  \normalbaselineskip=.8\normalbaselineskip
  \normallineskip=.8\normallineskip
  \normallineskiplimit=.8\normallineskiplimit
  \normalbaselines\rm		%make definitions take effect

  \if 2\ncolumns
    \let\maxcolumn=b
    \footline{\hss\rm\folio\hss}
    \def\makefootline{\vskip 2in \hsize=6.86in\line{\the\footline}}
  \else \if 3\ncolumns
    \let\maxcolumn=c
    \nopagenumbers
  \else
    \errhelp{You must set \columnsperpage equal to 1, 2, or 3.}
    \errmessage{Illegal number of columns per page}
  \fi\fi

  \intercolumnskip=.46in
  \def\abc{a}
  \output={%
      % This next line is useful when designing the layout.
      %\immediate\write16{Column \folio\abc\space starts with \firstmark}
      \if \maxcolumn\abc \multicolumnformat \global\def\abc{a}
      \else\if a\abc
	\global\setbox\columna\columnbox \global\def\abc{b}
        %% in case we never use \columnb (two-column mode)
        \global\setbox\columnb\hbox to -\intercolumnskip{}
      \else
	\global\setbox\columnb\columnbox \global\def\abc{c}\fi\fi}
  \def\multicolumnformat{\shipout\vbox{\makeheadline
      \hbox{\box\columna\hskip\intercolumnskip
        \box\columnb\hskip\intercolumnskip\columnbox}
      \makefootline}\advancepageno}
  \def\columnbox{\leftline{\pagebody}}

  \def\bye{\par\vfill\supereject
    \if a\abc \else\null\vfill\eject\fi
    \if a\abc \else\null\vfill\eject\fi
    \end}  
\fi

% we won't be using math mode much, so redefine some of the characters
% we might want to talk about
\catcode`\^=12
%\catcode`\_=12
\catcode`\~=12

\chardef\\=`\\
\chardef\{=`\{
\chardef\}=`\}
\chardef\underscore=`\_

\hyphenation{}

\parindent 0pt
\parskip .85ex plus .35ex minus .5ex

\def\small{\smallfont\textfont2=\smallsy\baselineskip=.8\baselineskip}

\outer\def\newcolumn{\vfill\eject}

\outer\def\title#1{{\titlefont\centerline{#1}}\vskip 1ex plus .5ex}

\outer\def\section#1{\par\filbreak
  \vskip .5ex  minus .1ex {\headingfont #1}\mark{#1}%
  \vskip .3ex  minus .1ex}

\outer\def\librarysection#1#2{\par\filbreak
  \vskip .5ex  minus .1ex {\headingfont #1}\quad{\headingfonttt<#2>}\mark{#1}%
  \vskip .3ex  minus .1ex}


\newdimen\keyindent

\def\beginindentedkeys{\keyindent=1em}
\def\endindentedkeys{\keyindent=0em}
\def\begindoubleindentedkeys{\keyindent=2em}
\def\enddoubleindentedkeys{\keyindent=1em}
\endindentedkeys

\def\paralign{\vskip\parskip\halign}

\def\<#1>{$\langle${\rm #1}$\rangle$}

\def\kbd#1{{\tt#1}\null}	%\null so not an abbrev even if period follows

\def\beginexample{\par\vskip1\jot
\hrule width.5\hsize
\vskip1\jot
\begingroup\parindent=2em
  \obeylines\obeyspaces\parskip0pt\tt}
{\obeyspaces\global\let =\ }
\def\endexample{\endgroup}

\def\Example{\qquad{\sl Example\/}.\enspace\ignorespaces}

\def\key#1#2{\leavevmode\hbox to \hsize{\vtop
  {\hsize=.75\hsize\rightskip=1em
  \hskip\keyindent\relax#1}\kbd{#2}\hfil}}

\newbox\metaxbox
\setbox\metaxbox\hbox{\kbd{M-x }}
\newdimen\metaxwidth
\metaxwidth=\wd\metaxbox

\def\metax#1#2{\leavevmode\hbox to \hsize{\hbox to .75\hsize
  {\hskip\keyindent\relax#1\hfil}%
  \hskip -\metaxwidth minus 1fil
  \kbd{#2}\hfil}}

\def\threecol#1#2#3{\hskip\keyindent\relax#1\hfil&\kbd{#2}\quad
  &\kbd{#3}\quad\cr}

% Define Italic Names
\def\makedef#1 {%
\expandafter\edef\csname#1\endcsname{\hbox{\it#1\/}}}
\makedef array
\makedef arg
\makedef const
\makedef dim
\makedef expr
\makedef filename
\makedef f
\makedef format
\makedef member
\makedef name
\makedef statement
\makedef statements
\makedef string
\makedef type
\makedef value
\makedef var

%**end of header


\title{Asymptote Reference Card}

\section{Program structure/functions}
\halign{\tt#\hfil&\qquad#\hfil\cr
import "\filename"&import module\cr
import "\filename" as name&import filename as module name\cr
include "\filename"&include verbatim text from file\cr
\type\ \f(\type,\dots);&optional function declaration\cr
\type\ \name;&variable declaration\cr
\type\ \f(\type\ \arg,\dots) \{&function definition\cr
\quad\statements\cr
\quad return \value;\cr
\}\cr
}

\section{Data types/declarations}
\key{boolean (true or false)}{bool}
\key{tri-state boolean (true, default, or false)}{bool3}
\key{integer}{int}
\key{float (double precision)}{real}
\key{ordered pair (complex number)}{pair}
\key{character string}{string}
\key{fixed piecewise cubic Bezier spline}{path}
\key{unresolved piecewise cubic Bezier spline}{guide}
\key{color, line type/width/cap, font, fill rule}{pen}
\key{label with position, alignment, pen attributes}{Label}
\key{drawing canvas}{picture}
\key{affine transform}{transform}
\key{constant (unchanging) value}{const}
\key{allocate in higher scope}{static}
\key{no value}{void}
\key{inhibit implicit argument casting}{explicit}
\key{structure}{struct}
\key{create name by data type}{typedef \type\ \name}

\section{3D data types (import three;)}
\key{ordered triple}{triple}
\key{3D path}{path3}
\key{3D guide}{guide3}
\key{3D affine transform}{transform3}

\section{Constants}
\key{exponential form}{6.02e23}
\key{\TeX\ string constant}{"abc\dots de"}
\key{\TeX\ strings: special characters}{\\\\, \\"}
\key{C strings: constant}{'abc\dots de'}
\key{C strings: special characters}{\\\\, \\" \\' \\?}
\key{C strings: newline, cr, tab, backspace}{\\n \\r \\t \\b}
\key{C strings: octal, hexadecimal bytes}{\\0-\\377 \\x0-\\xFF}

\section{Operators}
\key{arithmetic operations}{+ - * /}
\key{modulus (remainder)}{\%}
\key{comparisons}{== != > >= < <=}
\key{not}{!}
\key{and or (conditional evaluation of RHS)}{\&\& ||}
\key{and or xor}{\& | ^}
\key{cast expression to type}{(\type) \expr}
\key{increment decrement prefix operators}{++ --}
\key{assignment operators}{+= -= *= /= \%=}
\key{conditional expression}{\expr$_1$\ {?}\ \expr$_2$\ {:}\ \expr$_3$}
\key{structure member operator}{\name.\member}
\key{expression evaluation separator}{,}

\section{Flow control}
\key{statement terminator}{;}
\key{block delimeters}{\{\quad\}}
\key{comment delimeters}{/*\quad*/}
\key{comment to end of line delimiter}{//}
\key{exit from \kbd{while}/\kbd{do}/\kbd{for}}{break;}
\key{next iteration of \kbd{while}/\kbd{do}/\kbd{for}}{continue;}
\key{return value from function}{return \expr;}
\key{terminate execution}{exit();}
\key{abort execution with error message}{abort(string);}
\metax{{\bf Flow constructions} ({\tt if/while/for/do})\hidewidth}{}
\beginexample
if(\expr)\ \statement
else if(\expr)\ \statement
else \statement
\endexample
\beginexample
while(\expr)
\quad\statement
\endexample
\beginexample
for(\expr$_1$; \expr$_2$; \expr$_3$)
\quad\statement
\endexample
\beginexample
for(\type var : \array)
\quad\statement
\endexample
\beginexample
do \statement
\quad while(\expr);
\endexample

\section{Arrays}
\key{array}{\type[]\ \name;}
\key{array element i}{\name[i]}
\key{array indexed by elements of int array {\tt A}}{\name[A]}
\key{anonymous array}{new \type[\dim]}
\key{array containing {\tt n} deep copies of {\tt x}}{array(n,x)}
\key{length}{\name.length}
\key{cyclic flag}{\name.cyclic}
\key{pop element {\tt x}}{\name.pop()}
\key{push element {\tt x}}{\name.push(x)}
\key{append array {\tt a}}{\name.append(a)}
\key{insert rest arguments at index {\tt i}}{\name.insert(i,\dots)}
\key{delete element at index {\tt i}}{\name.delete(i)}
\key{delete elements with indices in [{\tt i},{\tt j}]}{\name.delete(i,j)}
\key{delete all elements}{\name.delete()}
\key{test whether element n is initialized}{\name.initialized(n)}
\key{array of indices of initialized elements}{\name.keys}
\key{complement of int array in {\tt \{0,\dots,n-1\}}}{complement(a,n)}
\key{deep copy of array {\tt a}}{copy(a)}
\key{array {\tt \{0,1,\dots,n-1\}}}{sequence(n)}
\key{array {\tt \{n,n+1,\dots,m\}}}{sequence(n,m)}
\key{array {\tt \{n-1,n-2,\dots,0\}}}{reverse(n)}
\key{array {\tt \{f(0),f(1),\dots,f(n-1)\}}}{sequence(f,n)}
\key{array obtained by applying {\tt f} to array {\tt a}}{map(f,a)}
\key{uniform partition of [{\tt a},{\tt b}] into n intervals}{uniform(a,b,n)}
\key{concat specified 1D arrays}{concat(a,b,\dots)}
\key{return sorted array}{sort(a)}
\key{return array sorted using ordering {\tt less}}{sort(a,{\tt less})}
\key{search sorted array {\tt a} for key}{search(a,key)}
\key{index of first true value of bool array {\tt a}}{find(a)}
\key{index of nth true value of bool array {\tt a}}{find(a,n)}

\section{Initialization}
\key{initialize variable}{\type\ \name=\value;}
\key{initialize array}{\type[]\ \name=\{\dots\};}

\section{path connectors}
\key{straight segment}{--}
\key{Bezi\'er segment with implicit control points}{..}
\key{Bezi\'er segment with explicit control points}{..controls c0 and c1..}
\key{concatenate}{\&}
\key{lift pen}{^^}
\key{..tension atleast 1..}{::}
\key{..tension atleast infinity..}{---}

\section{Labels}
\key{implicit cast of string {\tt s} to Label}{s}
\key{Label {\tt s} with relative position and alignment}{Label(s,real,pair)}
\key{Label {\tt s} with absolute position and alignment}{Label(s,pair,pair)}
\key{Label {\tt s} with specified pen}{Label(s,pen)}

\section{draw commands}
\key{draw path with current pen}{draw(path)}
\key{draw path with pen}{draw(path,pen)}
\key{draw labeled path}{draw(Label,path)}
\key{draw arrow with pen}{draw(path,pen,Arrow)}
\key{draw path on picture}{draw(picture,path)}
\key{draw visible portion of line through two pairs}{drawline(pair,pair)}

\section{fill commands}
\key{fill path with current pen}{fill(path)}
\key{fill path with pen}{fill(path,pen)}
\key{fill path on picture}{fill(picture,path)}

\section{label commands}
\key{label a pair with optional alignment z}{label(Label,pair,{\tt z})}
\key{label a path with optional alignment z}{label(Label,path,{\tt z})}
\key{add label to picture}{label(picture,Label)}

\section{clip commands}
\key{clip to path}{clip(path)}
\key{clip to path with fill rule}{clip(path,pen)}
\key{clip picture to path}{clip(picture,path)}

\section{pens}
\key{Grayscale pen from value in [0,1]}{gray(g)}
\key{RGB pen from values in [0,1]}{rgb(r,g,b)}
\key{CMYK pen from values in [0,1]}{cmyk(r,g,b)}
\key{RGB pen from heximdecimal string]}{rgb(string)}
\key{heximdecimal string from rgb pen]}{hex(pen)}
\key{hsv pen from values in [0,1]}{hsv(h,s,v)}
\key{invisible pen}{invisible}
\key{default pen}{defaultpen}
\key{current pen}{currentpen}
\key{solid pen}{solid}
\key{dotted pen}{dotted}
\key{wide dotted current pen}{Dotted}
\key{wide dotted pen}{Dotted(pen)}
\key{dashed pen}{dashed}
\key{long dashed pen}{longdashed}
\key{dash dotted pen}{dashdotted}
\key{long dash dotted pen}{longdashdotted}
\key{PostScript butt line cap}{squarecap}
\key{PostScript round line cap}{roundcap}
\key{PostScript projecting square line cap}{extendcap}
\key{miter join}{miterjoin}
\key{round join}{roundjoin}
\key{bevel join}{beveljoin}
\key{pen with miter limit}{miterlimit(real)}
\key{zero-winding fill rule}{zerowinding}
\key{even-odd fill rule}{evenodd}
\key{align to character bounding box (default)}{nobasealign}
\key{align to \TeX\ baseline}{basealign}
\key{pen with font size (pt)}{fontsize(real)}
\key{LaTeX pen from encoding,family,series,shape}{font(strings)}
\key{\TeX\ pen}{font(string)}
\key{scaled \TeX\ pen}{font(string,real)}
\key{PostScript font from strings}{Courier(series,shape)}
\key{pen with opacity in [0,1]}{opacity(real)}
\key{construct pen nib from polygonal path}{makepen(path)}
\key{pen mixing operator}{+}

\section{path operations}
\key{number of segments in path {\tt p}}{length(p)}
\key{number of nodes in path {\tt p}}{size(p)}
\key{is path {\tt p} cyclic?}{cyclic(p)}
\key{is segment {\tt i} of path {\tt p} straight?}{straight(p,i)}
\key{is path {\tt p} straight?}{piecewisestraight(p)}
\key{coordinates of path {\tt p} at time {\tt t}}{point(p,t)}
\key{direction of path {\tt p} at time {\tt t}}{dir(p,t)}
\key{direction of path {\tt p} at {\tt length(p)}}{dir(p)}
\key{unit(dir(p)+dir(q))}{dir(p,q)} 
\key{acceleration of path {\tt p} at time {\tt t}}{accel(p,t)}
\key{radius of curvature of path {\tt p} at time {\tt t}}{radius(p,t)}
\key{precontrol point of path {\tt p} at time {\tt t}}{precontrol(p,t)}
\key{postcontrol point of path {\tt p} at time {\tt t}}{postcontrol(p,t)}
\key{arclength of path {\tt p}}{arclength(p)}
\key{time at which {\tt arclength(p)=L}}{arctime(p,L)}
\key{point on path {\tt p} at arclength {\tt L}}{arcpoint(p,L)}
\key{first value {\tt t} at which {\tt dir(p,t)=z}}{dirtime(p,z)}
\key{time {\tt t} at relative fraction {\tt l} of {\tt arclength(p)}}{reltime(p,l)}
\key{point at relative fraction {\tt l} of {\tt arclength(p)}}{relpoint(p,l)}
\key{point midway along arclength of {\tt p}}{midpoint(p)}
\key{path running backwards along {\tt p}}{reverse(p)}
\key{subpath of {\tt p} between times {\tt a} and {\tt b}}{subpath(p,a,b)}
\key{times for one intersection of paths {\tt p} and {\tt q}}{intersect(p,q)}
\key{times at which {\tt p} reaches minimal extents}{mintimes(p)}
\key{times at which {\tt p} reaches maximal extents}{maxtimes(p)}
\key{intersection times of paths {\tt p} and {\tt q}}{intersections(p,q)}
\key{intersection times of path {\tt p} with `{\tt --a--b--}'}{intersections(p,a,b)}
\key{intersection times of path {\tt p} crossing $x=${\tt x}}{times(p,x)}
\key{intersection times of path {\tt p} crossing $y=${\tt z.y}}{times(p,z)}
\key{intersection point of paths {\tt p} and {\tt q}}{intersectionpoint(p,q)}
\key{intersection points of {\tt p} and {\tt q}}{intersectionpoints(p,q)}
\key{intersection of extension of {\tt P--Q} and {\tt p--q}}{extension(P,Q,p,q)}
\key{lower left point of bounding box of path {\tt p}}{min(p)}
\key{upper right point of bounding box of path {\tt p}}{max(p)}
\key{subpaths of {\tt p} split by {\tt n}th cut of {\tt knife}}{cut(p,knife,n)}
\key{winding number of path {\tt p} about pair {\tt z}}{windingnumber(p,z)}
\key{pair {\tt z} lies within path {\tt p}?}{interior(p,z)}
\key{pair {\tt z} lies within or on path {\tt p}?}{inside(p,z)}
\key{path surrounding region bounded by paths}{buildcycle(\dots)}
\key{path filled by \tt{draw(g,p)}}{strokepath(g,p)}
\key{unit square with lower-left vertex at origin}{unitsquare}
\key{unit circle centered at origin}{unitcircle}
\key{circle of radius {\tt r} about {\tt c}}{circle(c,r)}
\key{arc of radius {\tt r} about {\tt c} from angle {\tt a} to {\tt b}}{arc(c,r,a,b)}
\key{unit {\tt n}-sided polygon}{polygon(n)}
\key{unit {\tt n}-point cyclic cross}{cross(n)}

\section{pictures}
\key{add picture {\tt pic} to currentpicture}{add(pic)}
\key{add picture {\tt pic} about pair {\tt z}}{add(pic,z)}

\section{affine transforms}
\key{identity transform}{identity()}
\key{shift by values}{shift(real,real)}
\key{shift by pair}{shift(pair)}
\key{scale by {\tt x} in the $x$ direction}{xscale(x)}
\key{scale by {\tt y} in the $y$ direction}{yscale(y)}
\key{scale by {\tt x} in both directions}{scale(x)}
\key{scale by real values {\tt x} and {\tt y}}{scale(x,y)}
\key{map $(x,y) \rightarrow (x+${\tt s}$y,y)$}{slant(s)}
\key{rotate by real {\tt angle} in degrees about pair {\tt z}}{rotate(angle,z=(0,0))}
\key{reflect about line from {\tt P--Q}}{reflect(P,Q)}

\section{string operations}
\key{concatenate operator}{+}
\key{string length}{length(string)}
\key{position $\ge$ {\tt pos} of first occurence of {\tt t} in {\tt s}}{find({\tt s},{\tt t},pos=0)}
\key{position $\le$ {\tt pos} of last occurence of {\tt t} in {\tt s}}{rfind({\tt s},{\tt t},pos=-1)}
\key{string with {\tt t} inserted in {\tt s} at {\tt pos}}{insert({\tt s},{\tt pos},{\tt t})}
\key{string {\tt s} with {\tt n} characters at {\tt pos} erased}{erase({\tt s},{\tt pos},{\tt n})}
\key{substring of string {\tt s} of length {\tt n} at {\tt pos}}{substr({\tt s},{\tt pos},{\tt n})}
\key{string {\tt s} reversed}{reverse({\tt s})}
\key{string {\tt s} with {\tt before} changed to {\tt after}}{replace({\tt s},{\tt before},{\tt after})}
\key{string {\tt s} translated via {\tt \{\{before,after\},\dots\}}}{replace({\tt
s},string [][] table)}
\key{format {\tt x} using C-style format string {\tt s} }{format({\tt s},x)}
\key{casts hexadecimal string to an integer}{hex(s)}
\key{casts {\tt x} to string using precision {\tt digits}}{string(x,digits=realDigits)}
\key{current time formatted by {\tt format}}{time(format="\%a \%b \%d \%T \%Z \%Y")}
\key{time in seconds of string {\tt t} using {\tt format}}{seconds(t,format)}
\key{string corresponding to {\tt seconds} using {\tt format}}{time(seconds,format)}
\key{split {\tt s} into strings separated by {\tt delimiter}}{split(s,delimiter="")}

%%%%%%%%%%%%%%%%%%%%%%%%%% END LIBRARIES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% This goes at the bottom of the last page (column 6)
\copyrightnotice
%

\bye

% Local variables:
% compile-command: "tex AsyRefCard"
% End: