=================================================================== RCS file: /cvs/mandoc/eqn.7,v retrieving revision 1.1 retrieving revision 1.27 diff -u -p -r1.1 -r1.27 --- mandoc/eqn.7 2011/02/09 10:03:02 1.1 +++ mandoc/eqn.7 2011/09/02 19:37:35 1.27 @@ -1,4 +1,4 @@ -.\" $Id: eqn.7,v 1.1 2011/02/09 10:03:02 kristaps Exp $ +.\" $Id: eqn.7,v 1.27 2011/09/02 19:37:35 kristaps Exp $ .\" .\" Copyright (c) 2011 Kristaps Dzonsons .\" @@ -14,7 +14,7 @@ .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" -.Dd $Mdocdate: February 9 2011 $ +.Dd $Mdocdate: September 2 2011 $ .Dt EQN 7 .Os .Sh NAME @@ -30,23 +30,212 @@ and .Xr man 7 .Ux manual pages. -This manual describes the subset of the +It describes the +.Em structure +of an equation, not its mathematical meaning. +This manual describes the .Nm language accepted by the .Xr mandoc 1 -utility. +utility, which correspond to the Second Edition eqn specification (see +.Sx SEE ALSO +for references). .Pp Equations within .Xr mdoc 7 or .Xr man 7 -are enclosed by the -.Sq EQ +documents are enclosed by the standalone +.Sq \&.EQ and -.Sq EN -macro tags, whose precise syntax is documented in -.Xr roff 7 . -Equations consist of multi-line equation data. +.Sq \&.EN +tags. +Equations are multi-line blocks consisting of formulas and control +statements. +.Sh EQUATION STRUCTURE +Each equation is bracketed by +.Sq \&.EQ +and +.Sq \&.EN +strings. +.Em Note : +these are not the same as +.Xr roff 7 +macros, and may only be invoked as +.Sq \&.EQ . +.Pp +The equation grammar is as follows, where quoted strings are +case-sensitive literals in the input: +.Bd -literal -offset indent +eqn : box | eqn box +box : text + | \*q{\*q eqn \*q}\*q + | \*qdefine\*q text text + | \*qndefine\*q text text + | \*qtdefine\*q text text + | \*qgfont\*q text + | \*qgsize\*q text + | \*qset\*q text text + | \*qundef\*q text + | box pos box + | box mark + | \*qmatrix\*q \*q{\*q [col \*q{\*q list \*q}\*q ]* + | pile \*q{\*q list \*q}\*q + | font box + | \*qsize\*q text box + | \*qleft\*q text eqn [\*qright\*q text] +col : \*qlcol\*q | \*qrcol\*q | \*qccol\*q | \*qcol\*q +text : [^space\e\*q]+ | \e\*q.*\e\*q +pile : \*qlpile\*q | \*qcpile\*q | \*qrpile\*q | \*qpile\*q +pos : \*qover\*q | \*qsup\*q | \*qsub\*q | \*qto\*q | \*qfrom\*q +mark : \*qdot\*q | \*qdotdot\*q | \*qhat\*q | \*qtilde\*q | \*qvec\*q + | \*qdyad\*q | \*qbar\*q | \*qunder\*q +font : \*qroman\*q | \*qitalic\*q | \*qbold\*q | \*qfat\*q +list : eqn + | list \*qabove\*q eqn +space : [\e^~ \et] +.Ed +.Pp +White-space consists of the space, tab, circumflex, and tilde +characters. +If within a quoted string, these space characters are retained. +Quoted strings are also not scanned for replacement definitions. +.Pp +The following text terms are translated into a rendered glyph, if +available: alpha, beta, chi, delta, epsilon, eta, gamma, iota, kappa, +lambda, mu, nu, omega, omicron, phi, pi, psi, rho, sigma, tau, theta, +upsilon, xi, zeta, DELTA, GAMMA, LAMBDA, OMEGA, PHI, PI, PSI, SIGMA, +THETA, UPSILON, XI, inter (intersection), union (union), prod (product), +int (integral), sum (summation), grad (gradient), del (vector +differential), times (multiply), cdot (centre-dot), nothing (zero-width +space), approx (approximately equals), prime (prime), half (one-half), +partial (partial differential), inf (infinity), >> (much greater), << +(much less), \-> (left arrow), <\- (right arrow), += (plus-minus), != +(not equal), == (equivalence), <= (less-than-equal), and >= +(more-than-equal). +.Pp +The following control statements are available: +.Bl -tag -width Ds +.It Cm define +Replace all occurrences of a key with a value. +Its syntax is as follows: +.Pp +.D1 define Ar key cvalc +.Pp +The first character of the value string, +.Ar c , +is used as the delimiter for the value +.Ar val . +This allows for arbitrary enclosure of terms (not just quotes), such as +.Pp +.D1 define Ar foo 'bar baz' +.D1 define Ar foo cbar bazc +.Pp +It is an error to have an empty +.Ar key or +.Ar val . +Note that a quoted +.Ar key +causes errors in some +.Nm +implementations and should not be considered portable. +It is not expanded for replacements. +Definitions may refer to other definitions; these are evaluated +recursively when text replacement occurs and not when the definition is +created. +.Pp +Definitions can create arbitrary strings, for example, the following is +a legal construction. +.Bd -literal -offset indent +define foo 'define' +foo bar 'baz' +.Ed +.Pp +Self-referencing definitions will raise an error. +The +.Cm ndefine +statement is a synonym for +.Cm define , +while +.Cm tdefine +is discarded. +.It Cm gfont +Set the default font of subsequent output. +Its syntax is as follows: +.Pp +.D1 gfont Ar font +.Pp +In mandoc, this value is discarded. +.It Cm gsize +Set the default size of subsequent output. +Its syntax is as follows: +.Pp +.D1 gsize Ar size +.Pp +The +.Ar size +value should be an integer. +.It Cm set +Set an equation mode. +In mandoc, both arguments are thrown away. +Its syntax is as follows: +.Pp +.D1 set Ar key val +.Pp +The +.Ar key +and +.Ar val +are not expanded for replacements. +This statement is a GNU extension. +.It Cm undef +Unset a previously-defined key. +Its syntax is as follows: +.Pp +.D1 define Ar key +.Pp +Once invoked, the definition for +.Ar key +is discarded. +The +.Ar key +is not expanded for replacements. +This statement is a GNU extension. +.El +.Sh COMPATIBILITY +This section documents the compatibility of mandoc +.Nm +and the troff +.Nm +implementation (including GNU troff). +.Pp +.Bl -dash -compact +.It +The text string +.Sq \e\*q +is interpreted as a literal quote in troff. +In mandoc, this is interpreted as a comment. +.It +In troff, The circumflex and tilde white-space symbols map to +fixed-width spaces. +In mandoc, these characters are synonyms for the space character. +.It +The troff implementation of +.Nm +allows for equation alignment with the +.Cm mark +and +.Cm lineup +tokens. +mandoc discards these tokens. +The +.Cm back Ar n , +.Cm fwd Ar n , +.Cm up Ar n , +and +.Cm down Ar n +commands are also ignored. +.El .Sh SEE ALSO .Xr mandoc 1 , .Xr man 7 , @@ -62,18 +251,29 @@ Equations consist of multi-line equation data. .%P 151\(en157 .%D March, 1975 .Re -.\" .Sh HISTORY -.\" The tbl utility, a preprocessor for troff, was originally written by M. -.\" E. Lesk at Bell Labs in 1975. -.\" The GNU reimplementation of tbl, part of the groff package, was released -.\" in 1990 by James Clark. -.\" A standalone tbl implementation was written by Kristaps Dzonsons in -.\" 2010. -.\" This formed the basis of the implementation that is part of the -.\" .Xr mandoc 1 -.\" utility. +.Rs +.%A Brian W. Kernighan +.%A Lorinda L. Cherry +.%T Typesetting Mathematics, User's Guide +.%D 1976 +.Re +.Rs +.%A Brian W. Kernighan +.%A Lorinda L. Cherry +.%T Typesetting Mathematics, User's Guide (Second Edition) +.%D 1978 +.Re +.Sh HISTORY +The eqn utility, a preprocessor for troff, was originally written by +Brian W. Kernighan and Lorinda L. Cherry in 1975. +The GNU reimplementation of eqn, part of the GNU troff package, was +released in 1989 by James Clark. +The eqn component of +.Xr mandoc 1 +was added in 2011. .Sh AUTHORS -This partial +This .Nm reference was written by -.An Kristaps Dzonsons Aq kristaps@bsd.lv . +.An Kristaps Dzonsons , +.Mt kristaps@bsd.lv .