=================================================================== RCS file: /cvs/mandoc/roff.7,v retrieving revision 1.52 retrieving revision 1.56 diff -u -p -r1.52 -r1.56 --- mandoc/roff.7 2014/04/05 20:34:57 1.52 +++ mandoc/roff.7 2014/08/13 20:34:29 1.56 @@ -1,4 +1,4 @@ -.\" $Id: roff.7,v 1.52 2014/04/05 20:34:57 schwarze Exp $ +.\" $Id: roff.7,v 1.56 2014/08/13 20:34:29 kristaps Exp $ .\" .\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons .\" Copyright (c) 2010, 2011, 2013, 2014 Ingo Schwarze @@ -15,7 +15,7 @@ .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" -.Dd $Mdocdate: April 5 2014 $ +.Dd $Mdocdate: August 13 2014 $ .Dt ROFF 7 .Os .Sh NAME @@ -239,8 +239,9 @@ pica (~1/6 inch) .It p point (~1/72 inch) .It f -synonym for +scale .Sq u +by 65536 .It v default vertical span .It m @@ -254,7 +255,7 @@ width of rendered .Pq en character .It u -default horizontal span +default horizontal span for the terminal .It M mini-em (~1/100 em) .El @@ -262,7 +263,6 @@ mini-em (~1/100 em) Using anything other than .Sq m , .Sq n , -.Sq u , or .Sq v is necessarily non-portable across output media. @@ -409,24 +409,21 @@ and the number of arguments is not checked. Append to a macro definition. The syntax of this request is the same as that of .Sx \&de . -It is currently ignored by -.Xr mandoc 1 , -as are its children. .Ss \&ami Append to a macro definition, specifying the macro name indirectly. The syntax of this request is the same as that of .Sx \&dei . -It is currently ignored by -.Xr mandoc 1 , -as are its children. .Ss \&am1 Append to a macro definition, switching roff compatibility mode off during macro execution. The syntax of this request is the same as that of .Sx \&de1 . -It is currently ignored by -.Xr mandoc 1 , -as are its children. +Since +.Xr mandoc 1 +does not implement +.Nm +compatibility mode at all, it handles this request as an alias for +.Sx \&am . .Ss \&as Append to a user-defined string. The syntax of this request is the same as that of @@ -554,9 +551,13 @@ Define a macro, specifying the macro name indirectly. The syntax of this request is the same as that of .Sx \&de . -It is currently ignored by -.Xr mandoc 1 , -as are its children. +The request +.Pp +.D1 Pf . Cm \&dei Ar name Op Ar end +.Pp +has the same effect as: +.Pp +.D1 Pf . Cm \&de No \e* Ns Bo Ar name Bc Op \e* Ns Bq Ar end .Ss \&de1 Define a .Nm @@ -751,18 +752,12 @@ or .Pq troff mode , COND evaluates to false. .It -If COND starts with a digit, optionally prefixed by a minus sign, -it is evaluated as a numerical expression of the form -.Ar number operator number , -where -.Ar operator -is one of -.Sq < , -.Sq <= , -.Sq = , -.Sq >= , -or -.Sq > . +If COND starts with a parenthesis or with an optionally signed +integer number, it is evaluated according to the rules of +.Sx Numerical expressions +explained below. +It evaluates to true if the the result is positive, +or to false if the result is zero or negative. .It Otherwise, the first character of COND is regarded as a delimiter and COND evaluates to true if the string extending from its first @@ -904,11 +899,13 @@ A register is an arbitrary string value that defines s which influences parsing and/or formatting. Its syntax is as follows: .Pp -.D1 Pf \. Cm \&nr Ar name Oo +|- Oc Ns Ar value +.D1 Pf \. Cm \&nr Ar name Oo +|- Oc Ns Ar expression .Pp -The -.Ar value -may, at the moment, only be an integer. +For the syntax of +.Ar expression , +see +.Sx Numerical expressions +below. If it is prefixed by a sign, the register will be incremented or decremented instead of assigned to. .Pp @@ -1021,6 +1018,73 @@ Begin a table, which formats input in aligned rows and See .Xr tbl 7 for a description of the tbl language. +.Ss Numerical expressions +The +.Sx \&nr , +.Sx \&if , +and +.Sx \&ie +requests accept integer numerical expressions as arguments. +These are always evaluated using the C +.Vt int +type; integer overflow works the same way as in the C language. +Numbers consist of an arbitrary number of digits +.Sq 0 +to +.Sq 9 +prefixed by an optional sign +.Sq + +or +.Sq - . +.Pp +The following binary operators are implemented. +Unless otherwise stated, they behave as in the C language: +.Pp +.Bl -tag -width 2n -compact +.It Ic + +addition +.It Ic - +subtraction +.It Ic * +multiplication +.It Ic / +division +.It Ic % +remainder of division +.It Ic < +less than +.It Ic > +greater than +.It Ic == +equal to +.It Ic = +equal to, same effect as +.Ic == +(this differs from C) +.It Ic <= +less than or equal to +.It Ic >= +greater than or equal to +.It Ic <> +not equal to (corresponds to C +.Ic != ; +this one is of limited portability, it is supported by Heirloom roff, +but not by groff) +.It Ic & +logical and (corresponds to C +.Ic && ) +.It Ic \&: +logical or (corresponds to C +.Ic \&|| ) +.It Ic ? +maximum (not available in C) +.El +.Pp +There is no concept of precendence; evaluation proceeds from left to right, +except when subexpressions are enclosed in parantheses. +Inside parentheses, whitespace is ignored. .Sh ESCAPE SEQUENCE REFERENCE The .Xr mandoc 1 @@ -1109,10 +1173,15 @@ Digit width space character. Anchor definition; ignored by .Xr mandoc 1 . .Ss \eB\(aq Ns Ar string Ns \(aq -Test whether +Interpolate +.Sq 1 +if .Ar string -is a numerical expession; ignored by -.Xr mandoc 1 . +conforms to the syntax of +.Sx Numerical expressions +explained above and +.Sq 0 +otherwise. .Ss \eb\(aq Ns Ar string Ns \(aq Bracket building function; ignored by .Xr mandoc 1 . @@ -1236,9 +1305,13 @@ Vertical motion; ignored by .Xr mandoc 1 . .Ss \ew\(aq Ns Ar string Ns \(aq Interpolate the width of the -.Ar string ; -ignored by -.Xr mandoc 1 . +.Ar string . +The +.Xr mandoc 1 +implementation assumes that after expansion of user-defined strings, the +.Ar string +only contains normal characters, no escape sequences, and that each +character has a width of 24 basic units. .Ss \eX\(aq Ns Ar string Ns \(aq Output .Ar string @@ -1274,6 +1347,12 @@ The term refers to groff version 1.15. .Pp .Bl -dash -compact +.It +The +.Sq u +scaling unit is the default terminal unit. +In traditional troff systems, this unit would change depending on the +output media. .It In mandoc, the .Sx \&EQ ,