.\" $OpenBSD: B.in,v 1.4 2022/06/08 13:08:00 schwarze Exp $
.Dd $Mdocdate: June 8 2022 $
.Dt ESC-B 1
.Os
.Sh NAME
.Nm esc-B
.Nd the roff escape B sequence: validate numerical expression
.Sh DESCRIPTION
empty: \B''
.br
digit: \B'0'
.br
no number: \B'no number'
.br
trailing garbage: \B'1X'
.br
trailing operator: \B'1+'
.br
infix operator: \B'1+1'
.br
infix and trailing operator: \B'1+1+'
.br
chain of operations: \B'1+2+3+4'
.br
trailing para: \B'1+('
.br
unclosed para: \B'(1'
.br
empty pair of parentheses: \B'()'
.br
parentheses containing number: \B'(42)'
.br
complex expression: \B'3+(3*(5==5*2)*4)+(3*5)/2'
.br
other delimiter: \Bx1+1x
.Ss Argument delimiters
unsupported \e!: \B\!42\!u
.br
unsupported \er: \B\r42u
.br
ignored \e%: \B\%42\%u
.br
ignored \e&: \B\&42\&u
.br
ignored \e): \B\)42\)u
.br
ignored \e,: \B\,42\,u
.br
ignored \e/: \B\/42\/u
.br
ignored \e^: \B\^42\^u
.br
ignored \ea: \B\a42\au
.br
ignored \ed: \B\d42\du
.br
ignored \et: \B\t42\tu
.br
ignored \eu: \B\u42\uu
.br
ignored \e{: \B\{42\{u
.br
ignored \e|: \B\|42\|u
.br
ignored \e}: \B\}42\}u
.br
useless \e.: \B\.42.u
.\".br
.\"XXX useless \e\e: \B\\42\\u
.br
invalid \eG: \B\G42Gu
.br
special \e\ : \B\ 42\ u
.br
special \e\(aq: \B\'42\'u
.br
special \e-: \B\-42\-u
.br
special \e0: \B\042\0u
.br
special \e:: \B\:42\:u
.br
special \e_: \B\_42\_u
.br
special \e\(ga: \B\`42\`u
.br
special \ee: \B\e42\eu
.br
special \e~: \B\~42\~u
.br
break \ep: \B\p42\pu
.br
nospace \ec: \B\c42\cu
.\".br
.\"XXX skipchar \ec: \B\z42\zu
.br
.ds mystr x42xu
string expansion: \B\*[mystr]
.br
.nr myreg 23
register expansion: \B\n[myreg]u
.br
ignored \eO: \B\O142\O2u
.br
ignored \eY: \B\Y[mystr]42\Y[mystr]u
.br
ignored \ek: \B\k[myreg]42\k[myreg]u
.br
special character: \B\(hy42\(hyu
.br
ignored \eD: \B\D't 1'42\D't 2'u
.br
ignored \eL: \B\L'2'42u
.br
ignored \eX: \B\X'foo'42\X'bar'u
.br
ignored \eZ: \B\Z'foo'42\Z''u
.br
ignored \eb: \B\b'2'42\b''u
.br
ignored \ev: \B\v'2'42\v'0'u
.br
ignored \ex: \B\x'2'42\v'0'u
.br
horizontal motion: \B\h'1'42\h'3'u
.br
horizontal line: \B\l'4'42\l'2'u
.br
overstrike: \B\o'ab'42\o'cd'u