Pikchr: statement-list

A complete Pikchr source document consists of a list of zero or more statements. Individual statements within the list are separated from each other by semicolons (";") and/or newlines. Surplus semicolons and newlines are ignored. A zero-length string, or a string consisting of only semicolons and newlines, is a valid Pikchr document.

The statement-list is also a subpart of the syntax for the []-collection object.

Rules

statement
statement-list NEWLINE statement
statement-list ; statement

Bubble Chart

$r = 0.2in
linerad = 0.75*$r
linewid = 0.25

# Start and end blocks
#
box "statement-list" bold fit
line down 75% from last box.sw
dot rad 250% color black
X0: last.e + (0.3,0)
arrow from last dot to X0
move right 2in
box wid 5% ht 25% fill black
X9: last.w - (0.3,0)
arrow from X9 to last box.w


# The main rule that goes straight through from start to finish
#
box "statement" italic fit at 0.5<X0,X9>
arrow to X9
arrow from X0 to last box.w

# The by-pass line
#
arrow right $r from X0 then up $r \
  then right until even with 1/2 way between X0 and X9
line right until even with X9 - ($r,0) \
  then down until even with X9 then right $r

# The Loop-back rule
#
oval "\"&#92;n\"" fit at $r*1.2 below 1/2 way between X0 and X9
line right $r from X9-($r/2,0) then down until even with last oval \
   then to last oval.e ->
line from last oval.w left until even with X0-($r,0) \
   then up until even with X0 then right $r
oval "\";\"" fit at $r*1.2 below last oval
line from 2*$r right of 2nd last oval.e left $r \
   then down until even with last oval \
   then to last oval.e ->
line from last oval.w left $r then up until even with 2nd last oval \
   then left 2*$r ->

Whitespace

Whitespace other than a newline is ignored. If a backslash is followed by one or more whitespace characters ending in a newline, then the backslash and all of the spaces that follow, including the newline, are considered whitespace. Thus, a backslash at the end of a line causes a statement to continue onto the next line.

Comments

Three comment formats are supported:

The "#" character and all characters that follow up to but not including the next newline character. (Bourne-shell style comments.)
Two forward slashes ("//") and all characters that follow up to but not including the next newline character. (C++ style comments.)
The sequence "/*" and all characters that follow up to and including the next "*/". (C style comments.)

The first form (#-comments) is the only form supported by legacy-PIC. The C++ and C style commenting is new to Pikchr.

For #-comments and //-comments, the newline that follows is not part of the comment. Hence that newline will terminate the current statement. There is no way to escape the newline at the end of a #- or //-comment. If you need a comment at the end of a line but want to continue the statement on the next line, you must use /*..*/ style comments.