initial commit of files from my bachelor-thesis repo

8 files changed, 851 insertions, 0 deletions

diff --git a/ebnf.sno b/ebnf.sno
new file mode 100755
index 0000000..682be78
--- /dev/null
+++ b/ebnf.sno
@@ -0,0 +1,138 @@
+#!/usr/local/bin/snobol4 -b
+
+***
+*** Definitions
+***
+	define('optspace(pattern)')
+	define('string()')
+	define('serialize()')
+	strings = array(2)
+	str_no = 0
+
+	define('emit_groff(str)')
+
+	define('begin_rule()')
+	define('end_rule()')
+
+	define('emit_nonterm()')
+	define('emit_term()')
+	define('emit_empty()')
+
+	define('begin_exp()')
+	define('end_exp()')
+
+	define('begin_alt()')
+	define('end_alt()')
+	define('repeat()')
+	define('repeat_with()')
+
+	&anchor = 1
+	&fullscan = 1
+
+***
+*** EBNF grammar
+***
+	letter = &lcase &ucase
+	digit = "0123456789"
+
+	space = span(" " char(9) char(10) char(13)) | ""
+	eol = break(char(10) char(13))
+	nonterm =  ( "`" break("`") $ *string() "`"
++		   | (any(letter) (span(letter digit "_") | "")) $ *string() )
++		   (optspace("~") *nonterm | "")
+	term = ( "'" break("'") $ *string() "'"
++	       | '"' break('"') $ *string() '"' )
++	       (optspace("~") *term | "")
+
+	lhs = nonterm
+	exp = nonterm *emit_nonterm()
++	    | term *emit_term()
++	    | optspace("[") *emit_empty() *begin_alt() *rhs optspace("]") *end_alt()
++	    | optspace("{") *begin_exp() *rhs optspace("}") *end_exp()
++	      (optspace("~") term *repeat_with() | *repeat())
++	    | optspace("(") *begin_exp() *rhs optspace(")") *end_exp()
++           | *emit_empty()
+	rhs = exp
++	      ( optspace("|") *begin_alt() *rhs *end_alt()
++	      | optspace(",") *rhs
++	      | "")
+
+* NOTE: have to reset str_no if there is no lhs, since
+* strings may already contain a nonterminal
+	rule = ( lhs optspace("=" | ":=" | "::=")
++	       | *?(str_no = 0) "" $ *string() )
++	       *begin_rule() rhs optspace(";") *end_rule()
+	comment = optspace("(*" breakx("*") "*)" | "#" eol)
+	groff = optspace("." eol $ str) *emit_groff(str)
+	pic = optspace("%" eol $ output)
+	grammar = arbno(comment | groff | pic | rule) rpos(0)
+
+***
+*** MAIN
+***
+	lineno = 1
+
+loop	line = input :f(end)
+	line ".lf " int . lineno :s(next)
+	line ".EBNF" :s(src.l)
+	lineno = lineno + 1
+next	output = line :(loop)
+
+src.l	line = input
+	lineno = lineno + 1
+	line ".EBNF" :s(compile)
+	src = src line char(10) :(src.l)
+
+compile
+	output = ".PS"
+	output = 'copy "syntax.pic";'
+	(src ? grammar, terminal = "FAILURE")
+	output = 'reset;'
+	output = ".PE"
+	output = ".lf " (lineno + 1)
+	src = "" :(loop)
+
+***
+*** Procedures
+***
+optspace
+	optspace = space pattern space :(return)
+
+string
+	string = .strings[str_no = str_no + 1] :(nreturn)
+serialize
+* NOTE: will leave str_no == 0
+	serialize = '"' strings[str_no] '" ' serialize
+	eq(str_no = str_no - 1, 0) :s(return)f(serialize)
+
+emit_groff
+	output = 'command ".' str '";' :(return)
+
+begin_rule
+	output = 'begin_rule(' serialize() ');' :(return)
+end_rule
+	output = 'end_rule();' :(return)
+
+emit_nonterm
+	output = 'nonterminal(' serialize() ');' :(return)
+emit_term
+	output = 'terminal(' serialize() ');' :(return)
+emit_empty
+	output = 'empty();' :(return)
+
+begin_exp
+	output = 'begin_group();' :(return)
+end_exp
+	output = 'end_group();' :(return)
+
+begin_alt
+        output = 'begin_alt(last []);' :(return)
+end_alt
+	output = 'end_alt(2nd last []);' :(return)
+
+repeat	output = 'repeat(last []);' :(return)
+repeat_with
+	output = 'repeat_with(last [],' serialize() ');' :(return)
+
+end
+
diff --git a/groff.outlang b/groff.outlang
new file mode 100644
index 0000000..60e217e
--- /dev/null
+++ b/groff.outlang
@@ -0,0 +1,72 @@
+extension "mom"
+
+doctemplate
+"
+.NEWCOLOR green RGB #33CC00
+.NEWCOLOR red RGB #FF0000
+.NEWCOLOR darkred RGB #990000
+.NEWCOLOR blue RGB #0000FF
+.NEWCOLOR brown RGB #9A1900
+.NEWCOLOR pink RGB #CC33CC
+.NEWCOLOR yellow RGB #FFCC00
+.NEWCOLOR cyan RGB #66FFFF
+.NEWCOLOR purple RGB #993399
+.NEWCOLOR orange RGB #FF6600
+.NEWCOLOR brightorange RGB #FF9900
+.NEWCOLOR brightgreen RGB #33FF33
+.NEWCOLOR darkgreen RGB #009900
+.NEWCOLOR black RGB #000000
+.NEWCOLOR teal RGB #008080
+.NEWCOLOR gray RGB #808080
+.NEWCOLOR darkblue RGB #000080
+.NEWCOLOR white RGB #FFFFFF
+"
+
+"
+"
+end
+
+# NOTE: There must be a Typewrite Bold style
+# I'm using the Latin Modern fonts that have this style.
+# Otherwise you could use Mom's \*[BOLDER] escape.
+
+bold		"\f[TTB]$text\fP"
+italics		"\f[TTI]$text\fP"
+# FIXME: no way to implement underline generically
+#underline
+
+#notfixed	"\fR$text\fP"
+#fixed		"\fR$text\fP"
+
+color		"\*[$style]$text\*[black]"
+
+colormap
+"green" "green"
+"red" "red"
+"darkred" "darkred"
+"blue" "blue"
+"brown" "brown"
+"pink" "pink"
+"yellow" "yellow"
+"cyan" "cyan"
+"purple" "purple"
+"orange" "orange"
+"brightorange" "brightorange"
+"brightgreen" "brightgreen"
+"darkgreen" "darkgreen"
+"black" "black"
+"teal" "teal"
+"gray" "gray"
+"darkblue" "darkblue"
+"white" "white"
+default "black"
+end
+
+# lines may be empty, so begin them with the non-spacing \&
+# also, this allows "." and "'" at the beginning of the line
+lineprefix "\&"
+
+translations
+"\\" "\\e"
+#"\t" "   "
+end
diff --git a/highlight.sno b/highlight.sno
new file mode 100755
index 0000000..ce43a1b
--- /dev/null
+++ b/highlight.sno
@@ -0,0 +1,28 @@
+#!/usr/local/bin/snobol4 -b
+
+	&anchor = 1
+* flush OUTPUT immediately
+	output(.output, 6, "W")
+
+loop	line = input :f(end)
+	line ".HIGHLIGHT " rem . language :s(pipe)
+	output = line :(loop)
+
+* empty line to fixup line numbering
+pipe	output = "."
+* FIXME: hack to strip the last byte (linefeed) since source-highlight
+* is picky about newlines at the end of the file (will print another lineprefix)
+	output(.pipe, 100,,
++	       "| head -c -1 | source-highlight --outlang-def groff.outlang -s " language)
+
+pipe_l	line = input
+	line ".HIGHLIGHT" :s(close)
+	pipe = line :(pipe_l)
+
+close	endfile(100)
+* empty line to fixup line numbering
+* FIXME: the linefeed is necessary because source-highlight did not terminate
+* the last line
+	output = char(10) "." :(loop)
+
+end
diff --git a/plantuml.cfg b/plantuml.cfg
new file mode 100644
index 0000000..9be6fcf
--- /dev/null
+++ b/plantuml.cfg
@@ -0,0 +1,10 @@
+' CMU Serif is a TrueType Computer Modern Unicode font
+' This results in additional fonts in the final PDF, but is much easier
+' than trying to use the same fonts Groff uses
+skinparam defaultFontName CMU Serif
+skinparam defaultFontSize 9
+
+skinparam monochrome true
+
+skinparam shadowing false
+
diff --git a/sql.lang b/sql.lang
new file mode 100644
index 0000000..53195f8
--- /dev/null
+++ b/sql.lang
@@ -0,0 +1,46 @@
+type = "VARCHAR|TINYINT|TEXT|DATE|SMALLINT|MEDIUMINT|INT|INTEGER|BIGINT",
+"FLOAT|DOUBLE|DECIMAL|DATETIME|TIMESTAMP|TIME|YEAR|UNSIGNED",
+"CHAR|CHARACTER|VARYING|TINYBLOB|TINYTEXT|BLOB|MEDIUMBLOB|MEDIUMTEXT",
+"LONGBLOB|LONGTEXT|ENUM|BOOL|BINARY|VARBINARY" nonsensitive
+
+keyword = "ALL|ASC|AS|ALTER|AND|ADD|AUTO_INCREMENT",
+	"BETWEEN|BINARY|BOTH|BY|BOOLEAN",
+	"CHANGE|CHECK|COLUMNS|COLUMN|CROSS|CREATE",
+	"DATABASES|DATABASE|DATA|DELAYED|DESCRIBE|DESC|DISTINCT|DELETE|DROP|DEFAULT",
+	"ENCLOSED|ESCAPED|EXISTS|EXPLAIN",
+	"FIELDS|FIELD|FLUSH|FOR|FOREIGN|FUNCTION|FROM",
+	"GROUP|GRANT",
+	"HAVING",
+	"IGNORE|INDEX|INFILE|INSERT|INNER|INTO|IDENTIFIED|IN|IS|IF",
+	"JOIN",
+	"KEYS|KILL|KEY",
+	"LEADING|LIKE|LIMIT|LINES|LOAD|LOCAL|LOCK|LOW_PRIORITY|LEFT|LANGUAGE",
+	"MODIFY",
+	"NATURAL|NOT|NULL|NEXTVAL",
+	"OPTIMIZE|OPTION|OPTIONALLY|ORDER|OUTFILE|OR|OUTER|ON",
+	"PROCEDURE","PROCEDURAL|PRIMARY",
+	"READ|REFERENCES|REGEXP|RENAME|REPLACE|RETURN|REVOKE|RLIKE|RIGHT",
+	"SHOW|SONAME|STATUS|STRAIGHT_JOIN|SELECT|SETVAL|SET",
+	"TABLES|TERMINATED|TO|TRAILING","TRUNCATE|TABLE|TEMPORARY|TRIGGER|TRUSTED",
+	"UNION|UNIQUE|UNLOCK|USE|USING|UPDATE",
+	"VALUES|VARIABLES|VIEW",
+	"WITH|WRITE|WHERE",
+	"ZEROFILL|TYPE",
+	"XOR"
+	nonsensitive
+
+include "c_string.lang"
+
+environment string delim "`" "`" begin
+  specialchar = $SPECIALCHAR
+end
+
+include "script_comment.lang"
+
+include "c_comment.lang"
+
+comment start "--"
+
+include "symbols.lang"
+
+include "number.lang"
\ No newline at end of file
diff --git a/syntax.pic b/syntax.pic
new file mode 100644
index 0000000..6c2a6f3
--- /dev/null
+++ b/syntax.pic
@@ -0,0 +1,110 @@
+linewid = linewid/2;
+
+define begin_group {
+  [Start: Here;
+}
+define end_group {
+  End: Here;] with .Start at Here;
+  move to last [].End;
+}
+
+define terminal {
+  begin_group();
+  arrow;
+  command ".FT TT";
+  command ".DOC_PT_SIZE +4";
+  circle $1;
+  command ".DOC_PT_SIZE -4";
+  command ".FT R";
+  line;
+  end_group();
+}
+
+define nonterminal {
+  begin_group();
+  arrow;
+  command ".FT I";
+  box $1;
+  command ".FT R";
+  line;
+  end_group();
+}
+
+define keyword {
+  begin_group();
+  arrow;
+  command ".FT TT";
+  box $1;
+  command ".FT R";
+  line;
+  end_group();
+}
+
+define empty {
+  begin_group();
+  # straight line, as long as a box would be
+  line linewid+boxwid+linewid;
+  end_group();
+}
+
+###
+### repeat(block);
+### Block must have labels `Start` and `End`.
+###
+define repeat {
+  line from $1.End to $1.se - (0,circlerad*2);
+  arrow to ($1.Start,Here) then to $1.Start;
+  line from $1.End right linewid/2;
+}
+
+###
+### repeat(block,terminal_symbol);
+###
+define repeat_with {
+  command ".FT TT";
+  command ".DOC_PT_SIZE +4";
+  circle at bottom of $1 - (0,circlerad*2) $2;
+  command ".DOC_PT_SIZE -4";
+  command ".FT R";
+
+  arrow from $1.End to ($1.End,last circle) then \
+        to east of last circle;
+  arrow from west of last circle to ($1.Start,last circle .e) then \
+        to $1.Start;
+  line from $1.End right linewid/2;
+}
+
+### begin_alt(base);
+define begin_alt {
+  line from $1.Start to $1.sw - (0,boxht);
+  begin_group();
+}
+
+### end_alt(base);
+define end_alt {
+  end_group();
+  # base might be smaller than alternative
+  if (Here.x < $1.End.x) then {
+    line to ($1.End,Here);
+  }
+  arrow to (Here,$1.End);
+  # Extend end of base if it is smaller than alternative
+  # and leave linewid/2 space for next alternative
+  line from $1.End to Here + (linewid/2,0);
+}
+
+define begin_rule {
+  move down;
+  right;
+  command ".FT I";
+  {$1 at Here - (boxwid/2,0)}
+  command ".FT R";
+  begin_group();
+  line;
+}
+
+define end_rule {
+  arrow;
+  end_group();
+  move to last [].sw;
+}
diff --git a/uml-graph/sequence.pic b/uml-graph/sequence.pic
new file mode 100644
index 0000000..6aaa6a2
--- /dev/null
+++ b/uml-graph/sequence.pic
@@ -0,0 +1,407 @@
+#/usr/bin/pic2plot -Tps
+#
+# Pic macros for drawing UML sequence diagrams
+#
+# (C) Copyright 2004-2005 Diomidis Spinellis.
+#
+# Permission to use, copy, and distribute this software and its
+# documentation for any purpose and without fee is hereby granted,
+# provided that the above copyright notice appear in all copies and that
+# both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+# WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+# MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+#
+# $Id$
+#
+
+
+# Default parameters (can be redefined)
+
+# Spacing between messages
+spacing = 0.25;
+# Active box width
+awid = .1;
+# Box height
+boxht = 0.3;
+# Commend folding
+corner_fold=awid
+# Comment distance
+define comment_default_move {up 0.25 right 0.25};
+# Comment height
+comment_default_ht=0.5;
+# Comment width
+comment_default_wid=1;
+# Underline object name
+underline=1;
+
+# Create a new object(name,label)
+define object {
+	$1: box $2; move;
+	# Could also underline text with \mk\ul\ul\ul...\rt
+	if (underline) then {
+		line from $1.w + (.1, -.07) to $1.e + (-.1, -.07);
+	}
+	move to $1.e;
+	move right;
+	# Active is the level of activations of the object
+	# 0 : inactive : draw thin line swimlane
+	# 1 : active : draw thick swimlane
+	# > 1: nested : draw nested swimlane
+	active_$1 = 0;
+	lifestart_$1 = $1.s.y;
+}
+
+# Create a new external actor(name,label)
+define actor {
+	$1: [
+		XSEQC: circle rad 0.06;
+		XSEQL: line from XSEQC.s down .12;
+		line from XSEQL.start - (.15,.02) to XSEQL.start + (.15,-.02);
+		XSEQL1: line from XSEQL.end left .08 down .15;
+		XSEQL2: line from XSEQL.end right .08 down .15;
+		line at XSEQC.n invis "" "" "" $2;
+	]
+	move to $1.e;
+	move right;
+	active_$1 = 0;
+	lifestart_$1 = $1.s.y - .05;
+}
+
+# Create a new placeholder object(name)
+define placeholder_object {
+	$1: box invisible;
+	move;
+	move to $1.e;
+	move right;
+	active_$1 = 0;
+	lifestart_$1 = $1.s.y;
+}
+
+define pobject {
+	placeholder_object($1);
+}
+
+define extend_lifeline {
+	if (active_$1 > 0) then {
+                # draw the left edges of the boxes
+		move to ($1.x - awid/2, Here.y);
+		for level = 1 to active_$1 do {
+			line from (Here.x, lifestart_$1) to Here;
+			move right awid/2
+		}
+
+                # draw the right edge of the innermost box
+		move right awid/2;
+		line from (Here.x, lifestart_$1) to Here;
+	} else {
+		line from ($1.x, lifestart_$1) to ($1.x, Here.y) dashed;
+	}
+	lifestart_$1 = Here.y;
+}
+
+# complete(name)
+# Complete the lifeline of the object with the given name
+define complete {
+	extend_lifeline($1)
+	if (active_$1) then {
+		# draw bottom of all active boxes
+		line right ((active_$1 + 1) * awid/2) from ($1.x - awid/2, Here.y);
+	}
+}
+
+# Draw a message(from_object,to_object,label)
+define message {
+	down;
+	move spacing;
+	# Adjust so that lines and arrows do not fall into the
+	# active box.  Should be .5, but the arrow heads tend to
+	# overshoot.
+	if ($1.x <= $2.x) then {
+		off_from = awid * .6;
+		off_to = -awid * .6;
+	} else {
+		off_from = -awid * .6;
+		off_to = awid * .6;
+	}
+
+        # add half a box width for each level of nesting
+        if (active_$1 > 1) then {
+                off_from = off_from + (active_$1 - 1) * awid/2;
+        }
+
+        # add half a box width for each level of nesting
+        if (active_$2 > 1) then {
+                off_to = off_to + (active_$2 - 1) * awid/2;
+        }
+
+	if ($1.x == $2.x) then {
+		arrow from ($1.x + off_from, Here.y) right then down .25 then left $3 ljust " " " ";
+	} else {
+		arrow from ($1.x + off_from, Here.y) to ($2.x + off_to, Here.y) $3 " ";
+	}
+}
+
+# Display a lifeline constraint(object,label)
+define lifeline_constraint {
+        off_from = awid;
+        # add half a box width for each level of nesting
+        if (active_$1 > 1) then {
+                off_from = off_from + (active_$1 - 1) * awid/2;
+        }
+
+	box at ($1.x + off_from, Here.y) invis $2 ljust " " ;
+}
+
+define lconstraint {
+	lifeline_constraint($1,$2);
+}
+
+# Display an object constraint(label)
+# for the last object drawn
+define object_constraint {
+	{ box invis with .s at last box .nw $1 ljust; }
+}
+
+define oconstraint {
+	object_constraint($1);
+}
+
+# Draw a creation message(from_object,to_object,object_label)
+define create_message {
+	down;
+	move spacing;
+	if ($1.x <= $2.x) then {
+		off_from = awid * .6;
+		off_to = -boxwid * .51;
+	} else {
+		off_from = -awid * .6;
+		off_to = boxwid * .51;
+	}
+
+        # add half a box width for each level of nesting
+        if (active_$1 > 1) then {
+                off_from = off_from + (active_$1 - 1) * awid/2;
+        }
+
+	# See comment in destroy_message
+	XSEQA: arrow from ($1.x + off_from, Here.y) to ($2.x + off_to, Here.y) "«create»" " ";
+	if ($1.x <= $2.x) then {
+		{ XSEQB: box $3 with .w at XSEQA.end; }
+	} else {
+		{ XSEQB: box $3 with .e at XSEQA.end; }
+	}
+	{
+		line from XSEQB.w + (.1, -.07) to XSEQB.e + (-.1, -.07);
+	}
+	lifestart_$2 = XSEQB.s.y;
+	move (spacing + boxht) / 2;
+}
+
+define cmessage {
+	create_message($1,$2,$3);
+}
+
+# Draw an X for a given object
+define drawx {
+	{
+	line from($1.x - awid, lifestart_$1 - awid) to ($1.x + awid, lifestart_$1 + awid);
+	line from($1.x - awid, lifestart_$1 + awid) to ($1.x + awid, lifestart_$1 - awid);
+	}
+}
+
+# Draw a destroy message(from_object,to_object)
+define destroy_message {
+	down;
+	move spacing;
+	# The troff code is \(Fo \(Fc
+	# The groff code is also \[Fo] \[Fc]
+	# The pic2plot code is \Fo \Fc
+	# See http://www.delorie.com/gnu/docs/plotutils/plotutils_71.html
+	# To stay compatible with all we have to hardcode the characters
+	message($1,$2,"«destroy»");
+	complete($2);
+	drawx($2);
+}
+
+define dmessage {
+	destroy_message($1,$2);
+}
+
+# An object deletes itself: delete(object)
+define delete {
+	complete($1);
+	lifestart_$1 = lifestart_$1 - awid;
+	drawx($1);
+}
+
+# Draw a message return(from_object,to_object,label)
+define return_message {
+	down;
+	move spacing;
+	# See comment in message
+	if ($1.x <= $2.x) then {
+		off_from = awid * .6;
+		off_to = -awid * .6;
+	} else {
+		off_from = -awid * .6;
+		off_to = awid * .6;
+	}
+
+        # add half a box width for each level of nesting
+        if (active_$1 > 1) then {
+                off_from = off_from + (active_$1 - 1) * awid/2;
+        }
+
+        # add half a box width for each level of nesting
+        if (active_$2 > 1) then {
+                off_to = off_to + (active_$2 - 1) * awid/2;
+        }
+
+	arrow from  ($1.x + off_from, Here.y) to ($2.x + off_to, Here.y) dashed $3 " ";
+}
+
+define rmessage {
+	return_message($1,$2,$3);
+}
+
+# Object becomes active
+# Can be nested to show recursion
+define active {
+	extend_lifeline($1);
+	# draw top of new active box
+	line right awid from ($1.x + (active_$1 - 1) * awid/2, Here.y);
+	active_$1 = active_$1 + 1;
+}
+
+# Object becomes inactive
+# Can be nested to show recursion
+define inactive {
+	extend_lifeline($1);
+	active_$1 = active_$1 - 1;
+	# draw bottom of innermost active box
+	line right awid from ($1.x + (active_$1 - 1) * awid/2, Here.y);
+}
+
+# Time step
+# Useful at the beginning and the end
+# to show object states
+define step {
+	down;
+	move spacing;
+}
+
+# Switch to asynchronous messages
+define async {
+	arrowhead = 0;
+	arrowwid = arrowwid * 2;
+}
+
+# Switch to synchronous messages
+define sync {
+	arrowhead = 1;
+	arrowwid = arrowwid / 2;
+}
+
+# same as lifeline_constraint, but Text and empty string are exchanged.
+define lconstraint_below{
+        off_from = awid;
+        # add half a box width for each level of nesting
+        if (active_$1 > 1) then {
+                off_from = off_from + (active_$1 - 1) * awid/2;
+        }
+
+	box at ($1.x + off_from, Here.y) invis "" $2 ljust;
+}
+
+# begin_frame(left_object,name,label_text);
+define begin_frame {
+	# The lifeline will be cut here
+	extend_lifeline($1);
+	# draw the frame-label
+	$2: box $3 invis with .n at ($1.x, Here.y);
+	d = $2.e.y - $2.se.y;
+	line from $2.ne to $2.e then down d left d then to $2.sw;
+	# continue the lifeline below the frame-label
+	move to $2.s;
+	lifestart_$1 = Here.y;
+}
+
+# end_frame(right_object,name);
+define end_frame {
+	# dummy-box for the lower right corner:
+	box invis "" with .s at ($1.x, Here.y);
+	# draw the frame
+	frame_wid = last box.se.x - $2.nw.x
+	frame_ht = - last box.se.y + $2.nw.y
+	box with .nw at $2.nw wid frame_wid ht frame_ht;
+	# restore Here.y
+	move to last box.s;
+}
+
+# comment(object,[name],[line_movement], [box_size] text);
+define comment {
+	old_y = Here.y
+	# draw the first connecting line, at which's end the box wil be positioned
+	move to ($1.x, Here.y)
+	if "$3" == "" then {
+		line comment_default_move() dashed;
+	} else {
+		line $3 dashed;
+	}
+
+	# draw the box, use comment_default_xx if no explicit
+	# size is given together with the text in parameter 4
+	old_boxht=boxht;
+	old_boxwid=boxwid;
+	boxht=comment_default_ht;
+	boxwid=comment_default_wid;
+	if "$2" == "" then {
+		box invis $4;
+	} else {
+		$2: box invis $4;
+	}
+	boxht=old_boxht;
+	boxwid=old_boxwid;
+
+	# draw the frame of the comment
+	line from       last box.nw \
+		to          last box.ne - (corner_fold, 0) \
+		then to last box.ne - (0, corner_fold) \
+		then to last box.se \
+		then to last box.sw \
+		then to last box.nw ;
+	line from       last box.ne - (corner_fold, 0) \
+		to          last box.ne - (corner_fold, corner_fold) \
+		then to last box.ne - (0, corner_fold) ;
+
+	# restore Here.y
+	move to ($1.x, old_y)
+}
+
+# connect_to_comment(object,name);
+define connect_to_comment {
+	old_y = Here.y
+	# start at the object
+	move to ($1.x, Here.y)
+	# find the best connection-point of the comment to use as line-end
+	if $1.x < $2.w.x then {
+		line to $2.w dashed;
+	} else {
+		if $1.x > $2.e.x then {
+			line to $2.e dashed;
+		} else {
+			if Here.y < $2.s.y then {
+				line to $2.s dashed;
+			} else {
+				if Here.y > $2.n.y then {
+					line to $2.n dashed;
+				}
+			}
+		}
+	}
+	# restore Here.y
+	move to ($1.x, old_y)
+}
diff --git a/uml.sno b/uml.sno
new file mode 100755
index 0000000..9461884
--- /dev/null
+++ b/uml.sno
@@ -0,0 +1,40 @@
+#!/usr/local/bin/snobol4 -b
+
+	&anchor = 1
+
+	float = span("0123456789.")
+
+	count = 0
+	lineno = 1
+
+loop	line = input :f(end)
+	line ".lf " float . lineno :s(next)
+	line ".UML" rem . options :s(pipe)
+	lineno = lineno + 1
+next	output = line :(loop)
+
+pipe	filename = "uml_temp" (count = count + 1) ".pdf"
+	output(.pipe, 100,,
++	       "| plantuml -pipe -tsvg -failonerror -config plantuml.cfg | "
++	       "rsvg-convert -f pdf -o " filename)
+	pipe = "@startuml"
+
+pipe_l	line = input
+	lineno = lineno + 1
+	line ".UML" :s(close)
+	pipe = line :(pipe_l)
+
+close	pipe = "@enduml"
+	endfile(100)
+
+* get PDF dimensions
+	input(.pipe, 100,, "|pdfinfo " filename)
+get_info
+	pipe "Page size:" span(" ") float . width " x " float . height :f(get_info)
+	endfile(100)
+
+	output = ".PDF_IMAGE " filename " " width "p " height "p" options
+	output = ".lf " (lineno + 1) :(loop)
+
+end
+