pub const DEFAULT_RULES: &'static str = r#"
start '-' (E) ANY draw "M {W} L {E}";
start '-' (W) ANY draw "M {E} L {W}";
start '|' (N) ANY draw "M {S} L {N}";
start '|' (S) ANY draw "M {N} L {S}";
start '/' (SW,S,W) ANY draw "M {NE} L {SW}";
start '/' (NE,N,E) ANY draw "M {SW} L {NE}";
start '\' (SE,S,E) ANY draw "M {NW} L {SE}";
start '\' (NW,N,W) ANY draw "M {SE} L {NW}";
start '.' (W,E) "-=.'+oO><" draw "M {S} Q {C} {O}";
start '.' (E) "/.'+oO" draw "M {S}";
start '.' (W) "\.'+oO" draw "M {S}";
start "'" (W,E) "-=.'+oO><" draw "M {N} Q {C} {O}";
start "'" (E) "\.'+oO" draw "M {N}";
start "'" (W) "/.'+oO" draw "M {N}";
# This block adds support for little circles along a line,
# via the elliptical arc command `A`.
end "-|/\:=+" ANY 'o' draw "L {I/o} A 2,2 0 1 0 {RI/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {RI/o}";
# Commented out code below is the same mistake I have made elsewhere:
# there are "natural" directions for characters like `/` and `\`,
# which I have encoded in the SLOPE classes above. But that means you
# cannot just match willy-nilly against all LINES or LINES_AND_JOINTS
# in the `next` component of the tuple; you need to put in a stricter
# filter.
# Loud(("-|/\:=.'+oO", AnyDir, 'o', AnyDir, "-|/\:=.'+oO",
# "L {I} A 4,4 360 1 0 {O} A 4,4 180 0 0 {I} M {O}")),
step "-|/\:=.'+oO" ANY 'o' (W,E) "-=+" draw "L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
step "-|/\:=.'+oO" ANY 'o' (N,S) "|:+" draw "L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
step "-|/\:=.'+oO" ANY 'o' (NE,SW) "/+" draw "L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
step "-|/\:=.'+oO" ANY 'o' (NW,SE) "\+" draw "L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'o' (W,E) "-=+" draw "M {I} L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'o' (N,S) "|:+" draw "M {I} L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'o' (NE,SW) "/+" draw "M {I} L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'o' (NW,SE) "\+" draw "M {I} L {I/o} A 2,2 0 1 0 {O/o} A 2,2 0 0 0 {I/o} A 2,2 0 1 0 {O/o}";
# These are similar to all the circle rules above, but the above rules will sometimes
# yield small circles when joining pair of lines at a thin angle. Sometimes that's
# the right thing, but when you want the circle sizes to be regular, you can use this
# instead.
end "-|/\:=+" ANY 'O' draw "L {I/o} A 4,4 0 1 0 {RI/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {RI/o}";
step "-|/\:=.'+oO" ANY 'O' (W,E) "-=+" draw "L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
step "-|/\:=.'+oO" ANY 'O' (N,S) "|:+" draw "L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
step "-|/\:=.'+oO" ANY 'O' (NE,SW) "/+" draw "L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
step "-|/\:=.'+oO" ANY 'O' (NW,SE) "\+" draw "L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'O' (W,E) "-=+" draw "M {I} L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'O' (N,S) "|:+" draw "M {I} L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'O' (NE,SW) "/+" draw "M {I} L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
loop "-|/\:=.'+oO" ANY 'O' (NW,SE) "\+" draw "M {I} L {I/o} A 4,4 0 1 0 {O/o} A 4,4 0 0 0 {I/o} A 4,4 0 1 0 {O/o}";
# This block is made of special cases for rendering horizontal
# lines with curve characters in "interesting" ways.
# They are not necessarily consistent nor do they exhibit symmetry,
# but it seems better to do *something* rather than fall through
# to default handlers that often show nothing special at all
# along the path.
step "\" (E) '.' (E) "-|/\:=" draw "Q {SW} {S}";
end "\" (E) '.' draw "Q {SW} {S}";
step "/" (W) '.' (W) "-|/\:=" draw "Q {SE} {S}";
end "/" (W) '.' draw "Q {SE} {S}";
step "/" (E) "'" (E) "-|/\:=" draw "Q {NW} {N}";
end "/" (E) "'" draw "Q {NW} {N}";
step "\" (W) "'" (W) "-|/\:=" draw "Q {NE} {N}";
end "\" (W) "'" draw "Q {NE} {N}";
step "-=.'+oO><" (E) '.' (E) "-|/\:=" draw "Q {C} {S}";
end "-=.'+oO><" (E) '.' draw "Q {C} {S}";
step "-=.'+oO><" (W) '.' (W) "-|/\:=" draw "Q {C} {S}";
end "-=.'+oO><" (W) '.' draw "Q {C} {S}";
step "-=.'+oO><" (E) "'" (E) "-|/\:=" draw "Q {C} {N}";
end "-=.'+oO><" (E) "'" draw "Q {C} {N}";
step "-=.'+oO><" (W) "'" (W) "-|/\:=" draw "Q {C} {N}";
end "-=.'+oO><" (W) "'" draw "Q {C} {N}";
step ".'" (E) '-' (E) ANY draw "Q {W} {E}";
end ".'" (E) '-' draw "Q {W} {E}";
step ".'" (W) '-' (W) ANY draw "Q {E} {W}";
end ".'" (W) '-' draw "Q {E} {W}";
step "." (E) '/' (E) "'-\" draw "Q {SW} {NE}";
end "." (E) '/' draw "Q {SW} {NE}";
step "." (W) "\" (W) "'-/" draw "Q {SE} {NW}";
end "." (W) "\" draw "Q {SE} {NW}";
step "'" (E) "\" (E) ".-/" draw "Q {NW} {SE}";
end "'" (E) "\" draw "Q {NW} {SE}";
step "'" (W) '/' (W) ".-\" draw "Q {NE} {SW}";
end "'" (W) '/' draw "Q {NE} {SW}";
# These bits for `(` are another set of special cases for handling the
# sides of a diamond when I don't want to use `+`.
#
# By "diamond" I mean something like this:
#
# ```
# + <-- `.` also acceptable here
# / \
# ( )
# \ /
# + <-- likewise `'` works here.
# ```
#
# I don't want to use `+` here because I only want it to connect to the
# diamond
# and not to other neighboring lines (which is what `+` and other generic
# joints would imply).
# FIXME below cases seems like they are not always matching for some reason
step "/" (SW) '(' (SE) "\" draw "Q {C} {SE}";
step "/" (NE) ')' (NW) "\" draw "Q {C} {NW}";
step "\" (SE) ')' (SW) "/" draw "Q {C} {SW}";
step "\" (NW) '(' (NE) "/" draw "Q {C} {NE}";
step ANY ANY "/" (SW) '(' draw "L {SW}";
step ANY ANY "/" (NE) ')' draw "L {NE}";
step ANY ANY "\" (SE) ')' draw "L {SE}";
step ANY ANY "\" (NW) '(' draw "L {NW}";
step ANY (E) '-' (E) "-=.'+oO><" draw "L {E}";
end ANY (E) '-' draw "L {E}";
step ANY (W) '-' (W) "-=.'+oO><" draw "L {W}";
end ANY (W) '-' draw "L {W}";
step ANY (N) '|' (N) "|:.'+oO^v" draw "L {N}";
end ANY (N) '|' draw "L {N}";
step ANY (S) '|' (S) "|:.'+oO^v" draw "L {S}";
end ANY (S) '|' draw "L {S}";
start '=' (E) "-=.'+oO><" draw "M {W} L {E}" attrs [("stroke-dasharray", "5,2")];
start '=' (W) "-=.'+oO><" draw "M {E} L {W}" attrs [("stroke-dasharray", "5,2")];
start ':' (N) "|:.'+oO^v" draw "M {S} L {N}" attrs [("stroke-dasharray", "5,2")];
start ':' (S) "|:.'+oO^v" draw "M {N} L {S}" attrs [("stroke-dasharray", "5,2")];
step ANY (E) '=' (E) "-=.'+oO><" draw "L {E}" attrs [("stroke-dasharray", "5,2")];
end ANY (E) '=' draw "L {E}" attrs [("stroke-dasharray", "5,2")];
step ANY (W) '=' (W) "-=.'+oO><" draw "L {W}" attrs [("stroke-dasharray", "5,2")];
end ANY (W) '=' draw "L {W}" attrs [("stroke-dasharray", "5,2")];
step ANY (N) ':' (N) "|:.'+oO^v" draw "L {N}" attrs [("stroke-dasharray", "5,2")];
end ANY (N) ':' draw "L {N}" attrs [("stroke-dasharray", "5,2")];
step ANY (S) ':' (S) "|:.'+oO^v" draw "L {S}" attrs [("stroke-dasharray", "5,2")];
end ANY (S) ':' draw "L {S}" attrs [("stroke-dasharray", "5,2")];
start '+' ANY ANY draw "M {C}";
end ANY ANY '+' draw "L {C}";
# # Below is riskier than I actually want to take
# # on right now.
# ("-|/\:=.'+oO" ANY '+', May((AnyDir, ".'+oO")), "L {C}"),
step ANY (NE) '/' (NE) "/.'+oO" draw "L {NE}";
end ANY (NE) '/' draw "L {NE}";
step ANY (SW) '/' (SW) "/.'+oO" draw "L {SW}";
end ANY (SW) '/' draw "L {SW}";
step ANY (SE) '\' (SE) "\.'+oO" draw "L {SE}";
end ANY (SE) '\' draw "L {SE}";
step ANY (NW) '\' (NW) "\.'+oO" draw "L {NW}";
end ANY (NW) '\' draw "L {NW}";
step ANY (NE) '/' (E) ".'+oO" draw "L {NE}";
step ANY (SW) '/' (E) ".'+oO" draw "L {NE}";
step ANY (SE) '\' (E) ".'+oO" draw "L {SE}";
step ANY (NW) '\' (E) ".'+oO" draw "L {SE}";
step ANY (NW) '\' (W) ".'+oO" draw "L {NW}";
step ANY (SE) '\' (W) ".'+oO" draw "L {NW}";
step ANY (NE) '/' (W) ".'+oO" draw "L {SE}";
step ANY (SW) '/' (W) ".'+oO" draw "L {SE}";
step '>' (E) '+' ANY "-|/\:=.'+oO" draw "M {C}";
end '>' (E) '+' draw "M {C}";
step '<' (W) '+' ANY "-|/\:=.'+oO" draw "M {C}";
end '<' (W) '+' draw "M {C}";
step '^' (N) '+' ANY "-|/\:=.'+oO" draw "M {C}";
end '^' (N) '+' draw "M {C}";
step 'v' (S) '+' ANY "-|/\:=.'+oO" draw "M {C}";
end 'v' (S) '+' draw "M {C}";
step "-=" (E,W) '+' (E,W) "-=.'+oO><" draw "L {C}";
end "-=" (E,W) '+' draw "L {C}";
loop "-|/\\:=" ANY '+' (N,S) "|:.'+oO^v" draw "M {C}";
loop "-|/\\:=" ANY '+' (E,W) "-=.'+oO><" draw "M {C}";
loop "-|/\\:=" ANY '+' (NE,SW) "/.'+oO" draw "M {C}";
loop "-|/\\:=" ANY '+' (NW,SE) "\.'+oO" draw "M {C}";
step "-|/\\:=" ANY '+' (N,S) "|:.'+oO^v" draw "L {C}";
step "-|/\\:=" ANY '+' (E,W) "-=.'+oO><" draw "L {C}";
step "-|/\\:=" ANY '+' (NE,SW) "/.'+oO" draw "L {C}";
step "-|/\\:=" ANY '+' (NW,SE) "\.'+oO" draw "L {C}";
# The curves! .- .- .- .
# part 1: | / \ /| et cetera
step ANY (E,NE,N,NW,W) '.' (E,SE,S,SW,W) "-|/\\:=" draw "Q {C} {O}";
loop ANY (E,NE,N,NW,W) '.' (E,SE,S,SW,W) "-|/\\:=" draw "M {I} Q {C} {O}";
# curves | \/ /
# part 2: '- ' '- et cetera
step ANY (E,SE,S,SW,W) "'" (E,NE,N,NW,W) "-|/\\:=" draw "Q {C} {O}";
loop ANY (E,SE,S,SW,W) "'" (E,NE,N,NW,W) "-|/\\:=" draw "M {I} Q {C} {O}";
## Arrow Heads!
##
## Perhaps more importantly, this code builds in an
## assumption that each grid cell is 9x12 (or at least
## WxH for W>9 and H>12).
##
## An assumption along these lines is perhaps
## inevitable (I think its probably better to make
## such an assumpt than pretend
## that the cell is a NxN square and thus have the
## user be surprised when it turns out to be
## non-square).
##
## But the question remains: is building in the
## numbers 9 and 12 a good idea? Or should they be
## other numbers, like 3 and 4 (i.e. reduced form) or
## 36 and 48 (which are both immediately divisible by
## 2,3,4, and 6, which may be preferable to dealing in
## fractions).
# horizontal arrow heads
end '-' (E) '>' draw "L {C} l 3,0 m -3,-3 l 3,3 l -3,3 m 0,-3";
start '>' (W) '-' draw "M {C} l 3,0 m -3,-3 l 3,3 l -3,3 m 0,-3";
end '-' (W) '<' draw "L {C} l -3,0 m 3,-3 l -3,3 l 3,3 m 0,-3";
start '<' (E) '-' draw "M {C} l -3,0 m 3,-3 l -3,3 l 3,3 m 0,-3";
# vertical arrow heads
start '^' (S) '|' draw "M {C} l 0,-5 m -3,5 l 3,-5 l 3, 5 m -3,0";
start 'v' (N) '|' draw "M {C} l 0,5 m -3,-5 l 3, 5 l 3,-5 m -3,0";
end ANY (S) 'v' draw "L {C} l 0,5 m -3,-5 l 3, 5 l 3,-5 m -3,0";
start '^' (S) ':' draw "M {C} l 0,-5 m -3,5 l 3,-5 l 3, 5 m -3,0" attrs [("stroke-dasharray", "5,2")];
# arrow heads that join with other paths
step '|' (N) '^' (N) '+' draw "L {N} l 0,-5 m -3,5 l 3,-5 l 3, 5 m -3,0 m 0,-5";
step '+' (S) '^' (S) '|' draw "M {N} l 0,-5 m -3,5 l 3,-5 l 3, 5 m -3,0 M {N} L {C}";
step '|' (S) 'v' (S) '+' draw "L {S} l 0,5 m -3,-5 l 3, 5 l 3,-5 m -3,0 m 0, 5";
step '+' (N) 'v' (N) '|' draw "L {S} l 0,5 m -3,-5 l 3, 5 l 3,-5 m -3,0 m 0, 5 M {S} L {C}";
step '-' (E) '>' (E) '+' draw "L {E} m -2,0 l 4,0 m -4,-3 l 4,3 l -4,3 m 0,-3 m 4,0";
step '+' (W) '>' (W) '-' draw "M {E} m -2,0 l 4,0 m -4,-3 l 4,3 l -4,3 m 0,-3 m 4,0 M {E} L {C}";
step '-' (W) '<' (W) '+' draw "L {W} m 2,0 l -4,0 m 4,-3 l -4,3 l 4,3 m 0,-3 m -4,0";
step '+' (E) '<' (E) '-' draw "M {W} m 2,0 l -4,0 m 4,-3 l -4,3 l 4,3 m 0,-3 m -4,0 M {W} L {C}";
start '.' (E) '-' draw "M {S} Q {C} {E}";
start '.' (W) '-' draw "M {S} Q {C} {W}";
start "'" (E) '-' draw "M {N} Q {C} {E}";
start "'" (W) '-' draw "M {N} Q {C} {W}";
"#