jschappel
commented
1 year ago Hi @oliwial23 :wave:. This is not a bug but is the default behavior. If you wish to add custom formatting for the rules then you need to add a formatter to the graph.
I realize there is very little documentation for this so I will work on adding a scribble file this weekend explaining the whole library for you. In the meantime the way a formatter works is that you subscribe a to-string function for a graph attribute and then that function is called when we compile the dot file. Since in the dot language graphs, nodes, and edges can share the same attributes a formatter has 3 levels that the implementer can subscribe to-string functions to.
Below is an example for a custom formatter with an edge level to-string function added to the label attribute:
#lang fsm
(require "lib.rkt")
;; one-rule-per-line :: listof(string) -> string
;; creates a string where each value in the list is on a new line
(define (one-rule-per-line rules)
(string-join rules "\n"))
(define graph-formatters (formatters
(hash) ; graph level formatters
(hash) ; node level formatters
(hash 'label one-rule-per-line))) ; edge level formatters
;; -> image
;; Purpose: Creates a .png file from a .dot file, and returns a bitmap for a sample pda
(define (computation-diagram-pda)
(define fname "fsm")
;; image
;; Purpose: Stores a computation graph image
(define cgraph (create-graph
'cgraph
#:atb (hash 'rankdir "LR" 'label (format "word = ~a" '(a b c d d)))
#:fmtrs graph-formatters)) ; we add the formatters when we create the graph
(begin
(set! cgraph (add-node cgraph 'S #:atb (hash 'color "black" 'shape "circle" 'fontcolor "black")))
(set! cgraph (add-node cgraph 'X #:atb (hash 'color "black" 'shape "circle" 'fontcolor "black")))
(set! cgraph (add-node cgraph 'Y #:atb (hash 'color "black" 'shape "circle" 'fontcolor "black")))
(set! cgraph (add-node cgraph 'Z #:atb (hash 'color "black" 'shape "doublecircle" 'fontcolor "black")))
(set! cgraph (add-node cgraph 'ds #:atb (hash 'color "crimson" 'shape "circle" 'fontcolor "black")))
(set! cgraph (add-edge cgraph "[ε ε ε]" 'S 'X))
(set! cgraph (add-edge cgraph "[ε ε ε]" 'X 'Y))
(set! cgraph (add-edge cgraph "[ε ε ε]" 'Y 'Z))
(set! cgraph (add-edge cgraph "[ε ε ε]" 'S 'ds))
(set! cgraph (add-edge cgraph "[ε ε ε]" 'X 'ds))
(set! cgraph (add-edge cgraph "[ε ε ε]" 'Y 'ds))
(set! cgraph (add-edge cgraph "[ε ε ε]" 'Z 'ds))
(set! cgraph (add-edge cgraph "[a ε (c d)]" 'S 'S))
(set! cgraph (add-edge cgraph "[b ε (c d)]" 'X 'X))
(set! cgraph (add-edge cgraph "[c (c d) ε]" 'Y 'Y))
(set! cgraph (add-edge cgraph "[d (c d) ε]" 'Z 'Z))
(set! cgraph (add-edge cgraph "[b ε ε]" 'ds 'ds))
(set! cgraph (add-edge cgraph "[ε (c) ε]" 'ds 'ds))
(set! cgraph (add-edge cgraph "[ε (d) ε]" 'ds 'ds))
(set! cgraph (add-edge cgraph "[a ε ε]" 'ds 'ds))
(set! cgraph (add-edge cgraph "[c ε ε]" 'ds 'ds))
(set! cgraph (add-edge cgraph "[d ε ε]" 'ds 'ds))
(let [(res (graph->bitmap cgraph (current-directory) fname))]
(begin
(delete-file (string-append fname ".dot"))
(delete-file (string-append fname ".png"))
res))))
(computation-diagram-pda)
and this is the output (which i think is what you are looking for)
Describe the bug
A long list of rules in a pda graph is displayed horizontally, rather than in vertical array. This occurs specifically when using the function (graph->bitmap ...).
Steps to Reproduce
1) Use #lang fsm 2) Copy the following code, that converts a sample pda to a bitmap:
3) Run
(computation-diagram-pda)4) See error
Expected Behavior
The list of rules of the dead state should be arranged vertically, rather than horizontally.
OS Observed On
The operating system the bug was found on: macOS Ventura 13.1
Screenshots