51 lines
2.1 KiB
EmacsLisp
51 lines
2.1 KiB
EmacsLisp
(defun declare-node (node-text node-generation)
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"Declares a node in the graphviz source code. The node’s identifier will be
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~node-generation~, and it will bear the label ~node-text~."
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(concat (number-to-string node-generation)
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"[label=\""
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node-text
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"\"];"))
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(defun make-link (previous-node current-node)
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"This creates a link in the graphviz source code between the two nodes
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bearing ~previous-node~ and ~current-node~ respectively as their node
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identifier."
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(concat (number-to-string previous-node) " -- "
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(number-to-string current-node) ";"))
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(defun tree-to-dot-helper (tree current-generation previous-generation)
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"Helper to ~tree-to-dot~ that translates an Elisp tree with any number of
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children per node to a corresponding graphviz file that can be executed from
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dot.
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Arguments:
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- tree :: tree-to-convert
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- current-generation :: Generation number, incremented when changing from a node
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to another node from the same generation, multiplied by 10 when going from
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a node to one of its children.
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- previous-generation :: generation number from previous named node"
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(cond
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((null tree) "")
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((atom (car tree)) ;; '("text" () () ())
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(concat (declare-node (car tree) current-generation)
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(make-link previous-generation current-generation)
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(tree-to-dot-helper (cdr tree)
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(+ 1 (* 10 current-generation))
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current-generation)))
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((listp (car tree)) ;; '(() () ())
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(concat (tree-to-dot-helper (car tree) ;; child of current node
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current-generation
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previous-generation)
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(tree-to-dot-helper (cdr tree)
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(+ 1 current-generation)
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previous-generation)))))
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(defun tree-to-dot (tree)
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"Returns a graphviz’s dot compatible string representing an Elisp tree"
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(interactive)
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(if (null tree) ""
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(concat
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"graph{node[shape=plaintext];graph[bgcolor=\"transparent\"];"
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(declare-node (car tree) 0)
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(tree-to-dot-helper (cdr tree) 1 0)
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"}")))
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