graph: Backend must have name and description.

* guix/graph.scm (<graph-backend>): Add fields "name" and "description".
(%graphviz-backend): Provide values for name and description.
(export-graph): Ignore name and description when matching backends.
(graph-backend-name, graph-backend-description): New procedures.
* tests/graph.scm (make-recording-backend): Initialize name and
description fields of test graph-backend.
This commit is contained in:
Ricardo Wurmus 2016-10-20 08:47:03 +02:00
parent 089f385a21
commit 51377437a1
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2 changed files with 15 additions and 8 deletions

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@ -44,6 +44,8 @@ (define-module (guix graph)
%graphviz-backend
graph-backend?
graph-backend
graph-backend-name
graph-backend-description
export-graph))
@ -140,8 +142,10 @@ (define (node-reachable-count nodes node-edges)
;;;
(define-record-type <graph-backend>
(graph-backend prologue epilogue node edge)
(graph-backend name description prologue epilogue node edge)
graph-backend?
(name graph-backend-name)
(description graph-backend-description)
(prologue graph-backend-prologue)
(epilogue graph-backend-epilogue)
(node graph-backend-node)
@ -170,7 +174,9 @@ (define (emit-edge id1 id2 port)
id1 id2 (pop-color id1)))
(define %graphviz-backend
(graph-backend emit-prologue emit-epilogue
(graph-backend "graphviz"
"Generate graph in DOT format for use with Graphviz."
emit-prologue emit-epilogue
emit-node emit-edge))
(define* (export-graph sinks port
@ -181,7 +187,7 @@ (define* (export-graph sinks port
given BACKEND. Use NODE-TYPE to traverse the DAG. When REVERSE-EDGES? is
true, draw reverse arrows."
(match backend
(($ <graph-backend> emit-prologue emit-epilogue emit-node emit-edge)
(($ <graph-backend> _ _ emit-prologue emit-epilogue emit-node emit-edge)
(emit-prologue (node-type-name node-type) port)
(match node-type

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@ -57,7 +57,8 @@ (define (record-edge source target port)
(define (return)
(values (reverse nodes) (reverse edges)))
(values (graph-backend (const #t) (const #t)
(values (graph-backend "test" "This is the test backend."
(const #t) (const #t)
record-node record-edge)
return)))