Draft of the main graph generation macro.

main-draft.hl.rkt

@@ -0,0 +1,79 @@
+#lang aful/unhygienic hyper-literate type-expander/lang
+
+@chunk[<overview>
+       #;(define-syntax low-graph
+           (syntax-parser
+             [<signature>
+              <metadata>
+              ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+              <worklist>
+              <call-mapping-functions+placeholders>
+              <extract-placeholders> ;; and put them into the worklist
+              ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+              <inline-placeholders-within-node-boundaries>
+              ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+              <replace-indices-with-promises>
+              ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+              <equality-coalescing> ;; leave off as always-#f-unless-eq?
+              <invariants+auto-fill>
+              <inflexible-row-polymorphism>
+              <flexible-row-polymorphism>
+              <polymorphic-node-types-and-mappings>
+              ;<general-purpose-graph-algorithms>
+              ;<garbage-collection>
+              ]))
+
+       (define-syntax low-graph
+         (syntax-parser
+           [<signature+metadata>
+            ;; Phase 1: call the mapping functions on the input data
+            (: phase-1 (∀ (nodes-pvar … mapping-pvar … …)
+                          (→ (List (Listof mapping-arg-type) ddd)
+                             (List (Listof mapping-result-type) ddd))))
+            (define (phase-1 roots)
+              (work
+               roots
+               ((λ (mapping-arguments)
+                  (define result
+                    (let* ([mapping-name make-placeholder]
+                           …
+                           [arg convert-inflexible-to-flexible?]
+                           …
+                           [arg invariant-well-scopedness?]
+                           …)
+                      mapping-code))
+                  ;; returns placeholders + the result:
+                  (extract-placeholders result))
+                …)
+               (mapping-arg-type mapping-result-type) …))
+            (begin
+              ;; Maybe this should be done last, when all phases are available?
+              (define (phase1-many-roots) 'TODO)
+              (define (phase1-single-root-for-mapping) 'TODO)
+              …)
+            ;; Phase 2: inline placeholders within node boundaries
+            (generate-worklist
+             nodes
+             #'(…?))
+            (funcion which for a mapping-result → inserts nodes into worklist) …
+            (for the root mapping results
+              call the function to insert nodes and keep the surrounding part)
+            (for each mapping result
+              call the function to insert nodes)
+            ;; Phase 3: Replace indices with promises
+            ;; Phase 3a: have an empty set of invariant witnesses, and call the
+            ;;           invariants for checking
+            ;; Phase 3b: have the full set of invariant witnesses.
+            ;; TODO phase 3: auto-fill.
+            ]))
+
+       ; high-level graph API:
+       '(<metadata2>
+         <extending-existing-graph-types>
+         <invariants-for-extended-graph-types>
+         <auto-generate-mappings>)]
+
+Row polymorphism: make a generic struct->vector and vector->struct?
+
+@chunk[<*>
+       (void)]