From 06e0534895bee30d17cf240a7fa8cb29d00212c9 Mon Sep 17 00:00:00 2001
From: haskal <haskal@bepis.xyz>
Date: Mon, 27 Apr 2020 19:15:59 -0400
Subject: [PATCH] create compile script

---
 private/compile.rkt | 101 ++++++++++++++++++++++++++++++++++++++++++++
 racket-sass         |   2 +-
 scripts/init        |   3 ++
 3 files changed, 105 insertions(+), 1 deletion(-)
 create mode 100644 private/compile.rkt

diff --git a/private/compile.rkt b/private/compile.rkt
new file mode 100644
index 0000000..1361d40
--- /dev/null
+++ b/private/compile.rkt
@@ -0,0 +1,101 @@
+#lang racket
+
+;; compiler
+
+(struct rule [inputs output compiler] #:transparent)
+
+(define (generate-operations rules)
+  (define nodes (mutable-set))
+  (define edges (make-hash))
+  (define edges-rev (make-hash))
+  (define (edge-add! from to)
+    (when (equal? from to)
+      (error "loop edge" from to))
+    (set-add! nodes from)
+    (set-add! nodes to)
+    (if (hash-has-key? edges from)
+      (set-add! (hash-ref edges from) to)
+      (hash-set! edges from (mutable-set to)))
+    (if (hash-has-key? edges-rev to)
+      (set-add! (hash-ref edges-rev to) from)
+      (hash-set! edges-rev to (mutable-set from))))
+
+  ;; construct graph
+  (for ([rule (in-set rules)])
+    (for ([input (in-list (rule-inputs rule))])
+      (edge-add! input rule))
+    (when (hash-has-key? edges-rev (rule-output rule))
+      (error "duplicate output rule" (rule-output rule)))
+    (edge-add! rule (rule-output rule)))
+
+  ;; construct topological sort
+  (define (topo-sort nodes edges)
+    (define temp-mark (mutable-set))
+    (define perm-mark (mutable-set))
+    ;; visits recursively
+    (define (visit node sorted)
+      (cond
+        [(set-member? perm-mark node) sorted]
+        [(set-member? temp-mark node) (error "cycle detected")]
+        [else
+          (set-add! temp-mark node)
+
+          (define new-sorted
+            (for/fold ([s sorted]) ([neighbor (in-set (hash-ref edges node (set)))])
+              (visit neighbor s)))
+
+          (set-remove! temp-mark node)
+          (set-add! perm-mark node)
+          (cons node new-sorted)]))
+
+    (for/fold ([s '()]) ([node (in-set nodes)] #:unless (set-member? perm-mark node))
+      (visit node s)))
+
+  (define topo-sorted (topo-sort nodes edges))
+
+  ;; everything where either the output does not exist, or one of the inputs does not exist, or one
+  ;; of the inputs is newer than the output
+  (define (rule-dirty? rule)
+    (define (modt f)
+      (file-or-directory-modify-seconds f #f (lambda () #f)))
+    (define output-time (modt (rule-output rule)))
+    (define input-times (map modt (rule-inputs rule)))
+    (or (false? output-time)
+        (for/or ([time (in-list input-times)])
+          (or (false? time) (> time output-time)))))
+
+  (define initial-dirty (for/set ([rule (in-set rules)] #:when (rule-dirty? rule)) rule))
+  ;; propagate the dirty set recursively
+  ;; for each missing input, add the rule that generates the input
+  ;; if outputs have dependents, add the dependents
+  (define (expand-dirty rule [dset (mutable-set)])
+    (unless (set-member? dset rule)
+      (set-add! dset rule)
+      (for ([dep (in-set (hash-ref edges (rule-output rule) (set)))])
+        (expand-dirty dep dset))
+      (for ([input (in-list (rule-inputs rule))])
+        (unless (or (file-exists? input) (link-exists? input) (directory-exists? input))
+          (define dep-revs (hash-ref edges-rev input (set)))
+          (when (zero? (set-count dep-revs))
+            (error "no rule to generate" input))
+          (for ([dep-rev (in-set dep-revs)])
+            (expand-dirty dep-rev dset)))))
+    dset)
+  (define dirty
+    (for/fold ([d (set)]) ([item (in-set initial-dirty)])
+      (set-union d (expand-dirty item))))
+
+  (define dirty-sorted
+    (for/list ([item (in-list topo-sorted)] #:when (set-member? dirty item))
+      item))
+  (unless (= (set-count dirty) (length dirty-sorted))
+    (error "self-check failed lmao"))
+  dirty-sorted)
+
+
+(define compiler-rules
+  (set
+    (rule '("test.o") "my_binary" void)
+    (rule '("test.c") "test.o" void)))
+
+(generate-operations compiler-rules)
diff --git a/racket-sass b/racket-sass
index ce67a03..d45e54a 160000
--- a/racket-sass
+++ b/racket-sass
@@ -1 +1 @@
-Subproject commit ce67a0344c88e4ccadbdaac85de628bce9c82b39
+Subproject commit d45e54a24f34728172973931c86fc97d66a0b8d8
diff --git a/scripts/init b/scripts/init
index 8657074..8b1c542 100755
--- a/scripts/init
+++ b/scripts/init
@@ -42,7 +42,10 @@
 
 ; src and public
 (make-directory "src")
+(make-directory "src/posts")
+
 (make-directory "public")
+(make-directory "public/posts")
 
 ; task queue
 (define c (sqlite3-connect #:database "taskq.sqlite3" #:mode 'create))