From bf71791fc540a584dd6d88548c91192294d106bc Mon Sep 17 00:00:00 2001
From: dozens
Date: Tue, 25 Jun 2024 21:22:35 -0600
Subject: feat: add story engine

---
 src/story/story.fnl | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/story/story.fnl

(limited to 'src/story/story.fnl')

diff --git a/src/story/story.fnl b/src/story/story.fnl
new file mode 100644
index 0000000..f1ca812
--- /dev/null
+++ b/src/story/story.fnl
@@ -0,0 +1,58 @@
+(fn lines [filename callback]
+  (case (pcall #(with-open [file (io.open filename)] (each [line (file:lines)] (callback line))))
+    (false err) (print (string.format "Error: Could not open file %s\n%s" filename err))))
+
+(fn _create-corpus [lines data]
+  (var current-key nil)
+  (var corpus {})
+  (lines data
+    #(let [key (string.match $1 "^::%s+([%a-]+)")
+           blank (or (= nil $1) (= "" $1))]
+      (when (not blank)
+        (if (not key)
+          (let [list (. corpus current-key)]
+            (table.insert list $1)
+            (tset corpus current-key list))
+          (do
+            (set current-key key)
+            (tset corpus current-key []))))))
+  corpus)
+(local create-corpus (partial _create-corpus lines))
+
+(fn one-of [t]
+  "returns a random element of a sequential or non-sequential table"
+  (let [len (accumulate [l 0 _ _ (pairs t)] (+ l 1)) ;; do it the hard way
+                                                     ;; because nonseq tables
+                                                     ;; have no length?
+        handle (io.popen "echo $RANDOM")
+        output (handle:read "*a")
+        random (output:gsub "[\n\r]" "")
+        seed (math.randomseed random) ;; SIDE EFFECT
+        whatever (handle:close)       ;; SIDE EFFECT
+        idx (math.random len)
+        keys (accumulate [acc [] k v (pairs t)] (do (table.insert acc k) acc))
+        rndkey (. keys idx)
+        it (. t rndkey)]
+    it))
+
+(fn flatten [corpus origin]
+  (let [str (if (= "string" (type origin))
+              origin
+              (if (= "table" (type origin))
+                (one-of origin)
+                (error "Origin must be a table or a string")))
+        template-pattern "%[%[[%a-]+%]%]" ; [[word]]
+        word-pattern "%[%[([%a-]+)%]%]"   ; word
+        (i j) (string.find str template-pattern) ; indices
+        word (string.match str word-pattern)]    ; the actual keyword
+    (if (not i)
+      str
+      (let [next-str (string.format "%s%s%s"
+              (string.sub str 1 (- i 1))
+              (one-of (. corpus word))
+              (string.sub str (+ j 1)))]
+        (flatten corpus next-str j))))) ;; this is a tail call!
+
+{: create-corpus
+ : flatten
+ }
-- 
cgit 1.4.1-2-gfad0