implement memof-call; add CI scripts

Author: tiye

.github/workflows/tests.yaml

@@ -0,0 +1,27 @@
+name: Tests
+
+on:
+  push:
+    branches:
+      - master
+  pull_request: {}
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: wget
+      run: mkdir ci-bin/ && wget -O ci-bin/cr_once http://repo.calcit-lang.org/binaries/linux/cr_once
+    - name: "permission"
+      run: chmod +x ci-bin/cr_once
+
+    - name: "prepare modules"
+      run: >
+        mkdir -p ~/.config/calcit/modules/
+        && cd ~/.config/calcit/modules/
+        && git clone https://github.com/calcit-lang/calcit-test
+        && git clone https://github.com/calcit-lang/lilac
+
+    - name: "test"
+      run: env=ci ./ci-bin/cr_once

.gitignore

@@ -1,2 +1,3 @@
 
 .compact-inc.cirru
+.calcit-error.cirru

README.md

@@ -2,10 +2,74 @@
 Memof
 ----
 
-> port of memof.
+> A memoization library in calcit, port from [Cumulo/memof](https://github.com/Cumulo/memof).
 
 ### Usages
 
+The model behind memof is memoizationm but with cache invalidations. `new-loop!` is the API to tell memof new loop happened. If stored record is old enough, it will be removed.
+
+```cirru
+(ns demo.main (:require ([] memof.core :as memof)))
+
+; pass GC options
+defatom *states $ memof.core/new-caches ({})
+
+defn f1 (x y) (* x y)
+
+memof.core/write-record! *states f1 ([] 1 2) 3
+
+memof.core/access-record *states f1 ([] 1 2)
+; returns 3
+
+memof.core/new-loop! *states
+; when loop is large enough, it will trigger GC
+```
+
+A short hand for using it:
+
+```cirru
+memof.alias/memof-call f ([] 1 2) 3
+
+; handle this at first on reload!
+memof.alias/reset-memof-caches!
+```
+
+States structure:
+
+```edn
+{
+  :loop 0 ; counter
+  :entries { ; where entries are stored
+    f1 {
+      :hit-times 1, :missed-times 1
+      :records {
+        [p1 p2] {:value 1, :hit-times 1, :last-hit-loop 1, :initial-loop 1}
+      }
+    }
+  }
+  :gc { ; configurations
+    :trigger-loop 100, ; trigger GC every N loops
+    :elapse-loop 50 ; entries are considered unuseful after not used for N loops
+  }
+}
+```
+
+Methods:
+
+* `(new-states)` creates states holding all entries
+* `(show-summary @*states)` list entries after formatted
+* `(write-record! *states f params value)` write to cache, `params` supposed to be a collection
+* `(access-record *states f params)` access and return value(or `nil`)
+* `(new-loop! *states)` loop and trigger actions
+* `(perform-gc! *states)` remove entries that are probably no longer useful
+* `(reset-entries! *states)` clear entries
+* `(modify-gc-options! *states ({}))` modify GC options
+
+Set `memofVerbose=true` in environment to enable verbose mode to print debug logs.
+Alternatively, you can access and overwrite `memof.core/*verbose?` to enabled it.
+
+### Develop
+
 Install [calcit-runner](https://github.com/Cirru/calcit-runner.nim) to run demo:
 
 ```bash