initial commit

1 files changed, 42 insertions, 0 deletions

diff --git a/samples/io.js b/samples/io.js
new file mode 100644
index 0000000..a2a0ff0
--- /dev/null
+++ b/samples/io.js
@@ -0,0 +1,42 @@
+import * as io from "../src/io.js"
+import * as fs from "fs"
+
+const writeLine = str => io.DO(function* () {
+    const head = str[0]
+    const tail = str.slice(1)
+
+    yield io.write(head)
+    yield tail === "" ? io.write('\n') : writeLine(tail)
+})
+
+const readLine = io.bind(io.read)(ch =>
+    ch === '\r' ? io.unit("")
+                : io.bind(readLine)(line => io.unit(ch + line))
+)
+
+const nodeEffects = () => {
+    process.stdin.setRawMode(true)
+    const buffer = Buffer.alloc(1)
+    const fd = fs.openSync("/dev/tty", "rs")
+    return {
+        write: process.stdout.write.bind(process.stdout),
+        read: () => {
+            fs.readSync(fd, buffer, 0, 1)
+            return buffer.toString("utf8")
+        }
+    }
+}
+
+const Person = name => age => person => person(name)(age)
+
+const constructPerson = io.DO(function* () {
+    yield writeLine("Please enter your name!")
+    const name = yield readLine
+    yield writeLine(`Hello ${name}! Now please enter your age.`)
+    const age = yield readLine
+    return Person(name)(age) // arbitrary data!
+})
+
+console.log(constructPerson(nodeEffects())(st => v => v(
+    name => age => `Person(name: ${name}, age: ${age})`
+)));