5 files changed, 46 insertions, 0 deletions
diff --git a/src/stdlib/fs.ts b/src/stdlib/fs.ts
new file mode 100644
index 0000000..0bd6a2c
--- /dev/null
+++ b/src/stdlib/fs.ts
@@ -0,0 +1,6 @@
+import { EffectAtom } from './io'
+
+export interface WriteFile<_Path extends string, _Content extends string> extends EffectAtom { }
+
+export interface ReadFile<_Path extends string> extends EffectAtom<string> { }
+
diff --git a/src/stdlib/index.ts b/src/stdlib/index.ts
new file mode 100644
index 0000000..45197d9
--- /dev/null
+++ b/src/stdlib/index.ts
@@ -0,0 +1,4 @@
+export * from './io'
+export * from './fs'
+export * from './stdio'
+export * from './sys'
diff --git a/src/stdlib/io.ts b/src/stdlib/io.ts
new file mode 100644
index 0000000..00b74b1
--- /dev/null
+++ b/src/stdlib/io.ts
@@ -0,0 +1,18 @@
+export interface EffectAtom<T = unknown> { output: T }
+export type Effect = EffectAtom[]
+
+export interface Kind1<Inp = unknown, Out = unknown> {
+  input: Inp
+  return: Out
+}
+
+export interface Program<Effs extends Effect, ExitCode extends number = 0> {
+  effects: Effs,
+  exitCode: ExitCode,
+}
+
+export interface Bind<Eff extends EffectAtom, Fn extends Kind1> extends EffectAtom {
+  input: Eff
+  chainTo: Fn
+}
+
diff --git a/src/stdlib/stdio.ts b/src/stdlib/stdio.ts
new file mode 100644
index 0000000..96c27f8
--- /dev/null
+++ b/src/stdlib/stdio.ts
@@ -0,0 +1,10 @@
+import { EffectAtom } from './io'
+
+export interface PutString<_ extends string> extends EffectAtom { }
+
+export interface Print<_ extends any> extends EffectAtom { }
+
+export interface Debug<_ extends string, T> extends EffectAtom<T> { }
+
+export interface ReadLine extends EffectAtom<string> { }
+
diff --git a/src/stdlib/sys.ts b/src/stdlib/sys.ts
new file mode 100644
index 0000000..1a9b18e
--- /dev/null
+++ b/src/stdlib/sys.ts
@@ -0,0 +1,8 @@
+import { EffectAtom } from './io'
+
+export interface GetEnv<_Name extends string> extends EffectAtom<string> { }
+
+export interface GetArgs extends EffectAtom<string[]> { }
+
+export interface JsExpr<_Expr extends string> extends EffectAtom<any> { }
+