commit 0831b6c5ec0c51f15bd0d92258dd4bb556b65b32
Author: Yuri Tatishchev <itatishch@gmail.com>
Date:   Thu Feb 27 16:45:31 2025 -0800

    initial commit

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
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+++ b/.github/workflows/test.yml
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+name: test
+
+on:
+  push:
+    branches:
+      - master
+      - main
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: erlef/setup-beam@v1
+        with:
+          otp-version: "27.1.2"
+          gleam-version: "1.8.1"
+          rebar3-version: "3"
+          # elixir-version: "1"
+      - run: gleam deps download
+      - run: gleam test
+      - run: gleam format --check src test
diff --git a/.gitignore b/.gitignore
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+++ b/.gitignore
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+*.beam
+*.ez
+/build
+erl_crash.dump
+.idea/
diff --git a/README.md b/README.md
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+++ b/README.md
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+# glemt
+
+Computational theory automata, work in progress.
+
+## Development
+
+```sh
+gleam run   # Run the project
+gleam test  # Run the tests
+```
diff --git a/gleam.toml b/gleam.toml
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+++ b/gleam.toml
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+name = "glemt"
+version = "1.0.0"
+
+# Fill out these fields if you intend to generate HTML documentation or publish
+# your project to the Hex package manager.
+#
+# description = ""
+# licences = ["Apache-2.0"]
+# repository = { type = "github", user = "", repo = "" }
+# links = [{ title = "Website", href = "" }]
+#
+# For a full reference of all the available options, you can have a look at
+# https://gleam.run/writing-gleam/gleam-toml/.
+
+[dependencies]
+gleam_stdlib = ">= 0.44.0 and < 2.0.0"
+
+[dev-dependencies]
+gleeunit = ">= 1.0.0 and < 2.0.0"
diff --git a/manifest.toml b/manifest.toml
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+++ b/manifest.toml
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+# This file was generated by Gleam
+# You typically do not need to edit this file
+
+packages = [
+  { name = "gleam_stdlib", version = "0.55.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "32D8F4AE03771516950047813A9E359249BD9FBA5C33463FDB7B953D6F8E896B" },
+  { name = "gleeunit", version = "1.3.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "0E6C83834BA65EDCAAF4FE4FB94AC697D9262D83E6F58A750D63C9F6C8A9D9FF" },
+]
+
+[requirements]
+gleam_stdlib = { version = ">= 0.44.0 and < 2.0.0" }
+gleeunit = { version = ">= 1.0.0 and < 2.0.0" }
diff --git a/src/glemt.gleam b/src/glemt.gleam
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+++ b/src/glemt.gleam
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+import gleam/list
+import gleam/string
+import gleam/set.{type Set}
+import gleam/io
+
+//pub type State {
+//  State(Int)
+//}
+
+pub type State = Int
+
+//pub type AlphabetChar {
+//  AlphabetChar(String)
+//}
+
+pub type AlphabetChar = String
+
+pub type NFAError {
+  NoTransition
+}
+
+pub type NFA {
+  NFA(states: Set(State), alphabet: Set(AlphabetChar), transition_func: fn(State, AlphabetChar) -> Result(State, NFAError), init_state: State, accepting_states: Set(State))
+}
+
+//pub type DFAViolation {
+//  NotAllTransitionsDefined
+//  MultiplePossibleTransitions
+//}
+
+pub fn check_string(automaton: NFA, input: String) -> Bool {
+  let result = input
+  |> string.to_graphemes
+  |> list.try_fold(automaton.init_state, automaton.transition_func)
+
+  case result {
+    Ok(state) -> set.contains(automaton.accepting_states, state)
+    Error(_) -> False
+  }
+}
+
+pub fn even_a() -> NFA {
+  let states = set.from_list([0, 1])
+  let alphabet = set.from_list(["a"])
+  let transition_func = fn (state: State, char: AlphabetChar) -> Result(State, NFAError) {
+    case state, char {
+      0, "a" -> Ok(1)
+      1, "a" -> Ok(0)
+      _, _ -> Error(NoTransition)
+    }
+  }
+  let init_state = 0
+  let accepting_states = set.from_list([0])
+  NFA(states:, alphabet:, transition_func:, init_state:, accepting_states:)
+}
+
+pub fn main() {
+  io.println("Hello from glemt!")
+
+  let automaton = even_a()
+  io.debug(check_string(automaton, ""))
+  io.debug(check_string(automaton, "a"))
+  io.debug(check_string(automaton, "aa"))
+  io.debug(check_string(automaton, "aaab"))
+}
diff --git a/test/glemt_test.gleam b/test/glemt_test.gleam
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+++ b/test/glemt_test.gleam
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+import glemt
+import gleeunit
+import gleeunit/should
+
+pub fn main() {
+  gleeunit.main()
+}
+
+pub fn nfa_even_a_test() {
+  glemt.even_a()
+  |> glemt.check_string("")
+  |> should.equal(True)
+
+  glemt.even_a()
+  |> glemt.check_string("a")
+  |> should.equal(False)
+
+  glemt.even_a()
+  |> glemt.check_string("aa")
+  |> should.equal(True)
+
+  glemt.even_a()
+  |> glemt.check_string("aaa")
+  |> should.equal(False)
+
+  glemt.even_a()
+  |> glemt.check_string("aaaa")
+  |> should.equal(True)
+
+  glemt.even_a()
+  |> glemt.check_string("aab")
+  |> should.equal(False)
+
+  glemt.even_a()
+  |> glemt.check_string("baabaa")
+  |> should.equal(False)
+}