vine: add lambda calculus test

cspell.json

@@ -39,7 +39,8 @@
     "strs",
     "unpark",
     "vecs",
-    "visitee"
+    "visitee",
+    "whnf"
   ],
   "dictionaries": [
     "rust"

tests/programs/lambda.vi

@@ -0,0 +1,172 @@
+
+use std::data::Map;
+
+pub fn main(&io: &IO) {
+  while io.prompt("> ") is Some(line) {
+    match Term::parse(~_, line) {
+      Ok(term) { io.println(term.print_normal(0)) }
+      Err(err) { io.println("error: " ++ err) }
+    }
+  }
+}
+
+pub enum Term {
+  Lambda(List[~Term], Term),
+  Apply(Term, Term),
+  Spine(String, List[Term]),
+}
+
+pub mod Term {
+  fn whnf(term: Term) -> Term {
+    match term {
+      Term::Apply(fun, arg) {
+        fun = fun.whnf();
+        match fun {
+          Term::Lambda(param, body) {
+            bind(param, arg);
+            body.whnf()
+          }
+          Term::Spine(var, args) { Term::Spine(var, args ++ [arg]) }
+        }
+      }
+      term { term }
+    }
+  }
+
+  pub fn print_normal(term: Term, depth: N32) -> String {
+    match term.whnf() {
+      Term::Lambda(param, body) {
+        let var = new_var(depth);
+        bind(param, Term::Spine(var, []));
+        "\\" ++ var ++ ". " ++ body.print_normal(depth + 1)
+      }
+      Term::Spine(var, args) {
+        if args.len() == 0 {
+          var
+        } else {
+          let out = "(" ++ var;
+          let iter = args.into_iter();
+          while iter.next() is Some(arg) {
+            out ++= " " ++ arg.print_normal(depth);
+          }
+          out ++ ")"
+        }
+      }
+    }
+  }
+
+  fn bind(uses: List[~Term], term: Term) {
+    let iter = uses.into_iter();
+    while iter.next() is Some(out) {
+      ~out = term;
+    }
+  }
+
+  pub fn parse(io: IO, source: String) -> Result[Term, String] {
+    let err;
+    let parser = Parser({ io, scope: Map::new(String::cmp), chars: source.chars, error: move ~err });
+    let term = parser.parse_term();
+    ~parser.error = None;
+    if err is Some(error) {
+      Err(error)
+    } else {
+      Ok(term)
+    }
+  }
+}
+
+struct Parser {
+  io: IO,
+  scope: Map[String, List[List[~Term]]],
+  chars: List[Char],
+  error: ~Option[String],
+}
+
+mod Parser {
+  pub fn parse_term(&self: &Parser) -> Term {
+    let term = self.parse_atom();
+    self.skip_ws();
+    while self.chars.len() != 0 && self.chars.get(0).* != ')' {
+      term = Term::Apply(term, self.parse_atom());
+      self.skip_ws();
+    }
+    term
+  }
+
+  fn parse_atom(&self: &Parser) -> Term {
+    self.skip_ws();
+    if self.chars.len() == 0 {
+      self.error("expected term");
+    }
+    let char = self.chars.get(0).*;
+    self.io.println(String({ chars: [char] }));
+    if char == '\\' {
+      self.io.println("lambda");
+      self.chars.pop_front();
+      self.skip_ws();
+      let var = self.parse_var();
+      self.io.println(var);
+      self.expect_char('.');
+      self.scope.get_or_insert(var, []).*.push_front([]);
+      let body = self.parse_atom();
+      let uses = self.scope.get(&var).unwrap().*.pop_front().unwrap();
+      Term::Lambda(uses, body)
+    } else if char == '(' {
+      self.chars.pop_front();
+      let term = self.parse_term();
+      self.expect_char(')');
+      term
+    } else {
+      let var = self.parse_var();
+      if self.scope.get(&var) is Some(&binds) && binds.len() != 0 {
+        let term;
+        binds.get(0).*.push_back(move ~term);
+        term
+      } else {
+        self.error("unbound variable `" ++ var ++ "`")
+      }
+    }
+  }
+
+  fn parse_var(&self: &Parser) -> String {
+    let chars = [];
+    while self.chars.len() != 0 && self.chars.get(0).* is char && char.is_alphanumeric() {
+      self.chars.pop_front();
+      chars.push_back(char);
+    }
+    if chars.len() == 0 {
+      self.error("expected variable");
+    }
+    String({ chars })
+  }
+
+  fn expect_char(&self: &Parser, char: Char) {
+    self.skip_ws();
+    if !(self.chars.pop_front() is Some(c) && c == char) {
+      self.error("expected `" ++ String({ chars: [char] }) ++ "`");
+    }
+  }
+
+  fn skip_ws(&self: &Parser) {
+    while self.chars.len() != 0 && self.chars.get(0).*.is_whitespace() {
+      self.chars.pop_front();
+    }
+  }
+
+  fn error[T](&self: &Parser, error: String) -> T {
+    ~self.error = Some(error);
+    move self;
+    ~_
+  }
+}
+
+fn new_var(n: N32) -> String {
+  let chars = [];
+  n += 1;
+  while n > 0 {
+    n -= 1;
+    chars.push_front('a' + (n % 26));
+    n /= 26;
+  }
+  String({ chars })
+}

tests/snaps/vine/aoc_2024/day_01/compiled.iv

@@ -248,15 +248,15 @@
 
 ::std::numeric::N32::ascending { fn(ref(dup2066(w2 @lt(w11 w12)) w2) fn(ref(dup2067(w5 w11) w5) w12)) }
 
-::std::unicode::String::len { fn(ref(tup(dup2662(w2 w15) w4) tup(w2 w4)) w15) }
+::std::unicode::String::len { fn(ref(tup(dup2673(w2 w15) w4) tup(w2 w4)) w15) }
 
 ::std::unicode::String::split {
   fn(w2 fn(w3 w10))
   ::std::unicode::String::split::2 = x(w2 x(w3 x(tup(0 tup(w9 w9)) w10)))
 }
 
 ::std::unicode::String::split::2 {
-  x(w14 x(dup2673(w1 w20) x(w12 w18)))
+  x(w14 x(dup2684(w1 w20) x(w12 w18)))
   ::std::unicode::String::split_once = fn(w14 fn(w1 tup(w3 enum(::std::unicode::String::split::6 enum(::std::unicode::String::split::7 x(w20 x(w9 w18)))))))
   ::std::data::List::concat = fn(w12 fn(tup(1 tup(tup(w3 w15) w15)) w9))
 }
@@ -274,9 +274,9 @@
 }
 
 ::std::unicode::String::split_trim::2 {
-  x(w24 x(dup2698(w1 w44) x(w22 x(w21 x(x(w20 w41) w39)))))
+  x(w24 x(dup2709(w1 w44) x(w22 x(w21 x(x(w20 w41) w39)))))
   ::std::unicode::String::split_once = fn(w24 fn(w1 tup(w3 enum(::std::unicode::String::split_trim::24 enum(::std::unicode::String::split_trim::25 x(w44 x(w33 x(w42 x(x(w36 w41) w39)))))))))
-  ::std::unicode::String::len = fn(ref(w3 w7) @eq(0 dup2709(?(::std::unicode::String::split_trim::5 ::std::unicode::String::split_trim::4 x(w21 dup2702(?(::std::unicode::String::split_trim::11 ::std::unicode::String::split_trim::10 x(x(w22 w33) x(w31 x(w7 _)))) w42))) ?(::std::unicode::String::split_trim::17 ::std::unicode::String::split_trim::16 x(w36 dup2704(w20 w31))))))
+  ::std::unicode::String::len = fn(ref(w3 w7) @eq(0 dup2720(?(::std::unicode::String::split_trim::5 ::std::unicode::String::split_trim::4 x(w21 dup2713(?(::std::unicode::String::split_trim::11 ::std::unicode::String::split_trim::10 x(x(w22 w33) x(w31 x(w7 _)))) w42))) ?(::std::unicode::String::split_trim::17 ::std::unicode::String::split_trim::16 x(w36 dup2715(w20 w31))))))
 }
 
 ::std::unicode::String::split_trim::4 { x(?(0 1 w3) w3) }
@@ -331,7 +331,7 @@
 }
 
 ::std::unicode::String::split_once::9 {
-  enum(ref(dup2789(w1 w16) w1) x(w9 x(w8 x(w7 x(w6 x(w5 w15))))))
+  enum(ref(dup2800(w1 w16) w1) x(w9 x(w8 x(w7 x(w6 x(w5 w15))))))
   ::std::data::List::Iter::next = fn(ref(w5 w11) enum(::std::unicode::String::split_once::13 enum(::std::unicode::String::split_once::14 x(w9 x(w8 x(w7 x(w6 x(w11 x(w16 w15)))))))))
 }
 
@@ -340,7 +340,7 @@
   ::std::unicode::String::split_once::15 = x(w4 x(w3 w1))
 }
 
-::std::unicode::String::split_once::13 { enum(ref(dup2803(w1 w13) w1) x(w10 x(w9 x(w8 x(w7 x(w6 x(@ne(w13 ?(::std::unicode::String::split_once::6 ::std::unicode::String::split_once::17 x(w10 x(w9 x(w8 x(w7 x(w6 w15))))))) w15))))))) }
+::std::unicode::String::split_once::13 { enum(ref(dup2814(w1 w13) w1) x(w10 x(w9 x(w8 x(w7 x(w6 x(@ne(w13 ?(::std::unicode::String::split_once::6 ::std::unicode::String::split_once::17 x(w10 x(w9 x(w8 x(w7 x(w6 w15))))))) w15))))))) }
 
 ::std::unicode::String::split_once::14 {
   x(_ x(w5 x(w4 x(_ x(w2 x(_ w7))))))
@@ -383,7 +383,7 @@
   ::std::IO::print::2 = x(x(w3 w17) x(w9 w10))
 }
 
-::std::IO::print::2 { x(w4 x(dup2979(?(::std::IO::print::4 ::std::IO::print::3 x(w4 x(w6 w1))) w6) w1)) }
+::std::IO::print::2 { x(w4 x(dup2990(?(::std::IO::print::4 ::std::IO::print::3 x(w4 x(w6 w1))) w6) w1)) }
 
 ::std::IO::print::3 {
   x(x(w17 w21) x(@sub(1 w1) tup(w4 w5)))
@@ -402,7 +402,7 @@
 
 ::std::IO::full_input::2 {
   x(x(w9 w16) x(w7 w12))
-  ::std::IO::read_byte = fn(ref(w9 w1) fn(0 dup3073(@ne(0 ?(::std::IO::full_input::5 ::std::IO::full_input::4 x(x(w1 w16) x(w7 x(w13 w12))))) w13)))
+  ::std::IO::read_byte = fn(ref(w9 w1) fn(0 dup3084(@ne(0 ?(::std::IO::full_input::5 ::std::IO::full_input::4 x(x(w1 w16) x(w7 x(w13 w12))))) w13)))
 }
 
 ::std::IO::full_input::4 {

tests/snaps/vine/aoc_2024/day_02/compiled.iv

@@ -229,15 +229,15 @@
 
 ::std::numeric::N32::parse::11 { x(w10 w10) }
 
-::std::unicode::String::len { fn(ref(tup(dup2710(w2 w15) w4) tup(w2 w4)) w15) }
+::std::unicode::String::len { fn(ref(tup(dup2721(w2 w15) w4) tup(w2 w4)) w15) }
 
 ::std::unicode::String::split {
   fn(w2 fn(w3 w10))
   ::std::unicode::String::split::2 = x(w2 x(w3 x(tup(0 tup(w9 w9)) w10)))
 }
 
 ::std::unicode::String::split::2 {
-  x(w14 x(dup2721(w1 w20) x(w12 w18)))
+  x(w14 x(dup2732(w1 w20) x(w12 w18)))
   ::std::unicode::String::split_once = fn(w14 fn(w1 tup(w3 enum(::std::unicode::String::split::6 enum(::std::unicode::String::split::7 x(w20 x(w9 w18)))))))
   ::std::data::List::concat = fn(w12 fn(tup(1 tup(tup(w3 w15) w15)) w9))
 }
@@ -255,9 +255,9 @@
 }
 
 ::std::unicode::String::split_trim::2 {
-  x(w24 x(dup2746(w1 w44) x(w22 x(w21 x(x(w20 w41) w39)))))
+  x(w24 x(dup2757(w1 w44) x(w22 x(w21 x(x(w20 w41) w39)))))
   ::std::unicode::String::split_once = fn(w24 fn(w1 tup(w3 enum(::std::unicode::String::split_trim::24 enum(::std::unicode::String::split_trim::25 x(w44 x(w33 x(w42 x(x(w36 w41) w39)))))))))
-  ::std::unicode::String::len = fn(ref(w3 w7) @eq(0 dup2757(?(::std::unicode::String::split_trim::5 ::std::unicode::String::split_trim::4 x(w21 dup2750(?(::std::unicode::String::split_trim::11 ::std::unicode::String::split_trim::10 x(x(w22 w33) x(w31 x(w7 _)))) w42))) ?(::std::unicode::String::split_trim::17 ::std::unicode::String::split_trim::16 x(w36 dup2752(w20 w31))))))
+  ::std::unicode::String::len = fn(ref(w3 w7) @eq(0 dup2768(?(::std::unicode::String::split_trim::5 ::std::unicode::String::split_trim::4 x(w21 dup2761(?(::std::unicode::String::split_trim::11 ::std::unicode::String::split_trim::10 x(x(w22 w33) x(w31 x(w7 _)))) w42))) ?(::std::unicode::String::split_trim::17 ::std::unicode::String::split_trim::16 x(w36 dup2763(w20 w31))))))
 }
 
 ::std::unicode::String::split_trim::4 { x(?(0 1 w3) w3) }
@@ -312,7 +312,7 @@
 }
 
 ::std::unicode::String::split_once::9 {
-  enum(ref(dup2837(w1 w16) w1) x(w9 x(w8 x(w7 x(w6 x(w5 w15))))))
+  enum(ref(dup2848(w1 w16) w1) x(w9 x(w8 x(w7 x(w6 x(w5 w15))))))
   ::std::data::List::Iter::next = fn(ref(w5 w11) enum(::std::unicode::String::split_once::13 enum(::std::unicode::String::split_once::14 x(w9 x(w8 x(w7 x(w6 x(w11 x(w16 w15)))))))))
 }
 
@@ -321,7 +321,7 @@
   ::std::unicode::String::split_once::15 = x(w4 x(w3 w1))
 }
 
-::std::unicode::String::split_once::13 { enum(ref(dup2851(w1 w13) w1) x(w10 x(w9 x(w8 x(w7 x(w6 x(@ne(w13 ?(::std::unicode::String::split_once::6 ::std::unicode::String::split_once::17 x(w10 x(w9 x(w8 x(w7 x(w6 w15))))))) w15))))))) }
+::std::unicode::String::split_once::13 { enum(ref(dup2862(w1 w13) w1) x(w10 x(w9 x(w8 x(w7 x(w6 x(@ne(w13 ?(::std::unicode::String::split_once::6 ::std::unicode::String::split_once::17 x(w10 x(w9 x(w8 x(w7 x(w6 w15))))))) w15))))))) }
 
 ::std::unicode::String::split_once::14 {
   x(_ x(w5 x(w4 x(_ x(w2 x(_ w7))))))
@@ -364,7 +364,7 @@
   ::std::IO::print::2 = x(x(w3 w17) x(w9 w10))
 }
 
-::std::IO::print::2 { x(w4 x(dup3027(?(::std::IO::print::4 ::std::IO::print::3 x(w4 x(w6 w1))) w6) w1)) }
+::std::IO::print::2 { x(w4 x(dup3038(?(::std::IO::print::4 ::std::IO::print::3 x(w4 x(w6 w1))) w6) w1)) }
 
 ::std::IO::print::3 {
   x(x(w17 w21) x(@sub(1 w1) tup(w4 w5)))
@@ -383,7 +383,7 @@
 
 ::std::IO::full_input::2 {
   x(x(w9 w16) x(w7 w12))
-  ::std::IO::read_byte = fn(ref(w9 w1) fn(0 dup3121(@ne(0 ?(::std::IO::full_input::5 ::std::IO::full_input::4 x(x(w1 w16) x(w7 x(w13 w12))))) w13)))
+  ::std::IO::read_byte = fn(ref(w9 w1) fn(0 dup3132(@ne(0 ?(::std::IO::full_input::5 ::std::IO::full_input::4 x(x(w1 w16) x(w7 x(w13 w12))))) w13)))
 }
 
 ::std::IO::full_input::4 {

tests/snaps/vine/aoc_2024/day_03/compiled.iv

@@ -197,15 +197,15 @@
 
 ::std::numeric::N32::parse::11 { x(w10 w10) }
 
-::std::unicode::String::len { fn(ref(tup(dup2637(w2 w15) w4) tup(w2 w4)) w15) }
+::std::unicode::String::len { fn(ref(tup(dup2648(w2 w15) w4) tup(w2 w4)) w15) }
 
 ::std::unicode::String::split {
   fn(w2 fn(w3 w10))
   ::std::unicode::String::split::2 = x(w2 x(w3 x(tup(0 tup(w9 w9)) w10)))
 }
 
 ::std::unicode::String::split::2 {
-  x(w14 x(dup2648(w1 w20) x(w12 w18)))
+  x(w14 x(dup2659(w1 w20) x(w12 w18)))
   ::std::unicode::String::split_once = fn(w14 fn(w1 tup(w3 enum(::std::unicode::String::split::6 enum(::std::unicode::String::split::7 x(w20 x(w9 w18)))))))
   ::std::data::List::concat = fn(w12 fn(tup(1 tup(tup(w3 w15) w15)) w9))
 }
@@ -243,7 +243,7 @@
 }
 
 ::std::unicode::String::split_once::9 {
-  enum(ref(dup2764(w1 w16) w1) x(w9 x(w8 x(w7 x(w6 x(w5 w15))))))
+  enum(ref(dup2775(w1 w16) w1) x(w9 x(w8 x(w7 x(w6 x(w5 w15))))))
   ::std::data::List::Iter::next = fn(ref(w5 w11) enum(::std::unicode::String::split_once::13 enum(::std::unicode::String::split_once::14 x(w9 x(w8 x(w7 x(w6 x(w11 x(w16 w15)))))))))
 }
 
@@ -252,7 +252,7 @@
   ::std::unicode::String::split_once::15 = x(w4 x(w3 w1))
 }
 
-::std::unicode::String::split_once::13 { enum(ref(dup2778(w1 w13) w1) x(w10 x(w9 x(w8 x(w7 x(w6 x(@ne(w13 ?(::std::unicode::String::split_once::6 ::std::unicode::String::split_once::17 x(w10 x(w9 x(w8 x(w7 x(w6 w15))))))) w15))))))) }
+::std::unicode::String::split_once::13 { enum(ref(dup2789(w1 w13) w1) x(w10 x(w9 x(w8 x(w7 x(w6 x(@ne(w13 ?(::std::unicode::String::split_once::6 ::std::unicode::String::split_once::17 x(w10 x(w9 x(w8 x(w7 x(w6 w15))))))) w15))))))) }
 
 ::std::unicode::String::split_once::14 {
   x(_ x(w5 x(w4 x(_ x(w2 x(_ w7))))))
@@ -295,7 +295,7 @@
   ::std::IO::print::2 = x(x(w3 w17) x(w9 w10))
 }
 
-::std::IO::print::2 { x(w4 x(dup2954(?(::std::IO::print::4 ::std::IO::print::3 x(w4 x(w6 w1))) w6) w1)) }
+::std::IO::print::2 { x(w4 x(dup2965(?(::std::IO::print::4 ::std::IO::print::3 x(w4 x(w6 w1))) w6) w1)) }
 
 ::std::IO::print::3 {
   x(x(w17 w21) x(@sub(1 w1) tup(w4 w5)))
@@ -314,7 +314,7 @@
 
 ::std::IO::full_input::2 {
   x(x(w9 w16) x(w7 w12))
-  ::std::IO::read_byte = fn(ref(w9 w1) fn(0 dup3048(@ne(0 ?(::std::IO::full_input::5 ::std::IO::full_input::4 x(x(w1 w16) x(w7 x(w13 w12))))) w13)))
+  ::std::IO::read_byte = fn(ref(w9 w1) fn(0 dup3059(@ne(0 ?(::std::IO::full_input::5 ::std::IO::full_input::4 x(x(w1 w16) x(w7 x(w13 w12))))) w13)))
 }
 
 ::std::IO::full_input::4 {