Add first steps of AutoChomp

4 files changed, 178 insertions, 0 deletions

diff --git a/autochomp/Cargo.toml b/autochomp/Cargo.toml
new file mode 100644
index 0000000..4e20c49
--- /dev/null
+++ b/autochomp/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "autochomp"
+version = "0.1.0"
+authors = ["Greg Brown <gmb60@cam.ac.uk>"]
+edition = "2018"
+
+[build-dependencies]
+chomp = {path = ".."}
+
+[build-dependencies.syn]
+version = "1"
+features = ["extra-traits"]
+
+[dependencies]
+chewed = {path = "../chewed"}
diff --git a/autochomp/build.rs b/autochomp/build.rs
new file mode 100644
index 0000000..952d49c
--- /dev/null
+++ b/autochomp/build.rs
@@ -0,0 +1,73 @@
+use std::{
+    env,
+    error::Error,
+    fmt::Display,
+    fs,
+    io::{Read, Write},
+    path::Path,
+    process::exit,
+};
+
+use chomp::{
+    chomp::{
+        check::{InlineCall, TypeCheck},
+        context::Context,
+        visit::Visitable,
+    },
+    lower::{rust::RustBackend, Backend, GenerateCode},
+    nibble::cst::File,
+};
+
+const PATH: &str = "src/nibble.nb";
+
+#[derive(Debug)]
+struct UndecVar;
+
+impl Display for UndecVar {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Undeclared variable somewhere.")
+    }
+}
+impl Error for UndecVar {}
+
+fn main() {
+    println!("cargo:rerun-if-changed={}", PATH);
+
+    let out_dir = env::var("OUT_DIR").unwrap();
+
+    let mut input = String::new();
+    let res = fs::File::open(PATH)
+        .map_err(|e| Box::new(e) as Box<dyn Error>)
+        .and_then(|mut file| file.read_to_string(&mut input).map_err(|e| Box::new(e) as Box<dyn Error>))
+        .and_then(|_| syn::parse_str(&input).map_err(|e| Box::new(e) as Box<dyn Error>))
+        .and_then(|nibble: File| nibble.convert().ok_or(Box::new(UndecVar) as Box<dyn Error>))
+        .and_then(|(funs, goal)| {
+            funs.into_iter()
+                .try_rfold(goal, |goal, function| {
+                    goal.fold(&mut InlineCall::new(function))
+                })
+                .map_err(|e| Box::new(e) as Box<dyn Error>)
+        })
+        .and_then(|term| {
+            let mut context = Context::default();
+            term.fold(&mut TypeCheck {
+                context: &mut context,
+            })
+            .map_err(|e| Box::new(e) as Box<dyn Error>)
+        })
+        .map(|typed| {
+            let mut backend = RustBackend::default();
+            let id = typed.gen(&mut backend);
+            backend.emit_code(id)
+        })
+        .and_then(|code| {
+            fs::File::create(Path::new(&out_dir).join("nibble.rs"))
+                .and_then(|mut f| write!(f, "{}", code))
+                .map_err(|e| Box::new(e) as Box<dyn Error>)
+        });
+
+    if let Err(e) = res {
+        eprintln!("{}", e);
+        exit(1)
+    }
+}
diff --git a/autochomp/src/main.rs b/autochomp/src/main.rs
new file mode 100644
index 0000000..400cc2d
--- /dev/null
+++ b/autochomp/src/main.rs
@@ -0,0 +1,23 @@
+use std::{error::Error, io::{self, Read, Write}, process::exit};
+
+use chewed::Parse;
+
+mod nibble {
+    include!(concat!(env!("OUT_DIR"), "/nibble.rs"));
+}
+
+fn main() {
+    let mut input = String::new();
+    let res = io::stdin()
+        .read_to_string(&mut input)
+        .map_err(|e| Box::new(e) as Box<dyn Error>)
+        .and_then(|_| nibble::Ast::parse(input.chars().peekable()).map_err(|e| Box::new(e) as Box<dyn Error>))
+        .and_then(|ast| {
+            write!(io::stdout(), "{:?}", ast).map_err(|e| Box::new(e) as Box<dyn Error>)
+        });
+
+    if let Err(e) = res {
+        eprintln!("{}", e);
+        exit(1)
+    }
+}
diff --git a/autochomp/src/nibble.nb b/autochomp/src/nibble.nb
new file mode 100644
index 0000000..fed3d46
--- /dev/null
+++ b/autochomp/src/nibble.nb
@@ -0,0 +1,67 @@
+let opt(x) = _ | x;
+let plus(x) = [plus](x . opt(plus));
+let star(x) = opt(plus(x));
+let star_(base, step) = [rec](base | step . rec);
+
+let Pattern_Whitespace = "\t"|"\n"|"\x0B"|"\x0c"|"\r"|" "|"\u{85}"|"\u{200e}"|"\u{200f}"|"\u{2028}"|"\u{2029}";
+
+let digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";
+let oct_digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7";
+let hex_digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" |
+                "a" | "b" | "c" | "d" | "e" | "f" |
+                "A" | "B" | "C" | "D" | "E" | "F" ;
+
+let XID_Start =
+    "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" |
+    "i" | "j" | "k" | "l" | "m" | "n" | "o" | "p" |
+    "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x" |
+    "y" | "z" |
+    "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" |
+    "I" | "J" | "K" | "L" | "M" | "N" | "O" | "P" |
+    "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" |
+    "Y" | "Z" ;
+let XID_Continue =
+    XID_Start | "_" | "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
+
+let literal_char =
+    " " | "!"       | "#" | "$" | "%" | "&" | "'" |
+    "(" | ")" | "*" | "+" | "," | "-" | "." | "/" |
+    "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" |
+    "8" | "9" | ":" | ";" | "<" | "=" | ">" | "?" |
+    "@" | "A" | "B" | "C" | "D" | "E" | "F" | "G" |
+    "H" | "I" | "J" | "K" | "L" | "M" | "N" | "O" |
+    "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" |
+    "X" | "Y" | "Z" | "["       | "]" | "^" | "_" |
+    "`" | "a" | "b" | "c" | "d" | "e" | "f" | "g" |
+    "h" | "i" | "j" | "k" | "l" | "m" | "n" | "o" |
+    "p" | "q" | "r" | "s" | "t" | "u" | "v" | "w" |
+    "x" | "y" | "z" | "{" | "|" | "}" | "~" |
+    "\\" . ("\"" | "'" | "n" | "r" | "t" | "\\" | "0" |
+            "x" . oct_digit . hex_digit |
+            "u{" . hex_digit . opt(hex_digit . opt(hex_digit . opt(hex_digit . opt(hex_digit . opt(hex_digit))))) . "}");
+
+let ws = plus(Pattern_Whitespace);
+
+let punctuated(x, p) = [rec](x . opt(p . opt(ws) . opt(rec)));
+let list(x) = "(" . opt(ws) . punctuated(x, ",") . ")";
+
+let epsilon = "_";
+let ident = XID_Start . star(XID_Continue);
+let literal = "\"" . plus(literal_char) . "\"";
+let parens(expr) = "(" . opt(ws) . expr . ")";
+let fix(expr) = "[" . opt(ws) . ident . opt(ws) . "]" . opt(ws) . parens(expr);
+
+let term(expr) =
+      epsilon . opt(ws)
+    | literal . opt(ws)
+    | parens(expr) . opt(ws)
+    | fix(expr) . opt(ws)
+    | ident . opt(ws) . opt(list(expr) . opt(ws))
+    ;
+
+let seq(expr) = punctuated(term(expr), ".");
+let alt(expr) = punctuated(seq(expr), "|");
+let expr = [expr](alt(expr));
+let let = "let" . ws . ident . opt(ws) . opt(list(ident . opt(ws)) . opt(ws)) . "=" . opt(ws) . expr . ";";
+let goal = "match" . ws . expr . ";";
+match star_(goal, let);