refactor(users/glittershark): Rename to grfn r/2485

Rename my //users directory and all places that refer to glittershark to
grfn, including nix references and documentation.

This may require some extra attention inside of gerrit's database after
it lands to allow me to actually push things.

Change-Id: I4728b7ec2c60024392c1c1fa6e0d4a59b3e266fa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2933
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Reviewed-by: glittershark <grfn@gws.fyi>

1 files changed, 239 insertions, 0 deletions

diff --git a/users/grfn/achilles/src/parser/mod.rs b/users/grfn/achilles/src/parser/mod.rs
new file mode 100644
index 0000000000..3e0081bd39
--- /dev/null
+++ b/users/grfn/achilles/src/parser/mod.rs
@@ -0,0 +1,239 @@
+use nom::character::complete::{multispace0, multispace1};
+use nom::error::{ErrorKind, ParseError};
+use nom::{alt, char, complete, do_parse, eof, many0, named, separated_list0, tag, terminated};
+
+#[macro_use]
+pub(crate) mod macros;
+mod expr;
+mod type_;
+
+use crate::ast::{Arg, Decl, Fun, Ident};
+pub use expr::expr;
+use type_::function_type;
+pub use type_::type_;
+
+pub type Error = nom::Err<nom::error::Error<String>>;
+
+pub(crate) fn is_reserved(s: &str) -> bool {
+    matches!(
+        s,
+        "if" | "then"
+            | "else"
+            | "let"
+            | "in"
+            | "fn"
+            | "ty"
+            | "int"
+            | "float"
+            | "bool"
+            | "true"
+            | "false"
+            | "cstring"
+    )
+}
+
+pub(crate) fn ident<'a, E>(i: &'a str) -> nom::IResult<&'a str, Ident, E>
+where
+    E: ParseError<&'a str>,
+{
+    let mut chars = i.chars();
+    if let Some(f) = chars.next() {
+        if f.is_alphabetic() || f == '_' {
+            let mut idx = 1;
+            for c in chars {
+                if !(c.is_alphanumeric() || c == '_') {
+                    break;
+                }
+                idx += 1;
+            }
+            let id = &i[..idx];
+            if is_reserved(id) {
+                Err(nom::Err::Error(E::from_error_kind(i, ErrorKind::Satisfy)))
+            } else {
+                Ok((&i[idx..], Ident::from_str_unchecked(id)))
+            }
+        } else {
+            Err(nom::Err::Error(E::from_error_kind(i, ErrorKind::Satisfy)))
+        }
+    } else {
+        Err(nom::Err::Error(E::from_error_kind(i, ErrorKind::Eof)))
+    }
+}
+
+named!(ascripted_arg(&str) -> Arg, do_parse!(
+    complete!(char!('(')) >>
+        multispace0 >>
+        ident: ident >>
+        multispace0 >>
+        complete!(char!(':')) >>
+        multispace0 >>
+        type_: type_ >>
+        multispace0 >>
+        complete!(char!(')')) >>
+        (Arg {
+            ident,
+            type_: Some(type_)
+        })
+));
+
+named!(arg(&str) -> Arg, alt!(
+    ident => { |ident| Arg {ident, type_: None}} |
+    ascripted_arg
+));
+
+named!(extern_decl(&str) -> Decl, do_parse!(
+    complete!(tag!("extern"))
+        >> multispace1
+        >> name: ident
+        >> multispace0
+        >> char!(':')
+        >> multispace0
+        >> type_: function_type
+        >> multispace0
+        >> (Decl::Extern {
+            name,
+            type_
+        })
+));
+
+named!(fun_decl(&str) -> Decl, do_parse!(
+    complete!(tag!("fn"))
+        >> multispace1
+        >> name: ident
+        >> multispace1
+        >> args: separated_list0!(multispace1, arg)
+        >> multispace0
+        >> char!('=')
+        >> multispace0
+        >> body: expr
+        >> (Decl::Fun {
+            name,
+            body: Fun {
+                args,
+                body
+            }
+        })
+));
+
+named!(ascription_decl(&str) -> Decl, do_parse!(
+    complete!(tag!("ty"))
+        >> multispace1
+        >> name: ident
+        >> multispace0
+        >> complete!(char!(':'))
+        >> multispace0
+        >> type_: type_
+        >> multispace0
+        >> (Decl::Ascription {
+            name,
+            type_
+        })
+));
+
+named!(pub decl(&str) -> Decl, alt!(
+    ascription_decl |
+    fun_decl |
+    extern_decl
+));
+
+named!(pub toplevel(&str) -> Vec<Decl>, do_parse!(
+    decls: many0!(decl)
+        >> multispace0
+        >> eof!()
+        >> (decls)));
+
+#[cfg(test)]
+mod tests {
+    use std::convert::TryInto;
+
+    use crate::ast::{BinaryOperator, Expr, FunctionType, Literal, Type};
+
+    use super::*;
+    use expr::tests::ident_expr;
+
+    #[test]
+    fn fn_decl() {
+        let res = test_parse!(decl, "fn id x = x");
+        assert_eq!(
+            res,
+            Decl::Fun {
+                name: "id".try_into().unwrap(),
+                body: Fun {
+                    args: vec!["x".try_into().unwrap()],
+                    body: *ident_expr("x"),
+                }
+            }
+        )
+    }
+
+    #[test]
+    fn ascripted_fn_args() {
+        test_parse!(ascripted_arg, "(x : int)");
+        let res = test_parse!(decl, "fn plus1 (x : int) = x + 1");
+        assert_eq!(
+            res,
+            Decl::Fun {
+                name: "plus1".try_into().unwrap(),
+                body: Fun {
+                    args: vec![Arg {
+                        ident: "x".try_into().unwrap(),
+                        type_: Some(Type::Int),
+                    }],
+                    body: Expr::BinaryOp {
+                        lhs: ident_expr("x"),
+                        op: BinaryOperator::Add,
+                        rhs: Box::new(Expr::Literal(Literal::Int(1))),
+                    }
+                }
+            }
+        );
+    }
+
+    #[test]
+    fn multiple_decls() {
+        let res = test_parse!(
+            toplevel,
+            "fn id x = x
+             fn plus x y = x + y
+             fn main = plus (id 2) 7"
+        );
+        assert_eq!(res.len(), 3);
+        let res = test_parse!(
+            toplevel,
+            "fn id x = x\nfn plus x y = x + y\nfn main = plus (id 2) 7\n"
+        );
+        assert_eq!(res.len(), 3);
+    }
+
+    #[test]
+    fn top_level_ascription() {
+        let res = test_parse!(toplevel, "ty id : fn a -> a");
+        assert_eq!(
+            res,
+            vec![Decl::Ascription {
+                name: "id".try_into().unwrap(),
+                type_: Type::Function(FunctionType {
+                    args: vec![Type::Var("a".try_into().unwrap())],
+                    ret: Box::new(Type::Var("a".try_into().unwrap()))
+                })
+            }]
+        )
+    }
+
+    #[test]
+    fn return_unit() {
+        assert_eq!(
+            test_parse!(decl, "fn g _ = ()"),
+            Decl::Fun {
+                name: "g".try_into().unwrap(),
+                body: Fun {
+                    args: vec![Arg {
+                        ident: "_".try_into().unwrap(),
+                        type_: None,
+                    }],
+                    body: Expr::Literal(Literal::Unit),
+                },
+            }
+        )
+    }
+}