1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
use crate::r#type::{*, Type::*, TypeError::*, FunDefError::*};
use std::collections::HashMap;
pub fn arr(a: impl Into<Box<Type>>, b: impl Into<Box<Type>>) -> Type {
Arrow(a.into(), b.into())
}
pub fn vt(name: &str) -> Type {
VarType(name.to_string())
}
pub fn vecof(ty: impl Into<Box<Type>>) -> Type {
VecOf(ty.into())
}
use crate::sexp::{SExp::*, SLeaf::*};
impl SExp {
pub fn get_fun_type(self, mut ctx: HashMap<String, Type>) -> Result<Type, TypeError> {
let ls = self.clone().parts();
ls.get(0)
.filter(|t| **t == Atom(Fun))
.ok_or(InvalidFunDef(self.clone(), NoFunToken))?;
let argnames = ls.get(1)
.ok_or(InvalidFunDef(self.clone(), NoArgumentList))?
.clone().parts();
let argtype = ls.get(2)
.ok_or(InvalidFunDef(self.clone(), NoTypeList))?
.clone();
let rettype = ls.get(3)
.ok_or(InvalidFunDef(self.clone(), NoReturnType))?;
let funbody = ls.get(4)
.ok_or(InvalidFunDef(self.clone(), NoFunctionBody))?;
let mut argnamevec = vec![];
for name in argnames {
argnamevec.push(match name {
Atom(Var(s)) => Ok(s),
_ => Err(InvalidFunDef(self.clone(), InvalidArgumentList)),
}?);
}
let argtypes = match argtype {
Atom(Ty(List(v))) => Ok(v),
Atom(Ty(t)) => Ok(vec![t]),
_ => {
Err(InvalidFunDef(self.clone(), InvalidArgumentList))
},
}?;
let rettype = match rettype.clone().multistep() {
Ok(Atom(Ty(t))) => Ok(t),
_ => Err(InvalidFunDef(self.clone(), InvalidReturnType))
}?;
let additional_ctx = argnamevec.into_iter().zip(argtypes.clone());
for (name, ty) in additional_ctx {
ctx.insert(name, ty);
}
let argtype = if argtypes.len() == 0 {
NilType
} else if argtypes.len() == 1 {
argtypes[0].clone()
} else {
List(argtypes)
};
funbody.infer_type(ctx)?;
Ok(arr(argtype, rettype))
}
}
|
