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
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
use std::fmt;
use crate::r#type::{
Type,
TypeError,
FunDefError,
PatFail,
Type::*,
TypeError::*,
FunDefError::*,
PatFail::*
};
impl fmt::Display for Type {
/// Formats the type for display to the programmer
/// using this programming language.
///
/// Examples:
/// ```rust
/// use myslip::r#type::{Type::*, util::*};
/// assert_eq!(Integer.to_string(), "Int".to_string());
/// assert_eq!(Boolean.to_string(), "Bool".to_string());
/// assert_eq!(arr(Integer, Boolean).to_string(), "(Int -> Bool)".to_string());
/// assert_eq!(List(vec![Integer, Boolean, Integer]).to_string(), "(Int Bool Int)".to_string());
/// ```
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Integer => write!(f, "{}", "Int"),
Boolean => write!(f, "{}", "Bool"),
QuoteTy => write!(f, "{}", "Quote"),
VecType => write!(f, "{}", "Vector"),
LetType => write!(f, "{}", "Let"),
NilType => write!(f, "Nil"),
TypeLit => write!(f, "Type"),
VecOf(ty) => write!(f, "({} ...)", *ty),
Arrow(a, b) => write!(f, "({} -> {})", a, b),
List(types) => write!(
f,
"({})",
types.into_iter()
.map(|t| t.to_string())
.collect::<Vec<String>>()
.join(" ")
),
VarType(name) => write!(f, "{}", name),
}
}
}
impl fmt::Display for TypeError {
/// Formats this type error for display to humans.
///
/// Examples:
/// ```rust
/// use myslip::r#type::{TypeError::*, Type::*, util::*};
/// use myslip::sexp::{SExp, SExp::*, SLeaf::*, util::*};
///
/// assert_eq!(
/// UndefinedVariable(String::from("x")).to_string(),
/// "undefined variable: 'x'".to_string()
/// );
/// assert_eq!(
/// InvalidOperator {
/// operator: Atom(Int(1)),
/// expected: arr(VarType("?".to_string()), VarType("?".to_string())),
/// found: Integer
/// }.to_string(),
/// "invalid operator: '1'\nexpected: '(? -> ?)'\nfound: 'Int'".to_string()
/// );
/// assert_eq!(
/// InvalidArgList {
/// arglist: scons(1, scons(2, scons(3, Nil))),
/// expected: List(vec![Integer, Integer]),
/// found: List(vec![Integer, Integer, Integer]),
/// }.to_string(),
/// "invalid argument list: '(1 2 3)'\nexpected: '(Int Int)'\nfound: '(Int Int Int)'".to_string()
/// );
/// assert_eq!(
/// UnboundGeneric(String::from("?")).to_string(),
/// "unbound generic type: '?'".to_string()
/// );
/// assert_eq!(
/// ArgumentsDontMatchGeneric {
/// argtype: Integer,
/// generictype: arr(VarType("T".to_string()), Integer)
/// }.to_string(),
/// "incompatible argument type 'Int' and generic operator type '(T -> Int)'".to_string()
/// );
/// ```
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
UndefinedVariable(name) => write!(f, "undefined variable: '{}'", name),
UnboundGeneric(name) => write!(f, "unbound generic type: '{}'", name),
InvalidOperator { operator, expected, found } => {
write!(
f,
"invalid operator: '{}'\nexpected: '{}'\nfound: '{}'",
operator, expected, found
)
},
InvalidArgList { arglist, expected, found } => {
write!(
f,
"invalid argument list: '{}'\nexpected: '{}'\nfound: '{}'",
arglist, expected, found
)
},
InvalidPattern(ty) => write!(f, "invalid pattern: {ty}"),
ArgumentsDontMatchGeneric { argtype, generictype } => {
write!(
f,
"incompatible argument type '{}' and generic operator type '{}'",
argtype, generictype
)
},
LetAsOperator(letexp) => {
write!(
f,
"let used as operator instead of generating an operator: maybe try '({} ...)' instead",
letexp
)
},
DifferentTypeCaseArms(ty1, ty2) => write!(f, "arms of match have different types, '{ty1}' and '{ty2}'"),
FunAsAtom => write!(f, "'fn' used as atom doesn't make sense"),
CaseAsAtom => write!(f, "'case' used as atom doesn't make sense"),
RestAsAtom => write!(f, "'..[name]' used as atom doesn't make sense"),
InvalidFunDef(exp, err) => write!(f, "invalid function definition '{exp}': {err}"),
NoWildcardInCase(exp) => write!(f, "no wildcard in cases: '{exp}'"),
OtherError => write!(f, "uncategorized error"),
}
}
}
impl fmt::Display for PatFail {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
RestNotAtEnd(exp) =>
write!(f, "rest pattern should be at end in '{exp}'"),
NoArm(exp) =>
write!(f, "'{exp}' should consist of a pattern and a respective arm"),
RepeatedVariable(name, exp_in) =>
write!(f, "repeated pattern variable '{name}' in '{exp_in}'"),
TypeMismatch { pattern, expected, found } =>
write!(
f,
"type mismatch in '{}' — expected type '{}', found '{}'",
pattern,
expected,
found,
),
}
}
}
impl fmt::Display for FunDefError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
NoFunToken =>
write!(
f,
"no '{}'-token at start of definition",
crate::sexp::SLeaf::Fun
),
NoArgumentList =>
write!(
f,
"no list of argument names"
),
NoTypeList =>
write!(
f,
"no list of argument types"
),
NoReturnType =>
write!(
f,
"no return type supplied"
),
NoFunctionBody =>
write!(
f,
"function has no body"
),
InvalidArgumentList => write!(f, "invalid argument list"),
InvalidTypeList => write!(f, "invalid argument type list"),
InvalidReturnType => write!(f, "invalid return type"),
}
}
}
|
