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1 | (* HCoop Domtool (http://hcoop.sourceforge.net/) |
2 | * Copyright (c) 2006-2007, Adam Chlipala |
3 | * |
4 | * This program is free software; you can redistribute it and/or |
5 | * modify it under the terms of the GNU General Public License |
6 | * as published by the Free Software Foundation; either version 2 |
7 | * of the License, or (at your option) any later version. |
8 | * |
9 | * This program is distributed in the hope that it will be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12 | * GNU General Public License for more details. |
13 | * |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write to the Free Software |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
17 | *) |
18 | |
19 | (* Error message generation *) |
20 | |
21 | structure Describe :> DESCRIBE = struct |
22 | |
23 | open Ast Print |
24 | |
25 | structure SM = StringMap |
26 | |
27 | exception UnequalDomains |
28 | |
29 | fun eqRecord f (r1, r2) = |
30 | (SM.appi (fn (k, v1) => |
31 | case SM.find (r2, k) of |
32 | NONE => raise UnequalDomains |
33 | | SOME v2 => |
34 | if f (v1, v2) then |
35 | () |
36 | else |
37 | raise UnequalDomains) r1; |
38 | SM.appi (fn (k, v2) => |
39 | case SM.find (r1, k) of |
40 | NONE => raise UnequalDomains |
41 | | SOME v1 => |
42 | if f (v1, v2) then |
43 | () |
44 | else |
45 | raise UnequalDomains) r2; |
46 | true) |
47 | handle UnequalDomains => false |
48 | |
49 | fun eqPred ((p1, _), (p2, _)) = |
50 | case (p1, p2) of |
51 | (CRoot, CRoot) => true |
52 | | (CConst s1, CConst s2) => s1 = s2 |
53 | | (CPrefix p1, CPrefix p2) => eqPred (p1, p2) |
54 | | (CNot p1, CNot p2) => eqPred (p1, p2) |
55 | | (CAnd (p1, q1), CAnd (p2, q2)) => |
56 | eqPred (p1, p2) andalso eqPred (q1, q2) |
57 | |
58 | | _ => false |
59 | |
60 | fun eqTy (t1All as (t1, _), t2All as (t2, _)) = |
61 | case (t1, t2) of |
62 | (TBase s1, TBase s2) => s1 = s2 |
63 | | (TList t1, TList t2) => eqTy (t1, t2) |
64 | | (TArrow (d1, r1), TArrow (d2, r2)) => |
65 | eqTy (d1, d2) andalso eqTy (r1, r2) |
66 | |
67 | | (TAction (p1, d1, r1), TAction (p2, d2, r2)) => |
68 | eqPred (p1, p2) andalso eqRecord eqTy (d1, d2) |
69 | andalso eqRecord eqTy (r1, r2) |
70 | |
71 | | (TNested (p1, q1), TNested (p2, q2)) => |
72 | eqPred (p1, p2) andalso eqTy (q1, q2) |
73 | |
74 | | (TUnif (_, ref (SOME t1)), _) => eqTy (t1, t2All) |
75 | | (_, TUnif (_, ref (SOME t2))) => eqTy (t1All, t2) |
76 | |
77 | | (TUnif (_, r1), TUnif (_, r2)) => r1 = r2 |
78 | |
79 | | (TError, TError) => true |
80 | |
81 | | _ => false |
82 | |
83 | fun describe_unification_error t ue = |
84 | case ue of |
85 | UnifyPred (p1, p2) => |
86 | (print "Reason: Incompatible contexts.\n"; |
87 | preface ("Have:", p_pred p1); |
88 | preface ("Need:", p_pred p2)) |
89 | | UnifyTyp (t1, t2) => |
90 | if eqTy (t, t1) then |
91 | () |
92 | else |
93 | (print "Reason: Incompatible types.\n"; |
94 | preface ("Have:", p_typ t1); |
95 | preface ("Need:", p_typ t2)) |
96 | | UnifyOccurs (name, t') => |
97 | if eqTy (t, t') then |
98 | () |
99 | else |
100 | (print "Reason: Occurs check failed for "; |
101 | print name; |
102 | print " in:\n"; |
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103 | output (p_typ t)) |
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104 | |
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105 | fun will_be_action (t, _) = |
106 | case t of |
107 | TArrow (_, t') => will_be_action t' |
108 | | TAction _ => true |
109 | | TNested _ => true |
110 | | TUnif (_, ref (SOME t')) => will_be_action t' |
111 | | _ => false |
112 | |
113 | fun get_first_arg (t, _) = |
114 | case t of |
115 | TArrow (t', _) => t' |
116 | | TUnif (_, ref (SOME t')) => get_first_arg t' |
117 | | _ => raise Fail "get_first_arg failed!" |
118 | |
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119 | fun hint te = |
120 | case te of |
121 | WrongType (_, _, (TBase "string", _), (TBase "your_domain", _), _) => |
122 | SOME "Did you forget to request permission to configure this domain? See:\n\thttps://members.hcoop.net/portal/domain" |
123 | | WrongType (_, (EString dom, _), (TBase "string", _), (TBase "domain", _), _) => |
124 | if CharVector.exists Char.isUpper dom then |
125 | SOME "Uppercase letters aren't allowed in domain strings." |
126 | else |
127 | NONE |
128 | | _ => NONE |
129 | |
130 | fun describe_type_error' loc te = |
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131 | case te of |
132 | WrongType (place, e, t1, t2, ueo) => |
133 | (ErrorMsg.error (SOME loc) (place ^ " has wrong type."); |
134 | preface (" Expression:", p_exp e); |
135 | preface ("Actual type:", p_typ t1); |
136 | preface ("Needed type:", p_typ t2); |
137 | Option.app (describe_unification_error t1) ueo) |
138 | | WrongForm (place, form, e, t, ueo) => |
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139 | if form = "action" andalso will_be_action t then |
140 | (ErrorMsg.error (SOME loc) "Not enough arguments passed to configuration function."; |
141 | preface (" Expression so far:", p_exp e); |
142 | preface ("Next argument type:", p_typ (get_first_arg t))) |
143 | else |
144 | (ErrorMsg.error (SOME loc) (place ^ " has a non-" ^ form ^ " type."); |
145 | preface ("Expression:", p_exp e); |
146 | preface (" Type:", p_typ t); |
147 | Option.app (describe_unification_error t) ueo) |
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148 | | UnboundVariable name => |
149 | ErrorMsg.error (SOME loc) ("Unbound variable " ^ name ^ ".\n") |
150 | | WrongPred (place, p1, p2) => |
151 | (ErrorMsg.error (SOME loc) ("Context incompatibility for " ^ place ^ "."); |
152 | preface ("Have:", p_pred p1); |
153 | preface ("Need:", p_pred p2)) |
154 | |
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155 | fun ununify (tAll as (t, _)) = |
156 | case t of |
157 | TUnif (_, ref (SOME t)) => ununify t |
158 | | _ => tAll |
159 | |
160 | fun normalize_error err = |
161 | case err of |
162 | WrongType (s, e, t1, t2, ueo) => |
163 | WrongType (s, e, ununify t1, ununify t2, ueo) |
164 | | WrongForm (s1, s2, e, t, ueo) => |
165 | WrongForm (s1, s2, e, ununify t, ueo) |
166 | | UnboundVariable _ => err |
167 | | WrongPred _ => err |
168 | |
169 | fun describe_type_error loc te = |
170 | let |
171 | val te = normalize_error te |
172 | in |
173 | describe_type_error' loc te; |
174 | Option.app (fn s => (print "Hint Monster says:\n"; |
175 | print s; |
176 | print "\n")) |
177 | (hint te) |
178 | end |
179 | |
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180 | end |