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
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
#include <iostream>
#include <cstdlib>
#include <setjmp.h>
#include <readline/readline.h>
#include <readline/history.h>
#include "shared.hh"
#include "eval.hh"
#include "eval-inline.hh"
#include "store-api.hh"
#include "common-opts.hh"
using namespace std;
using namespace nix;
string programId = "nix-repl";
struct NixRepl
{
string curDir;
EvalState state;
StaticEnv staticEnv;
Env * env;
int displ;
NixRepl();
void mainLoop();
void processLine(string line);
void addAttrsToScope(Value & attrs);
void addVarToScope(const Symbol & name, Value * v);
Expr * parseString(string s);
void evalString(string s, Value & v);
};
void printHelp()
{
std::cout << "Usage: nix-repl\n";
}
/* Apparently, the only way to get readline() to return on Ctrl-C
(SIGINT) is to use siglongjmp(). That's fucked up... */
static sigjmp_buf sigintJmpBuf;
static void sigintHandler(int signo)
{
siglongjmp(sigintJmpBuf, 1);
}
bool getLine(string & line)
{
struct sigaction act, old;
act.sa_handler = sigintHandler;
sigfillset(&act.sa_mask);
act.sa_flags = 0;
if (sigaction(SIGINT, &act, &old))
throw SysError("installing handler for SIGINT");
if (sigsetjmp(sigintJmpBuf, 1))
line = "";
else {
char * s = readline("nix-repl> ");
if (!s) return false;
line = chomp(string(s));
free(s);
if (line != "") {
add_history(line.c_str());
append_history(1, 0);
}
}
_isInterrupted = 0;
if (sigaction(SIGINT, &old, 0))
throw SysError("restoring handler for SIGINT");
return true;
}
string removeWhitespace(string s)
{
s = chomp(s);
size_t n = s.find_first_not_of(" \n\r\t");
if (n != string::npos) s = string(s, n);
return s;
}
NixRepl::NixRepl()
: staticEnv(false, &state.staticBaseEnv)
{
curDir = absPath(".");
env = &state.allocEnv(32768);
env->up = &state.baseEnv;
displ = 0;
store = openStore();
}
void NixRepl::mainLoop()
{
std::cerr << "Welcome to Nix version " << NIX_VERSION << ". Type :? for help." << std::endl << std::endl;
using_history();
read_history(0);
while (true) {
string line;
if (!getLine(line)) break;
try {
processLine(removeWhitespace(line));
} catch (Error & e) {
printMsg(lvlError, e.msg());
}
std::cout << std::endl;
}
std::cout << std::endl;
}
void NixRepl::processLine(string line)
{
if (line == "") return;
if (string(line, 0, 2) == ":a") {
Value v;
evalString(string(line, 2), v);
addAttrsToScope(v);
}
else if (string(line, 0, 2) == ":l") {
state.resetFileCache();
Path path = lookupFileArg(state, removeWhitespace(string(line, 2)));
Value v, v2;
state.evalFile(path, v);
Bindings bindings;
state.autoCallFunction(bindings, v, v2);
addAttrsToScope(v2);
}
else if (string(line, 0, 2) == ":t") {
Value v;
evalString(string(line, 2), v);
std::cout << showType(v) << std::endl;
}
else if (string(line, 0, 1) == ":") {
throw Error(format("unknown command ‘%1%’") % string(line, 0, 2));
}
else {
Value v;
evalString(line, v);
state.strictForceValue(v);
std::cout << v << std::endl;
}
}
void NixRepl::addAttrsToScope(Value & attrs)
{
state.forceAttrs(attrs);
foreach (Bindings::iterator, i, *attrs.attrs)
addVarToScope(i->name, i->value);
}
void NixRepl::addVarToScope(const Symbol & name, Value * v)
{
staticEnv.vars[name] = displ;
env->values[displ++] = v;
}
Expr * NixRepl::parseString(string s)
{
Expr * e = state.parseExprFromString(s, curDir, staticEnv);
return e;
}
void NixRepl::evalString(string s, Value & v)
{
Expr * e = parseString(s);
e->eval(state, *env, v);
state.forceValue(v);
}
void run(nix::Strings args)
{
NixRepl repl;
repl.mainLoop();
}
|
