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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Paul Phillips
*/
package scala.tools.nsc
package interpreter
import scala.collection.mutable
trait Imports {
self: IMain =>
import global._
import definitions.{ ScalaPackage, JavaLangPackage, PredefModule }
import memberHandlers._
/** Synthetic import handlers for the language defined imports. */
private def makeWildcardImportHandler(sym: Symbol): ImportHandler = {
val hd :: tl = sym.fullName.split('.').toList map newTermName
val tree = Import(
tl.foldLeft(Ident(hd): Tree)((x, y) => Select(x, y)),
ImportSelector.wildList
)
tree setSymbol sym
new ImportHandler(tree)
}
/** Symbols whose contents are language-defined to be imported. */
def languageWildcardSyms: List[Symbol] = List(JavaLangPackage, ScalaPackage, PredefModule)
def languageWildcardHandlers = languageWildcardSyms map makeWildcardImportHandler
def allImportedNames = importHandlers flatMap (_.importedNames)
/** Types which have been wildcard imported, such as:
* val x = "abc" ; import x._ // type java.lang.String
* import java.lang.String._ // object java.lang.String
*
* Used by tab completion.
*
* XXX right now this gets import x._ and import java.lang.String._,
* but doesn't figure out import String._. There's a lot of ad hoc
* scope twiddling which should be swept away in favor of digging
* into the compiler scopes.
*/
def sessionWildcards: List[Type] = {
importHandlers filter (_.importsWildcard) map (_.targetType) distinct
}
def languageSymbols = languageWildcardSyms flatMap membersAtPickler
def sessionImportedSymbols = importHandlers flatMap (_.importedSymbols)
def importedSymbols = languageSymbols ++ sessionImportedSymbols
def importedTermSymbols = importedSymbols collect { case x: TermSymbol => x }
/** Tuples of (source, imported symbols) in the order they were imported.
*/
def importedSymbolsBySource: List[(Symbol, List[Symbol])] = {
val lang = languageWildcardSyms map (sym => (sym, membersAtPickler(sym)))
val session = importHandlers filter (_.targetType != NoType) map { mh =>
(mh.targetType.typeSymbol, mh.importedSymbols)
}
lang ++ session
}
def implicitSymbolsBySource: List[(Symbol, List[Symbol])] = {
importedSymbolsBySource map {
case (k, vs) => (k, vs filter (_.isImplicit))
} filterNot (_._2.isEmpty)
}
/** Compute imports that allow definitions from previous
* requests to be visible in a new request. Returns
* three or four pieces of related code:
*
* 0. Header code fragment that should go at the beginning
* of the compilation unit, specifically, import Predef.
*
* 1. An initial code fragment that should go before
* the code of the new request.
*
* 2. A code fragment that should go after the code
* of the new request.
*
* 3. An access path which can be traversed to access
* any bindings inside code wrapped by #1 and #2 .
*
* The argument is a set of Names that need to be imported.
*
* Limitations: This method is not as precise as it could be.
* (1) It does not process wildcard imports to see what exactly
* they import.
* (2) If it imports any names from a request, it imports all
* of them, which is not really necessary.
* (3) It imports multiple same-named implicits, but only the
* last one imported is actually usable.
*/
case class ComputedImports(header: String, prepend: String, append: String, access: String)
protected def importsCode(wanted: Set[Name], wrapper: Request#Wrapper, definesClass: Boolean, generousImports: Boolean): ComputedImports = {
val header, code, trailingBraces, accessPath = new StringBuilder
val currentImps = mutable.HashSet[Name]()
var predefEscapes = false // only emit predef import header if name not resolved in history, loosely
/** Narrow down the list of requests from which imports
* should be taken. Removes requests which cannot contribute
* useful imports for the specified set of wanted names.
*/
case class ReqAndHandler(req: Request, handler: MemberHandler)
def reqsToUse: List[ReqAndHandler] = {
/** Loop through a list of MemberHandlers and select which ones to keep.
* 'wanted' is the set of names that need to be imported.
*/
def select(reqs: List[ReqAndHandler], wanted: Set[Name]): List[ReqAndHandler] = {
// Single symbol imports might be implicits! See bug #1752. Rather than
// try to finesse this, we will mimic all imports for now.
def keepHandler(handler: MemberHandler) = handler match {
// While defining classes in class based mode - implicits are not needed.
case h: ImportHandler if isClassBased && definesClass => h.importedNames.exists(x => wanted.contains(x))
case _: ImportHandler => true
case x if generousImports => x.definesImplicit || (x.definedNames exists (d => wanted.exists(w => d.startsWith(w))))
case x => x.definesImplicit || (x.definedNames exists wanted)
}
reqs match {
case Nil => predefEscapes = wanted contains PredefModule.name ; Nil
case rh :: rest if !keepHandler(rh.handler) => select(rest, wanted)
case rh :: rest =>
import rh.handler._
val augment = rh match {
case ReqAndHandler(_, _: ImportHandler) => referencedNames // for "import a.b", add "a" to names to be resolved
case _ => Nil
}
val newWanted = wanted ++ augment -- definedNames -- importedNames
rh :: select(rest, newWanted)
}
}
/** Flatten the handlers out and pair each with the original request */
select(allReqAndHandlers reverseMap { case (r, h) => ReqAndHandler(r, h) }, wanted).reverse
}
// add code for a new object to hold some imports
def addWrapper() {
import nme.{ INTERPRETER_IMPORT_WRAPPER => iw }
code append (wrapper.prewrap format iw)
trailingBraces append wrapper.postwrap
accessPath append s".$iw"
currentImps.clear()
}
def maybeWrap(names: Name*) = if (names exists currentImps) addWrapper()
def wrapBeforeAndAfter[T](op: => T): T = {
addWrapper()
try op finally addWrapper()
}
// imports from Predef are relocated to the template header to allow hiding.
def checkHeader(h: ImportHandler) = h.referencedNames contains PredefModule.name
// loop through previous requests, adding imports for each one
wrapBeforeAndAfter {
// Reusing a single temporary value when import from a line with multiple definitions.
val tempValLines = mutable.Set[Int]()
for (ReqAndHandler(req, handler) <- reqsToUse) {
val objName = req.lineRep.readPathInstance
if (isReplTrace)
code.append(ss"// $objName definedNames ${handler.definedNames}, curImps $currentImps\n")
handler match {
case h: ImportHandler if checkHeader(h) =>
header.clear()
header append f"${h.member}%n"
// If the user entered an import, then just use it; add an import wrapping
// level if the import might conflict with some other import
case x: ImportHandler if x.importsWildcard =>
wrapBeforeAndAfter(code append (x.member + "\n"))
case x: ImportHandler =>
maybeWrap(x.importedNames: _*)
code append (x.member + "\n")
currentImps ++= x.importedNames
case x if isClassBased =>
for (sym <- x.definedSymbols) {
maybeWrap(sym.name)
x match {
case _: ClassHandler =>
code.append(s"import ${objName}${req.accessPath}.`${sym.name}`\n")
case _ =>
val valName = s"${req.lineRep.packageName}${req.lineRep.readName}"
if (!tempValLines.contains(req.lineRep.lineId)) {
code.append(s"val $valName: ${objName}.type = $objName\n")
tempValLines += req.lineRep.lineId
}
code.append(s"import ${valName}${req.accessPath}.`${sym.name}`\n")
}
currentImps += sym.name
}
// For other requests, import each defined name.
// import them explicitly instead of with _, so that
// ambiguity errors will not be generated. Also, quote
// the name of the variable, so that we don't need to
// handle quoting keywords separately.
case x =>
for (sym <- x.definedSymbols) {
maybeWrap(sym.name)
code append s"import ${x.path}\n"
currentImps += sym.name
}
}
}
}
val computedHeader = if (predefEscapes) header.toString else ""
ComputedImports(computedHeader, code.toString, trailingBraces.toString, accessPath.toString)
}
private def allReqAndHandlers =
prevRequestList flatMap (req => req.handlers map (req -> _))
private def membersAtPickler(sym: Symbol): List[Symbol] =
enteringPickler(sym.info.nonPrivateMembers.toList)
}
|
