made nimresolve part of the compiler

compiler/modulepaths.nim

@@ -1,9 +1,103 @@
 #
+#
+#           The Nim Compiler
+#        (c) Copyright 2017 Contributors
+#
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
 #
 
-import ast, renderer, gorgeimpl, strutils, msgs, options, idents, ospaths
+import ast, renderer, strutils, msgs, options, idents, os
+
+import nimblecmd
+
+const
+  considerParentDirs = not defined(noParentProjects)
+  considerNimbleDirs = not defined(noNimbleDirs)
+
+proc findInNimbleDir(pkg, subdir, dir: string): string =
+  var best = ""
+  var bestv = ""
+  for k, p in os.walkDir(dir, relative=true):
+    if k == pcDir and p.len > pkg.len+1 and
+        p[pkg.len] == '-' and p.startsWith(pkg):
+      let (_, a) = getPathVersion(p)
+      if bestv.len == 0 or bestv < a:
+        bestv = a
+        best = dir / p
+
+  if best.len > 0:
+    var f: File
+    if open(f, best / changeFileExt(pkg, ".nimble-link")):
+      # the second line contains what we're interested in, see:
+      # https://github.com/nim-lang/nimble#nimble-link
+      var override = ""
+      discard readLine(f, override)
+      discard readLine(f, override)
+      close(f)
+      if not override.isAbsolute():
+        best = best / override
+      else:
+        best = override
+  let f = if subdir.len == 0: pkg else: subdir
+  let res = addFileExt(best / f, "nim")
+  if best.len > 0 and fileExists(res):
+    result = res
+
+const stdlibDirs = [
+  "pure", "core", "arch",
+  "pure/collections",
+  "pure/concurrency", "impure",
+  "wrappers", "wrappers/linenoise",
+  "windows", "posix", "js"]
+
+proc resolveDollar(project, source, pkg, subdir: string; info: TLineInfo): string =
+  template attempt(a) =
+    let x = addFileExt(a, "nim")
+    if fileExists(x): return x
+
+  case pkg
+  of "stdlib":
+    if subdir.len == 0:
+      return options.libpath
+    else:
+      for candidate in stdlibDirs:
+        attempt(options.libpath / candidate / subdir)
+  of "root":
+    let root = project.splitFile.dir
+    if subdir.len == 0:
+      return root
+    else:
+      attempt(root / subdir)
+  else:
+    when considerParentDirs:
+      var p = parentDir(source.splitFile.dir)
+      # support 'import $karax':
+      let f = if subdir.len == 0: pkg else: subdir
+
+      while p.len > 0:
+        let dir = p / pkg
+        if dirExists(dir):
+          attempt(dir / f)
+          # 2nd attempt: try to use 'karax/karax'
+          attempt(dir / pkg / f)
+          # 3rd attempt: try to use 'karax/src/karax'
+          attempt(dir / "src" / f)
+          attempt(dir / "src" / pkg / f)
+        p = parentDir(p)
+
+    when considerNimbleDirs:
+      if not options.gNoNimblePath:
+        var nimbleDir = getEnv("NIMBLE_DIR")
+        if nimbleDir.len == 0: nimbleDir = getHomeDir() / ".nimble"
+        result = findInNimbleDir(pkg, subdir, nimbleDir / "pkgs")
+        if result.len > 0: return result
+        when not defined(windows):
+          result = findInNimbleDir(pkg, subdir, "/opt/nimble/pkgs")
+          if result.len > 0: return result
+
+proc scriptableImport(pkg, sub: string; info: TLineInfo): string =
+  result = resolveDollar(gProjectFull, info.toFullPath(), pkg, sub, info)
 
 proc lookupPackage(pkg, subdir: PNode): string =
   let sub = if subdir != nil: renderTree(subdir, {renderNoComments}).replace(" ") else: ""