Implemented `nimble c`.

readme.markdown

@@ -29,7 +29,7 @@ the following commands to clone nimble, compile it and then install it.
     git clone https://github.com/nim-lang/nimble.git
     cd nimble
     nim c -r src/nimble install
-    
+
 After these steps nimble should be compiled and installed. You should then add
 ``~/.nimble/bin`` to your ``$PATH``. Updating nimble can then be done by
 executing ``nimble install nimble``.
@@ -118,7 +118,7 @@ Example:
 Nimble always fetches and installs the latest version of a package. Note that
 latest version is defined as the latest tagged version in the git (or hg)
 repository, if the package has no tagged versions then the latest commit in the
-remote repository will be installed. If you already have that version installed 
+remote repository will be installed. If you already have that version installed
 Nimble will ask you whether you wish it to overwrite your local copy.
 
 You can force Nimble to download the latest commit from the package's repo, for
@@ -139,7 +139,7 @@ In this case a version which is greater than ``0.5`` will be installed.
 If you don't specify a parameter and there is a ``package.nimble`` file in your
 current working directory then Nimble will install the package residing in
 the current working directory. This can be useful for developers who are testing
-locally their ``.nimble`` files before submitting them to the official package 
+locally their ``.nimble`` files before submitting them to the official package
 list. See [developers.markdown](developers.markdown) for more info on this.
 
 A URL to a repository can also be specified, Nimble will automatically detect
@@ -161,6 +161,16 @@ The ``build`` command is mostly used by developers who want to test building
 their ``.nimble`` package. The ``install`` command calls ``build`` implicitly,
 so there is rarely any reason to use this command directly.
 
+### nimble c
+
+The ``c`` (or ``compile``, ``js``, ``cc``, ``cpp``) command can be used by
+developers to compile individual modules inside their package. All options
+passed to Nimble will also be passed to the Nim compiler during compilation.
+
+Nimble will use the backend specified in the package's ``.nimble`` file if
+the command ``c`` or ``compile`` is specified. The more specific ``js``, ``cc``,
+``cpp`` can be used to override that.
+
 ### nimble list
 
 The ``list`` command will display the known list of packages available for
@@ -183,7 +193,7 @@ substrings). Example:
       tags:        library, opengl, math, game
       description: OpenGL math library
       license:     CC0
-     
+
     extmath:
       url:         git://github.com/achesak/extmath.nim (git)
       tags:        library, math, trigonometry

src/nimble.nim

@@ -23,7 +23,7 @@ type
 
   ActionType = enum
     actionNil, actionUpdate, actionInit, actionInstall, actionSearch,
-    actionList, actionBuild, actionPath, actionUninstall
+    actionList, actionBuild, actionPath, actionUninstall, actionCompile
 
   Action = object
     case typ: ActionType
@@ -38,7 +38,11 @@ type
       search: seq[string] # Search string.
     of actionInit:
       projName: string
-    else:nil
+    of actionCompile:
+      file: string
+      backend: string
+      compileOptions: seq[string]
+    else: nil
 
   ForcePrompt = enum
     dontForcePrompt, forcePromptYes, forcePromptNo
@@ -52,6 +56,8 @@ Commands:
   init         [pkgname]          Initializes a new Nimble project.
   uninstall    [pkgname, ...]     Uninstalls a list of packages.
   build                           Builds a package.
+  c, cc, js    [opts, ...] f.nim  Builds a file inside a package. Passes options
+                                  to the Nim compiler.
   update       [url]              Updates package list. A package list URL can
                                   be optionally specified.
   search       [--ver] pkg/tag    Searches for a specified package. Search is
@@ -148,6 +154,12 @@ proc parseCmdLine(): Options =
           result.action.packages = @[]
         of "build":
           result.action.typ = actionBuild
+        of "c", "compile", "js", "cpp", "cc":
+          result.action.typ = actionCompile
+          result.action.compileOptions = @[]
+          result.action.file = ""
+          if key == "c" or key == "compile": result.action.backend = ""
+          else: result.action.backend = key
         of "init":
           result.action.typ = actionInit
           result.action.projName = ""
@@ -185,19 +197,28 @@ proc parseCmdLine(): Options =
             raise newException(NimbleError,
                 "Can only initialize one package at a time.")
           result.action.projName = key
+        of actionCompile:
+          result.action.file = key
         of actionList, actionBuild:
           writeHelp()
         else:
           discard
     of cmdLongOption, cmdShortOption:
-      case key
-      of "help", "h": writeHelp()
-      of "version", "v": writeVersion()
-      of "accept", "y": result.forcePrompts = forcePromptYes
-      of "reject", "n": result.forcePrompts = forcePromptNo
-      of "ver": result.queryVersions = true
-      of "installed", "i": result.queryInstalled = true
-      else: discard
+      case result.action.typ
+      of actionCompile:
+        if val == "":
+          result.action.compileOptions.add("--" & key)
+        else:
+          result.action.compileOptions.add("--" & key & ":" & val)
+      else:
+        case key
+        of "help", "h": writeHelp()
+        of "version", "v": writeVersion()
+        of "accept", "y": result.forcePrompts = forcePromptYes
+        of "reject", "n": result.forcePrompts = forcePromptNo
+        of "ver": result.queryVersions = true
+        of "installed", "i": result.queryInstalled = true
+        else: discard
     of cmdEnd: assert(false) # cannot happen
   if result.action.typ == actionNil:
     writeHelp()
@@ -640,6 +661,31 @@ proc build(options: Options) =
   let paths = processDeps(pkginfo, options)
   buildFromDir(pkgInfo, paths)
 
+proc compile(options: Options) =
+  var pkgInfo = getPkgInfo(getCurrentDir())
+  let paths = processDeps(pkginfo, options)
+  let realDir = pkgInfo.getRealDir()
+
+  var args = ""
+  for path in paths: args.add("--path:\"" & path & "\" ")
+  for option in options.action.compileOptions:
+    args.add(option & " ")
+
+  let bin = options.action.file
+  let backend =
+    if options.action.backend.len > 0:
+      options.action.backend
+    else:
+      pkgInfo.backend
+
+  if bin == "":
+    raise newException(NimbleError, "You need to specify a file to compile.")
+
+  echo("Compiling ", bin, " (", pkgInfo.name, ") using ", backend,
+       " backend...")
+  doCmd(getNimBin() & " $# --noBabelPath $# \"$#\"" %
+        [backend, args, bin])
+
 proc search(options: Options) =
   ## Searches for matches in ``options.action.search``.
   ##
@@ -855,6 +901,8 @@ proc doAction(options: Options) =
     listPaths(options)
   of actionBuild:
     build(options)
+  of actionCompile:
+    compile(options)
   of actionInit:
     init(options)
   of actionNil: