From d984032f1e219294a2f5615c38dc541ad536b113 Mon Sep 17 00:00:00 2001
From: Dominik Picheta <dominikpicheta@googlemail.com>
Date: Fri, 28 Jan 2011 01:09:41 +0000
Subject: [PATCH] Slight change for .babel file format, dependExists now checks
 for installed packages.

---
 babel.babel   |  7 ++++---
 installer.nim | 26 +++++++++++++++++---------
 parser.nim    |  6 ++++--
 3 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/babel.babel b/babel.babel
index b299cb1..0709250 100644
--- a/babel.babel
+++ b/babel.babel
@@ -1,4 +1,5 @@
 ; Babel library
+[Package]
 name          = "babel"
 version       = "0.1.0"
 author        = "Dominik Picheta"
@@ -9,8 +10,8 @@ description   = """Babel framework: Specifies a common interface for programmers
 [Library]
 Depends        = "nimrod >= 0.8.10"
 ExposedModules = "parser, installer, version" ; No need for .nim
-Files          = "babel.babel"
+;Files          = "babel.babel"
 
-;[Bin babel]
+;[Exe]
 ;Depends       = "nimrod >= 0.8.11"
-;
+;Exe           = "babel"
diff --git a/installer.nim b/installer.nim
index 326c8bc..3870d06 100644
--- a/installer.nim
+++ b/installer.nim
@@ -5,6 +5,12 @@ type
 
   TDepend = tuple[name: String, verRange: PVersionRange]
 
+proc getBabelDir(): string =
+  when defined(windows):
+    result = getHomeDir() / "babel"
+  else:
+    result = getHomeDir() / ".babel"
+
 proc getNimVersion(cmd: string = "nimrod"): String =
   var output = execProcess(cmd & " -v")
   var line = splitLines(output)[0]
@@ -28,10 +34,15 @@ proc dependExists(name: string, verRange: PVersionRange): Bool =
                          nimVer & ") doesn't satisfy dependency")
     else: return True
   else:
-    # TODO: Figure out how to check whether a package has been installed...
-    # ... Perhaps a list of all the packages that have been installed?
-    # ... or just look for the package in PATH + $nimrod/lib/babel/packageName
-    assert(False)
+    for kind, path in walkDir(getBabelDir() / "lib"):
+      if kind == pcDir:
+        var dir = path.extractFilename()
+        if dir.startsWith(name):
+          var ver = copy(dir, name.len() + 1)
+          if withinRange(newVersion(ver), verRange):
+            return True
+
+  return False
 
 proc verifyDepends(proj: TProject): seq[TDepend] =
   result = @[]
@@ -43,7 +54,7 @@ proc verifyDepends(proj: TProject): seq[TDepend] =
       nameStr = spl[0]
     elif spl.len > 1:
       nameStr = spl[0]
-      spl.del(0)
+      spl.delete(0)
       verStr  = join(spl, " ")
     else:
       raise newException(EInstall, "Incorrect dependency got: " & i)
@@ -65,10 +76,7 @@ proc createDirs(dirs: seq[string]) =
 proc copyFiles(proj: TProject) =
   # This will create a $home/.babel and lib/ or bin/. It will also copy all the
   # files listed in proj.modules and proj.files.
-  when defined(windows):
-    var babelDir = getHomeDir() / "babel"
-  else:
-    var babelDir = getHomeDir() / ".babel"
+  var babelDir = getBabelDir()
 
   var dirs = @[babelDir, babelDir / "lib", babelDir / "bin"]
 
diff --git a/parser.nim b/parser.nim
index bc7bdbf..481e805 100644
--- a/parser.nim
+++ b/parser.nim
@@ -19,7 +19,7 @@ type
 
     unknownFields*: seq[string] # TODO:
     
-  EParseErr* = object of EIO
+  EParseErr* = object of EInvalidValue
 
 proc initProj(): TProject =
   result.name = ""
@@ -63,7 +63,7 @@ proc parseBabel*(file: string): TProject =
         break
       of cfgKeyValuePair:
         case section
-        of "":
+        of "package":
           case normalize(e.key):
           of "name":
             result.name = e.value
@@ -110,6 +110,8 @@ proc parseBabel*(file: string): TProject =
           result.library = True
         of "bin":
           result.executable = True
+        of "package":
+          nil
         else:
           p.parseErr("Unknown section: " & section)