From 9b95ca407d38fecb23a39cf0f6d92ed838e57623 Mon Sep 17 00:00:00 2001
From: Zahary Karadjov <zahary@gmail.comy>
Date: Wed, 7 Sep 2011 15:47:03 +0300
Subject: Some very small steps towards an uuid generation module.

I did some basic research on cross-platform UUID generation and didn't want to lose any information, so this code only represents what I learned (uuidMacTime should work tho).
---
 lib/pure/uuid.nim | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 lib/pure/uuid.nim

(limited to 'lib/pure')

diff --git a/lib/pure/uuid.nim b/lib/pure/uuid.nim
new file mode 100644
index 000000000..36fa9e445
--- /dev/null
+++ b/lib/pure/uuid.nim
@@ -0,0 +1,30 @@
+# This module implements the RFC 4122 specification for generating universally unique identifiers
+# http://en.wikipedia.org/wiki/Universally_unique_identifier
+
+# This module is a work-in-progress
+# If you want to help with the implementation, take a loot at:
+# http://dsource.org/projects/tango/docs/current/tango.util.uuid.Uuid.html
+
+type TUuid* = array[0..15, char]
+
+when defined(windows):
+  # This is actually available only on Windows 2000+
+  type PUuid* {.importc: "UUID __RPC_FAR *", header: "<Rpc.h>".} = ptr TUuid
+  proc uuid1Sys*(uuid: PUuid) {.importc: "UuidCreateSequential", header: "<Rpc.h>".}
+
+else:
+  type PUuid {.importc: "uuid_t", header: "<uuid/uuid.h>".} = ptr TUuid
+  proc uuid1Sys*(uuid: PUuid) {.importc: "uuid_generate_time", header: "<uuid/uuid.h>".}
+
+# v1 UUIDs include the MAC address of the machine generating the ID and a timestamp
+# This scheme has the strongest guaranty of uniqueness, but discloses when the ID was generated
+proc uuidMacTime* : TUuid = uuid1Sys(addr(result))
+
+# v4 UUID are created entirely using a random number generator.
+# Some bits have fixed value in order to indicate the UUID type
+proc uuidRandom*[RandomGenerator](rand: RandomGenerator) : TUuid = nil
+
+# v3 and v5 UUIDs are derived from given namespace and name using a secure hashing algorithm.
+# v3 uses MD5, v5 uses SHA1.
+proc uuidByName*[Hash](namespace: TUuid, name: string, hasher: Hash, v: int) : TUuid = nil
+
-- 
cgit 1.4.1-2-gfad0


From dbcca9b3b994e3339c9a03c3846b7162147679fd Mon Sep 17 00:00:00 2001
From: Zahary Karadjov <zahary@gmail.comy>
Date: Wed, 7 Sep 2011 22:05:21 +0300
Subject: Moved the parseAST magics to evals.nim

Added string interpolation helper routines in parserutils

Added a proof-of-concept string interpolation user-land macros (currently, only as a test case):
  the interpolated expression could either be transformed to
  concat("literal string ", $(interpolated), " end") or
  "literal string $1 end" % [$(interpolated)]

Added a very initial definition of Optional[T] generic type

A new overload of ParseIdent was added in hope to get around the fact that the
old one doesn't work correctly in macros, but the problem persists.
---
 compiler/evals.nim                 | 29 +++++++++++-
 compiler/semexprs.nim              | 42 +++---------------
 compiler/semfold.nim               |  1 +
 lib/pure/parseutils.nim            | 91 ++++++++++++++++++++++++++++++++++++++
 lib/system.nim                     |  9 +++-
 tests/accept/run/tstringinterp.nim | 82 ++++++++++++++++++++++++++++++++++
 6 files changed, 215 insertions(+), 39 deletions(-)
 create mode 100644 tests/accept/run/tstringinterp.nim

(limited to 'lib/pure')

diff --git a/compiler/evals.nim b/compiler/evals.nim
index a61bd24cf..65c64f4d3 100755
--- a/compiler/evals.nim
+++ b/compiler/evals.nim
@@ -16,7 +16,7 @@
 import 
   strutils, magicsys, lists, options, ast, astalgo, trees, treetab, nimsets, 
   msgs, os, condsyms, idents, renderer, types, passes, semfold, transf, 
-  ropes
+  parser, ropes
 
 type 
   PStackFrame* = ref TStackFrame
@@ -752,6 +752,31 @@ proc evalRepr(c: PEvalContext, n: PNode): PNode =
 proc isEmpty(n: PNode): bool = 
   result = (n != nil) and (n.kind == nkEmpty)
 
+# The lexer marks multi-line strings as residing at the line where they are closed
+# This function returns the line where the string begins
+# Maybe the lexer should mark both the beginning and the end of expressions, then
+# this function could be removed
+proc stringStartingLine(s: PNode): int =
+  var totalLines = 0
+  for ln in splitLines(s.strVal): inc totalLines
+
+  result = s.info.line - totalLines
+
+proc evalParseExpr(c: PEvalContext, n: Pnode): Pnode =
+  var code = evalAux(c, n.sons[1], {})
+  var ast = parseString(code.getStrValue, code.info.toFilename, code.stringStartingLine)
+
+  if sonsLen(ast) != 1:
+    GlobalError(code.info, errExprExpected, "multiple statements")
+
+  result = ast.sons[0]
+  result.typ = newType(tyExpr, c.module)
+
+proc evalParseStmt(c: PEvalContext, n: Pnode): Pnode =
+  var code = evalAux(c, n.sons[1], {})
+  result = parseString(code.getStrValue, code.info.toFilename, code.stringStartingLine)
+  result.typ = newType(tyStmt, c.module)
+
 proc evalMagicOrCall(c: PEvalContext, n: PNode): PNode = 
   var m = getMagic(n)
   case m
@@ -776,6 +801,8 @@ proc evalMagicOrCall(c: PEvalContext, n: PNode): PNode =
   of mAppendStrCh: result = evalAppendStrCh(c, n)
   of mAppendStrStr: result = evalAppendStrStr(c, n)
   of mAppendSeqElem: result = evalAppendSeqElem(c, n)
+  of mParseExprToAst: result = evalParseExpr(c, n)
+  of mParseStmtToAst: result = evalParseStmt(c, n)
   of mNLen: 
     result = evalAux(c, n.sons[1], {efLValue})
     if isSpecial(result): return 
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index 5f4c7749a..af4d4b6bc 100755
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -889,44 +889,16 @@ proc setMs(n: PNode, s: PSym): PNode =
   n.sons[0].info = n.info
 
 proc expectStringArg(c: PContext, n: PNode, i: int): PNode =
-  result = c.semConstExpr(c, n.sons[i+1])
+  result = c.semAndEvalConstExpr(n.sons[i+1])
 
   if result.kind notin {nkStrLit, nkRStrLit, nkTripleStrLit}:
-     GlobalError(result.info, errStringLiteralExpected)
+    GlobalError(result.info, errStringLiteralExpected)
 
-# The lexer marks multi-line strings as residing at the line where they are closed
-# This function returns the line where the string begins
-# Maybe the lexer should mark both the beginning and the end of expressions, then
-# this function could be removed
-proc stringStartingLine(s: PNode): int =
-  var totalLines = 0
-  for ln in splitLines(s.strVal): inc totalLines
-
-  result = s.info.line - totalLines
-
-proc semParseExprToAst(c: PContext, n: PNode, flags: TExprFlags): PNode =
-  if sonsLen(n) == 2:
-    var code = expectStringArg(c, n, 0)
-    var ast = parseString(code.strVal, code.info.toFilename, code.stringStartingLine)
-
-    if sonsLen(ast) != 1:
-      GlobalError(code.info, errExprExpected, "multiple statements")
-
-    result = newMetaNodeIT(ast.sons[0], code.info, newTypeS(tyExpr, c))
-  else:
-    result = semDirectOp(c, n, flags)
-
-proc semParseStmtToAst(c: PContext, n: PNode, flags: TExprFlags): PNode =
+proc semExpandMacroToAst(c: PContext, n: PNode, flags: TExprFlags): PNode =
   if sonsLen(n) == 2:
-    var code = expectStringArg(c, n, 0)
-    var ast = parseString(code.strVal, code.info.toFilename, code.stringStartingLine)
+    if not isCallExpr(n.sons[1]):
+      GlobalError(n.info, errXisNoMacroOrTemplate, n.renderTree)
 
-    result = newMetaNodeIT(ast, code.info, newTypeS(tyStmt, c))
-  else:
-    result = semDirectOp(c, n, flags)
-
-proc semExpandMacroToAst(c: PContext, n: PNode, flags: TExprFlags): PNode =
-  if sonsLen(n) == 2 and isCallExpr(n.sons[1]):
     var macroCall = n.sons[1]
 
     var s = qualifiedLookup(c, macroCall.sons[0], {checkUndeclared})
@@ -943,7 +915,7 @@ proc semExpandMacroToAst(c: PContext, n: PNode, flags: TExprFlags): PNode =
     var macroRetType = newTypeS(s.typ.sons[0].kind, c)
     result = newMetaNodeIT(expanded, n.info, macroRetType)
   else:
-    GlobalError(n.info, errXisNoMacroOrTemplate, n.renderTree)
+    result = semDirectOp(c, n, flags)
 
 proc semSlurp(c: PContext, n: PNode, flags: TExprFlags): PNode = 
   if sonsLen(n) == 2:
@@ -981,8 +953,6 @@ proc semMagic(c: PContext, n: PNode, s: PSym, flags: TExprFlags): PNode =
     else:
       result = semDirectOp(c, n, flags)
   of mSlurp: result = semSlurp(c, n, flags)
-  of mParseExprToAst: result = semParseExprToAst(c, n, flags)
-  of mParseStmtToAst: result = semParseStmtToAst(c, n, flags)
   of mExpandMacroToAst: result = semExpandMacroToAst(c, n, flags)
   else: result = semDirectOp(c, n, flags)
 
diff --git a/compiler/semfold.nim b/compiler/semfold.nim
index 61e63a69f..570656a39 100755
--- a/compiler/semfold.nim
+++ b/compiler/semfold.nim
@@ -208,6 +208,7 @@ proc evalOp(m: TMagic, n, a, b, c: PNode): PNode =
   of mNewString, mNewStringOfCap, 
      mExit, mInc, ast.mDec, mEcho, mAssert, mSwap, mAppendStrCh, 
      mAppendStrStr, mAppendSeqElem, mSetLengthStr, mSetLengthSeq, 
+     mParseExprToAst, mParseStmtToAst,
      mNLen..mNError, mEqRef: 
     nil
   else: InternalError(a.info, "evalOp(" & $m & ')')
diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim
index d3346ecde..a046aff36 100755
--- a/lib/pure/parseutils.nim
+++ b/lib/pure/parseutils.nim
@@ -76,6 +76,19 @@ proc parseIdent*(s: string, ident: var string, start = 0): int =
     ident = substr(s, start, i-1)
     result = i-start
 
+proc parseIdent*(s: string, start = 0): TOptional[string] =
+  ## parses an identifier and stores it in ``ident``. Returns
+  ## the number of the parsed characters or 0 in case of an error.
+  result.hasValue = false
+  var i = start
+
+  if s[i] in IdentStartChars:
+    inc(i)
+    while s[i] in IdentChars: inc(i)
+    
+    result.hasValue = true
+    result.value = substr(s, start, i-1)
+
 proc parseToken*(s: string, token: var string, validChars: set[char],
                  start = 0): int {.inline, deprecated.} =
   ## parses a token and stores it in ``token``. Returns
@@ -254,4 +267,82 @@ proc parseFloat*(s: string, number: var float, start = 0): int {.
   result = parseBiggestFloat(s, bf, start)
   number = bf
   
+proc isEscaped*(s: string, pos: int) : bool =
+  assert pos >= 0 and pos < s.len
+
+  var
+    backslashes = 0
+    j = pos - 1
+
+  while j >= 0:
+    if s[j] == '\\':
+      inc backslashes
+      dec j
+    else:
+      break
+
+  return backslashes mod 2 != 0
+
+type
+  TInterpStrFragment* = tuple[interpStart, interpEnd, exprStart, exprEnd: int]
+
+iterator interpolatedFragments*(s: string): TInterpStrFragment =
+  var i = 0
+  while i < s.len:
+    # The $ sign marks the start of an interpolation.
+    #
+    # It's followed either by a varialbe name or an opening bracket 
+    # (so it should be before the end of the string)
+    # if the dollar sign is escaped, don't trigger interpolation
+    if s[i] == '$' and i < (s.len - 1) and not isEscaped(s, i):
+      var next = s[i+1]
+      
+      if next == '{':
+        inc i
+
+        var
+          brackets = {'{', '}'}
+          nestingCount = 1
+          start = i + 1
+
+        # find closing braket, while respecting any nested brackets
+        while i < s.len:
+          inc i, skipUntil(s, brackets, i+1) + 1
+          
+          if not isEscaped(s, i):
+            if s[i] == '}':
+              dec nestingCount
+              if nestingCount == 0: break
+            else:
+              inc nestingCount
+
+        var t : TInterpStrFragment
+        t.interpStart = start - 2
+        t.interpEnd = i
+        t.exprStart = start
+        t.exprEnd = i - 1
+
+        yield t
+        
+      else:
+        var 
+          start = i + 1
+          identifier = parseIdent(s, i+1)
+        
+        if identifier.hasValue:
+          inc i, identifier.value.len
+
+          var t : TInterpStrFragment
+          t.interpStart = start - 1
+          t.interpEnd = i
+          t.exprStart = start
+          t.exprEnd = i
+
+          yield t
+
+        else:
+          raise newException(EInvalidValue, "Unable to parse a varible name at " & s[i..s.len])
+       
+    inc i
+
 {.pop.}
diff --git a/lib/system.nim b/lib/system.nim
index 2e754ece7..3fc4733b2 100755
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -710,7 +710,7 @@ proc `&` * (x, y: string): string {.
 proc `&` * (x: char, y: string): string {.
   magic: "ConStrStr", noSideEffect, merge.}
   ## is the `concatenation operator`. It concatenates `x` and `y`.
-  
+
 # implementation note: These must all have the same magic value "ConStrStr" so
 # that the merge optimization works properly. 
 
@@ -895,7 +895,12 @@ type # these work for most platforms:
   PFloat64* = ptr Float64 ## an alias for ``ptr float64``
   PInt64* = ptr Int64 ## an alias for ``ptr int64``
   PInt32* = ptr Int32 ## an alias for ``ptr int32``
-  
+
+type TOptional*[T] = object
+  case hasValue* : bool
+  of true: value*: T
+  of false: nil
+ 
 proc toFloat*(i: int): float {.
   magic: "ToFloat", noSideEffect, importc: "toFloat".}
   ## converts an integer `i` into a ``float``. If the conversion
diff --git a/tests/accept/run/tstringinterp.nim b/tests/accept/run/tstringinterp.nim
new file mode 100644
index 000000000..83bd37709
--- /dev/null
+++ b/tests/accept/run/tstringinterp.nim
@@ -0,0 +1,82 @@
+discard """
+  file: "tstringinterp.nim"
+  output: "Hello Alice \$ 64 | Hello Bob, 10"
+"""
+
+import macros, parseutils, strutils
+
+proc concat(strings: openarray[string]) : string =
+  result = newString(0)
+  for s in items(strings): result.add(s)
+
+# This will run though the intee
+template ProcessInterpolations(e: expr) =
+  var 
+    s = e[1].strVal
+    stringStart = 0
+ 
+  for i in interpolatedFragments(s):
+    var leadingString = s[stringStart..i.interpStart-1]
+    var interpolatedExpr = s[i.exprStart..i.exprEnd]
+
+    addString(leadingString)
+
+    var interpTargetAst = parseExpr("$(x)")
+    interpTargetAst[1][0] = parseExpr(interpolatedExpr)
+    addExpr(interpTargetAst)
+    
+    stringStart = i.interpEnd + 1
+
+  if stringStart != s.len:
+    var endingString = s[stringStart..s.len]
+    addString(endingString)
+
+macro formatStyleInterpolation(e: expr): expr =
+  var 
+    formatString = ""
+    arrayNode = newNimNode(nnkBracket)
+    idx = 1
+
+  proc addString(s: string) =
+    formatString.add(s)
+
+  proc addExpr(e: expr) =
+    arrayNode.add(e)
+    formatString.add("$" & $(idx))
+    inc idx
+    
+  ProcessInterpolations(e)
+
+  result = parseExpr("\"x\" % [y]")
+  result[1].strVal = formatString
+  result[2] = arrayNode
+
+macro concatStyleInterpolation(e: expr): expr =
+  var args : seq[PNimrodNode]
+  newSeq(args, 0)
+
+  proc addString(s: string)  = args.add(newStrLitNode(s))
+  proc addExpr(e: expr)      = args.add(e)
+
+  ProcessInterpolations(e)
+
+  result = newCall("concat", args)
+
+###
+
+proc sum(a, b, c: int): int =
+  return (a + b + c)
+
+var 
+  alice = "Alice"
+  bob = "Bob"
+  a = 10
+  b = 20
+  c = 34
+
+var
+  s1 = concatStyleInterpolation"Hello ${alice} \$ ${sum (a, b, c)}"
+  s2 = formatStyleInterpolation"Hello ${bob}, ${sum (alice.len, bob.len, 2)}"
+
+write(stdout, s1 & " | " & s2)
+
-- 
cgit 1.4.1-2-gfad0


From 9acfc43119d42d7265497fd6ae60eda3903d9938 Mon Sep 17 00:00:00 2001
From: Zahary Karadjov <zahary@gmail.comy>
Date: Sun, 11 Sep 2011 21:43:12 +0300
Subject: using statement (ala C#) implemented as macro (added as test).

simplified the usage of the interpolatedFragments iterator.
---
 compiler/parser.nim                  |   3 +-
 compiler/semexprs.nim                |   2 +-
 lib/pure/parseutils.nim              |  69 ++++++++++++++----------
 tests/accept/run/tstringinterp.nim   |  25 +++------
 tests/accept/run/tusingstatement.nim | 102 +++++++++++++++++++++++++++++++++++
 5 files changed, 152 insertions(+), 49 deletions(-)
 create mode 100644 tests/accept/run/tusingstatement.nim

(limited to 'lib/pure')

diff --git a/compiler/parser.nim b/compiler/parser.nim
index c371e09cb..df21c9916 100755
--- a/compiler/parser.nim
+++ b/compiler/parser.nim
@@ -1381,6 +1381,7 @@ proc parseString(s: string, filename: string = "", line: int = 0): PNode =
 
   var parser : TParser
   OpenParser(parser, filename, stream)
-  
+
   result = parser.parseAll
+  CloseParser(parser)
   
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index af4d4b6bc..6dbbba7b8 100755
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -903,7 +903,7 @@ proc semExpandMacroToAst(c: PContext, n: PNode, flags: TExprFlags): PNode =
 
     var s = qualifiedLookup(c, macroCall.sons[0], {checkUndeclared})
     if s == nil:
-      GlobalError(n.info, errUndeclaredIdentifier, macroCall.sons[0].strVal)
+      GlobalError(n.info, errUndeclaredIdentifier, macroCall.sons[0].renderTree)
 
     var expanded : Pnode
 
diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim
index a046aff36..1f4e54b96 100755
--- a/lib/pure/parseutils.nim
+++ b/lib/pure/parseutils.nim
@@ -76,18 +76,17 @@ proc parseIdent*(s: string, ident: var string, start = 0): int =
     ident = substr(s, start, i-1)
     result = i-start
 
-proc parseIdent*(s: string, start = 0): TOptional[string] =
-  ## parses an identifier and stores it in ``ident``. Returns
-  ## the number of the parsed characters or 0 in case of an error.
-  result.hasValue = false
+proc parseIdent*(s: string, start = 0): string =
+  ## parses an identifier and stores it in ``ident``. 
+  ## Returns the parsed identifier or an empty string in case of an error.
+  result = ""
   var i = start
 
   if s[i] in IdentStartChars:
     inc(i)
     while s[i] in IdentChars: inc(i)
     
-    result.hasValue = true
-    result.value = substr(s, start, i-1)
+    result = substr(s, start, i-1)
 
 proc parseToken*(s: string, token: var string, validChars: set[char],
                  start = 0): int {.inline, deprecated.} =
@@ -284,10 +283,20 @@ proc isEscaped*(s: string, pos: int) : bool =
   return backslashes mod 2 != 0
 
 type
-  TInterpStrFragment* = tuple[interpStart, interpEnd, exprStart, exprEnd: int]
+  TInterpolatedKind* = enum
+    ikString, ikExpr
+
+  TInterpStrFragment* = tuple[kind: TInterpolatedKind, value: string]
 
 iterator interpolatedFragments*(s: string): TInterpStrFragment =
-  var i = 0
+  var 
+    i = 0
+    tokenStart = 0
+
+  proc token(kind: TInterpolatedKind, value: string): TInterpStrFragment =
+    result.kind = kind
+    result.value = value
+
   while i < s.len:
     # The $ sign marks the start of an interpolation.
     #
@@ -295,17 +304,22 @@ iterator interpolatedFragments*(s: string): TInterpStrFragment =
     # (so it should be before the end of the string)
     # if the dollar sign is escaped, don't trigger interpolation
     if s[i] == '$' and i < (s.len - 1) and not isEscaped(s, i):
+      # Interpolation starts here.
+      # Return any string that we've ran over so far.
+      if i != tokenStart:
+        yield token(ikString, s[tokenStart..i-1])
+
       var next = s[i+1]
-      
       if next == '{':
+        # Complex expression: ${foo(bar) in {1..100}}
+        # Find closing braket, while respecting any nested brackets
         inc i
+        tokenStart = i + 1
 
         var
           brackets = {'{', '}'}
           nestingCount = 1
-          start = i + 1
-
-        # find closing braket, while respecting any nested brackets
+        
         while i < s.len:
           inc i, skipUntil(s, brackets, i+1) + 1
           
@@ -316,33 +330,30 @@ iterator interpolatedFragments*(s: string): TInterpStrFragment =
             else:
               inc nestingCount
 
-        var t : TInterpStrFragment
-        t.interpStart = start - 2
-        t.interpEnd = i
-        t.exprStart = start
-        t.exprEnd = i - 1
+        yield token(ikExpr, s[tokenStart..(i-1)])
 
-        yield t
+        tokenStart = i + 1
         
       else:
-        var 
-          start = i + 1
-          identifier = parseIdent(s, i+1)
+        tokenStart = i + 1
+        var identifier = parseIdent(s, i+1)
         
-        if identifier.hasValue:
-          inc i, identifier.value.len
+        if identifier.len >  0:
+          inc i, identifier.len
 
-          var t : TInterpStrFragment
-          t.interpStart = start - 1
-          t.interpEnd = i
-          t.exprStart = start
-          t.exprEnd = i
+          yield token(ikExpr, s[tokenStart..i])
 
-          yield t
+          tokenStart = i + 1
 
         else:
           raise newException(EInvalidValue, "Unable to parse a varible name at " & s[i..s.len])
        
     inc i
+  #end while
+
+  # We've reached the end of the string without finding a new interpolation.
+  # Return the last fragment at string.
+  if i != tokenStart:
+    yield token(ikString, s[tokenStart..i])
 
 {.pop.}
diff --git a/tests/accept/run/tstringinterp.nim b/tests/accept/run/tstringinterp.nim
index 83bd37709..55baae7ec 100644
--- a/tests/accept/run/tstringinterp.nim
+++ b/tests/accept/run/tstringinterp.nim
@@ -1,6 +1,6 @@
 discard """
   file: "tstringinterp.nim"
-  output: "Hello Alice \$ 64 | Hello Bob, 10"
+  output: "Hello Alice, 64 | Hello Bob, 10"
 """
 
 import macros, parseutils, strutils
@@ -13,23 +13,12 @@ proc concat(strings: openarray[string]) : string =
 template ProcessInterpolations(e: expr) =
   var 
     s = e[1].strVal
-    stringStart = 0
- 
-  for i in interpolatedFragments(s):
-    var leadingString = s[stringStart..i.interpStart-1]
-    var interpolatedExpr = s[i.exprStart..i.exprEnd]
-
-    addString(leadingString)
-
-    var interpTargetAst = parseExpr("$(x)")
-    interpTargetAst[1][0] = parseExpr(interpolatedExpr)
-    addExpr(interpTargetAst)
     
-    stringStart = i.interpEnd + 1
-
-  if stringStart != s.len:
-    var endingString = s[stringStart..s.len]
-    addString(endingString)
+  for f in interpolatedFragments(s):
+    if f.kind  == ikString:
+      addString(f.value)
+    else:
+      addExpr(f.value)
 
 macro formatStyleInterpolation(e: expr): expr =
   var 
@@ -75,7 +64,7 @@ var
   c = 34
 
 var
-  s1 = concatStyleInterpolation"Hello ${alice} \$ ${sum (a, b, c)}"
+  s1 = concatStyleInterpolation"Hello ${alice}, ${sum (a, b, c)}}"
   s2 = formatStyleInterpolation"Hello ${bob}, ${sum (alice.len, bob.len, 2)}"
 
 write(stdout, s1 & " | " & s2)
diff --git a/tests/accept/run/tusingstatement.nim b/tests/accept/run/tusingstatement.nim
new file mode 100644
index 000000000..0017af556
--- /dev/null
+++ b/tests/accept/run/tusingstatement.nim
@@ -0,0 +1,102 @@
+discard """
+  file: "tusingstatement.nim"
+  output: "Using test.Closing test."
+"""
+
+import 
+  macros
+
+# This macro mimics the using statement from C#
+#
+# XXX: 
+#  It doen't match the C# version exactly yet.
+#  In particular, it's not recursive, which prevents it from dealing 
+#  with exceptions thrown from the variable initializers when multiple.
+#  variables are used.
+#
+#  Also, since nimrod relies less on exceptions in general, a more
+#  idiomatic definition could be:
+#  var x = init()
+#  if opened(x): 
+#    try:
+#      body
+#    finally:
+#      close(x)
+#
+#  `opened` here could be an overloaded proc which any type can define.
+#  A common practice can be returing an Optional[Resource] obj for which
+#  `opened` is defined to `optional.hasValue`
+macro using(e: expr) : stmt =
+  if e.len != 2:
+    error "Using statement: unexpected number of arguments. Got " &
+      $e.len & ", expected: 1 or more variable assignments and a block"
+
+  var args = e[0]
+  var body = e[1]
+  
+  var 
+    variables : seq[PNimrodNode]
+    closingCalls : seq[PNimrodNode]
+
+  newSeq(variables, 0)
+  newSeq(closingCalls, 0)
+
+  for i in countup(1, args.len-1):
+    if args[i].kind == nnkExprEqExpr:
+      var varName = args[i][0]
+      var varValue = args[i][1]
+ 
+      var varAssignment = newNimNode(nnkIdentDefs)
+      varAssignment.add(varName)
+      varAssignment.add(newNimNode(nnkEmpty)) # empty means no type
+      varAssignment.add(varValue)
+      variables.add(varAssignment)
+
+      closingCalls.add(newCall(!"close", varName))
+    else:
+      error "Using statement: Unexpected expression. Got " &
+        $args[i].kind & " instead of assignment."
+  
+  var varSection = newNimNode(nnkVarSection)
+  varSection.add(variables)
+
+  var finallyBlock = newNimNode(nnkStmtList)
+  finallyBlock.add(closingCalls)
+
+  # XXX: Use a template here once getAst is working properly
+  var targetAst = parseStmt"""block:
+    var
+      x = foo()
+      y = bar()
+
+    try:
+      body()
+
+    finally:
+      close x
+      close y
+  """
+
+  targetAst[0][1][0] = varSection
+  targetAst[0][1][1][0] = body
+  targetAst[0][1][1][1][0] = finallyBlock
+  
+  return targetAst
+
+type 
+  TResource* = object
+    field*: string
+
+proc openResource(param: string): TResource =
+  result.field = param
+
+proc close(r: var TResource) =
+  write(stdout, "Closing " & r.field & ".")
+
+proc use(r: var TResource) =
+  write(stdout, "Using " & r.field & ".")
+
+using(r = openResource("test")):
+  use r
+
+
-- 
cgit 1.4.1-2-gfad0