implemented 'bind' for macros

lib/core/macros.nim

@@ -91,7 +91,7 @@ type
 const
   nnkLiterals* = {nnkCharLit..nnkNilLit}
   nnkCallKinds* = {nnkCall, nnkInfix, nnkPrefix, nnkPostfix, nnkCommand,
-                      nnkCallStrLit}
+                   nnkCallStrLit}
 
 # Nodes should be reference counted to make the `copy` operation very fast!
 # However, this is difficult to achieve: modify(n[0][1]) should propagate to
@@ -185,6 +185,10 @@ proc newIdentNode*(i: string): PNimrodNode {.compileTime.} =
   ## creates an identifier node from `i`
   result = newNimNode(nnkIdent)
   result.ident = !i
+
+proc bindSym*(ident: string): PNimrodNode {.magic: "NGetBoundSym".}
+  ## creates a node that binds `ident` to a symbol node. The bound symbol
+  ## needs to be predeclared in a ``bind`` statement!
 
 proc toStrLit*(n: PNimrodNode): PNimrodNode {.compileTime.} =
   ## converts the AST `n` to the concrete Nimrod code and wraps that 
@@ -249,6 +253,14 @@ proc expectLen*(n: PNimrodNode, len: int) {.compileTime.} =
   ## compilation aborts with an error message. This is useful for writing
   ## macros that check its number of arguments. 
   if n.len != len: error("macro expects a node with " & $len & " children")
+
+proc newCall*(theProc: PNimrodNode,
+              args: varargs[PNimrodNode]): PNimrodNode {.compileTime.} =
+  ## produces a new call node. `theProc` is the proc that is called with
+  ## the arguments ``args[0..]``.
+  result = newNimNode(nnkCall)
+  result.add(theProc)
+  result.add(args)
 
 proc newCall*(theProc: TNimrodIdent,
               args: varargs[PNimrodNode]): PNimrodNode {.compileTime.} =

lib/pure/terminal.nim

@@ -319,23 +319,22 @@ proc isatty*(f: TFile): bool =
   
   result = isatty(fileHandle(f)) != 0'i32
 
-# XXX: 
-# These should be private, but there is no yet 
-# facility for binding local symbols within macros
-proc styledEchoProcessArg*(s: string)               = write stdout, s
-proc styledEchoProcessArg*(style: TStyle)           = setStyle({style})
-proc styledEchoProcessArg*(style: set[TStyle])      = setStyle style
-proc styledEchoProcessArg*(color: TForegroundColor) = setForeGroundColor color
-proc styledEchoProcessArg*(color: TBackgroundColor) = setBackGroundColor color
+proc styledEchoProcessArg(s: string)               = write stdout, s
+proc styledEchoProcessArg(style: TStyle)           = setStyle({style})
+proc styledEchoProcessArg(style: set[TStyle])      = setStyle style
+proc styledEchoProcessArg(color: TForegroundColor) = setForeGroundColor color
+proc styledEchoProcessArg(color: TBackgroundColor) = setBackGroundColor color
 
 macro styledEcho*(m: stmt): stmt =
+  bind styledEchoProcessArg, write, resetAttributes, stdout
+  
   result = newNimNode(nnkStmtList)
 
   for i in countup(1, m.len - 1):
-    result.add(newCall(!"styledEchoProcessArg", m[i]))
+    result.add(newCall(bindSym"styledEchoProcessArg", m[i]))
 
-  result.add(newCall(!"write", newIdentNode("stdout"), newStrLitNode("\n")))
-  result.add(newCall(!"resetAttributes"))
+  result.add(newCall(bindSym"write", bindSym"stdout", newStrLitNode("\n")))
+  result.add(newCall(bindSym"resetAttributes"))
 
 when isMainModule:
   system.addQuitProc(resetAttributes)
@@ -347,3 +346,5 @@ when isMainModule:
   setForeGroundColor(fgBlue)
   writeln(stdout, "ordinary text")
 
+  styledEcho("styled text ", {styleBright, styleBlink, styleUnderscore}) 
+