Merge branch 'master' of github.com:Araq/Nimrod

lib/core/macros.nim

@@ -209,6 +209,17 @@ proc getAst*(macroOrTemplate: expr): expr {.magic: "ExpandToAst".}
   ##   macro FooMacro() = 
   ##     var ast = getAst(BarTemplate())
 
+template emit*(s: expr): stmt =
+  ## accepts a single sting argument and treats it as nimrod code
+  ## that should be inserted verbatim in the program
+  ## Example:
+  ## 
+  ##   emit("echo " & '"' & "hello world".toUpper & '"')
+  ##
+  block:
+    const evaluated = s
+    eval: result = evaluated.parseStmt
+
 proc expectKind*(n: PNimrodNode, k: TNimrodNodeKind) {.compileTime.} =
   ## checks that `n` is of kind `k`. If this is not the case,
   ## compilation aborts with an error message. This is useful for writing

lib/system.nim

@@ -2213,6 +2213,20 @@ proc shallow*(s: var string) {.noSideEffect, inline.} =
     var s = cast[PGenericSeq](s)
     s.reserved = s.reserved or seqShallowFlag
 
+template static*(e: expr): expr =
+  ## evaluates a given expression `e` at compile-time
+  ## even if it has side effects
+  block:
+    const res = e
+    res
+
+template eval*(blk: stmt): stmt =
+  ## executes a block of code at compile time just as if it was a macro
+  ## optonally, the block can return an AST tree that will replace the 
+  ## eval expression
+  block:
+    macro payload(x: stmt): stmt = blk
+    payload()
 
 when defined(initDebugger):
   initDebugger()

web/news.txt

@@ -20,6 +20,14 @@ Library Additions
 - Added ``system.shallow`` that can be used to speed up string and sequence
   assignments.
 
+- Added ``system.static`` that can force compile-time evaluation of certain
+  expressions
+
+- Added ``system.eval`` that can execute an anonymous block of code at
+  compile time as if was a macro
+
+- Added ``macros.emit`` that can emit an arbitrary computed string as nimrod
+  code during compilation
 
 2012-02-09 Version 0.8.14 released
 ==================================