Merge branch 'devel' of https://github.com/Araq/Nimrod into devel

compiler/semfold.nim

@@ -404,7 +404,7 @@ proc evalOp(m: TMagic, n, a, b, c: PNode): PNode =
      mExit, mInc, ast.mDec, mEcho, mSwap, mAppendStrCh, 
      mAppendStrStr, mAppendSeqElem, mSetLengthStr, mSetLengthSeq, 
      mParseExprToAst, mParseStmtToAst, mExpandToAst, mTypeTrait,
-     mNLen..mNError, mEqRef, mSlurp, mStaticExec, mNGenSym: 
+     mNLen..mNError, mEqRef, mSlurp, mStaticExec, mNGenSym, mSpawn:
     discard
   of mRand:
     result = newIntNodeT(math.random(a.getInt.int), n)

compiler/suggest.nim

@@ -253,6 +253,7 @@ proc findUsages(node: PNode, s: PSym) =
     lastLineInfo = node.info
 
 proc findDefinition(node: PNode, s: PSym) =
+  if node.isNil or s.isNil: return
   if isTracked(node.info, s.name.s.len):
     suggestWriteln(symToStr(s, isLocal=false, sectionDef))
     suggestQuit()

compiler/vm.nim

@@ -354,6 +354,11 @@ template handleJmpBack() {.dirty.} =
       globalError(c.debug[pc], errTooManyIterations)
   dec(c.loopIterations)
 
+proc skipColon(n: PNode): PNode =
+  result = n
+  if n.kind == nkExprColonExpr:
+    result = n.sons[1]
+
 proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
   var pc = start
   var tos = tos
@@ -454,7 +459,7 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
       decodeBC(rkNode)
       let src = regs[rb].node
       if src.kind notin {nkEmpty..nkNilLit}:
-        let n = src.sons[rc]
+        let n = src.sons[rc].skipColon
         regs[ra].node = n
       else:
         stackTrace(c, tos, pc, errNilAccess)
@@ -1099,6 +1104,7 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
                                      c.module)
     of opcGorge:
       decodeBC(rkNode)
+      createStr regs[ra]
       regs[ra].node.strVal = opGorge(regs[rb].node.strVal,
                                      regs[rc].node.strVal)
     of opcNError:

compiler/vmgen.nim

@@ -70,6 +70,9 @@ proc echoCode*(c: PCtx, start=0) {.deprecated.} =
   echo buf
 
 proc gABC(ctx: PCtx; n: PNode; opc: TOpcode; a, b, c: TRegister = 0) =
+  ## Takes the registers `b` and `c`, applies the operation `opc` to them, and
+  ## stores the result into register `a`
+  ## The node is needed for debug information
   assert opc.ord < 255
   let ins = (opc.uint32 or (a.uint32 shl 8'u32) or
                            (b.uint32 shl 16'u32) or
@@ -78,13 +81,20 @@ proc gABC(ctx: PCtx; n: PNode; opc: TOpcode; a, b, c: TRegister = 0) =
   ctx.debug.add(n.info)
 
 proc gABI(c: PCtx; n: PNode; opc: TOpcode; a, b: TRegister; imm: BiggestInt) =
+  # Takes the `b` register and the immediate `imm`, appies the operation `opc`,
+  # and stores the output value into `a`.
+  # `imm` is signed and must be within [-127, 128]
+  assert(imm >= -127 and imm <= 128)
   let ins = (opc.uint32 or (a.uint32 shl 8'u32) or
                            (b.uint32 shl 16'u32) or
                            (imm+byteExcess).uint32 shl 24'u32).TInstr
   c.code.add(ins)
   c.debug.add(n.info)
 
 proc gABx(c: PCtx; n: PNode; opc: TOpcode; a: TRegister = 0; bx: int) =
+  # Applies `opc` to `bx` and stores it into register `a`
+  # `bx` must be signed and in the range [-32767, 32768]
+  assert(bx >= -32767 and bx <= 32768)
   let ins = (opc.uint32 or a.uint32 shl 8'u32 or 
             (bx+wordExcess).uint32 shl 16'u32).TInstr
   c.code.add(ins)
@@ -316,15 +326,7 @@ proc genAndOr(c: PCtx; n: PNode; opc: TOpcode; dest: var TDest) =
   c.patch(L1)
 
 proc canonValue*(n: PNode): PNode =
-  if n.kind == nkExprColonExpr:
-    result = n.sons[1]
-  elif n.hasSubnodeWith(nkExprColonExpr):
-    result = n.copyNode
-    newSeq(result.sons, n.len)
-    for i in 0.. <n.len:
-      result.sons[i] = canonValue(n.sons[i])
-  else:
-    result = n
+  result = n
 
 proc rawGenLiteral(c: PCtx; n: PNode): int =
   result = c.constants.len

doc/tut1.txt

@@ -132,7 +132,7 @@ a backslash:
     TMyObject {.final, pure, acyclic.} = object  # comment continues: \
       # we have lots of space here to comment 'TMyObject'.
       # This line belongs to the comment as it's properly aligned.
-
+
 
 Comments are tokens; they are only allowed at certain places in the input file
 as they belong to the syntax tree! This feature enables perfect source-to-source
@@ -150,6 +150,18 @@ the syntax, watch their indentation:
 **Note**: To comment out a large piece of code, it is often better to use a
 ``when false:`` statement.
 
+.. code-block:: nimrod
+  when false:
+    brokenCode()
+
+Another option is to use the `discard`_ statement together with
+*long string literals* to create block comments:
+
+.. code-block:: nimrod
+  discard """ You can have any nimrod code text commented 
+  out inside this with no indentation restrictions.
+        yes("May I ask a pointless question?") """
+
 
 Numbers
 -------
@@ -575,27 +587,46 @@ Some terminology: in the example ``question`` is called a (formal) *parameter*,
 
 Result variable
 ---------------
-A procedure that returns a value has an implicit ``result`` variable that
-represents the return value. A ``return`` statement with no expression is a
-shorthand for ``return result``. So all three code snippets are equivalent:
-
-.. code-block:: nimrod
-  return 42
-
-.. code-block:: nimrod
-  result = 42
-  return
-
-.. code-block:: nimrod
-  result = 42
-  return result
-
-
+A procedure that returns a value has an implicit ``result`` variable declared 
+that represents the return value. A ``return`` statement with no expression is a
+shorthand for ``return result``. The ``result`` value is always returned 
+automatically at the end a procedure if there is no ``return`` statement at
+the exit.
+
+.. code-block:: nimrod
+  proc sumTillNegative(x: varargs[int]): int = 
+    for i in x:
+      if i < 0:
+        return
+      result = result + i  
+
+  echo sumTillNegative() # echos 0
+  echo sumTillNegative(3, 4, 5) # echos 12
+  echo sumTillNegative(3, 4 , -1 , 6) # echos 7
+
+The ``result`` variable is already implicitly declared at the start of the 
+function, so declaring it again with 'var result', for example, would shadow it
+with a normal variable of the same name. The result variable is also already
+initialised with the type's default value. Note that referential data types will
+be ``nil`` at the start of the procedure, and thus may require manual
+initialisation.
+
+
 Parameters
 ----------
-Parameters are constant in the procedure body. Their value cannot be changed
-because this allows the compiler to implement parameter passing in the most
-efficient way. If the procedure needs to modify the argument for the
+Parameters are constant in the procedure body. By default, their value cannot be
+changed because this allows the compiler to implement parameter passing in the 
+most efficient way. If a mutable variable is needed inside the procedure, it has
+to be declared with ``var`` in the procedure body. Shadowing the parameter name
+is possible, and actually an idiom: 
+
+.. code-block:: nimrod
+  proc printSeq(s: seq, nprinted: int = -1) =
+    var nprinted = if nprinted == -1: s.len else: min(nprinted, s.len)
+    for i in 0 .. <nprinted:
+      echo s[i]
+
+If the procedure needs to modify the argument for the
 caller, a ``var`` parameter can be used:
 
 .. code-block:: nimrod
@@ -634,6 +665,9 @@ been declared with the ``discardable`` pragma:
 
   p(3, 4) # now valid
 
+The discard statement can also be used to create block comments as described
+in the `Comments`_.
+
 
 Named arguments
 ---------------

lib/pure/future.nim

@@ -26,8 +26,15 @@ proc createProcType(p, b: PNimrodNode): PNimrodNode {.compileTime.} =
     for i in 0 .. <p.len:
       let ident = p[i]
       var identDefs = newNimNode(nnkIdentDefs)
-      identDefs.add newIdentNode("i" & $i)
-      identDefs.add(ident)
+      case ident.kind
+      of nnkExprColonExpr:
+        identDefs.add ident[0]
+        identDefs.add ident[1]
+      of nnkIdent:
+        identDefs.add newIdentNode("i" & $i)
+        identDefs.add(ident)
+      else:
+        error("Incorrect type list in proc type declaration.")
       identDefs.add newEmptyNode()
       formalParams.add identDefs
   of nnkIdent:
@@ -47,7 +54,7 @@ proc createProcType(p, b: PNimrodNode): PNimrodNode {.compileTime.} =
 macro `=>`*(p, b: expr): expr {.immediate.} =
   ## Syntax sugar for anonymous procedures.
   ##
-  ## ..code-block:: nimrod
+  ## .. code-block:: nimrod
   ##
   ##   proc passTwoAndTwo(f: (int, int) -> int): int =
   ##     f(2, 2)
@@ -98,7 +105,7 @@ macro `=>`*(p, b: expr): expr {.immediate.} =
 macro `->`*(p, b: expr): expr {.immediate.} =
   ## Syntax sugar for procedure types.
   ##
-  ## ..code-block:: nimrod
+  ## .. code-block:: nimrod
   ##
   ##   proc pass2(f: (float, float) -> float): float =
   ##     f(2, 2)