From e01e0a4b4056ac4a42797bab9f10822ae8996607 Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Sun, 13 Sep 2015 22:42:21 +0200
Subject: [PATCH] next steps in binding [] properly

---
 compiler/semcall.nim  |  2 +-
 compiler/semdata.nim  |  3 ++-
 compiler/semexprs.nim | 43 +++++++++++++++++++++++++++++--------------
 compiler/sigmatch.nim |  1 +
 4 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/compiler/semcall.nim b/compiler/semcall.nim
index 6787afe27..f9fadeec7 100644
--- a/compiler/semcall.nim
+++ b/compiler/semcall.nim
@@ -308,7 +308,7 @@ proc semResolvedCall(c: PContext, n: PNode, x: TCandidate): PNode =
   let gp = finalCallee.ast.sons[genericParamsPos]
   if gp.kind != nkEmpty:
     if x.calleeSym.kind notin {skMacro, skTemplate}:
-      if x.calleeSym.magic == mArrPut:
+      if x.calleeSym.magic in {mArrGet, mArrPut}:
         finalCallee = x.calleeSym
       else:
         finalCallee = generateInstance(c, x.calleeSym, x.bindings, n.info)
diff --git a/compiler/semdata.nim b/compiler/semdata.nim
index 345a8c0d1..e6456293c 100644
--- a/compiler/semdata.nim
+++ b/compiler/semdata.nim
@@ -45,7 +45,8 @@ type
   TExprFlag* = enum
     efLValue, efWantIterator, efInTypeof,
     efWantStmt, efAllowStmt, efDetermineType,
-    efAllowDestructor, efWantValue, efOperand, efNoSemCheck
+    efAllowDestructor, efWantValue, efOperand, efNoSemCheck,
+    efNoProcvarCheck
   TExprFlags* = set[TExprFlag]
 
   TTypeAttachedOp* = enum
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index 20b6775a5..84cbbdc93 100644
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -52,7 +52,7 @@ proc semExprWithType(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
     result.typ = errorType(c)
   else:
     # XXX tyGenericInst here?
-    semProcvarCheck(c, result)
+    if efNoProcvarCheck notin flags: semProcvarCheck(c, result)
     if result.typ.kind == tyVar: result = newDeref(result)
     semDestructorCheck(c, result, flags)
 
@@ -1156,7 +1156,7 @@ proc semSubscript(c: PContext, n: PNode, flags: TExprFlags): PNode =
     result.add(x[0])
     return
   checkMinSonsLen(n, 2)
-  n.sons[0] = semExprWithType(c, n.sons[0])
+  n.sons[0] = semExprWithType(c, n.sons[0], {efNoProcvarCheck})
   let arr = skipTypes(n.sons[0].typ, {tyGenericInst, tyVar, tyPtr, tyRef})
   case arr.kind
   of tyArray, tyOpenArray, tyVarargs, tyArrayConstr, tySequence, tyString,
@@ -1196,7 +1196,17 @@ proc semSubscript(c: PContext, n: PNode, flags: TExprFlags): PNode =
       localError(n.info, errIndexTypesDoNotMatch)
     result = n
   else:
-    c.p.bracketExpr = n.sons[0]
+    let s = if n.sons[0].kind == nkSym: n.sons[0].sym
+            elif n[0].kind in nkSymChoices: n.sons[0][0].sym
+            else: nil
+    if s != nil and s.kind in {skProc, skMethod, skConverter}+skIterators:
+      # type parameters: partial generic specialization
+      n.sons[0] = semSymGenericInstantiation(c, n.sons[0], s)
+      result = explicitGenericInstantiation(c, n, s)
+    elif s != nil and s.kind == skType:
+      result = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
+    else:
+      c.p.bracketExpr = n.sons[0]
 
 proc semArrayAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
   let oldBracketExpr = c.p.bracketExpr
@@ -2073,6 +2083,19 @@ proc semExport(c: PContext, n: PNode): PNode =
     c.module.ast.add x
   result = n
 
+proc shouldBeBracketExpr(n: PNode): bool =
+  assert n.kind in nkCallKinds
+  let a = n.sons[0]
+  if a.kind in nkCallKinds:
+    let b = a[0]
+    if b.kind in nkSymChoices:
+      for i in 0..<b.len:
+        if b[i].sym.magic == mArrGet:
+          let be = newNodeI(nkBracketExpr, n.info)
+          for i in 1..<a.len: be.add(a[i])
+          n.sons[0] = be
+          return true
+
 proc setGenericParams(c: PContext, n: PNode) =
   for i in 1 .. <n.len:
     n[i].typ = semTypeNode(c, n[i], nil)
@@ -2180,7 +2203,8 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
       else:
         #liMessage(n.info, warnUser, renderTree(n));
         result = semIndirectOp(c, n, flags)
-    elif n[0].kind == nkBracketExpr and isSymChoice(n[0][0]):
+    elif (n[0].kind == nkBracketExpr or shouldBeBracketExpr(n)) and
+        isSymChoice(n[0][0]):
       # indirectOp can deal with explicit instantiations; the fixes
       # the 'newSeq[T](x)' bug
       setGenericParams(c, n.sons[0])
@@ -2201,16 +2225,7 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
         result = semExpr(c, result, flags)
   of nkBracketExpr:
     checkMinSonsLen(n, 1)
-    var s = qualifiedLookUp(c, n.sons[0], {checkUndeclared})
-    if (s != nil and s.kind in {skProc, skMethod, skConverter}+skIterators) or
-        n[0].kind in nkSymChoices:
-      # type parameters: partial generic specialization
-      n.sons[0] = semSymGenericInstantiation(c, n.sons[0], s)
-      result = explicitGenericInstantiation(c, n, s)
-    elif s != nil and s.kind in {skType}:
-      result = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
-    else:
-      result = semArrayAccess(c, n, flags)
+    result = semArrayAccess(c, n, flags)
   of nkCurlyExpr:
     result = semExpr(c, buildOverloadedSubscripts(n, getIdent"{}"), flags)
   of nkPragmaExpr:
diff --git a/compiler/sigmatch.nim b/compiler/sigmatch.nim
index 5b111d8bc..b25f40c50 100644
--- a/compiler/sigmatch.nim
+++ b/compiler/sigmatch.nim
@@ -1696,6 +1696,7 @@ proc partialMatch*(c: PContext, n, nOrig: PNode, m: var TCandidate) =
 proc matches*(c: PContext, n, nOrig: PNode, m: var TCandidate) =
   if m.calleeSym != nil and m.calleeSym.magic == mArrGet:
     m.state = csMatch
+    m.call = n
     return
   var marker = initIntSet()
   matchesAux(c, n, nOrig, m, marker)