# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1341525111 -7200
# Node ID e9b25a4d49038ee9c95eb522cb5263fc3ab20a8b
# Parent  39f7dc0698c4ade0735c339483087f636b274d30
Added string "display" representations for the nodes, allowing ASTs to be
printed and appear as source code.

diff -r 39f7dc0698c4 -r e9b25a4d4903 compiler/ast.py
--- a/compiler/ast.py	Tue Jun 12 00:20:29 2012 +0200
+++ b/compiler/ast.py	Thu Jul 05 23:51:51 2012 +0200
@@ -18,6 +18,26 @@
 def flatten_nodes(seq):
     return [n for n in flatten(seq) if isinstance(n, Node)]
 
+def indent(s):
+    return s.replace("\n", "\n\t")
+
+def decode_function(node):
+    star = (node.flags & 4 != 0) and 1 or 0
+    dstar = (node.flags & 8 != 0) and 1 or 0
+    argnames = node.argnames[:]
+
+    # Add stars to star and dstar parameters.
+
+    if star:
+        argnames[-dstar-star] = "*%s" % argnames[-dstar-star]
+    if dstar:
+        argnames[-dstar] = "**%s" % argnames[-dstar]
+
+    # Map defaults to parameters.
+
+    defaults = [None] * (len(node.argnames) - star - dstar - len(node.defaults)) + list(node.defaults) + [None] * (star + dstar)
+    return [(default and "%s=%s" % (argname, default) or argname) for (argname, default) in zip(argnames, defaults)]
+
 nodes = {}
 
 class Node:
@@ -52,6 +72,9 @@
     def __repr__(self):
         return "Expression(%r)" % (self.node,)
 
+    def __str__(self):
+        return str(self.node)
+
     def visit(self, visitor, *args):
         return visitor.visitExpression(self, *args)
 
@@ -70,6 +93,9 @@
     def __repr__(self):
         return "Add((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s + %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitAdd(self, *args)
 
@@ -89,6 +115,9 @@
     def __repr__(self):
         return "And(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return " and ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitAnd(self, *args)
 
@@ -108,6 +137,9 @@
     def __repr__(self):
         return "AssAttr(%r, %r, %r)" % (self.expr, self.attrname, self.flags)
 
+    def __str__(self):
+        return "%s.%s" % (self.expr, self.attrname) # NOTE: self.flags not used
+
     def visit(self, visitor, *args):
         return visitor.visitAssAttr(self, *args)
 
@@ -127,6 +159,9 @@
     def __repr__(self):
         return "AssList(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return "[%s]" % ", ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitAssList(self, *args)
 
@@ -145,6 +180,9 @@
     def __repr__(self):
         return "AssName(%r, %r)" % (self.name, self.flags)
 
+    def __str__(self):
+        return str(self.name) # NOTE: self.flags not used
+
     def visit(self, visitor, *args):
         return visitor.visitAssName(self, *args)
 
@@ -164,6 +202,9 @@
     def __repr__(self):
         return "AssTuple(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return "(%s)" % ", ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitAssTuple(self, *args)
 
@@ -189,6 +230,9 @@
     def __repr__(self):
         return "Assert(%r, %r)" % (self.test, self.fail)
 
+    def __str__(self):
+        return "assert %s%s" % (self.test, self.fail and ", %s" % self.fail or "")
+
     def visit(self, visitor, *args):
         return visitor.visitAssert(self, *args)
 
@@ -213,6 +257,9 @@
     def __repr__(self):
         return "Assign(%r, %r)" % (self.nodes, self.expr)
 
+    def __str__(self):
+        return "%s = %s" % (", ".join(map(str, self.nodes)), self.expr)
+
     def visit(self, visitor, *args):
         return visitor.visitAssign(self, *args)
 
@@ -232,6 +279,9 @@
     def __repr__(self):
         return "AugAssign(%r, %r, %r)" % (self.node, self.op, self.expr)
 
+    def __str__(self):
+        return "%s %s %s" % (self.node, self.op, self.expr)
+
     def visit(self, visitor, *args):
         return visitor.visitAugAssign(self, *args)
 
@@ -249,6 +299,9 @@
     def __repr__(self):
         return "Backquote(%r)" % (self.expr,)
 
+    def __str__(self):
+        return "`%s`" % self.expr
+
     def visit(self, visitor, *args):
         return visitor.visitBackquote(self, *args)
 
@@ -268,6 +321,9 @@
     def __repr__(self):
         return "Bitand(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return " & ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitBitand(self, *args)
 
@@ -287,6 +343,9 @@
     def __repr__(self):
         return "Bitor(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return " | ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitBitor(self, *args)
 
@@ -306,6 +365,9 @@
     def __repr__(self):
         return "Bitxor(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return " ^ ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitBitxor(self, *args)
 
@@ -322,6 +384,9 @@
     def __repr__(self):
         return "Break()"
 
+    def __str__(self):
+        return "break"
+
     def visit(self, visitor, *args):
         return visitor.visitBreak(self, *args)
 
@@ -354,6 +419,11 @@
     def __repr__(self):
         return "CallFunc(%r, %r, %r, %r)" % (self.node, self.args, self.star_args, self.dstar_args)
 
+    def __str__(self):
+        star_args = self.star_args and ["*%s" % self.star_args] or []
+        dstar_args = self.dstar_args and ["**%s" % self.dstar_args] or []
+        return "%s(%s)" % (self.node, ", ".join(map(str, self.args + star_args + dstar_args)))
+
     def visit(self, visitor, *args):
         return visitor.visitCallFunc(self, *args)
 
@@ -382,6 +452,15 @@
     def __repr__(self):
         return "Class(%r, %r, %r, %r)" % (self.name, self.bases, self.doc, self.code)
 
+    def __str__(self):
+        return "%sclass %s%s:%s%s" % (
+            self.decorators and "%s\n" % "\n".join([("@%s" % decorator) for decorator in self.decorators]) or "",
+            self.name,
+            self.bases and "(%s)" % ", ".join(map(str, self.bases)) or "",
+            indent(self.doc and "\n%r" % self.doc or ""),
+            indent("\n%s" % self.code)
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitClass(self, *args)
 
@@ -406,6 +485,9 @@
     def __repr__(self):
         return "Compare(%r, %r)" % (self.expr, self.ops)
 
+    def __str__(self):
+        return "%s %s" % (self.expr, " ".join([("%s %s" % op) for op in self.ops]))
+
     def visit(self, visitor, *args):
         return visitor.visitCompare(self, *args)
 
@@ -423,6 +505,9 @@
     def __repr__(self):
         return "Const(%r)" % (self.value,)
 
+    def __str__(self):
+        return repr(self.value)
+
     def visit(self, visitor, *args):
         return visitor.visitConst(self, *args)
 
@@ -439,6 +524,9 @@
     def __repr__(self):
         return "Continue()"
 
+    def __str__(self):
+        return "continue"
+
     def visit(self, visitor, *args):
         return visitor.visitContinue(self, *args)
 
@@ -458,6 +546,9 @@
     def __repr__(self):
         return "Decorators(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return "\n".join([("@%s" % node) for node in self.nodes])
+
     def visit(self, visitor, *args):
         return visitor.visitDecorators(self, *args)
 
@@ -477,6 +568,9 @@
     def __repr__(self):
         return "Dict(%r)" % (self.items,)
 
+    def __str__(self):
+        return "{%s}" % ", ".join(map(str, self.items))
+
     def visit(self, visitor, *args):
         return visitor.visitDict(self, *args)
 
@@ -494,6 +588,9 @@
     def __repr__(self):
         return "Discard(%r)" % (self.expr,)
 
+    def __str__(self):
+        return str(self.expr)
+
     def visit(self, visitor, *args):
         return visitor.visitDiscard(self, *args)
 
@@ -512,6 +609,9 @@
     def __repr__(self):
         return "Div((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s / %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitDiv(self, *args)
 
@@ -528,6 +628,9 @@
     def __repr__(self):
         return "Ellipsis()"
 
+    def __str__(self):
+        return "..."
+
     def visit(self, visitor, *args):
         return visitor.visitEllipsis(self, *args)
 
@@ -557,6 +660,10 @@
     def __repr__(self):
         return "Exec(%r, %r, %r)" % (self.expr, self.locals, self.globals)
 
+    def __str__(self):
+        return "exec %s%s%s" % (self.expr, self.locals and ", %s" % self.locals or "",
+            self.globals and ", %s" % self.globals or "")
+
     def visit(self, visitor, *args):
         return visitor.visitExec(self, *args)
 
@@ -575,6 +682,9 @@
     def __repr__(self):
         return "FloorDiv((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s // %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitFloorDiv(self, *args)
 
@@ -606,6 +716,13 @@
     def __repr__(self):
         return "For(%r, %r, %r, %r)" % (self.assign, self.list, self.body, self.else_)
 
+    def __str__(self):
+        return "for %s in %s:%s%s" % (
+            self.assign, self.list,
+            indent("\n%s" % self.body),
+            self.else_ and "\nelse:%s" % indent("\n%s" % self.else_) or ""
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitFor(self, *args)
 
@@ -625,6 +742,10 @@
     def __repr__(self):
         return "From(%r, %r, %r)" % (self.modname, self.names, self.level)
 
+    def __str__(self):
+        return "from %s import %s" % (self.modname,
+            ", ".join([(alias and "%s as %s" % (name, alias) or name) for (name, alias) in self.names]))
+
     def visit(self, visitor, *args):
         return visitor.visitFrom(self, *args)
 
@@ -644,8 +765,6 @@
         if flags & CO_VARKEYWORDS:
             self.kwargs = 1
 
-
-
     def getChildren(self):
         children = []
         children.append(self.decorators)
@@ -668,6 +787,17 @@
     def __repr__(self):
         return "Function(%r, %r, %r, %r, %r, %r, %r)" % (self.decorators, self.name, self.argnames, self.defaults, self.flags, self.doc, self.code)
 
+    def __str__(self):
+        parameters = decode_function(self)
+
+        return "%sdef %s(%s):%s%s" % (
+            self.decorators and "%s\n" % "\n".join([("@%s" % decorator) for decorator in self.decorators]) or "",
+            self.name,
+            ", ".join(parameters),
+            indent(self.doc and "\n%r" % self.doc or ""),
+            indent("\n%s" % self.code)
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitFunction(self, *args)
 
@@ -687,6 +817,9 @@
     def __repr__(self):
         return "GenExpr(%r)" % (self.code,)
 
+    def __str__(self):
+        return str(self.code)
+
     def visit(self, visitor, *args):
         return visitor.visitGenExpr(self, *args)
 
@@ -698,7 +831,6 @@
         self.lineno = lineno
         self.is_outmost = False
 
-
     def getChildren(self):
         children = []
         children.append(self.assign)
@@ -716,6 +848,12 @@
     def __repr__(self):
         return "GenExprFor(%r, %r, %r)" % (self.assign, self.iter, self.ifs)
 
+    def __str__(self):
+        return "for %s in %s%s" % (
+            self.assign, self.iter,
+            self.ifs and " ".join(map(str, self.ifs)) or ""
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitGenExprFor(self, *args)
 
@@ -733,6 +871,9 @@
     def __repr__(self):
         return "GenExprIf(%r)" % (self.test,)
 
+    def __str__(self):
+        return "if %s" % self.test
+
     def visit(self, visitor, *args):
         return visitor.visitGenExprIf(self, *args)
 
@@ -757,6 +898,9 @@
     def __repr__(self):
         return "GenExprInner(%r, %r)" % (self.expr, self.quals)
 
+    def __str__(self):
+        return "%s %s" % (self.expr, " ".join(map(str, self.quals)))
+
     def visit(self, visitor, *args):
         return visitor.visitGenExprInner(self, *args)
 
@@ -775,6 +919,9 @@
     def __repr__(self):
         return "Getattr(%r, %r)" % (self.expr, self.attrname)
 
+    def __str__(self):
+        return "%s.%s" % (self.expr, self.attrname)
+
     def visit(self, visitor, *args):
         return visitor.visitGetattr(self, *args)
 
@@ -792,6 +939,9 @@
     def __repr__(self):
         return "Global(%r)" % (self.names,)
 
+    def __str__(self):
+        return "global %s" % ", ".join(map(str, self.names))
+
     def visit(self, visitor, *args):
         return visitor.visitGlobal(self, *args)
 
@@ -817,6 +967,13 @@
     def __repr__(self):
         return "If(%r, %r)" % (self.tests, self.else_)
 
+    def __str__(self):
+        tests = [("%sif %s:%s" % (i > 0 and "el" or "", test, indent("\n%s" % body))) for (i, (test, body)) in enumerate(self.tests)]
+        return "%s%s" % (
+            "\n".join(tests),
+            self.else_ and "\nelse:%s" % indent("\n%s" % self.else_) or ""
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitIf(self, *args)
 
@@ -836,6 +993,9 @@
     def __repr__(self):
         return "IfExp(%r, %r, %r)" % (self.test, self.then, self.else_)
 
+    def __str__(self):
+        return "%s if %s else %s" % (self.then, self.test, self.else_)
+
     def visit(self, visitor, *args):
         return visitor.visitIfExp(self, *args)
 
@@ -853,6 +1013,10 @@
     def __repr__(self):
         return "Import(%r)" % (self.names,)
 
+    def __str__(self):
+        return "import %s" % (
+            ", ".join([(alias and "%s as %s" % (name, alias) or name) for (name, alias) in self.names]))
+
     def visit(self, visitor, *args):
         return visitor.visitImport(self, *args)
 
@@ -870,6 +1034,9 @@
     def __repr__(self):
         return "Invert(%r)" % (self.expr,)
 
+    def __str__(self):
+        return "~%s" % self.expr
+
     def visit(self, visitor, *args):
         return visitor.visitInvert(self, *args)
 
@@ -888,6 +1055,9 @@
     def __repr__(self):
         return "Keyword(%r, %r)" % (self.name, self.expr)
 
+    def __str__(self):
+        return "%s=%s" % (self.name, self.expr)
+
     def visit(self, visitor, *args):
         return visitor.visitKeyword(self, *args)
 
@@ -923,6 +1093,10 @@
     def __repr__(self):
         return "Lambda(%r, %r, %r, %r)" % (self.argnames, self.defaults, self.flags, self.code)
 
+    def __str__(self):
+        parameters = decode_function(self)
+        return "lambda %s: %s" % (", ".join(parameters), self.code)
+
     def visit(self, visitor, *args):
         return visitor.visitLambda(self, *args)
 
@@ -941,6 +1115,9 @@
     def __repr__(self):
         return "LeftShift((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s << %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitLeftShift(self, *args)
 
@@ -960,6 +1137,9 @@
     def __repr__(self):
         return "List(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return "[%s]" % ", ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitList(self, *args)
 
@@ -984,6 +1164,9 @@
     def __repr__(self):
         return "ListComp(%r, %r)" % (self.expr, self.quals)
 
+    def __str__(self):
+        return "%s %s" % (self.expr, " ".join(map(str, self.quals)))
+
     def visit(self, visitor, *args):
         return visitor.visitListComp(self, *args)
 
@@ -1011,6 +1194,12 @@
     def __repr__(self):
         return "ListCompFor(%r, %r, %r)" % (self.assign, self.list, self.ifs)
 
+    def __str__(self):
+        return "for %s in %s%s" % (
+            self.assign, self.list,
+            self.ifs and " ".join(map(str, self.ifs)) or ""
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitListCompFor(self, *args)
 
@@ -1028,6 +1217,9 @@
     def __repr__(self):
         return "ListCompIf(%r)" % (self.test,)
 
+    def __str__(self):
+        return "if %s" % self.test
+
     def visit(self, visitor, *args):
         return visitor.visitListCompIf(self, *args)
 
@@ -1046,6 +1238,9 @@
     def __repr__(self):
         return "Mod((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s %% %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitMod(self, *args)
 
@@ -1064,6 +1259,9 @@
     def __repr__(self):
         return "Module(%r, %r)" % (self.doc, self.node)
 
+    def __str__(self):
+        return "%s%s" % (self.doc and "%r\n" % self.doc or "", self.node)
+
     def visit(self, visitor, *args):
         return visitor.visitModule(self, *args)
 
@@ -1082,6 +1280,9 @@
     def __repr__(self):
         return "Mul((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s * %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitMul(self, *args)
 
@@ -1099,6 +1300,9 @@
     def __repr__(self):
         return "Name(%r)" % (self.name,)
 
+    def __str__(self):
+        return str(self.name)
+
     def visit(self, visitor, *args):
         return visitor.visitName(self, *args)
 
@@ -1116,6 +1320,9 @@
     def __repr__(self):
         return "Not(%r)" % (self.expr,)
 
+    def __str__(self):
+        return "not %s" % self.expr
+
     def visit(self, visitor, *args):
         return visitor.visitNot(self, *args)
 
@@ -1135,6 +1342,9 @@
     def __repr__(self):
         return "Or(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return " or ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitOr(self, *args)
 
@@ -1151,6 +1361,9 @@
     def __repr__(self):
         return "Pass()"
 
+    def __str__(self):
+        return "pass"
+
     def visit(self, visitor, *args):
         return visitor.visitPass(self, *args)
 
@@ -1169,6 +1382,9 @@
     def __repr__(self):
         return "Power((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s ** %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitPower(self, *args)
 
@@ -1194,6 +1410,10 @@
     def __repr__(self):
         return "Print(%r, %r)" % (self.nodes, self.dest)
 
+    def __str__(self):
+        dest = self.dest and [">>%s" % self.dest] or []
+        return "print %s," % ", ".join(map(str, dest + self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitPrint(self, *args)
 
@@ -1219,6 +1439,10 @@
     def __repr__(self):
         return "Printnl(%r, %r)" % (self.nodes, self.dest)
 
+    def __str__(self):
+        dest = self.dest and [">>%s" % self.dest] or []
+        return "print %s" % ", ".join(map(str, dest + self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitPrintnl(self, *args)
 
@@ -1249,6 +1473,12 @@
     def __repr__(self):
         return "Raise(%r, %r, %r)" % (self.expr1, self.expr2, self.expr3)
 
+    def __str__(self):
+        args = self.expr1 and [self.expr1] or []
+        args += self.expr2 and [self.expr2] or []
+        args += self.expr3 and [self.expr3] or []
+        return "raise %s" % ", ".join(map(str, args))
+
     def visit(self, visitor, *args):
         return visitor.visitRaise(self, *args)
 
@@ -1266,6 +1496,9 @@
     def __repr__(self):
         return "Return(%r)" % (self.value,)
 
+    def __str__(self):
+        return "return %s" % self.value
+
     def visit(self, visitor, *args):
         return visitor.visitReturn(self, *args)
 
@@ -1284,6 +1517,9 @@
     def __repr__(self):
         return "RightShift((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s >> %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitRightShift(self, *args)
 
@@ -1315,6 +1551,12 @@
     def __repr__(self):
         return "Slice(%r, %r, %r, %r)" % (self.expr, self.flags, self.lower, self.upper)
 
+    def __str__(self):
+        args = []
+        args = self.lower is not None and [self.lower] or []
+        args = self.upper is not None and [self.upper] or []
+        return "%s[%s]" % (self.expr, ":".join(map(str, args)))
+
     def visit(self, visitor, *args):
         return visitor.visitSlice(self, *args)
 
@@ -1334,6 +1576,9 @@
     def __repr__(self):
         return "Sliceobj(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return ":".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitSliceobj(self, *args)
 
@@ -1353,6 +1598,9 @@
     def __repr__(self):
         return "Stmt(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return "\n".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitStmt(self, *args)
 
@@ -1371,6 +1619,9 @@
     def __repr__(self):
         return "Sub((%r, %r))" % (self.left, self.right)
 
+    def __str__(self):
+        return "%s - %s" % (self.left, self.right)
+
     def visit(self, visitor, *args):
         return visitor.visitSub(self, *args)
 
@@ -1397,6 +1648,9 @@
     def __repr__(self):
         return "Subscript(%r, %r, %r)" % (self.expr, self.flags, self.subs)
 
+    def __str__(self):
+        return "%s[%s]" % (self.expr, ",".join(map(str, self.subs)))
+
     def visit(self, visitor, *args):
         return visitor.visitSubscript(self, *args)
 
@@ -1425,6 +1679,18 @@
     def __repr__(self):
         return "TryExcept(%r, %r, %r)" % (self.body, self.handlers, self.else_)
 
+    def __str__(self):
+        handlers = [
+            ("\nexcept%s%s:%s" % (spec and " %s" % spec or "", assign and ", %s" % assign or "", indent("\n%s" % statement)))
+            for (spec, assign, statement) in self.handlers
+            ]
+
+        return "try:%s%s%s" % (
+            indent("\n%s" % self.body),
+            "".join(handlers),
+            self.else_ and "\nelse:%s" % indent("\n%s" % self.else_) or ""
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitTryExcept(self, *args)
 
@@ -1443,6 +1709,12 @@
     def __repr__(self):
         return "TryFinally(%r, %r)" % (self.body, self.final)
 
+    def __str__(self):
+        return "try:%s\nfinally:%s" % (
+            indent("\n%s" % self.body),
+            indent("\n%s" % self.final)
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitTryFinally(self, *args)
 
@@ -1462,6 +1734,9 @@
     def __repr__(self):
         return "Tuple(%r)" % (self.nodes,)
 
+    def __str__(self):
+        return "(%s)" % ", ".join(map(str, self.nodes))
+
     def visit(self, visitor, *args):
         return visitor.visitTuple(self, *args)
 
@@ -1479,6 +1754,9 @@
     def __repr__(self):
         return "UnaryAdd(%r)" % (self.expr,)
 
+    def __str__(self):
+        return "+%s" % self.expr
+
     def visit(self, visitor, *args):
         return visitor.visitUnaryAdd(self, *args)
 
@@ -1496,6 +1774,9 @@
     def __repr__(self):
         return "UnarySub(%r)" % (self.expr,)
 
+    def __str__(self):
+        return "-%s" % self.expr
+
     def visit(self, visitor, *args):
         return visitor.visitUnarySub(self, *args)
 
@@ -1524,6 +1805,13 @@
     def __repr__(self):
         return "While(%r, %r, %r)" % (self.test, self.body, self.else_)
 
+    def __str__(self):
+        return "while %s:%s%s" % (
+            self.test,
+            indent("\n%s" % self.body),
+            self.else_ and "\nelse:%s" % indent("\n%s" % self.else_) or ""
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitWhile(self, *args)
 
@@ -1552,6 +1840,13 @@
     def __repr__(self):
         return "With(%r, %r, %r)" % (self.expr, self.vars, self.body)
 
+    def __str__(self):
+        return "with %s%s:%s" % (
+            self.expr,
+            self.vars and " as %s" % ", ".join(map(str, self.vars)),
+            indent("\n%s" % self.body),
+            )
+
     def visit(self, visitor, *args):
         return visitor.visitWith(self, *args)
 
@@ -1569,6 +1864,9 @@
     def __repr__(self):
         return "Yield(%r)" % (self.value,)
 
+    def __str__(self):
+        return "yield %s" % self.value
+
     def visit(self, visitor, *args):
         return visitor.visitYield(self, *args)