#!/usr/bin/env python

# Translate an abstract syntax tree into tree-structured intermediate
# code, performing type checking as a side effect
import sys
    
from absyn import *
import fsymbol
import fractparser
import fractlexer
import ir
import canon
import stdlib

from fracttypes import *
    
class TBase:
    def __init__(self,prefix,dump=None):
        #print "translating"
        self.symbols = fsymbol.T(prefix)
        self.canon = canon.T(self.symbols,dump)
        self.errors = []
        self.warnings = []
        self.sections = {}
        self.canon_sections = {}
        self.output_sections = {}
        self.defaults = {}
        self.fakeNode = Empty(-1) # node used for code not written by user
        
        self.dumpCanon = 0
        self.dumpDecorated = 0
        self.dumpProbs = 0
        self.dumpTranslation = 0
        self.dumpVars = 0
        self.dumpPreCanon = 0
        
        if dump != None:
            for k in dump.keys():
                self.__dict__[k]=1

    def post_init(self):
        if self.dumpProbs:
            print self.errors
            print self.warnings
            
        if self.dumpDecorated:
            print f.pretty()

        if self.dumpVars:
            for (name,sym) in self.symbols.items():
                if self.symbols.is_user(name):
                    try:
                        print name,": ",sym
                    except Exception, err:
                        print "Error \"%s\" dumping %s" %(err,name)

        if self.dumpTranslation:
            print self.dumpSections(f,self.canon_sections)

    def is_direct(self):
        return self.symbols.is_direct()
    
    def merge(self,other,name):
        for (k,s) in other.output_sections.items():
            self.output_sections[name + k] = s
        self.symbols.merge(other.symbols)

    def dumpSections(self,f,dict):
        print f.leaf + "{"
        for (name,tree) in dict.items():
            if isinstance(tree,ir.T):
                print " " + name + "("
                print tree.pretty(2) + " )"
            elif isinstance(tree,types.ListType):
                print " " + name + "("
                for t in tree:
                    print t.pretty(2)
                print " )"
            elif tree == None:
                pass
            else:
                print "Unknown tree %s in section %s" % (tree, name)
        print "}\n"

    def pretty(self):
        if self.errors:
            return string.join(self.errors,"\n")
        out = []
        for (name,tree) in self.sections.items():
            if isinstance(tree,ir.T):
                out.append( " " + name + "(")
                out.append(tree.pretty(2) + " )")
            elif isinstance(tree,types.ListType):
                out.append(" " + name + "(")
                for t in tree:
                    out.append(t.pretty(2))
                out.append(" )")
            elif tree == None:
                pass
            else:
                out.append("Unknown tree %s in section %s" % (tree, name))
        return string.join(out,"\n")
    
    def error(self,msg):
        self.errors.append(msg)
    def warning(self,msg):
        self.warnings.append(msg)
            
    def canonicalize(self):
        for (k,tree) in self.sections.items():
            startLabel = "t__start_" + self.symbols.prefix + k
            endLabel = "t__end_" + self.symbols.prefix + k
            self.canon_sections[k] = self.canon.canonicalize(tree,startLabel,endLabel)

    def dupSectionWarning(self,sect):
        self.warning(
                    ("Formula contains a fractint-style implicit %s section "+
                    "and an explicit UltraFractal %s section. "+
                    "Using explicit section.") % (sect,sect))
        
    def sectionOrNone(self,sectname):
        if self.sections.has_key(sectname):
            return self.sections[sectname]
        return None
    
    def default(self,node):
        self.add_to_section("default", self.setlist(node))

    def add_to_section(self,sectname,stmlist):
        current = self.sections.get(sectname)
        if current == None:
            self.sections[sectname] = stmlist
        else:
            self.sections[sectname].children += stmlist.children
        
    def global_(self,node):
        self.add_to_section("global", self.stmlist(node))

    def final(self,node):
        self.add_to_section("final",self.stmlist(node))

    def setlist(self, node):
        children = filter(lambda c : c.type != "empty", node.children)
        settings = map(lambda c: self.setting(c), children)        
        seq = ir.Seq(filter(lambda c: c != None, settings), node)
        return seq

    def paramsetting(self,node,var):
        name = node.children[0]
        if name.leaf == "visible":
            #FIXME ignore visibility for now, parser can't deal with it
            return
        val = self.const_exp(node.children[1])
        setattr(var,name.leaf,val)

    def expand_enum(self, node, v, name):
        if hasattr(v, "enum"):
            if isinstance(v.default, ir.Const) \
                   and v.default.datatype == String:
                try:
                    val = self.find_index_nocase(v.enum.value, v.default.value)
                    v.default = ir.Const(val,node,Int)
                except ValueError:
                    msg = "%d: enum value '%s' invalid for param %s" % \
                          (node.pos, v.default.value, name)
                    raise TranslationError(msg)
        return v.default

    def param(self,node):
        # translate a param block
        
        # find if this is an enum, override type if so
        for child in node.children:
            if child.type == "set" and child.children[0].leaf == "enum":
                node.datatype = fracttypes.Int
                break

        if node.datatype == None:
            # datatype not specified. Must try to infer from default value
            # in the meantime, will assume it's complex
            datatype = fracttypes.Complex
        else:
            datatype = node.datatype

        # normalize name
        if node.leaf[0] == "@":
            name = node.leaf
        else:
            name = "@" + node.leaf

        # create param if not already present
        v = self.symbols.get(name)    
        set_v = False
        if not v:
            v = Var(datatype, default_value(datatype), node.pos)
            set_v = True

        # check only declared once
        if v.declared:
            self.raise_declare_error(v,node)
        
        v.declared = True
        
        # process settings        
        for child in node.children:
            if child.type == "set":
                self.paramsetting(child,v)
            else:
                self.error("%d: invalid statement in parameter block" % node.pos)

        if hasattr(v,"default") and v.default != None:
            if node.datatype == None:
                v.type = v.default.datatype
                v.value = default_value(v.type)

            v.default = self.expand_enum(node, v, name)
            v.default = self.const_convert(v.default,v.type)

        # if we created new var, write it back
        if set_v:
            self.symbols[name] = v

    def funcsetting(self,node,func):
        name = node.children[0].leaf
        if name == "default":
            fname = node.children[1].leaf
            fol = self.symbols.get(fname)
            if fol == None:
                msg = "%d: unknown default function '%s'" % (node.pos,fname)
                raise TranslationError(msg)
                
            # is there an overload which matches our args?
            typelist = func.args
            found = False
            for ol in fol:
                if ol.matchesArgs(typelist) and ol.ret == func.ret:
                    found = True
                    break

            if not found:
                # no suitable overload discovered, modify our type
                f = fol[0]
                func.ret = f.ret
                func.args = f.args
            
            func.set_func(stdlib,fname)
        elif name == "visible":
            # fixme can't deal with visibility calculations yet
            return
        elif name == "argtype":
            func.args = [node.datatype]
        else:
            val = self.const_exp(node.children[1])
            setattr(func,name,val)
        
    def func(self, node):
        # translate a func block
        name = "@" + node.leaf

        fol = self.symbols.get(name)
        set_f = False
        if not fol:
            # FIXME make more general
            argtype = [Complex]
            fname = "ident"
            if node.datatype == Hyper:
                argtype = [Hyper]
            elif node.datatype == Color:
                argtype = [Color, Color]
                fname = "mergenormal"
            f = Func(argtype,node.datatype,stdlib,fname)
            set_f = True
        else:
            # check only declared once
            if fol.declared:
                self.raise_declare_error(fol,node)
            f = fol[0]

        # create func
        for child in node.children:
            if child.type == "set":
                self.funcsetting(child,f)
            else:
                self.error("%d: invalid statement in func block" % node.pos)

        if set_f:
            fol = fsymbol.OverloadList([f])
            fol.declared = True
            self.symbols[name] = fol 

    def raise_declare_error(self, obj, node):
        type = isinstance(obj, fracttypes.Var) and "parameter" or "function"
        msg = "%d: %s '%s' has already been declared" % (node.pos, type, node.leaf)
        raise TranslationError(msg)

    def setting(self,node):
        if node.type == "param":
            return self.param(node)
        elif node.type == "func":
            return self.func(node)
        elif node.type == "heading":
            #print "heading"
            pass
        elif node.type == "set":
            return self.set(node)
        else:
            self.error("%d: invalid statement in default section" % node.pos)

    def make_const(self, node, type):
        parts = []
        for i in xrange(len(node.children)):
            parts.append(self.const_convert(
                self.const_exp(node.children[i]), fracttypes.Float))
        return ir.Const(parts, node, type)
    
    def const_exp(self,node):
        # FIXME should compute full constant expressions
        if node.type == "const":
            return self.const(node)
        elif node.type == "binop" and node.leaf == "complex":
            re = self.const_convert(self.const_exp(node.children[0]),
                                    fracttypes.Float)
            im = self.const_convert(self.const_exp(node.children[1]),
                                    fracttypes.Float)

            return ir.Const([re, im],node,fracttypes.Complex)
        
        elif node.type == "unop" and node.leaf == "t__neg":
            val = self.const_exp(node.children[0])
            val.value = -val.value
            return val
        elif node.type == "string":
            return self.string(node)
        elif node.type == "funcall" and node.leaf == "hyper":
            return self.make_const(node, fracttypes.Hyper)
        elif node.type == "funcall" and node.leaf == "rgb":
            const = self.make_const(node, fracttypes.Color)
            const.children.append(
                ir.Const(1.0, node, fracttypes.Float))
            return const
        elif node.type == "funcall" and node.leaf == "rgba":
            return self.make_const(node, fracttypes.Color)
        else:
            #print node.pretty()
            self.error("%d: only constants can be used in default sections" %
                       node.pos)

    def const_convert(self,val,type_out):
        if not fracttypes.canBeCast(val.datatype,type_out):
            self.error("%d: Cannot convert %s (%s) to %s" % \
                  (val.node.pos, fracttypes.strOfType(val.datatype),
                   val.value, fracttypes.strOfType(type_out)))            
            return val
        
        if val.datatype == type_out:
            return val

        retval = ir.Const(fracttypes.default_value(type_out),
                          val.node,type_out)
        
        if val.datatype == fracttypes.Complex:
            if type_out == fracttypes.Bool or \
               type_out == fracttypes.Int or \
               type_out == fracttypes.Float:
                retval.value = float(val.value[0])
            else:
                raise Exception("ICE: Weird types in const_convert")
        elif type_out == fracttypes.Complex:
            retval.value = [ir.Const(float(val.value),val.node,fracttypes.Float),
                            ir.Const(0.0,val.node,fracttypes.Float)]
        else:
            retval.value = float(val.value)
            
        return retval

    def is4D(self):
        return self.symbols.has_user_key("#zwpixel")

    def set(self,node):
        name = node.children[0].leaf
        if name == "method":
            # skip this, we don't use it
            return
        val = node.children[1]
        self.defaults[name] = self.const_exp(val)
    
    def stmlist(self, node):
        children = filter(lambda c : c.type != "empty", node.children)
        seq = ir.Seq(map(lambda c: self.stm(c), children), node)
        return seq

    def stmlist_with_label(self, node, label):        
        seq = self.stmlist(node)
        seq.children.insert(0, label)
        return seq
    
    def stm(self,node):
        if node.type == "decl":
            r = self.decl(node)
        elif node.type == "assign":
            r = self.assign(node)
        elif node.type == "if":
            r = self.if_(node)
        elif node.type == "while":
            r = self.while_(node)
        else:
            r = self.exp(node)
        return r

    def isCompare(self,node):
        op = node.leaf
        return node.type == "binop" and \
               (op == ">" or op == ">=" or op == "<" or op == "<=" or \
                op == "==" or op == "!=")

    def isShortcut(self,node):
        op = node.leaf
        return node.type == "binop" and (op == '&&' or op == '||')

    def newLabel(self,node):
        return ir.Label(self.symbols.newLabel(),node)

    def newTemp(self, node):
        return ir.Var(self.symbols.newTemp(node.datatype),node, node.datatype)
    
    def makeCompare(self,node):
        'convert a node into a comparison op'
        if not self.isCompare(node):
            # insert a "fake" comparison to zero
            node = Binop('!=', node, Const(0,node.pos), node.pos)
        return node

    def while_(self, node):
        '''the result of a while loop is:
        seq(
        label(start)
        cjump(test, end, body)
        seq(label(body), bodyCode, jump start)
        label(end)
        )'''
        start = self.newLabel(node)
        body = self.newLabel(node)
        end = self.newLabel(node)

        node.children[0] = self.makeCompare(node.children[0])

        # convert boolean operation
        children = map(lambda n : self.exp(n) , node.children[0].children)
        children = self.expand_enums(node, children)
        op = self.findOp(node.children[0].leaf, node.children[0].pos,children)
        convertedChildren = self.coerceList(op.args,children)

        # convert main block of code inside while loop
        bodyCode = self.stmlist_with_label(node.children[1],body)
        bodyCode.children.append(ir.Jump(start.name, node))
        
        # construct actual if operation
        test = ir.CJump(node.children[0].leaf,
                        convertedChildren[0],
                        convertedChildren[1],
                        body.name, end.name, node)

        # overall code
        whilestm = ir.Seq([start,test,bodyCode,end],node)
        return whilestm
        
    def if_(self,node):
        '''the result of an if is:
        seq(
            cjump(test,falseDest,trueDest)
            seq(label(trueDest), trueCode, jump end)
            seq(label(falseDest), falseCode)
            label(end)
        )'''
        
        trueDest = self.newLabel(node)
        falseDest = self.newLabel(node)
        doneDest = self.newLabel(node)

        node.children[0] = self.makeCompare(node.children[0])
        
        # convert boolean operation
        children = map(lambda n : self.exp(n) , node.children[0].children)
        children = self.expand_enums(node, children)
        op = self.findOp(node.children[0].leaf, node.children[0].pos,children)
        convertedChildren = self.coerceList(op.args,children)

        # convert blocks of code we jump to
        trueBlock = self.stmlist_with_label(node.children[1],trueDest)
        trueBlock.children.append(ir.Jump(doneDest.name, node))

        falseBlock = self.stmlist_with_label(node.children[2], falseDest)
        
        # construct actual if operation
        test = ir.CJump(node.children[0].leaf,
                         convertedChildren[0],
                         convertedChildren[1],
                         trueDest.name, falseDest.name, node)

        # overall code
        ifstm = ir.Seq([test,trueBlock,falseBlock,doneDest],node)
        return ifstm
        
    def assign(self, node):
        '''assign a new value to a variable, creating it if required'''
        lvalue = node.children[0]
        lhs = expectedType = None
        if lvalue.type == "id":
            name = lvalue.leaf
            if not self.symbols.has_key(name):
                # implicitly create a new var - a warning?
                self.symbols[name] = \
                    Var(Complex,default_value(Complex),lvalue.pos)

            if isinstance(self.symbols[name],fracttypes.Var): 
                expectedType = self.symbols[name].type
            else:
                msg = "%d: %s is not a variable, assignment to it is not allowed" % (node.pos, name)
                raise TranslationError(msg)
            
            lhs = ir.Var(name, node, expectedType)
            
        elif lvalue.type == "funcall":
            lhs = self.funcall(lvalue)
            expectedType = lhs.datatype
        else:
            self.error("Internal Compiler Error: bad lvalue %s for assign on %d:"\
                       % (lvalue.type, node.pos))
        rhs = self.exp(node.children[1])

        return ir.Move(lhs,self.coerce(rhs,expectedType),node,expectedType)

    def findOp(self, func, pos, list):
        ' find the most appropriate overload for this op'
        try:
            overloadList = self.symbols[func]
        except KeyError:
            if func[0] == "@":
                # an attempt to call an undeclared parameter function,
                # create it now. Point to ident by default
                overloadList = self.symbols[func] = fsymbol.OverloadList([
                    Func([Complex],Complex,stdlib,"ident")])
            else:
                raise
        
        typelist = map(lambda ir : ir.datatype , list)
        for ol in overloadList:
            if ol.matchesArgs(typelist):
                return ol
        
        raise TranslationError(
            "Invalid argument types %s for %s on line %s" % \
            (map(fracttypes.strOfType,typelist), func, pos))
    
    def decl(self,node):
        if node.children:
            exp = self.stm(node.children[0])
        else:
            # default initializer
            exp = ir.Const(fracttypes.default_value(node.datatype),
                           node, node.datatype)

        try:
            self.symbols[node.leaf] = Var(node.datatype,
                                          default_value(node.datatype), node.pos)
            return ir.Move(
                ir.Var(node.leaf, node, node.datatype),                
                self.coerce(exp, node.datatype),
                node, node.datatype)
        
        except KeyError, e:
            self.error("Invalid declaration on line %d: %s" % (node.pos,e))

    def exp(self,node):
        if node.type == "const":
            r = self.const(node)
        elif node.type == "id":
            r = self.id(node)
        elif node.type == "binop":
            r = self.binop(node)
        elif node.type == "unop":
            r = self.unop(node)
        elif node.type == "funcall":
            r = self.funcall(node)
        elif node.type == "assign":
            r = self.assign(node)
        elif node.type == "string":
            r = self.string(node)
        else:
            self.badNode(node,"exp")

        return r

    def seq_with_label(self,stm,label, node):
        return ir.Seq([label, stm], node)

    def unop(self, node):
        children = map(lambda n: self.exp(n) , node.children)
        op = self.findOp(node.leaf, node.pos,children)
        children = self.coerceList(op.args,children)
        return ir.Unop(node.leaf, children, node, op.ret)

    def funcall(self, node):
        children = map(lambda n: self.exp(n) , node.children)
        try:
            op = self.findOp(node.leaf, node.pos, children)
        except TranslationError, err:
            # hack to support old Fractint formulas which use exp(1,0)
            # instead of exp((1,0))
            # convert the args into a single complex and see if call
            try:
                cop = self.findOp('complex',node.pos,children)
                children = self.coerceList(cop.args,children)
                children = [ir.Binop("complex", children, node, cop.ret)]
                op = self.findOp(node.leaf, node.pos,children)
            except Exception, err2:
                raise err
            
        except KeyError, err:
            raise TranslationError(
                    "Unknown function %s on line %d" % (node.leaf,node.pos))

        children = self.coerceList(op.args,children)
        return ir.Call(node.leaf, children, node, op.ret)
    
    def shortcut(self, node):
        # convert into an if-expression
        trueDest = self.newLabel(node)
        falseDest = self.newLabel(node)
        doneDest = self.newLabel(node)
        
        node.children[0] = self.makeCompare(node.children[0])

        children = map(lambda n : self.exp(n) , node.children)        
        op = self.findOp(node.leaf, node.pos ,children)
        children = self.coerceList(op.args,children)

        temp = ir.Var(self.symbols.newTemp(Bool),node, Bool)
        
        # a && b = eseq(if(a) then t = (bool)b else t = false; t)
        #        = eseq(cjump(==,a,0,td,fd),
        #               lab(td),move(t,b),jmp(end),
        #               lab(fd),move(t,0),jmp(end),
        #               lab(end), t)
        if node.leaf == "&&":
            # code to calc B and store in temp
            trueBlock = ir.Seq(
                [trueDest, ir.Move(temp, children[1],node, children[1].datatype),
                 ir.Jump(doneDest.name, node)], node)
            
            # code to set temp to false
            falseBlock = ir.Seq(
                [falseDest,
                 ir.Move(temp, ir.Const(0,node,Bool),node, Bool),
                 ir.Jump(doneDest.name, node)], node)
            
        else:
            # a || b = eseq(if(a) then t = true else t = (bool)b; t)

            # code to set temp to true
            trueBlock = ir.Seq(
                [trueDest,
                 ir.Move(temp, ir.Const(1,node,Bool),node, Bool),
                 ir.Jump(doneDest.name, node)], node)

            # set temp to (bool)b
            falseBlock = ir.Seq(
                [falseDest,
                 ir.Move(temp, children[1],node, children[1].datatype),
                 ir.Jump(doneDest.name, node)], node)
            
        # construct actual if operation
        test = ir.CJump(children[0].op,
                        children[0].children[0],
                        children[0].children[1],
                        trueDest.name, falseDest.name, node)
        
        r = ir.ESeq([test, trueBlock, falseBlock, doneDest],
                    temp, node, op.ret)
        return r

    def find_index_nocase(self,list,value):
        i = 0
        v = value.lower()
        for item in list:
            if item.lower() == v:
                return i
            i += 1
        raise ValueError, "not found"
    
    def expand_enums(self, node, children):
        'special case for @foo <binop> "enum"'
        lhs = children[0]
        rhs = children[1]
        if isinstance(lhs, ir.Var):
            var = self.symbols[lhs.name]
            if hasattr(var, "enum"):
                if isinstance(rhs, ir.Const) and rhs.datatype == String:
                    try:
                        val = self.find_index_nocase(var.enum.value,rhs.value)
                        children[1] = ir.Const(val,node,Int)
                    except ValueError:
                        msg = "%d: enum value '%s' invalid for param %s" % \
                              (node.pos, rhs.value, lhs.name)
                        raise TranslationError(msg)
                    
        return children
    
    def binop(self, node):
        if self.isShortcut(node):
            return self.shortcut(node)
        else:
            children = map(lambda n : self.exp(n) , node.children)
            children = self.expand_enums(node, children)
            op = self.findOp(node.leaf, node.pos,children)
            children = self.coerceList(op.args,children)

            return ir.Binop(node.leaf,
                            children,
                            node,op.ret)
    
    def id(self, node):
        try:
            node.datatype = self.symbols[node.leaf].type
        except KeyError, e:
            self.warning(
                "Uninitialized variable %s referenced on line %d" % \
                (node.leaf, node.pos))
            try:
                self.symbols[node.leaf] = Var(
                    fracttypes.Complex, default_value(Complex), node.pos)
            except KeyError, e:
                raise TranslationError("%d: %s" % (node.pos, e.args[0]))
            
            node.datatype = fracttypes.Complex
        except AttributeError:
            # if this is a function, it's an error unless it has an overload
            # which takes no arguments
            try:
                op = self.findOp(node.leaf, node.pos, [])
                return ir.Call(node.leaf, [], node, op.ret)
            except TranslationError:
                # couldn't find one, treat this as an accidental function use
                pass
            
            msg = "%d: '%s' is a function name and cannot be used here. Perhaps you meant to call the function instead?" % \
                      (node.pos, node.leaf)
            raise TranslationError(msg)
        
        return ir.Var(node.leaf, node, node.datatype)
        
    def const(self,node):
        return ir.Const(node.leaf, node, node.datatype)        

    def string(self,node):
        if node.children == None or node.children == []:
            return ir.Const(node.leaf, node, node.datatype)
        else:
            strings = [node.leaf]
            strings += map(lambda n : n.leaf, node.children)
            return ir.Enum(strings, node, node.datatype)
    
    def coerceList(self,expList,typeList):
        return map( lambda (exp,ty) : self.coerce(exp,ty) ,
                    zip(typeList, expList))
    
    def coerce(self, exp, expectedType):
        '''insert code to cast exp to expectedType 
           or produce an error if conversion is not permitted'''

        #if exp.datatype == None or expectedType == None:
        #    raise TranslationError("Internal Compiler Error: coercing an untyped node")
        if exp.datatype == expectedType:
            return exp

        if fracttypes.canBeCast(exp.datatype, expectedType):
            self.warnCast(exp, expectedType)
            return ir.Cast(exp, exp.node, expectedType)
        else:
            self.badCast(exp,expectedType)
            
    def init(self,node):
        self.add_to_section("init", self.stmlist(node))

    def loop(self, node):
        self.add_to_section("loop",self.stmlist(node))

    def bailout(self,node):
        # ensure that last stm is a bool
        if self.sections.get("bailout"):
            raise TranslationError("Internal Compiler Error: conflicting bailouts")
        bailList = self.stmlist(node)
        try:
            bail_stm = self.coerce(bailList.children[-1],Bool)
            # manufacture a Move so not discarded by codegen
            bail_stm = ir.Move(
                ir.Var("__bailout",node, Bool),
                bail_stm,node,Bool)
            bailList.children[-1] = bail_stm            
            self.sections["bailout"] = bailList
        except IndexError:
            self.warnings.append("No bailout expression found. Calculation will never bail out.")

    def badNode(self, node, rule):
        msg = "Internal Compiler Error: Unexpected node '%s' in %s" % \
            (node.type, rule)
        raise TranslationError(msg)

    def badCast(self, exp, expectedType):
        raise TranslationError(
           ("invalid type %s for %s on line %s, expecting %s" %
            (strOfType(exp.datatype), exp.node.leaf, exp.node.pos, strOfType(expectedType))))
    def warnCast(self,exp,expectedType):
        msg = "Warning: conversion from %s to %s on line %s" % \
        (strOfType(exp.datatype), strOfType(expectedType), exp.node.pos)
        self.warnings.append(msg)

class T(TBase):
    def __init__(self,f,dump=None):
        TBase.__init__(self,"f",dump)

        # magic vars always included in funcs
        self.symbols["__bailout"] = Var(Bool, 0)

        try:
            self.main(f)
            if self.dumpPreCanon:
                self.dumpSections(f,self.sections)
            self.canonicalize()
        except TranslationError, e:
            self.errors.append(e.msg)

        self.post_init()

    def main(self, f):
        if len(f.children) == 0:
            return
        
        if f.children[0].type == "error":
            self.error(f.children[0].leaf)
            return

        self.canonicalizeSections(f)

        # reference gradient, even if user doesn't do so explicitly
        self.symbols.ensure("@_gradient", Var(Gradient, 0, -1))
        self.symbols["@_gradient"].default = ir.Const(0, f, Gradient)
        
        # lookup sections in order
        s = f.childByName("default")
        if s: self.default(s)
        s = f.childByName("global")
        if s: self.global_(s)
        s = f.childByName("init")
        if s: self.init(s)
        s = f.childByName("loop")
        if s: self.loop(s)
        s = f.childByName("bailout")
        if s: self.bailout(s)
        s = f.childByName("final")
        if s: self.final(s)

        #  ignore switch and builtin for now

    def canonicalizeSections(self,f):        
        '''a nameless section (started by ':') is the same as a loop
           section with the last stm as a bailout section - make this
           change'''

        # a "nameless" section is really an init section
        s = f.childByName("nameless")
        if s and s.children != []:
            oldinit = f.childByName("init")
            if oldinit:
                self.dupSectionWarning("init")
            else:
                s.leaf = "init"
        
        s = f.childByName("")
        if not s or s.children == []:
            return
        elif len(s.children) == 1:
            self.warning("No bailout condition specified")
            bailout = []
            loop = s.children
        else:
            bailout = [s.children[-1]]
            loop = s.children[:-1]
            
        oldbailout = f.childByName("bailout")
        if oldbailout:
            self.dupSectionWarning("bailout")
        else:
            f.children.append(Stmlist("bailout",bailout, -1))
        
        oldloop = f.childByName("loop")
        if oldloop:
            self.dupSectionWarning("loop")
        else:
            f.children.append(Stmlist("loop",loop,loop[0].pos))

        f.children.remove(s)

        if self.dumpCanon:
            print f.pretty()

class ParFile(TBase):
    "For translating Fractint .par files"
    def __init__(self,f,dump=None):
        TBase.__init__(self,"g",dump)

        self.grad = []
        self.main(f)
        
    def main(self, f):
        if len(f.children) == 0:
            return
        
        if f.children[0].type == "error":
            self.error(f.children[0].leaf)
            return

        # lookup sections in order
        s = f.childByName("nameless")
        if s: self.params(s)

    def params(self, node):
        self.add_to_section("gradient", self.setlist(node))
        
    def set(self,node):
        name = node.children[0].leaf
        val = self.const_exp(node.children[1])
        return ir.Move(
            ir.Var(name, node, val.datatype),
            val, node, val.datatype)
    
class GradientFunc(TBase):
    "For translating UltraFractal .ugr files"
    def __init__(self,f,dump=None):
        TBase.__init__(self,"g",dump)

        self.grad = []
        self.main(f)
        
    def main(self, f):
        if len(f.children) == 0:
            return
        
        if f.children[0].type == "error":
            self.error(f.children[0].leaf)
            return

        # lookup sections in order
        s = f.childByName("gradient")
        if s: self.gradient(s)
        s = f.childByName("opacity")
        if s: self.opacity(s)

    def gradient(self, node):
        self.add_to_section("gradient", self.setlist(node))
        
    def opacity(self, node):
        self.add_to_section("opacity",self.setlist(node))

    def set(self,node):
        name = node.children[0].leaf
        val = self.const_exp(node.children[1])
        return ir.Move(
            ir.Var(name, node, val.datatype),
            val, node, val.datatype)
        
class ColorFunc(TBase):
    "For translating .ucl files"
    def __init__(self,f,name,dump=None):
        TBase.__init__(self,name,dump)

        # magic vars always included in colorfuncs
        density = Var(Float, 0.0, -1)
        density.default = ir.Const(1.0,-1,fracttypes.Float)
        
        self.symbols["@_offset"] = Var(Float, 0.0, -1)
        self.symbols["@_density"] = density

        try:
            self.main(f)
            if self.dumpPreCanon:
                self.dumpSections(f,self.sections)
            self.canonicalize()
        except TranslationError, e:
            self.errors.append(e.msg)

        self.post_init()

    def index_calc(self, var):
        # @transfer(var) * @density + @offset
        return \
            Binop('+', 
                  Binop('*', 
                        ID("@_density",-1),
                        Funcall("@_transfer",[var],-1), -1),
                  ID("@_offset",-1),-1)

    def funcall(self, node):
        # special handling for gradient function to insert density,
        # offset and transfer
        if node.leaf == "gradient":
            children = [ self.exp(self.index_calc(node.children[0]))]
            op = self.findOp(node.leaf, node.pos, children)
            children = self.coerceList(op.args,children)
            return ir.Call(node.leaf, children, node, op.ret)
        else:
            return TBase.funcall(self,node)

    def final(self,f):
        # append [#index = @transfer(#index) * @density + @offset]
        transfer = Stmlist(
            "",
            [ Assign(ID("#index",-1), self.index_calc(ID("#index",-1)), -1)],
            -1)
        
        TBase.final(self,f)
        TBase.final(self,transfer)
        
    def main(self,f):
        if f.children[0].type == "error":
            self.error(f.children[0].leaf)
            return
            
        self.canonicalizeSections(f)
        s = f.childByName("default")
        if s: self.default(s)
        s = f.childByName("global")
        if s: self.global_(s)
        s = f.childByName("init")
        if s:
            self.init(s)
        s = f.childByName("loop")
        if s: self.loop(s)
        s = f.childByName("final")
        if s: self.final(s)

    def canonicalizeSections(self,f):
        '''if there are no section headers in a colorfunc,
        just a final block is implied'''
        s = f.childByName("nameless")
        if s:
            oldfinal = f.childByName("final")
            if oldfinal:
                self.dupSectionWarning("final")
            else:
                s.leaf = "final"

        if self.dumpCanon:
            print f.pretty()

parser = fractparser.parser

def main(args):
    for arg in args:
        s = open(arg,"r").read() # read in a whole file
        result = parser.parse(s)
        for formula in result.children:
            print formula.leaf
            t = T(formula)
            if t.errors != []:
                print "Errors translating %s:" % formula.leaf
                for e in t.errors:
                    print "\t",e

# debugging
if __name__ == '__main__':
    main(sys.argv[1:])