func (this *ifExprs) addIfExpr(cond funcs.Bool, then, els *ast.Pattern) {
// efficienctly append the then and else return to two copies of the current returns.
if this.ret != nil {
this.cond = cond
thenterms := make([]*ast.Pattern, len(this.ret)+1)
copy(thenterms, this.ret)
thenterms[len(thenterms)-1] = then
this.then = &ifExprs{ret: thenterms}
this.els = &ifExprs{ret: append(this.ret, els)}
this.ret = nil
return
}
// remove duplicate condition
if funcs.Equal(this.cond, cond) {
this.then.addReturn(then)
this.els.addReturn(els)
return
}
// remove impossible (always false) then condition
if funcs.IsFalse(funcs.Simplify(funcs.And(this.cond, cond))) {
this.then.addReturn(els)
this.els.addIfExpr(cond, then, els)
return
}
// remove impossible (always false) else condition
if funcs.IsFalse(funcs.Simplify(funcs.And(this.cond, funcs.Not(cond)))) {
this.then.addIfExpr(cond, then, els)
this.els.addReturn(then)
return
}
this.then.addIfExpr(cond, then, els)
this.els.addIfExpr(cond, then, els)
return
}
//NameToFunc compiles a parsed name expression into a function.
func NameToFunc(n *ast.NameExpr) funcs.Bool {
typ := n.GetValue()
switch v := typ.(type) {
case *ast.Name:
if v.DoubleValue != nil {
return funcs.DoubleEq(funcs.DoubleVar(), funcs.DoubleConst(v.GetDoubleValue()))
} else if v.IntValue != nil {
return funcs.IntEq(funcs.IntVar(), funcs.IntConst(v.GetIntValue()))
} else if v.UintValue != nil {
return funcs.UintEq(funcs.UintVar(), funcs.UintConst(v.GetUintValue()))
} else if v.BoolValue != nil {
return funcs.BoolEq(funcs.BoolVar(), funcs.BoolConst(v.GetBoolValue()))
} else if v.StringValue != nil {
return funcs.StringEq(funcs.StringVar(), funcs.StringConst(v.GetStringValue()))
} else if v.BytesValue != nil {
return funcs.BytesEq(funcs.BytesVar(), funcs.BytesConst(v.GetBytesValue()))
}
panic(fmt.Sprintf("unknown name expr name %#v", v))
case *ast.AnyName:
return funcs.BoolConst(true)
case *ast.AnyNameExcept:
return funcs.Not(NameToFunc(v.GetExcept()))
case *ast.NameChoice:
return funcs.Or(NameToFunc(v.GetLeft()), NameToFunc(v.GetRight()))
}
panic(fmt.Sprintf("unknown name expr typ %T", typ))
}