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
}
func TestSimplifyFalseLeaf(t *testing.T) {
input := combinator.Value(funcs.And(funcs.StringEq(funcs.StringVar(), funcs.StringConst("a")), funcs.StringEq(funcs.StringVar(), funcs.StringConst("b"))))
expected := ast.NewNot(ast.NewZAny())
output := NewSimplifier(input.Grammar()).Simplify(input)
t.Logf("%v", output)
if !expected.Equal(output) {
t.Fatalf("expected %v, but got %v", expected, output)
}
}
func TestSimplifyRecordLeaf2(t *testing.T) {
input := ast.NewAnd(
ast.NewContains(ast.NewTreeNode(ast.NewStringName("A"), ast.NewContains(ast.NewTreeNode(ast.NewStringName("B"), combinator.Value(funcs.Contains(funcs.StringVar(), funcs.StringConst("a"))))))),
ast.NewContains(ast.NewTreeNode(ast.NewStringName("A"), ast.NewContains(ast.NewTreeNode(ast.NewStringName("B"), combinator.Value(funcs.Contains(funcs.StringVar(), funcs.StringConst("b"))))))),
)
t.Logf("input: %v", input)
expected := ast.NewContains(ast.NewTreeNode(ast.NewStringName("A"), ast.NewContains(ast.NewTreeNode(ast.NewStringName("B"), combinator.Value(funcs.And(
funcs.Contains(funcs.StringVar(), funcs.StringConst("a")),
funcs.Contains(funcs.StringVar(), funcs.StringConst("b")),
))))))
output := NewSimplifier(input.Grammar()).OptimizeForRecord().Simplify(input)
expected.Format()
output.Format()
t.Logf("%v", output)
if !expected.Equal(output) {
t.Fatalf("expected %v, but got %v", expected, output)
}
}
