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mirror of https://github.com/miguelmota/cointop synced 2024-11-10 13:10:26 +00:00
cointop/vendor/github.com/antonmedv/expr/checker/checker.go
2021-08-31 07:58:56 +10:00

616 lines
14 KiB
Go

package checker
import (
"fmt"
"reflect"
"github.com/antonmedv/expr/ast"
"github.com/antonmedv/expr/conf"
"github.com/antonmedv/expr/file"
"github.com/antonmedv/expr/parser"
)
var errorType = reflect.TypeOf((*error)(nil)).Elem()
func Check(tree *parser.Tree, config *conf.Config) (reflect.Type, error) {
v := &visitor{
collections: make([]reflect.Type, 0),
}
if config != nil {
v.types = config.Types
v.operators = config.Operators
v.expect = config.Expect
v.strict = config.Strict
v.defaultType = config.DefaultType
}
t := v.visit(tree.Node)
if v.expect != reflect.Invalid {
switch v.expect {
case reflect.Int64, reflect.Float64:
if !isNumber(t) {
return nil, fmt.Errorf("expected %v, but got %v", v.expect, t)
}
default:
if t.Kind() != v.expect {
return nil, fmt.Errorf("expected %v, but got %v", v.expect, t)
}
}
}
if v.err != nil {
return t, v.err.Bind(tree.Source)
}
return t, nil
}
type visitor struct {
types conf.TypesTable
operators conf.OperatorsTable
expect reflect.Kind
collections []reflect.Type
strict bool
defaultType reflect.Type
err *file.Error
}
func (v *visitor) visit(node ast.Node) reflect.Type {
var t reflect.Type
switch n := node.(type) {
case *ast.NilNode:
t = v.NilNode(n)
case *ast.IdentifierNode:
t = v.IdentifierNode(n)
case *ast.IntegerNode:
t = v.IntegerNode(n)
case *ast.FloatNode:
t = v.FloatNode(n)
case *ast.BoolNode:
t = v.BoolNode(n)
case *ast.StringNode:
t = v.StringNode(n)
case *ast.ConstantNode:
t = v.ConstantNode(n)
case *ast.UnaryNode:
t = v.UnaryNode(n)
case *ast.BinaryNode:
t = v.BinaryNode(n)
case *ast.MatchesNode:
t = v.MatchesNode(n)
case *ast.PropertyNode:
t = v.PropertyNode(n)
case *ast.IndexNode:
t = v.IndexNode(n)
case *ast.SliceNode:
t = v.SliceNode(n)
case *ast.MethodNode:
t = v.MethodNode(n)
case *ast.FunctionNode:
t = v.FunctionNode(n)
case *ast.BuiltinNode:
t = v.BuiltinNode(n)
case *ast.ClosureNode:
t = v.ClosureNode(n)
case *ast.PointerNode:
t = v.PointerNode(n)
case *ast.ConditionalNode:
t = v.ConditionalNode(n)
case *ast.ArrayNode:
t = v.ArrayNode(n)
case *ast.MapNode:
t = v.MapNode(n)
case *ast.PairNode:
t = v.PairNode(n)
default:
panic(fmt.Sprintf("undefined node type (%T)", node))
}
node.SetType(t)
return t
}
func (v *visitor) error(node ast.Node, format string, args ...interface{}) reflect.Type {
if v.err == nil { // show first error
v.err = &file.Error{
Location: node.Location(),
Message: fmt.Sprintf(format, args...),
}
}
return interfaceType // interface represent undefined type
}
func (v *visitor) NilNode(*ast.NilNode) reflect.Type {
return nilType
}
func (v *visitor) IdentifierNode(node *ast.IdentifierNode) reflect.Type {
if v.types == nil {
return interfaceType
}
if t, ok := v.types[node.Value]; ok {
if t.Ambiguous {
return v.error(node, "ambiguous identifier %v", node.Value)
}
return t.Type
}
if !v.strict {
if v.defaultType != nil {
return v.defaultType
}
return interfaceType
}
if !node.NilSafe {
return v.error(node, "unknown name %v", node.Value)
}
return nilType
}
func (v *visitor) IntegerNode(*ast.IntegerNode) reflect.Type {
return integerType
}
func (v *visitor) FloatNode(*ast.FloatNode) reflect.Type {
return floatType
}
func (v *visitor) BoolNode(*ast.BoolNode) reflect.Type {
return boolType
}
func (v *visitor) StringNode(*ast.StringNode) reflect.Type {
return stringType
}
func (v *visitor) ConstantNode(node *ast.ConstantNode) reflect.Type {
return reflect.TypeOf(node.Value)
}
func (v *visitor) UnaryNode(node *ast.UnaryNode) reflect.Type {
t := v.visit(node.Node)
switch node.Operator {
case "!", "not":
if isBool(t) {
return boolType
}
case "+", "-":
if isNumber(t) {
return t
}
default:
return v.error(node, "unknown operator (%v)", node.Operator)
}
return v.error(node, `invalid operation: %v (mismatched type %v)`, node.Operator, t)
}
func (v *visitor) BinaryNode(node *ast.BinaryNode) reflect.Type {
l := v.visit(node.Left)
r := v.visit(node.Right)
// check operator overloading
if fns, ok := v.operators[node.Operator]; ok {
t, _, ok := conf.FindSuitableOperatorOverload(fns, v.types, l, r)
if ok {
return t
}
}
switch node.Operator {
case "==", "!=":
if isNumber(l) && isNumber(r) {
return boolType
}
if isComparable(l, r) {
return boolType
}
case "or", "||", "and", "&&":
if isBool(l) && isBool(r) {
return boolType
}
case "in", "not in":
if isString(l) && isStruct(r) {
return boolType
}
if isMap(r) {
return boolType
}
if isArray(r) {
return boolType
}
case "<", ">", ">=", "<=":
if isNumber(l) && isNumber(r) {
return boolType
}
if isString(l) && isString(r) {
return boolType
}
case "/", "-", "*":
if isNumber(l) && isNumber(r) {
return combined(l, r)
}
case "**":
if isNumber(l) && isNumber(r) {
return floatType
}
case "%":
if isInteger(l) && isInteger(r) {
return combined(l, r)
}
case "+":
if isNumber(l) && isNumber(r) {
return combined(l, r)
}
if isString(l) && isString(r) {
return stringType
}
case "contains", "startsWith", "endsWith":
if isString(l) && isString(r) {
return boolType
}
case "..":
if isInteger(l) && isInteger(r) {
return reflect.SliceOf(integerType)
}
default:
return v.error(node, "unknown operator (%v)", node.Operator)
}
return v.error(node, `invalid operation: %v (mismatched types %v and %v)`, node.Operator, l, r)
}
func (v *visitor) MatchesNode(node *ast.MatchesNode) reflect.Type {
l := v.visit(node.Left)
r := v.visit(node.Right)
if isString(l) && isString(r) {
return boolType
}
return v.error(node, `invalid operation: matches (mismatched types %v and %v)`, l, r)
}
func (v *visitor) PropertyNode(node *ast.PropertyNode) reflect.Type {
t := v.visit(node.Node)
if t, ok := fieldType(t, node.Property); ok {
return t
}
if !node.NilSafe {
return v.error(node, "type %v has no field %v", t, node.Property)
}
return nil
}
func (v *visitor) IndexNode(node *ast.IndexNode) reflect.Type {
t := v.visit(node.Node)
i := v.visit(node.Index)
if t, ok := indexType(t); ok {
if !isInteger(i) && !isString(i) {
return v.error(node, "invalid operation: cannot use %v as index to %v", i, t)
}
return t
}
return v.error(node, "invalid operation: type %v does not support indexing", t)
}
func (v *visitor) SliceNode(node *ast.SliceNode) reflect.Type {
t := v.visit(node.Node)
_, isIndex := indexType(t)
if isIndex || isString(t) {
if node.From != nil {
from := v.visit(node.From)
if !isInteger(from) {
return v.error(node.From, "invalid operation: non-integer slice index %v", from)
}
}
if node.To != nil {
to := v.visit(node.To)
if !isInteger(to) {
return v.error(node.To, "invalid operation: non-integer slice index %v", to)
}
}
return t
}
return v.error(node, "invalid operation: cannot slice %v", t)
}
func (v *visitor) FunctionNode(node *ast.FunctionNode) reflect.Type {
if f, ok := v.types[node.Name]; ok {
if fn, ok := isFuncType(f.Type); ok {
inputParamsCount := 1 // for functions
if f.Method {
inputParamsCount = 2 // for methods
}
if !isInterface(fn) &&
fn.IsVariadic() &&
fn.NumIn() == inputParamsCount &&
((fn.NumOut() == 1 && // Function with one return value
fn.Out(0).Kind() == reflect.Interface) ||
(fn.NumOut() == 2 && // Function with one return value and an error
fn.Out(0).Kind() == reflect.Interface &&
fn.Out(1) == errorType)) {
rest := fn.In(fn.NumIn() - 1) // function has only one param for functions and two for methods
if rest.Kind() == reflect.Slice && rest.Elem().Kind() == reflect.Interface {
node.Fast = true
}
}
return v.checkFunc(fn, f.Method, node, node.Name, node.Arguments)
}
}
if !v.strict {
if v.defaultType != nil {
return v.defaultType
}
return interfaceType
}
return v.error(node, "unknown func %v", node.Name)
}
func (v *visitor) MethodNode(node *ast.MethodNode) reflect.Type {
t := v.visit(node.Node)
if f, method, ok := methodType(t, node.Method); ok {
if fn, ok := isFuncType(f); ok {
return v.checkFunc(fn, method, node, node.Method, node.Arguments)
}
}
if !node.NilSafe {
return v.error(node, "type %v has no method %v", t, node.Method)
}
return nil
}
// checkFunc checks func arguments and returns "return type" of func or method.
func (v *visitor) checkFunc(fn reflect.Type, method bool, node ast.Node, name string, arguments []ast.Node) reflect.Type {
if isInterface(fn) {
return interfaceType
}
if fn.NumOut() == 0 {
return v.error(node, "func %v doesn't return value", name)
}
if numOut := fn.NumOut(); numOut > 2 {
return v.error(node, "func %v returns more then two values", name)
}
numIn := fn.NumIn()
// If func is method on an env, first argument should be a receiver,
// and actual arguments less then numIn by one.
if method {
numIn--
}
if fn.IsVariadic() {
if len(arguments) < numIn-1 {
return v.error(node, "not enough arguments to call %v", name)
}
} else {
if len(arguments) > numIn {
return v.error(node, "too many arguments to call %v", name)
}
if len(arguments) < numIn {
return v.error(node, "not enough arguments to call %v", name)
}
}
offset := 0
// Skip first argument in case of the receiver.
if method {
offset = 1
}
for i, arg := range arguments {
t := v.visit(arg)
var in reflect.Type
if fn.IsVariadic() && i >= numIn-1 {
// For variadic arguments fn(xs ...int), go replaces type of xs (int) with ([]int).
// As we compare arguments one by one, we need underling type.
in = fn.In(fn.NumIn() - 1)
in, _ = indexType(in)
} else {
in = fn.In(i + offset)
}
if isIntegerOrArithmeticOperation(arg) {
t = in
setTypeForIntegers(arg, t)
}
if t == nil {
continue
}
if !t.AssignableTo(in) && t.Kind() != reflect.Interface {
return v.error(arg, "cannot use %v as argument (type %v) to call %v ", t, in, name)
}
}
return fn.Out(0)
}
func (v *visitor) BuiltinNode(node *ast.BuiltinNode) reflect.Type {
switch node.Name {
case "len":
param := v.visit(node.Arguments[0])
if isArray(param) || isMap(param) || isString(param) {
return integerType
}
return v.error(node, "invalid argument for len (type %v)", param)
case "all", "none", "any", "one":
collection := v.visit(node.Arguments[0])
if !isArray(collection) {
return v.error(node.Arguments[0], "builtin %v takes only array (got %v)", node.Name, collection)
}
v.collections = append(v.collections, collection)
closure := v.visit(node.Arguments[1])
v.collections = v.collections[:len(v.collections)-1]
if isFunc(closure) &&
closure.NumOut() == 1 &&
closure.NumIn() == 1 && isInterface(closure.In(0)) {
if !isBool(closure.Out(0)) {
return v.error(node.Arguments[1], "closure should return boolean (got %v)", closure.Out(0).String())
}
return boolType
}
return v.error(node.Arguments[1], "closure should has one input and one output param")
case "filter":
collection := v.visit(node.Arguments[0])
if !isArray(collection) {
return v.error(node.Arguments[0], "builtin %v takes only array (got %v)", node.Name, collection)
}
v.collections = append(v.collections, collection)
closure := v.visit(node.Arguments[1])
v.collections = v.collections[:len(v.collections)-1]
if isFunc(closure) &&
closure.NumOut() == 1 &&
closure.NumIn() == 1 && isInterface(closure.In(0)) {
if !isBool(closure.Out(0)) {
return v.error(node.Arguments[1], "closure should return boolean (got %v)", closure.Out(0).String())
}
if isInterface(collection) {
return arrayType
}
return reflect.SliceOf(collection.Elem())
}
return v.error(node.Arguments[1], "closure should has one input and one output param")
case "map":
collection := v.visit(node.Arguments[0])
if !isArray(collection) {
return v.error(node.Arguments[0], "builtin %v takes only array (got %v)", node.Name, collection)
}
v.collections = append(v.collections, collection)
closure := v.visit(node.Arguments[1])
v.collections = v.collections[:len(v.collections)-1]
if isFunc(closure) &&
closure.NumOut() == 1 &&
closure.NumIn() == 1 && isInterface(closure.In(0)) {
return reflect.SliceOf(closure.Out(0))
}
return v.error(node.Arguments[1], "closure should has one input and one output param")
case "count":
collection := v.visit(node.Arguments[0])
if !isArray(collection) {
return v.error(node.Arguments[0], "builtin %v takes only array (got %v)", node.Name, collection)
}
v.collections = append(v.collections, collection)
closure := v.visit(node.Arguments[1])
v.collections = v.collections[:len(v.collections)-1]
if isFunc(closure) &&
closure.NumOut() == 1 &&
closure.NumIn() == 1 && isInterface(closure.In(0)) {
if !isBool(closure.Out(0)) {
return v.error(node.Arguments[1], "closure should return boolean (got %v)", closure.Out(0).String())
}
return integerType
}
return v.error(node.Arguments[1], "closure should has one input and one output param")
default:
return v.error(node, "unknown builtin %v", node.Name)
}
}
func (v *visitor) ClosureNode(node *ast.ClosureNode) reflect.Type {
t := v.visit(node.Node)
return reflect.FuncOf([]reflect.Type{interfaceType}, []reflect.Type{t}, false)
}
func (v *visitor) PointerNode(node *ast.PointerNode) reflect.Type {
if len(v.collections) == 0 {
return v.error(node, "cannot use pointer accessor outside closure")
}
collection := v.collections[len(v.collections)-1]
if t, ok := indexType(collection); ok {
return t
}
return v.error(node, "cannot use %v as array", collection)
}
func (v *visitor) ConditionalNode(node *ast.ConditionalNode) reflect.Type {
c := v.visit(node.Cond)
if !isBool(c) {
return v.error(node.Cond, "non-bool expression (type %v) used as condition", c)
}
t1 := v.visit(node.Exp1)
t2 := v.visit(node.Exp2)
if t1 == nil && t2 != nil {
return t2
}
if t1 != nil && t2 == nil {
return t1
}
if t1 == nil && t2 == nil {
return nilType
}
if t1.AssignableTo(t2) {
return t1
}
return interfaceType
}
func (v *visitor) ArrayNode(node *ast.ArrayNode) reflect.Type {
for _, node := range node.Nodes {
_ = v.visit(node)
}
return arrayType
}
func (v *visitor) MapNode(node *ast.MapNode) reflect.Type {
for _, pair := range node.Pairs {
v.visit(pair)
}
return mapType
}
func (v *visitor) PairNode(node *ast.PairNode) reflect.Type {
v.visit(node.Key)
v.visit(node.Value)
return nilType
}