mirror of
https://github.com/ceph/ceph-csi.git
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845 lines
28 KiB
Go
845 lines
28 KiB
Go
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// Copyright 2023 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Package decls contains function and variable declaration structs and helper methods.
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package decls
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import (
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"fmt"
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"strings"
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chkdecls "github.com/google/cel-go/checker/decls"
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"github.com/google/cel-go/common/functions"
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"github.com/google/cel-go/common/types"
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"github.com/google/cel-go/common/types/ref"
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exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
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)
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// NewFunction creates a new function declaration with a set of function options to configure overloads
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// and function definitions (implementations).
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//
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// Functions are checked for name collisions and singleton redefinition.
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func NewFunction(name string, opts ...FunctionOpt) (*FunctionDecl, error) {
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fn := &FunctionDecl{
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name: name,
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overloads: map[string]*OverloadDecl{},
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overloadOrdinals: []string{},
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}
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var err error
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for _, opt := range opts {
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fn, err = opt(fn)
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if err != nil {
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return nil, err
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}
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}
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if len(fn.overloads) == 0 {
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return nil, fmt.Errorf("function %s must have at least one overload", name)
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}
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return fn, nil
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}
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// FunctionDecl defines a function name, overload set, and optionally a singleton definition for all
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// overload instances.
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type FunctionDecl struct {
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name string
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// overloads associated with the function name.
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overloads map[string]*OverloadDecl
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// singleton implementation of the function for all overloads.
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//
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// If this option is set, an error will occur if any overloads specify a per-overload implementation
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// or if another function with the same name attempts to redefine the singleton.
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singleton *functions.Overload
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// disableTypeGuards is a performance optimization to disable detailed runtime type checks which could
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// add overhead on common operations. Setting this option true leaves error checks and argument checks
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// intact.
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disableTypeGuards bool
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// state indicates that the binding should be provided as a declaration, as a runtime binding, or both.
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state declarationState
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// overloadOrdinals indicates the order in which the overload was declared.
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overloadOrdinals []string
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}
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type declarationState int
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const (
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declarationStateUnset declarationState = iota
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declarationDisabled
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declarationEnabled
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)
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// Name returns the function name in human-readable terms, e.g. 'contains' of 'math.least'
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func (f *FunctionDecl) Name() string {
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if f == nil {
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return ""
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}
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return f.name
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}
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// IsDeclarationDisabled indicates that the function implementation should be added to the dispatcher, but the
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// declaration should not be exposed for use in expressions.
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func (f *FunctionDecl) IsDeclarationDisabled() bool {
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return f.state == declarationDisabled
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}
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// Merge combines an existing function declaration with another.
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//
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// If a function is extended, by say adding new overloads to an existing function, then it is merged with the
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// prior definition of the function at which point its overloads must not collide with pre-existing overloads
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// and its bindings (singleton, or per-overload) must not conflict with previous definitions either.
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func (f *FunctionDecl) Merge(other *FunctionDecl) (*FunctionDecl, error) {
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if f == other {
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return f, nil
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}
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if f.Name() != other.Name() {
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return nil, fmt.Errorf("cannot merge unrelated functions. %s and %s", f.Name(), other.Name())
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}
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merged := &FunctionDecl{
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name: f.Name(),
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overloads: make(map[string]*OverloadDecl, len(f.overloads)),
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singleton: f.singleton,
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overloadOrdinals: make([]string, len(f.overloads)),
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// if one function is expecting type-guards and the other is not, then they
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// must not be disabled.
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disableTypeGuards: f.disableTypeGuards && other.disableTypeGuards,
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// default to the current functions declaration state.
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state: f.state,
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}
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// If the other state indicates that the declaration should be explicitly enabled or
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// disabled, then update the merged state with the most recent value.
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if other.state != declarationStateUnset {
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merged.state = other.state
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}
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// baseline copy of the overloads and their ordinals
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copy(merged.overloadOrdinals, f.overloadOrdinals)
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for oID, o := range f.overloads {
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merged.overloads[oID] = o
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}
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// overloads and their ordinals are added from the left
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for _, oID := range other.overloadOrdinals {
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o := other.overloads[oID]
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err := merged.AddOverload(o)
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if err != nil {
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return nil, fmt.Errorf("function declaration merge failed: %v", err)
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}
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}
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if other.singleton != nil {
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if merged.singleton != nil && merged.singleton != other.singleton {
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return nil, fmt.Errorf("function already has a singleton binding: %s", f.Name())
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}
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merged.singleton = other.singleton
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}
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return merged, nil
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}
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// AddOverload ensures that the new overload does not collide with an existing overload signature;
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// however, if the function signatures are identical, the implementation may be rewritten as its
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// difficult to compare functions by object identity.
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func (f *FunctionDecl) AddOverload(overload *OverloadDecl) error {
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if f == nil {
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return fmt.Errorf("nil function cannot add overload: %s", overload.ID())
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}
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for oID, o := range f.overloads {
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if oID != overload.ID() && o.SignatureOverlaps(overload) {
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return fmt.Errorf("overload signature collision in function %s: %s collides with %s", f.Name(), oID, overload.ID())
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}
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if oID == overload.ID() {
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if o.SignatureEquals(overload) && o.IsNonStrict() == overload.IsNonStrict() {
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// Allow redefinition of an overload implementation so long as the signatures match.
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f.overloads[oID] = overload
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return nil
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}
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return fmt.Errorf("overload redefinition in function. %s: %s has multiple definitions", f.Name(), oID)
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}
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}
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f.overloadOrdinals = append(f.overloadOrdinals, overload.ID())
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f.overloads[overload.ID()] = overload
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return nil
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}
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// OverloadDecls returns the overload declarations in the order in which they were declared.
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func (f *FunctionDecl) OverloadDecls() []*OverloadDecl {
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if f == nil {
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return []*OverloadDecl{}
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}
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overloads := make([]*OverloadDecl, 0, len(f.overloads))
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for _, oID := range f.overloadOrdinals {
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overloads = append(overloads, f.overloads[oID])
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}
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return overloads
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}
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// Bindings produces a set of function bindings, if any are defined.
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func (f *FunctionDecl) Bindings() ([]*functions.Overload, error) {
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if f == nil {
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return []*functions.Overload{}, nil
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}
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overloads := []*functions.Overload{}
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nonStrict := false
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for _, oID := range f.overloadOrdinals {
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o := f.overloads[oID]
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if o.hasBinding() {
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overload := &functions.Overload{
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Operator: o.ID(),
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Unary: o.guardedUnaryOp(f.Name(), f.disableTypeGuards),
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Binary: o.guardedBinaryOp(f.Name(), f.disableTypeGuards),
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Function: o.guardedFunctionOp(f.Name(), f.disableTypeGuards),
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OperandTrait: o.OperandTrait(),
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NonStrict: o.IsNonStrict(),
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}
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overloads = append(overloads, overload)
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nonStrict = nonStrict || o.IsNonStrict()
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}
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}
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if f.singleton != nil {
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if len(overloads) != 0 {
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return nil, fmt.Errorf("singleton function incompatible with specialized overloads: %s", f.Name())
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}
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overloads = []*functions.Overload{
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{
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Operator: f.Name(),
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Unary: f.singleton.Unary,
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Binary: f.singleton.Binary,
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Function: f.singleton.Function,
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OperandTrait: f.singleton.OperandTrait,
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},
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}
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// fall-through to return single overload case.
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}
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if len(overloads) == 0 {
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return overloads, nil
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}
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// Single overload. Replicate an entry for it using the function name as well.
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if len(overloads) == 1 {
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if overloads[0].Operator == f.Name() {
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return overloads, nil
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}
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return append(overloads, &functions.Overload{
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Operator: f.Name(),
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Unary: overloads[0].Unary,
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Binary: overloads[0].Binary,
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Function: overloads[0].Function,
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NonStrict: overloads[0].NonStrict,
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OperandTrait: overloads[0].OperandTrait,
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}), nil
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}
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// All of the defined overloads are wrapped into a top-level function which
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// performs dynamic dispatch to the proper overload based on the argument types.
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bindings := append([]*functions.Overload{}, overloads...)
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funcDispatch := func(args ...ref.Val) ref.Val {
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for _, oID := range f.overloadOrdinals {
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o := f.overloads[oID]
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// During dynamic dispatch over multiple functions, signature agreement checks
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// are preserved in order to assist with the function resolution step.
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switch len(args) {
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case 1:
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if o.unaryOp != nil && o.matchesRuntimeSignature( /* disableTypeGuards=*/ false, args...) {
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return o.unaryOp(args[0])
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}
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case 2:
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if o.binaryOp != nil && o.matchesRuntimeSignature( /* disableTypeGuards=*/ false, args...) {
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return o.binaryOp(args[0], args[1])
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}
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}
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if o.functionOp != nil && o.matchesRuntimeSignature( /* disableTypeGuards=*/ false, args...) {
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return o.functionOp(args...)
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}
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// eventually this will fall through to the noSuchOverload below.
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}
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return MaybeNoSuchOverload(f.Name(), args...)
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}
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function := &functions.Overload{
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Operator: f.Name(),
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Function: funcDispatch,
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NonStrict: nonStrict,
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}
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return append(bindings, function), nil
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}
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// MaybeNoSuchOverload determines whether to propagate an error if one is provided as an argument, or
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// to return an unknown set, or to produce a new error for a missing function signature.
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func MaybeNoSuchOverload(funcName string, args ...ref.Val) ref.Val {
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argTypes := make([]string, len(args))
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var unk *types.Unknown = nil
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for i, arg := range args {
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if types.IsError(arg) {
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return arg
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}
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if types.IsUnknown(arg) {
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unk = types.MergeUnknowns(arg.(*types.Unknown), unk)
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}
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argTypes[i] = arg.Type().TypeName()
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}
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if unk != nil {
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return unk
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}
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signature := strings.Join(argTypes, ", ")
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return types.NewErr("no such overload: %s(%s)", funcName, signature)
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}
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// FunctionOpt defines a functional option for mutating a function declaration.
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type FunctionOpt func(*FunctionDecl) (*FunctionDecl, error)
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// DisableTypeGuards disables automatically generated function invocation guards on direct overload calls.
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// Type guards remain on during dynamic dispatch for parsed-only expressions.
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func DisableTypeGuards(value bool) FunctionOpt {
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return func(fn *FunctionDecl) (*FunctionDecl, error) {
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fn.disableTypeGuards = value
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return fn, nil
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}
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}
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// DisableDeclaration indicates that the function declaration should be disabled, but the runtime function
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// binding should be provided. Marking a function as runtime-only is a safe way to manage deprecations
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// of function declarations while still preserving the runtime behavior for previously compiled expressions.
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func DisableDeclaration(value bool) FunctionOpt {
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return func(fn *FunctionDecl) (*FunctionDecl, error) {
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if value {
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fn.state = declarationDisabled
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} else {
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fn.state = declarationEnabled
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}
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return fn, nil
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}
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}
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// SingletonUnaryBinding creates a singleton function definition to be used for all function overloads.
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//
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// Note, this approach works well if operand is expected to have a specific trait which it implements,
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// e.g. traits.ContainerType. Otherwise, prefer per-overload function bindings.
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func SingletonUnaryBinding(fn functions.UnaryOp, traits ...int) FunctionOpt {
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trait := 0
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for _, t := range traits {
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trait = trait | t
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}
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return func(f *FunctionDecl) (*FunctionDecl, error) {
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if f.singleton != nil {
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return nil, fmt.Errorf("function already has a singleton binding: %s", f.Name())
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}
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f.singleton = &functions.Overload{
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Operator: f.Name(),
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Unary: fn,
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OperandTrait: trait,
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}
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return f, nil
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}
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}
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// SingletonBinaryBinding creates a singleton function definition to be used with all function overloads.
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//
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// Note, this approach works well if operand is expected to have a specific trait which it implements,
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// e.g. traits.ContainerType. Otherwise, prefer per-overload function bindings.
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func SingletonBinaryBinding(fn functions.BinaryOp, traits ...int) FunctionOpt {
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trait := 0
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for _, t := range traits {
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trait = trait | t
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}
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return func(f *FunctionDecl) (*FunctionDecl, error) {
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if f.singleton != nil {
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return nil, fmt.Errorf("function already has a singleton binding: %s", f.Name())
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}
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f.singleton = &functions.Overload{
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Operator: f.Name(),
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Binary: fn,
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OperandTrait: trait,
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}
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return f, nil
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}
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}
|
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// SingletonFunctionBinding creates a singleton function definition to be used with all function overloads.
|
||
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//
|
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// Note, this approach works well if operand is expected to have a specific trait which it implements,
|
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// e.g. traits.ContainerType. Otherwise, prefer per-overload function bindings.
|
||
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func SingletonFunctionBinding(fn functions.FunctionOp, traits ...int) FunctionOpt {
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trait := 0
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for _, t := range traits {
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trait = trait | t
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}
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return func(f *FunctionDecl) (*FunctionDecl, error) {
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if f.singleton != nil {
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return nil, fmt.Errorf("function already has a singleton binding: %s", f.Name())
|
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}
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f.singleton = &functions.Overload{
|
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Operator: f.Name(),
|
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Function: fn,
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OperandTrait: trait,
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}
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return f, nil
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}
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}
|
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|
||
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// Overload defines a new global overload with an overload id, argument types, and result type. Through the
|
||
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// use of OverloadOpt options, the overload may also be configured with a binding, an operand trait, and to
|
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// be non-strict.
|
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//
|
||
|
// Note: function bindings should be commonly configured with Overload instances whereas operand traits and
|
||
|
// strict-ness should be rare occurrences.
|
||
|
func Overload(overloadID string,
|
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|
args []*types.Type, resultType *types.Type,
|
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opts ...OverloadOpt) FunctionOpt {
|
||
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return newOverload(overloadID, false, args, resultType, opts...)
|
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}
|
||
|
|
||
|
// MemberOverload defines a new receiver-style overload (or member function) with an overload id, argument types,
|
||
|
// and result type. Through the use of OverloadOpt options, the overload may also be configured with a binding,
|
||
|
// an operand trait, and to be non-strict.
|
||
|
//
|
||
|
// Note: function bindings should be commonly configured with Overload instances whereas operand traits and
|
||
|
// strict-ness should be rare occurrences.
|
||
|
func MemberOverload(overloadID string,
|
||
|
args []*types.Type, resultType *types.Type,
|
||
|
opts ...OverloadOpt) FunctionOpt {
|
||
|
return newOverload(overloadID, true, args, resultType, opts...)
|
||
|
}
|
||
|
|
||
|
func newOverload(overloadID string,
|
||
|
memberFunction bool, args []*types.Type, resultType *types.Type,
|
||
|
opts ...OverloadOpt) FunctionOpt {
|
||
|
return func(f *FunctionDecl) (*FunctionDecl, error) {
|
||
|
overload, err := newOverloadInternal(overloadID, memberFunction, args, resultType, opts...)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
err = f.AddOverload(overload)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
return f, nil
|
||
|
}
|
||
|
}
|
||
|
|
||
|
func newOverloadInternal(overloadID string,
|
||
|
memberFunction bool, args []*types.Type, resultType *types.Type,
|
||
|
opts ...OverloadOpt) (*OverloadDecl, error) {
|
||
|
overload := &OverloadDecl{
|
||
|
id: overloadID,
|
||
|
argTypes: args,
|
||
|
resultType: resultType,
|
||
|
isMemberFunction: memberFunction,
|
||
|
}
|
||
|
var err error
|
||
|
for _, opt := range opts {
|
||
|
overload, err = opt(overload)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
}
|
||
|
return overload, nil
|
||
|
}
|
||
|
|
||
|
// OverloadDecl contains the definition of a single overload id with a specific signature, and an optional
|
||
|
// implementation.
|
||
|
type OverloadDecl struct {
|
||
|
id string
|
||
|
argTypes []*types.Type
|
||
|
resultType *types.Type
|
||
|
isMemberFunction bool
|
||
|
// nonStrict indicates that the function will accept error and unknown arguments as inputs.
|
||
|
nonStrict bool
|
||
|
// operandTrait indicates whether the member argument should have a specific type-trait.
|
||
|
//
|
||
|
// This is useful for creating overloads which operate on a type-interface rather than a concrete type.
|
||
|
operandTrait int
|
||
|
|
||
|
// Function implementation options. Optional, but encouraged.
|
||
|
// unaryOp is a function binding that takes a single argument.
|
||
|
unaryOp functions.UnaryOp
|
||
|
// binaryOp is a function binding that takes two arguments.
|
||
|
binaryOp functions.BinaryOp
|
||
|
// functionOp is a catch-all for zero-arity and three-plus arity functions.
|
||
|
functionOp functions.FunctionOp
|
||
|
}
|
||
|
|
||
|
// ID mirrors the overload signature and provides a unique id which may be referenced within the type-checker
|
||
|
// and interpreter to optimize performance.
|
||
|
//
|
||
|
// The ID format is usually one of two styles:
|
||
|
// global: <functionName>_<argType>_<argTypeN>
|
||
|
// member: <memberType>_<functionName>_<argType>_<argTypeN>
|
||
|
func (o *OverloadDecl) ID() string {
|
||
|
if o == nil {
|
||
|
return ""
|
||
|
}
|
||
|
return o.id
|
||
|
}
|
||
|
|
||
|
// ArgTypes contains the set of argument types expected by the overload.
|
||
|
//
|
||
|
// For member functions ArgTypes[0] represents the member operand type.
|
||
|
func (o *OverloadDecl) ArgTypes() []*types.Type {
|
||
|
if o == nil {
|
||
|
return emptyArgs
|
||
|
}
|
||
|
return o.argTypes
|
||
|
}
|
||
|
|
||
|
// IsMemberFunction indicates whether the overload is a member function
|
||
|
func (o *OverloadDecl) IsMemberFunction() bool {
|
||
|
if o == nil {
|
||
|
return false
|
||
|
}
|
||
|
return o.isMemberFunction
|
||
|
}
|
||
|
|
||
|
// IsNonStrict returns whether the overload accepts errors and unknown values as arguments.
|
||
|
func (o *OverloadDecl) IsNonStrict() bool {
|
||
|
if o == nil {
|
||
|
return false
|
||
|
}
|
||
|
return o.nonStrict
|
||
|
}
|
||
|
|
||
|
// OperandTrait returns the trait mask of the first operand to the overload call, e.g.
|
||
|
// `traits.Indexer`
|
||
|
func (o *OverloadDecl) OperandTrait() int {
|
||
|
if o == nil {
|
||
|
return 0
|
||
|
}
|
||
|
return o.operandTrait
|
||
|
}
|
||
|
|
||
|
// ResultType indicates the output type from calling the function.
|
||
|
func (o *OverloadDecl) ResultType() *types.Type {
|
||
|
if o == nil {
|
||
|
// *types.Type is nil-safe
|
||
|
return nil
|
||
|
}
|
||
|
return o.resultType
|
||
|
}
|
||
|
|
||
|
// TypeParams returns the type parameter names associated with the overload.
|
||
|
func (o *OverloadDecl) TypeParams() []string {
|
||
|
typeParams := map[string]struct{}{}
|
||
|
collectParamNames(typeParams, o.ResultType())
|
||
|
for _, arg := range o.ArgTypes() {
|
||
|
collectParamNames(typeParams, arg)
|
||
|
}
|
||
|
params := make([]string, 0, len(typeParams))
|
||
|
for param := range typeParams {
|
||
|
params = append(params, param)
|
||
|
}
|
||
|
return params
|
||
|
}
|
||
|
|
||
|
// SignatureEquals determines whether the incoming overload declaration signature is equal to the current signature.
|
||
|
//
|
||
|
// Result type, operand trait, and strict-ness are not considered as part of signature equality.
|
||
|
func (o *OverloadDecl) SignatureEquals(other *OverloadDecl) bool {
|
||
|
if o == other {
|
||
|
return true
|
||
|
}
|
||
|
if o.ID() != other.ID() || o.IsMemberFunction() != other.IsMemberFunction() || len(o.ArgTypes()) != len(other.ArgTypes()) {
|
||
|
return false
|
||
|
}
|
||
|
for i, at := range o.ArgTypes() {
|
||
|
oat := other.ArgTypes()[i]
|
||
|
if !at.IsEquivalentType(oat) {
|
||
|
return false
|
||
|
}
|
||
|
}
|
||
|
return o.ResultType().IsEquivalentType(other.ResultType())
|
||
|
}
|
||
|
|
||
|
// SignatureOverlaps indicates whether two functions have non-equal, but overloapping function signatures.
|
||
|
//
|
||
|
// For example, list(dyn) collides with list(string) since the 'dyn' type can contain a 'string' type.
|
||
|
func (o *OverloadDecl) SignatureOverlaps(other *OverloadDecl) bool {
|
||
|
if o.IsMemberFunction() != other.IsMemberFunction() || len(o.ArgTypes()) != len(other.ArgTypes()) {
|
||
|
return false
|
||
|
}
|
||
|
argsOverlap := true
|
||
|
for i, argType := range o.ArgTypes() {
|
||
|
otherArgType := other.ArgTypes()[i]
|
||
|
argsOverlap = argsOverlap &&
|
||
|
(argType.IsAssignableType(otherArgType) ||
|
||
|
otherArgType.IsAssignableType(argType))
|
||
|
}
|
||
|
return argsOverlap
|
||
|
}
|
||
|
|
||
|
// hasBinding indicates whether the overload already has a definition.
|
||
|
func (o *OverloadDecl) hasBinding() bool {
|
||
|
return o != nil && (o.unaryOp != nil || o.binaryOp != nil || o.functionOp != nil)
|
||
|
}
|
||
|
|
||
|
// guardedUnaryOp creates an invocation guard around the provided unary operator, if one is defined.
|
||
|
func (o *OverloadDecl) guardedUnaryOp(funcName string, disableTypeGuards bool) functions.UnaryOp {
|
||
|
if o.unaryOp == nil {
|
||
|
return nil
|
||
|
}
|
||
|
return func(arg ref.Val) ref.Val {
|
||
|
if !o.matchesRuntimeUnarySignature(disableTypeGuards, arg) {
|
||
|
return MaybeNoSuchOverload(funcName, arg)
|
||
|
}
|
||
|
return o.unaryOp(arg)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// guardedBinaryOp creates an invocation guard around the provided binary operator, if one is defined.
|
||
|
func (o *OverloadDecl) guardedBinaryOp(funcName string, disableTypeGuards bool) functions.BinaryOp {
|
||
|
if o.binaryOp == nil {
|
||
|
return nil
|
||
|
}
|
||
|
return func(arg1, arg2 ref.Val) ref.Val {
|
||
|
if !o.matchesRuntimeBinarySignature(disableTypeGuards, arg1, arg2) {
|
||
|
return MaybeNoSuchOverload(funcName, arg1, arg2)
|
||
|
}
|
||
|
return o.binaryOp(arg1, arg2)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// guardedFunctionOp creates an invocation guard around the provided variadic function binding, if one is provided.
|
||
|
func (o *OverloadDecl) guardedFunctionOp(funcName string, disableTypeGuards bool) functions.FunctionOp {
|
||
|
if o.functionOp == nil {
|
||
|
return nil
|
||
|
}
|
||
|
return func(args ...ref.Val) ref.Val {
|
||
|
if !o.matchesRuntimeSignature(disableTypeGuards, args...) {
|
||
|
return MaybeNoSuchOverload(funcName, args...)
|
||
|
}
|
||
|
return o.functionOp(args...)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// matchesRuntimeUnarySignature indicates whether the argument type is runtime assiganble to the overload's expected argument.
|
||
|
func (o *OverloadDecl) matchesRuntimeUnarySignature(disableTypeGuards bool, arg ref.Val) bool {
|
||
|
return matchRuntimeArgType(o.IsNonStrict(), disableTypeGuards, o.ArgTypes()[0], arg) &&
|
||
|
matchOperandTrait(o.OperandTrait(), arg)
|
||
|
}
|
||
|
|
||
|
// matchesRuntimeBinarySignature indicates whether the argument types are runtime assiganble to the overload's expected arguments.
|
||
|
func (o *OverloadDecl) matchesRuntimeBinarySignature(disableTypeGuards bool, arg1, arg2 ref.Val) bool {
|
||
|
return matchRuntimeArgType(o.IsNonStrict(), disableTypeGuards, o.ArgTypes()[0], arg1) &&
|
||
|
matchRuntimeArgType(o.IsNonStrict(), disableTypeGuards, o.ArgTypes()[1], arg2) &&
|
||
|
matchOperandTrait(o.OperandTrait(), arg1)
|
||
|
}
|
||
|
|
||
|
// matchesRuntimeSignature indicates whether the argument types are runtime assiganble to the overload's expected arguments.
|
||
|
func (o *OverloadDecl) matchesRuntimeSignature(disableTypeGuards bool, args ...ref.Val) bool {
|
||
|
if len(args) != len(o.ArgTypes()) {
|
||
|
return false
|
||
|
}
|
||
|
if len(args) == 0 {
|
||
|
return true
|
||
|
}
|
||
|
for i, arg := range args {
|
||
|
if !matchRuntimeArgType(o.IsNonStrict(), disableTypeGuards, o.ArgTypes()[i], arg) {
|
||
|
return false
|
||
|
}
|
||
|
}
|
||
|
return matchOperandTrait(o.OperandTrait(), args[0])
|
||
|
}
|
||
|
|
||
|
func matchRuntimeArgType(nonStrict, disableTypeGuards bool, argType *types.Type, arg ref.Val) bool {
|
||
|
if nonStrict && (disableTypeGuards || types.IsUnknownOrError(arg)) {
|
||
|
return true
|
||
|
}
|
||
|
if types.IsUnknownOrError(arg) {
|
||
|
return false
|
||
|
}
|
||
|
return disableTypeGuards || argType.IsAssignableRuntimeType(arg)
|
||
|
}
|
||
|
|
||
|
func matchOperandTrait(trait int, arg ref.Val) bool {
|
||
|
return trait == 0 || arg.Type().HasTrait(trait) || types.IsUnknownOrError(arg)
|
||
|
}
|
||
|
|
||
|
// OverloadOpt is a functional option for configuring a function overload.
|
||
|
type OverloadOpt func(*OverloadDecl) (*OverloadDecl, error)
|
||
|
|
||
|
// UnaryBinding provides the implementation of a unary overload. The provided function is protected by a runtime
|
||
|
// type-guard which ensures runtime type agreement between the overload signature and runtime argument types.
|
||
|
func UnaryBinding(binding functions.UnaryOp) OverloadOpt {
|
||
|
return func(o *OverloadDecl) (*OverloadDecl, error) {
|
||
|
if o.hasBinding() {
|
||
|
return nil, fmt.Errorf("overload already has a binding: %s", o.ID())
|
||
|
}
|
||
|
if len(o.ArgTypes()) != 1 {
|
||
|
return nil, fmt.Errorf("unary function bound to non-unary overload: %s", o.ID())
|
||
|
}
|
||
|
o.unaryOp = binding
|
||
|
return o, nil
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// BinaryBinding provides the implementation of a binary overload. The provided function is protected by a runtime
|
||
|
// type-guard which ensures runtime type agreement between the overload signature and runtime argument types.
|
||
|
func BinaryBinding(binding functions.BinaryOp) OverloadOpt {
|
||
|
return func(o *OverloadDecl) (*OverloadDecl, error) {
|
||
|
if o.hasBinding() {
|
||
|
return nil, fmt.Errorf("overload already has a binding: %s", o.ID())
|
||
|
}
|
||
|
if len(o.ArgTypes()) != 2 {
|
||
|
return nil, fmt.Errorf("binary function bound to non-binary overload: %s", o.ID())
|
||
|
}
|
||
|
o.binaryOp = binding
|
||
|
return o, nil
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// FunctionBinding provides the implementation of a variadic overload. The provided function is protected by a runtime
|
||
|
// type-guard which ensures runtime type agreement between the overload signature and runtime argument types.
|
||
|
func FunctionBinding(binding functions.FunctionOp) OverloadOpt {
|
||
|
return func(o *OverloadDecl) (*OverloadDecl, error) {
|
||
|
if o.hasBinding() {
|
||
|
return nil, fmt.Errorf("overload already has a binding: %s", o.ID())
|
||
|
}
|
||
|
o.functionOp = binding
|
||
|
return o, nil
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// OverloadIsNonStrict enables the function to be called with error and unknown argument values.
|
||
|
//
|
||
|
// Note: do not use this option unless absoluately necessary as it should be an uncommon feature.
|
||
|
func OverloadIsNonStrict() OverloadOpt {
|
||
|
return func(o *OverloadDecl) (*OverloadDecl, error) {
|
||
|
o.nonStrict = true
|
||
|
return o, nil
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// OverloadOperandTrait configures a set of traits which the first argument to the overload must implement in order to be
|
||
|
// successfully invoked.
|
||
|
func OverloadOperandTrait(trait int) OverloadOpt {
|
||
|
return func(o *OverloadDecl) (*OverloadDecl, error) {
|
||
|
o.operandTrait = trait
|
||
|
return o, nil
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// NewConstant creates a new constant declaration.
|
||
|
func NewConstant(name string, t *types.Type, v ref.Val) *VariableDecl {
|
||
|
return &VariableDecl{name: name, varType: t, value: v}
|
||
|
}
|
||
|
|
||
|
// NewVariable creates a new variable declaration.
|
||
|
func NewVariable(name string, t *types.Type) *VariableDecl {
|
||
|
return &VariableDecl{name: name, varType: t}
|
||
|
}
|
||
|
|
||
|
// VariableDecl defines a variable declaration which may optionally have a constant value.
|
||
|
type VariableDecl struct {
|
||
|
name string
|
||
|
varType *types.Type
|
||
|
value ref.Val
|
||
|
}
|
||
|
|
||
|
// Name returns the fully-qualified variable name
|
||
|
func (v *VariableDecl) Name() string {
|
||
|
if v == nil {
|
||
|
return ""
|
||
|
}
|
||
|
return v.name
|
||
|
}
|
||
|
|
||
|
// Type returns the types.Type value associated with the variable.
|
||
|
func (v *VariableDecl) Type() *types.Type {
|
||
|
if v == nil {
|
||
|
// types.Type is nil-safe
|
||
|
return nil
|
||
|
}
|
||
|
return v.varType
|
||
|
}
|
||
|
|
||
|
// Value returns the constant value associated with the declaration.
|
||
|
func (v *VariableDecl) Value() ref.Val {
|
||
|
if v == nil {
|
||
|
return nil
|
||
|
}
|
||
|
return v.value
|
||
|
}
|
||
|
|
||
|
// DeclarationIsEquivalent returns true if one variable declaration has the same name and same type as the input.
|
||
|
func (v *VariableDecl) DeclarationIsEquivalent(other *VariableDecl) bool {
|
||
|
if v == other {
|
||
|
return true
|
||
|
}
|
||
|
return v.Name() == other.Name() && v.Type().IsEquivalentType(other.Type())
|
||
|
}
|
||
|
|
||
|
// VariableDeclToExprDecl converts a go-native variable declaration into a protobuf-type variable declaration.
|
||
|
func VariableDeclToExprDecl(v *VariableDecl) (*exprpb.Decl, error) {
|
||
|
varType, err := types.TypeToExprType(v.Type())
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
return chkdecls.NewVar(v.Name(), varType), nil
|
||
|
}
|
||
|
|
||
|
// TypeVariable creates a new type identifier for use within a types.Provider
|
||
|
func TypeVariable(t *types.Type) *VariableDecl {
|
||
|
return NewVariable(t.TypeName(), types.NewTypeTypeWithParam(t))
|
||
|
}
|
||
|
|
||
|
// FunctionDeclToExprDecl converts a go-native function declaration into a protobuf-typed function declaration.
|
||
|
func FunctionDeclToExprDecl(f *FunctionDecl) (*exprpb.Decl, error) {
|
||
|
overloads := make([]*exprpb.Decl_FunctionDecl_Overload, len(f.overloads))
|
||
|
for i, oID := range f.overloadOrdinals {
|
||
|
o := f.overloads[oID]
|
||
|
paramNames := map[string]struct{}{}
|
||
|
argTypes := make([]*exprpb.Type, len(o.ArgTypes()))
|
||
|
for j, a := range o.ArgTypes() {
|
||
|
collectParamNames(paramNames, a)
|
||
|
at, err := types.TypeToExprType(a)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
argTypes[j] = at
|
||
|
}
|
||
|
collectParamNames(paramNames, o.ResultType())
|
||
|
resultType, err := types.TypeToExprType(o.ResultType())
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
if len(paramNames) == 0 {
|
||
|
if o.IsMemberFunction() {
|
||
|
overloads[i] = chkdecls.NewInstanceOverload(oID, argTypes, resultType)
|
||
|
} else {
|
||
|
overloads[i] = chkdecls.NewOverload(oID, argTypes, resultType)
|
||
|
}
|
||
|
} else {
|
||
|
params := []string{}
|
||
|
for pn := range paramNames {
|
||
|
params = append(params, pn)
|
||
|
}
|
||
|
if o.IsMemberFunction() {
|
||
|
overloads[i] = chkdecls.NewParameterizedInstanceOverload(oID, argTypes, resultType, params)
|
||
|
} else {
|
||
|
overloads[i] = chkdecls.NewParameterizedOverload(oID, argTypes, resultType, params)
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
return chkdecls.NewFunction(f.Name(), overloads...), nil
|
||
|
}
|
||
|
|
||
|
func collectParamNames(paramNames map[string]struct{}, arg *types.Type) {
|
||
|
if arg.Kind() == types.TypeParamKind {
|
||
|
paramNames[arg.TypeName()] = struct{}{}
|
||
|
}
|
||
|
for _, param := range arg.Parameters() {
|
||
|
collectParamNames(paramNames, param)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
var (
|
||
|
emptyArgs = []*types.Type{}
|
||
|
)
|