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- /*
- * ECAL
- *
- * Copyright 2020 Matthias Ladkau. All rights reserved.
- *
- * This Source Code Form is subject to the terms of the MIT
- * License, If a copy of the MIT License was not distributed with this
- * file, You can obtain one at https://opensource.org/licenses/MIT.
- */
- package interpreter
- import (
- "encoding/json"
- "fmt"
- "strings"
- "devt.de/krotik/ecal/parser"
- "devt.de/krotik/ecal/scope"
- "devt.de/krotik/ecal/util"
- )
- /*
- returnRuntime is a special runtime for return statements in functions.
- */
- type returnRuntime struct {
- *baseRuntime
- }
- /*
- voidRuntimeInst returns a new runtime component instance.
- */
- func returnRuntimeInst(erp *ECALRuntimeProvider, node *parser.ASTNode) parser.Runtime {
- return &returnRuntime{newBaseRuntime(erp, node)}
- }
- /*
- Validate this node and all its child nodes.
- */
- func (rt *returnRuntime) Validate() error {
- return rt.baseRuntime.Validate()
- }
- /*
- Eval evaluate this runtime component.
- */
- func (rt *returnRuntime) Eval(vs parser.Scope, is map[string]interface{}, tid uint64) (interface{}, error) {
- _, err := rt.baseRuntime.Eval(vs, is, tid)
- if err == nil {
- var res interface{}
- if res, err = rt.node.Children[0].Runtime.Eval(vs, is, tid); err == nil {
- rerr := rt.erp.NewRuntimeError(util.ErrReturn, fmt.Sprintf("Return value: %v", res), rt.node)
- err = &returnValue{
- rerr.(*util.RuntimeError),
- res,
- }
- }
- }
- return nil, err
- }
- type returnValue struct {
- *util.RuntimeError
- returnValue interface{}
- }
- /*
- funcRuntime is the runtime component for function declarations.
- */
- type funcRuntime struct {
- *baseRuntime
- }
- /*
- funcRuntimeInst returns a new runtime component instance.
- */
- func funcRuntimeInst(erp *ECALRuntimeProvider, node *parser.ASTNode) parser.Runtime {
- return &funcRuntime{newBaseRuntime(erp, node)}
- }
- /*
- Eval evaluate this runtime component.
- */
- func (rt *funcRuntime) Eval(vs parser.Scope, is map[string]interface{}, tid uint64) (interface{}, error) {
- var fc interface{}
- _, err := rt.baseRuntime.Eval(vs, is, tid)
- if err == nil {
- name := ""
- if rt.node.Children[0].Name == parser.NodeIDENTIFIER {
- name = rt.node.Children[0].Token.Val
- }
- fc = &function{name, nil, nil, rt.node, vs}
- if name != "" {
- vs.SetValue(name, fc)
- }
- }
- return fc, err
- }
- /*
- function models a function in ECAL. It can have a context object attached - this.
- */
- type function struct {
- name string
- super []interface{} // Super function pointer
- this interface{} // Function context
- declaration *parser.ASTNode // Function declaration node
- declarationVS parser.Scope // Function declaration scope
- }
- /*
- Run executes this function. The function is called with parameters and might also
- have a reference to a context state - this.
- */
- func (f *function) Run(instanceID string, vs parser.Scope, is map[string]interface{}, tid uint64, args []interface{}) (interface{}, error) {
- var res interface{}
- var err error
- nameOffset := 0
- if f.declaration.Children[0].Name == parser.NodeIDENTIFIER {
- nameOffset = 1
- }
- params := f.declaration.Children[0+nameOffset].Children
- body := f.declaration.Children[1+nameOffset]
- // Create varscope for the body - not a child scope but a new root
- fvs := scope.NewScope(fmt.Sprintf("%v %v", scope.FuncPrefix, f.name))
- if f.this != nil {
- fvs.SetValue("this", f.this)
- }
- if f.super != nil {
- fvs.SetValue("super", f.super)
- }
- for i, p := range params {
- var name string
- var val interface{}
- if err == nil {
- name = ""
- if p.Name == parser.NodeIDENTIFIER {
- name = p.Token.Val
- if i < len(args) {
- val = args[i]
- }
- } else if p.Name == parser.NodePRESET {
- name = p.Children[0].Token.Val
- if i < len(args) {
- val = args[i]
- } else {
- val, err = p.Children[1].Runtime.Eval(vs, is, tid)
- }
- }
- if name != "" {
- fvs.SetValue(name, val)
- }
- }
- }
- if err == nil {
- scope.SetParentOfScope(fvs, f.declarationVS)
- res, err = body.Runtime.Eval(fvs, make(map[string]interface{}), tid)
- // Check for return value (delivered as error object)
- if rval, ok := err.(*returnValue); ok {
- res = rval.returnValue
- err = nil
- }
- }
- return res, err
- }
- /*
- DocString returns a descriptive string.
- */
- func (f *function) DocString() (string, error) {
- if len(f.declaration.Meta) > 0 {
- return strings.TrimSpace(f.declaration.Meta[0].Value()), nil
- }
- return fmt.Sprintf("Declared function: %v (%v)", f.name, f.declaration.Token.PosString()), nil
- }
- /*
- String returns a string representation of this function.
- */
- func (f *function) String() string {
- return fmt.Sprintf("ecal.function: %v (%v)", f.name, f.declaration.Token.PosString())
- }
- /*
- MarshalJSON returns a string representation of this function - a function cannot
- be JSON encoded.
- */
- func (f *function) MarshalJSON() ([]byte, error) {
- return json.Marshal(f.String())
- }
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