/
assignment.go
172 lines (150 loc) · 4.74 KB
/
assignment.go
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package vm
import (
"fmt"
"strings"
"github.com/grubby/grubby/ast"
. "github.com/grubby/grubby/interpreter/vm/builtins"
)
func interpretAssignmentInContext(
vm *vm,
assignment ast.Assignment,
context Value,
) (Value, error) {
returnValue, err := vm.executeWithContext(context, assignment.RHS)
if err != nil {
return nil, err
}
switch assignment.LHS.(type) {
case ast.BareReference:
ref := assignment.LHS.(ast.BareReference)
vm.ObjectSpace[ref.Name] = returnValue
case ast.GlobalVariable:
globalVar := assignment.LHS.(ast.GlobalVariable)
vm.CurrentGlobals[globalVar.Name] = returnValue
case ast.InstanceVariable:
ivar := assignment.LHS.(ast.InstanceVariable)
context.SetInstanceVariable(ivar.Name, returnValue)
case ast.ClassVariable:
classVar := assignment.LHS.(ast.ClassVariable)
context.SetClassVariable(classVar.Name, returnValue)
case ast.Constant:
var target Module
if vm.currentModuleName == "" {
target = vm.CurrentClasses["Object"]
} else {
target = vm.CurrentClasses[vm.currentModuleName]
if target == nil {
target = vm.CurrentModules[vm.currentModuleName]
}
if target == nil {
panic(fmt.Sprintf("unexpected nil target when looking up module %s to set constant %s", vm.currentModuleName, assignment.LHS.(ast.Constant).Name))
}
}
target.SetConstant(assignment.LHS.(ast.Constant).Name, returnValue)
case ast.Class:
asClass := assignment.LHS.(ast.Class)
if asClass.Namespace != "" {
var target Value
namespace := asClass.Namespace
for _, nameToLookup := range strings.Split(namespace, "::") {
class, err := vm.GetClass(nameToLookup)
if err != nil {
module, err := vm.GetModule(nameToLookup)
if err != nil {
return nil, err
}
target = module
} else {
target = class
}
}
target.(Module).SetConstant(asClass.Name, returnValue)
}
default:
panic(fmt.Sprintf("unimplemented assignment failure: %#v", assignment.LHS))
}
return returnValue, nil
}
func interpretConditionalAssignmentInContext(
vm *vm,
conditionalAssignment ast.ConditionalAssignment,
context Value,
) (Value, error) {
returnValue, err := vm.executeWithContext(context, conditionalAssignment.RHS)
if err != nil {
return nil, err
}
switch conditionalAssignment.LHS.(type) {
case ast.BareReference:
ref := conditionalAssignment.LHS.(ast.BareReference)
if vm.ObjectSpace[ref.Name] != nil && vm.ObjectSpace[ref.Name].IsTruthy() {
return vm.ObjectSpace[ref.Name], nil
}
vm.ObjectSpace[ref.Name] = returnValue
case ast.GlobalVariable:
globalVar := conditionalAssignment.LHS.(ast.GlobalVariable)
if vm.CurrentGlobals[globalVar.Name] != nil && vm.CurrentGlobals[globalVar.Name].IsTruthy() {
return vm.CurrentGlobals[globalVar.Name], nil
}
vm.CurrentGlobals[globalVar.Name] = returnValue
case ast.InstanceVariable:
ivar := conditionalAssignment.LHS.(ast.InstanceVariable)
existingIvar := context.GetInstanceVariable(ivar.Name)
if existingIvar != nil && existingIvar.IsTruthy() {
return existingIvar, nil
}
context.SetInstanceVariable(ivar.Name, returnValue)
case ast.ClassVariable:
classVar := conditionalAssignment.LHS.(ast.ClassVariable)
existingClassVar := context.GetClassVariable(classVar.Name)
if existingClassVar != nil && existingClassVar.IsTruthy() {
return existingClassVar, nil
}
context.SetClassVariable(classVar.Name, returnValue)
case ast.Constant:
var target Module
if vm.currentModuleName == "" {
target = vm.CurrentClasses["Object"]
} else {
target = vm.CurrentClasses[vm.currentModuleName]
if target == nil {
target = vm.CurrentModules[vm.currentModuleName]
}
if target == nil {
panic(fmt.Sprintf("unexpected nil target when looking up module %s to set constant %s", vm.currentModuleName, conditionalAssignment.LHS.(ast.Constant).Name))
}
}
name := conditionalAssignment.LHS.(ast.Constant).Name
constant, err := target.Constant(name)
if err == nil && constant.IsTruthy() {
return constant, nil
}
target.SetConstant(name, returnValue)
case ast.Class:
asClass := conditionalAssignment.LHS.(ast.Class)
if asClass.Namespace != "" {
var target Value
namespace := asClass.Namespace
for _, nameToLookup := range strings.Split(namespace, "::") {
class, err := vm.GetClass(nameToLookup)
if err != nil {
module, err := vm.GetModule(nameToLookup)
if err != nil {
return nil, err
}
target = module
} else {
target = class
}
}
constant, err := target.(Module).Constant(asClass.Name)
if err == nil && constant.IsTruthy() {
return constant, nil
}
target.(Module).SetConstant(asClass.Name, returnValue)
}
default:
panic(fmt.Sprintf("unimplemented conditionalAssignment failure: %#v", conditionalAssignment.LHS))
}
return returnValue, nil
}