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-rw-r--r--pkg/lang/compiler/compiler.go41
-rw-r--r--pkg/lang/compiler/compiler_test.go37
-rw-r--r--pkg/lang/compiler/scope/scope_chain.go60
-rw-r--r--pkg/lang/compiler/scope/scopes.go8
-rw-r--r--pkg/lang/compiler/scope/symbol.go23
5 files changed, 147 insertions, 22 deletions
diff --git a/pkg/lang/compiler/compiler.go b/pkg/lang/compiler/compiler.go
index 0424862..5e2a645 100644
--- a/pkg/lang/compiler/compiler.go
+++ b/pkg/lang/compiler/compiler.go
@@ -112,8 +112,8 @@ func (comp *Compiler) compileFnDeclStmt(t *code.Builder, fnDeclStmt ast.StmtFnDe
return err
}
- // Function declaration scopes do not pollute stack
- _ = comp.scopes.Exit()
+ fnScope := comp.scopes.CurrentFunction()
+ _ = comp.scopes.Exit() // Function declaration scopes do not pollute stack
comp.funcs = append(comp.funcs, &functionTarget)
@@ -127,7 +127,15 @@ func (comp *Compiler) compileFnDeclStmt(t *code.Builder, fnDeclStmt ast.StmtFnDe
t.AppendInt(int64(len(fnDeclStmt.Args)))
}
- // TODO: Attach the function environment
+ for _, outsideSymbol := range fnScope.OutsideSymbolsInEnv() {
+ // TODO: Implement env inheritance
+ if comp.scopes.CurrentFunction().ID() != outsideSymbol.ScopeID() {
+ panic("env inheritance not implemented")
+ }
+
+ t.AppendOp(code.OpAddToEnv)
+ t.AppendInt(int64(outsideSymbol.IndexInScope()))
+ }
return nil
}
@@ -537,18 +545,24 @@ func (comp *Compiler) compileAssignExpr(t *code.Builder, expr ast.ExprBinary) er
return fmt.Errorf("variable %s not declared", name)
}
- if symbolId.SymbolKind() != scope.SymbolKindVariable {
- return fmt.Errorf("can't assign to a %v", symbolId.SymbolKind())
- }
-
- symbol := comp.scopes.GetVariable(symbolId)
-
if err := comp.compileExpr(t, expr.Right); err != nil {
return err
}
- t.AppendOp(code.OpSetLocal)
- t.AppendInt(int64(symbol.Data().LocalIndex()))
+ switch symbolId.SymbolKind() {
+ case scope.SymbolKindVariable:
+ symbol := comp.scopes.GetVariable(symbolId)
+
+ t.AppendOp(code.OpSetLocal)
+ t.AppendInt(int64(symbol.Data().LocalIndex()))
+ case scope.SymbolKindEnv:
+ symbol := comp.scopes.GetEnv(symbolId)
+
+ t.AppendOp(code.OpSetEnv)
+ t.AppendInt(int64(symbol.Data().IndexInEnv()))
+ default:
+ panic("unknown symbol kind")
+ }
return nil
}
@@ -639,6 +653,11 @@ func (comp *Compiler) compileIdentExpr(t *code.Builder, expr ast.ExprIdent) erro
t.AppendOp(code.OpGetLocal)
t.AppendInt(int64(symbol.Data().LocalIndex()))
+ case scope.SymbolKindEnv:
+ symbol := comp.scopes.GetEnv(symbolId)
+
+ t.AppendOp(code.OpGetEnv)
+ t.AppendInt(int64(symbol.Data().IndexInEnv()))
default:
panic(fmt.Errorf("unknown symbol kind: %v", symbolId.SymbolKind()))
}
diff --git a/pkg/lang/compiler/compiler_test.go b/pkg/lang/compiler/compiler_test.go
index 07586a6..9c21a3b 100644
--- a/pkg/lang/compiler/compiler_test.go
+++ b/pkg/lang/compiler/compiler_test.go
@@ -486,6 +486,43 @@ func TestFunctionArgs(t *testing.T) {
mustCompileTo(t, src, expected)
}
+func TestClosureEnv(t *testing.T) {
+ src := `
+ fn create() {
+ var x = 0
+ fn closure() {
+ x = x + 1
+ return x
+ }
+
+ return closure
+ }
+ `
+
+ expected := `
+ push_function @create
+ halt
+
+ @closure:
+ get_env 0
+ push_int 1
+ add
+ set_env 0
+ get_env 0
+ ret
+
+ @create:
+ push_int 0
+ push_function @closure
+ add_to_env 0
+
+ get_local 1
+ ret
+ `
+
+ mustCompileTo(t, src, expected)
+}
+
func mustCompileTo(t *testing.T, src, expected string) {
scanner := scanner.New(strings.NewReader(src))
tokens, err := scanner.Scan()
diff --git a/pkg/lang/compiler/scope/scope_chain.go b/pkg/lang/compiler/scope/scope_chain.go
index f4b9f46..1b83c75 100644
--- a/pkg/lang/compiler/scope/scope_chain.go
+++ b/pkg/lang/compiler/scope/scope_chain.go
@@ -91,19 +91,14 @@ func (sc *ScopeChain) Exit() int {
id := sc.CurrentScopeID()
stackSpace := len(sc.symbolScopes[id].variableSymbols)
- sc.symbolScopes[id] = SymbolScope{}
sc.symbolScopes = sc.symbolScopes[:id]
if sc.CurrentLoop() != nil && sc.CurrentLoop().id == id {
- lastLoopScope := len(sc.loopScopes) - 1
- sc.loopScopes[lastLoopScope] = LoopScope{}
- sc.loopScopes = sc.loopScopes[:lastLoopScope]
+ sc.loopScopes = sc.loopScopes[:len(sc.loopScopes)-1]
}
if sc.CurrentFunction().id == id {
- lastFunctionScope := len(sc.functionScopes) - 1
- sc.functionScopes[lastFunctionScope] = FunctionScope{}
- sc.functionScopes = sc.functionScopes[:lastFunctionScope]
+ sc.functionScopes = sc.functionScopes[:len(sc.functionScopes)-1]
}
return stackSpace
@@ -178,11 +173,23 @@ func (sc *ScopeChain) CreateFunctionSubUnit(subUnitName string) code.Marker {
}
func (sc *ScopeChain) Lookup(name string) (SymbolID, bool) {
- if id, ok := sc.nameToSymbol[name]; ok {
- return id, true
+ id, ok := sc.nameToSymbol[name]
+ if !ok {
+ return SymbolID{}, false
}
- return SymbolID{}, false
+ // Check whether the symbol is outside the current function scope.
+ fnScope := sc.CurrentFunction()
+ if id.scopeID < fnScope.id {
+ // Return env symbol instead of a local symbol.
+ return SymbolID{
+ symbolKind: SymbolKindEnv,
+ scopeID: id.scopeID,
+ indexInScope: id.indexInScope,
+ }, true
+ }
+
+ return id, true
}
func (sc *ScopeChain) GetVariable(id SymbolID) Symbol[SymbolVariable] {
@@ -192,3 +199,36 @@ func (sc *ScopeChain) GetVariable(id SymbolID) Symbol[SymbolVariable] {
return sc.symbolScopes[id.scopeID].variableSymbols[id.indexInScope]
}
+
+func (sc *ScopeChain) GetEnv(id SymbolID) Symbol[SymbolEnv] {
+ if id.symbolKind != SymbolKindEnv {
+ panic("incorrect symbol id kind given")
+ }
+
+ symbol := sc.symbolScopes[id.scopeID].variableSymbols[id.indexInScope]
+
+ // Add the local to the function scope, if it is not already there.
+ fnScope := sc.CurrentFunction()
+
+ var indexInEnv int
+ alreadyUsed := false
+ for i, env := range fnScope.outsideSymbolsInEnv {
+ if env == id {
+ alreadyUsed = true
+ indexInEnv = i
+ break
+ }
+ }
+
+ if !alreadyUsed {
+ indexInEnv = len(fnScope.outsideSymbolsInEnv)
+ fnScope.outsideSymbolsInEnv = append(fnScope.outsideSymbolsInEnv, id)
+ }
+
+ return Symbol[SymbolEnv]{
+ name: symbol.name,
+ data: SymbolEnv{
+ indexInEnv: indexInEnv,
+ },
+ }
+}
diff --git a/pkg/lang/compiler/scope/scopes.go b/pkg/lang/compiler/scope/scopes.go
index e34b45a..7a1b20c 100644
--- a/pkg/lang/compiler/scope/scopes.go
+++ b/pkg/lang/compiler/scope/scopes.go
@@ -26,6 +26,8 @@ type FunctionScope struct {
id ScopeID
unit code.Marker
subUnitCount int
+
+ outsideSymbolsInEnv []SymbolID
}
func NewFunctionScope(id ScopeID, unit code.Marker) FunctionScope {
@@ -33,6 +35,8 @@ func NewFunctionScope(id ScopeID, unit code.Marker) FunctionScope {
id: id,
unit: unit,
subUnitCount: 0,
+
+ outsideSymbolsInEnv: make([]SymbolID, 0),
}
}
@@ -44,6 +48,10 @@ func (sf FunctionScope) Unit() code.Marker {
return sf.unit
}
+func (sf FunctionScope) OutsideSymbolsInEnv() []SymbolID {
+ return sf.outsideSymbolsInEnv
+}
+
func (sf FunctionScope) IsRootScope() bool {
return sf.ID() == ScopeID(0)
}
diff --git a/pkg/lang/compiler/scope/symbol.go b/pkg/lang/compiler/scope/symbol.go
index 3b50108..b87d5aa 100644
--- a/pkg/lang/compiler/scope/symbol.go
+++ b/pkg/lang/compiler/scope/symbol.go
@@ -10,17 +10,30 @@ func (id SymbolID) SymbolKind() SymbolKind {
return id.symbolKind
}
+func (id SymbolID) ScopeID() ScopeID {
+ return id.scopeID
+}
+
+func (id SymbolID) IndexInScope() int {
+ return id.indexInScope
+}
+
type SymbolKind int
const (
// A variable symbol is bound to a local on the stack.
SymbolKindVariable SymbolKind = iota
+ // An env symbol is bound to a local on the stack, outside of the function's scope.
+ // Emitted at lookup time, so the SymbolScope has no array for them.
+ SymbolKindEnv SymbolKind = iota
)
func (s SymbolKind) String() string {
switch s {
case SymbolKindVariable:
return "variable"
+ case SymbolKindEnv:
+ return "env"
default:
panic("unknown symbol kind")
}
@@ -36,7 +49,7 @@ func (s Symbol[D]) Data() D {
}
type SymbolData interface {
- SymbolVariable
+ SymbolVariable | SymbolEnv
}
type SymbolVariable struct {
@@ -46,3 +59,11 @@ type SymbolVariable struct {
func (sv SymbolVariable) LocalIndex() int {
return sv.localIndex
}
+
+type SymbolEnv struct {
+ indexInEnv int
+}
+
+func (se SymbolEnv) IndexInEnv() int {
+ return se.indexInEnv
+}
generated by cgit v1.3.1 (git 2.54.0) at 2026-10-18 22:24:45 +0000