[starlark] Add initial support for embedded Starlark interpreter. [se…

…e issue #29]

sources/lib/execution.go

@@ -347,6 +347,33 @@ func prepareExecution_0 (
 				_interpreterScriptBuffer.WriteString (_scriptletBody)
 			}
 
+		case "<starlark>" :
+			if _libraryUrl != "" {
+				_interpreterExecutable = _selfExecutable
+				_interpreterArgument0 = "[z-run:library]"
+				_interpreterArguments = append (
+						_interpreterArguments,
+						_scriptletInterpreterArguments ...,
+					)
+				_interpreterArguments = append (
+						_interpreterArguments,
+						fmt.Sprintf (":: %s", _scriptletLabel),
+					)
+				_interpreterScriptUnused = true
+			} else {
+				_interpreterExecutable = _selfExecutable
+				_interpreterArgument0 = fmt.Sprintf ("[z-run:starlark] [%s]", _scriptletLabel)
+				_interpreterArguments = append (
+						_interpreterArguments,
+						_scriptletInterpreterArguments ...,
+					)
+				_interpreterArguments = append (
+						_interpreterArguments,
+						fmt.Sprintf ("/dev/fd/%d", _interpreterScriptInput),
+					)
+				_interpreterScriptBuffer.WriteString (_scriptletBody)
+			}
+
 		case "<menu>" :
 			_interpreterExecutable = _selfExecutable
 			_interpreterArgument0 = fmt.Sprintf ("[z-run:menu] [%s]", _scriptletLabel)
@@ -607,6 +634,17 @@ func executeScriptlet (_library LibraryStore, _scriptlet *Scriptlet, _fork bool,
 			} else {
 				return _error
 			}
+		case "<starlark>" :
+			if _error := executeStarlark (_library, _scriptlet, _context); _error == nil {
+				if ! _fork {
+					os.Exit (0)
+					panic (0x44d7fe22)
+				} else {
+					return nil
+				}
+			} else {
+				return _error
+			}
 	}
 
 	var _libraryFingerprint string

sources/lib/parser.go

@@ -248,7 +248,7 @@ func parseInterpreter (_scriptlet *Scriptlet) (*Error) {
 	switch _scriptlet.Interpreter {
 		case "<detect>" :
 			// NOP
-		case "<exec>", "<print>", "<template>", "<menu>", "<go>", "<go+>" :
+		case "<exec>", "<print>", "<template>", "<starlark>", "<menu>", "<go>", "<go+>" :
 			return nil
 		case "<bash>", "<bash+>", "<python3+>" :
 			return nil
@@ -342,6 +342,23 @@ func parseInterpreter_0 (_scriptletLabel string, _scriptletBody_0 string, _scrip
 		_interpreterArgumentsExtraAllowed = true
 		_interpreterEnvironment = nil
 
+	} else if strings.HasPrefix (_scriptletHeader, "<starlark>") {
+
+		_scriptletHeader = _scriptletHeader[10:]
+		_scriptletHeader = strings.Trim (_scriptletHeader, " ")
+
+		if _scriptletHeader != "" {
+			_errorReturn = errorf (0xc7d23157, "invalid header for `%s` (starlark with arguments)", _scriptletLabel)
+			return
+		}
+
+		_interpreter = "<starlark>"
+		_interpreterExecutable = ""
+		_interpreterArguments = nil
+		_interpreterArgumentsExtraDash = false
+		_interpreterArgumentsExtraAllowed = true
+		_interpreterEnvironment = nil
+
 	} else if strings.HasPrefix (_scriptletHeader, "<print>") {
 
 		_scriptletHeader = _scriptletHeader[7:]

sources/lib/premain.go

@@ -243,6 +243,8 @@ func PreMain () () {
 		_argument0 = "[z-run:print]"
 	} else if strings.HasPrefix (_argument0, "[z-run:template] ") {
 		_argument0 = "[z-run:template]"
+	} else if strings.HasPrefix (_argument0, "[z-run:starlark] ") {
+		_argument0 = "[z-run:starlark]"
 	}
 
 
@@ -318,6 +320,9 @@ func PreMain () () {
 		case "[z-run:template]" :
 			// NOP
 
+		case "[z-run:starlark]" :
+			// NOP
+
 		case "[z-run:scriptlet]" :
 			// NOP
 
@@ -391,6 +396,10 @@ func PreMain () () {
 				_argument0 = "[z-run:template]"
 				_arguments = _arguments[1:]
 
+			case "--starlark" :
+				_argument0 = "[z-run:starlark]"
+				_arguments = _arguments[1:]
+
 			default :
 				_argument0 = "[z-run]"
 		}
@@ -453,6 +462,13 @@ func PreMain () () {
 				panic (0x32241835)
 			}
 
+		case "[z-run:starlark]" :
+			if _error := starlarkMain (_executable, _arguments, _environment); _error != nil {
+				panic (abortError (_error))
+			} else {
+				panic (0xd6f5b038)
+			}
+
 		case "[z-run:menu]" :
 			if _error := menuMain (_executable, _arguments, _environment); _error != nil {
 				panic (abortError (_error))

sources/lib/starlark.go

@@ -0,0 +1,108 @@
+
+
+package zrun
+
+
+import "os"
+
+import "go.starlark.net/starlark"
+
+
+
+
+func starlarkMain (_selfExecutable string, _arguments []string, _environment map[string]string) (*Error) {
+
+	if len (_arguments) < 1 {
+		return errorf (0xd776bfb0, "invalid arguments")
+	}
+
+	var _sourcePath = _arguments[0]
+	_arguments = _arguments[1:]
+
+	var _sourceBody string
+	if _, _data, _error := loadFromFile (_sourcePath); _error == nil {
+		_sourceBody = string (_data)
+	} else {
+		return _error
+	}
+
+	_error := executeStarlark_0 (
+			_sourceBody,
+			_arguments,
+			_environment,
+			_selfExecutable,
+			"",
+			"",
+			"",
+			nil,
+		)
+	if _error != nil {
+		return _error
+	}
+
+	os.Exit (0)
+	panic (0x340179ee)
+}
+
+
+
+
+func executeStarlark (_library LibraryStore, _scriptlet *Scriptlet, _context *Context) (*Error) {
+
+	if _scriptlet.Interpreter != "<starlark>" {
+		return errorf (0x8044a656, "invalid interpreter")
+	}
+
+	_libraryUrl := _library.Url ()
+	_libraryFingerprint := ""
+	if _libraryFingerprint_0, _error := _library.Fingerprint (); _error == nil {
+		_libraryFingerprint = _libraryFingerprint_0
+	} else {
+		return _error
+	}
+
+	_extraFunctions := make (map[string]interface{}, 16)
+
+	return executeStarlark_0 (
+			_scriptlet.Body,
+			_context.cleanArguments,
+			_context.cleanEnvironment,
+			_context.selfExecutable,
+			_context.workspace,
+			_libraryUrl,
+			_libraryFingerprint,
+			_extraFunctions,
+		)
+}
+
+
+
+
+func executeStarlark_0 (
+			_source string,
+			_arguments []string,
+			_environment map[string]string,
+			_selfExecutable string,
+			_workspace string,
+			_libraryUrl string,
+			_libraryFingerprint string,
+			_extraFunctions map[string]interface{},
+		) (*Error) {
+
+	_thread := & starlark.Thread {
+			Name : "scriptlet",
+			Print : func (_thread *starlark.Thread, _message string) () {
+					logf ('>', 0x98499c0a, "%s", _message)
+				},
+			Load : nil,
+		}
+
+	_builtins := starlark.StringDict {}
+
+	if _, _error := starlark.ExecFile (_thread, "<scriptlet>", _source, _builtins); _error != nil {
+		return errorw (0x4027d940, _error)
+	}
+
+	return nil
+}
+