examples/full/main.arf

@@ -9,7 +9,7 @@ data pv helloText:String "Hello, world!"
 
 # this is a struct definition
 objt ro Greeter:Obj
-	wr text:String "Hi."
+	rw text:String "Hi."
 
 # this is a function
 func ro main

parser/body.go

@@ -39,6 +39,14 @@ func (parser *ParsingOperation) parseBody () (err error) {
 			parser.tree.objtSections[section.name] = section
 			if err != nil { return }
 		case "face":
+			var section *FaceSection
+			section, err = parser.parseFaceSection()
+			if parser.tree.faceSections == nil {
+				parser.tree.faceSections =
+					make(map[string] *FaceSection)
+			}
+			parser.tree.faceSections[section.name] = section
+			if err != nil { return }
 		case "enum":
 			var section *EnumSection
 			section, err = parser.parseEnumSection()

parser/face.go

@@ -0,0 +1,132 @@
+package parser
+
+import "git.tebibyte.media/sashakoshka/arf/types"
+import "git.tebibyte.media/sashakoshka/arf/lexer"
+import "git.tebibyte.media/sashakoshka/arf/infoerr"
+
+// parseFaceSection parses an interface section.
+func (parser *ParsingOperation) parseFaceSection () (
+	section *FaceSection,
+	err     error,
+) {
+	err = parser.expect(lexer.TokenKindName)
+	if err != nil { return }
+	
+	section = &FaceSection {
+		location: parser.token.Location(),
+		behaviors:  make(map[string] FaceBehavior),
+	}
+
+	// get permission
+	err = parser.nextToken(lexer.TokenKindPermission)
+	if err != nil { return }
+	section.permission = parser.token.Value().(types.Permission)
+
+	// get name
+	err = parser.nextToken(lexer.TokenKindName)
+	if err != nil { return }
+	section.name = parser.token.Value().(string)
+
+	// parse inherited interface
+	err = parser.nextToken(lexer.TokenKindColon)
+	if err != nil { return }
+	err = parser.nextToken(lexer.TokenKindName)
+	if err != nil { return }
+	section.inherits = parser.token.Value().(string)
+	if err != nil { return }
+	err = parser.nextToken(lexer.TokenKindNewline)
+	if err != nil { return }
+	err = parser.nextToken()
+	if err != nil { return }
+
+	// parse members
+	for {
+		// if we've left the block, stop parsing
+		if !parser.token.Is(lexer.TokenKindIndent) { return }
+		if parser.token.Value().(int) != 1         { return }
+
+		// parse behavior
+		behaviorBeginning := parser.token.Location()
+		var behavior FaceBehavior
+		behavior, err = parser.parseFaceBehavior()
+
+		// add to section
+		_, exists := section.behaviors[behavior.name]
+		if exists {
+			err = infoerr.NewError (
+				behaviorBeginning,
+				"multiple behaviors named " + behavior.name +
+				" in this interface",
+				infoerr.ErrorKindError)
+			return
+		}
+		section.behaviors[behavior.name] = behavior
+		
+		if err != nil { return }
+	}
+	return
+}
+
+// parseFaceBehavior parses a single interface behavior. Indentation level is
+// assumed.
+func (parser *ParsingOperation) parseFaceBehavior () (
+	behavior FaceBehavior,
+	err      error,
+) {
+	err = parser.expect(lexer.TokenKindIndent)
+	if err != nil { return }
+
+	// get name
+	err = parser.nextToken(lexer.TokenKindName)
+	if err != nil { return }
+	behavior.name = parser.token.Value().(string)
+
+	err = parser.nextToken(lexer.TokenKindNewline)
+	if err != nil { return }
+	err = parser.nextToken()
+	if err != nil { return }
+	
+	for {
+		// if we've left the block, stop parsing
+		if !parser.token.Is(lexer.TokenKindIndent) { return }
+		if parser.token.Value().(int) != 2         { return }
+
+		// get preceding symbol
+		err = parser.nextToken (
+			lexer.TokenKindGreaterThan,
+			lexer.TokenKindLessThan)
+		if err != nil { return }
+		kind := parser.token.Kind()
+
+		var declaration Declaration
+
+		// get name
+		err = parser.nextToken(lexer.TokenKindName)
+		if err != nil { return }
+		declaration.name = parser.token.Value().(string)
+
+		// parse inherited type
+		err = parser.nextToken(lexer.TokenKindColon)
+		if err != nil { return }
+		err = parser.nextToken()
+		if err != nil { return }
+		declaration.what, err = parser.parseType()
+		if err != nil { return }
+		err = parser.expect(lexer.TokenKindNewline)
+		if err != nil { return }
+		err = parser.nextToken()
+		if err != nil { return }
+
+		if kind == lexer.TokenKindGreaterThan {
+			behavior.inputs = append (
+				behavior.inputs,
+				declaration)
+		} else {
+			behavior.outputs = append (
+				behavior.outputs,
+				declaration)
+		}
+	}
+	
+	return
+}

parser/parser_test.go

@@ -192,3 +192,21 @@ enum ro Weekday:Int
 	wednesday
 `, test)
 }
+
+func Test (test *testing.T) {
+	checkTree ("../tests/parser/face",
+`:arf
+---
+face ro Destroyer:Face
+	destroy
+face ro ReadWriter:Face
+	read
+		> into:{Byte ..}
+		< read:Int
+		< err:Error
+	write
+		> data:{Byte ..}
+		< wrote:Int
+		< err:Error
+`, test)
+}

parser/tree-tostring.go

@@ -61,6 +61,11 @@ func (tree *SyntaxTree) ToString (indent int) (output string) {
 		output += tree.enumSections[name].ToString(indent)
 	}
 
+	faceSectionKeys := sortMapKeysAlphabetically(tree.faceSections)
+	for _, name := range faceSectionKeys {
+		output += tree.faceSections[name].ToString(indent)
+	}
+
 	dataSectionKeys := sortMapKeysAlphabetically(tree.dataSections)
 	for _, name := range dataSectionKeys {
 		output += tree.dataSections[name].ToString(indent)
@@ -353,3 +358,32 @@ func (section *EnumSection) ToString (indent int) (output string) {
 	}
 	return
 }
+
+func (section *FaceSection) ToString (indent int) (output string) {
+	output += doIndent (
+		indent,
+		"face ",
+		section.permission.ToString(), " ",
+		section.name, ":",
+		section.inherits, "\n")
+
+	for _, name := range sortMapKeysAlphabetically(section.behaviors) {
+		behavior := section.behaviors[name]
+		output += behavior.ToString(indent + 1)
+	}
+	return
+}
+
+func (behavior *FaceBehavior) ToString (indent int) (output string) {
+	output += doIndent(indent, behavior.name, "\n")
+	
+	for _, inputItem := range behavior.inputs {
+		output += doIndent(indent + 1, "> ", inputItem.ToString(), "\n")
+	}
+	
+	for _, outputItem := range behavior.outputs {
+		output += doIndent(indent + 1, "< ", outputItem.ToString(), "\n")
+	}
+
+	return
+}

parser/tree.go

@@ -14,6 +14,7 @@ type SyntaxTree struct {
 	typeSections map[string] *TypeSection
 	objtSections map[string] *ObjtSection
 	enumSections map[string] *EnumSection
+	faceSections map[string] *FaceSection
 	dataSections map[string] *DataSection
 }
 
@@ -203,3 +204,22 @@ type EnumSection struct {
 	// TODO: order matters here we need to store these in an array
 	members    map[string] Argument
 }
+
+// FaceBehavior represents a behavior of an interface section.
+type FaceBehavior struct {
+	location file.Location
+	name string
+
+	inputs  []Declaration
+	outputs []Declaration
+}
+
+// FaceSection represents an interface type section.
+type FaceSection struct {
+	location file.Location
+	name     string
+	inherits string
+	
+	permission types.Permission
+	behaviors  map[string] FaceBehavior
+}

tests/parser/face/main.arf

@@ -0,0 +1,15 @@
+:arf
+---
+
+face ro ReadWriter:Face
+	write
+		> data:{Byte ..}
+		< wrote:Int
+		< err:Error
+	read
+		> into:{Byte ..}
+		< read:Int
+		< err:Error
+
+face ro Destroyer:Face
+	destroy