Merge pull request 'syntax-tree-accessors' (#2) from syntax-tree-accessors into main

Reviewed-on: arf/arf#2

parser/accessors.go

@@ -0,0 +1,276 @@
+package parser
+
+import "git.tebibyte.media/arf/arf/types"
+
+// LookupSection looks returns the section under the give name. If the section
+// does not exist, nil is returned.
+func (tree SyntaxTree) LookupSection (name string) (section Section) {
+	section = tree.sections[name]
+	return
+}
+
+// Sections returns an iterator for the tree's sections
+func (tree SyntaxTree) Sections () (iterator types.Iterator[Section]) {
+	iterator = types.NewIterator(tree.sections)
+	return
+}
+
+// Kind returns the section's kind (SectionKindType).
+func (section TypeSection) Kind () (kind SectionKind) {
+	kind = SectionKindType
+	return
+}
+
+// Kind returns the section's kind (SectionKindObjt).
+func (section ObjtSection) Kind () (kind SectionKind) {
+	kind = SectionKindObjt
+	return
+}
+
+// Kind returns the section's kind (SectionKindEnum).
+func (section EnumSection) Kind () (kind SectionKind) {
+	kind = SectionKindEnum
+	return
+}
+
+// Kind returns the section's kind (SectionKindFace).
+func (section FaceSection) Kind () (kind SectionKind) {
+	kind = SectionKindFace
+	return
+}
+
+// Kind returns the section's kind (SectionKindData).
+func (section DataSection) Kind () (kind SectionKind) {
+	kind = SectionKindData
+	return
+}
+
+// Kind returns the section's kind (SectionKindFunc).
+func (section FuncSection) Kind () (kind SectionKind) {
+	kind = SectionKindFunc
+	return
+}
+
+// Length returns the amount of names in the identifier.
+func (identifier Identifier) Length () (length int) {
+	length = len(identifier.trail)
+	return
+}
+
+// Item returns the name at the specified index.
+func (identifier Identifier) Item (index int) (item string) {
+	item = identifier.trail[index]
+	return
+}
+
+// Kind returns the type's kind.
+func (what Type) Kind () (kind TypeKind) {
+	kind = what.kind
+	return
+}
+
+// Mutable returns whether or not the type's data is mutable.
+func (what Type) Mutable () (mutable bool) {
+	mutable = what.mutable
+	return
+}
+
+// Length returns the length of the type if the type is a fixed length array.
+// Otherwise, it just returns zero.
+func (what Type) Length () (length uint64) {
+	if what.kind == TypeKindArray {
+		length = what.length
+	}
+	return
+}
+
+// Name returns the name of the type, if it is a basic type. Otherwise, it
+// returns a zero value identifier.
+func (what Type) Name () (name Identifier) {
+	if what.kind == TypeKindBasic {
+		name = what.name
+	}
+	return
+}
+
+// Points returns the type that this type points to, or is an array of. If the
+// type is a basic type, this returns a zero value type.
+func (what Type) Points () (points Type) {
+	if what.kind != TypeKindBasic {
+		points = *what.points
+	}
+	return
+}
+
+// Values returns an iterator for the initialization values.
+func (values ObjectInitializationValues) Sections () (
+	iterator types.Iterator[Argument],
+) {
+	iterator = types.NewIterator(values.attributes)
+	return
+}
+
+// Length returns the amount of values.
+func (values ArrayInitializationValues) Length () (length int) {
+	length = len(values.values)
+	return
+}
+
+// Item returns the value at index.
+func (values ArrayInitializationValues) Value (index int) (value Argument) {
+	value = values.values[index]
+	return
+}
+
+// Kind returns what kind of argument it is.
+func (argument Argument) Kind () (kind ArgumentKind) {
+	kind = argument.kind
+	return
+}
+
+// Value returns the underlying value of the argument. You can use Kind() to
+// find out what to cast this to.
+func (argument Argument) Value () (value any) {
+	value = argument.value
+	return
+}
+
+// BitWidth returns the bit width of the object member. If it is zero, it should
+// be treated as unspecified.
+func (member ObjtMember) BitWidth () (width uint64) {
+	width = member.bitWidth
+	return
+}
+
+// Length returns the amount of members in the section.
+func (section ObjtSection) Length () (length int) {
+	length = len(section.members)
+	return
+}
+
+// Item returns the member at index.
+func (section ObjtSection) Item (index int) (member ObjtMember) {
+	member = section.members[index]
+	return
+}
+
+// Length returns the amount of members in the section.
+func (section EnumSection) Length () (length int) {
+	length = len(section.members)
+	return
+}
+
+// Item returns the member at index.
+func (section EnumSection) Item (index int) (member EnumMember) {
+	member = section.members[index]
+	return
+}
+
+// InputsLength returns the amount of inputs in the behavior.
+func (behavior FaceBehavior) IntputsLength () (length int) {
+	length = len(behavior.inputs)
+	return
+}
+
+// Input returns the input at index.
+func (behavior FaceBehavior) Input (index int) (input Declaration) {
+	input = behavior.inputs[index]
+	return
+}
+
+// OutputsLength returns the amount of outputs in the behavior.
+func (behavior FaceBehavior) OutputsLength () (length int) {
+	length = len(behavior.outputs)
+	return
+}
+
+// Output returns the output at index.
+func (behavior FaceBehavior) Output (index int) (output Declaration) {
+	output = behavior.outputs[index]
+	return
+}
+
+// Behaviors returns an iterator for the interface's behaviors.
+func (section FaceSection) Behaviors () (iterator types.Iterator[FaceBehavior]) {
+	iterator = types.NewIterator(section.behaviors)
+	return
+}
+
+// Kind returns what kind of phrase it is.
+func (phrase Phrase) Kind () (kind PhraseKind) {
+	kind = phrase.kind
+	return
+}
+
+// ArgumentsLength returns the amount of arguments in the phrase.
+func (phrase Phrase) ArgumentsLength () (length int) {
+	length = len(phrase.arguments)
+	return
+}
+
+// Argument returns the argument at index.
+func (phrase Phrase) Argument (index int) (argument Argument) {
+	argument = phrase.arguments[index]
+	return
+}
+
+// ReturnsToLength returns the amount of things the phrase returns to.
+func (phrase Phrase) ReturnsToLength () (length int) {
+	length = len(phrase.returnsTo)
+	return
+}
+
+// ReturnTo returns the thing alskdjaslkdjsa whatever i dont even know wtf.
+func (phrase Phrase) ReturnTo (index int) (returnTo Argument) {
+	returnTo = phrase.returnsTo[index]
+	return
+}
+
+// Block returns the block under the phrase, if it is a control flow statement.
+func (phrase Phrase) Block () (block Block) {
+	block = phrase.block
+	return
+}
+
+// Receiver returns the method receiver, if there is one. Otherwise, it returns
+// nil.
+func (section FuncSection) Receiver () (receiver *Declaration) {
+	receiver = section.receiver
+	return
+}
+
+// InputsLength returns the number of inputs in the function.
+func (section FuncSection) InputsLength () (length int) {
+	length = len(section.inputs)
+	return
+}
+
+// Input returns the input at index.
+func (section FuncSection) Input (index int) (input Declaration) {
+	input = section.inputs[index]
+	return
+}
+
+// OutputsLength returns the number of outputs in the function.
+func (section FuncSection) OutputsLength () (length int) {
+	length = len(section.outputs)
+	return
+}
+
+// Output returns the output at index.
+func (section FuncSection) Output (index int) (output FuncOutput) {
+	output = section.outputs[index]
+	return
+}
+
+// Root returns the root block of the section.
+func (section FuncSection) Root () (root Block) {
+	root = section.root
+	return
+}
+
+// External returns whether or not the function is an external function or not.
+func (section FuncSection) External () (external bool) {
+	external = section.external
+	return
+}

parser/argument.go

@@ -42,12 +42,14 @@ func (parser *ParsingOperation) parseArgument () (argument Argument, err error)
 				return
 			}
 			
+			declaration := Declaration { }
+			declaration.what = what
+			declaration.name = identifier.trail[0]
+			declaration.location = argument.Location()
+
 			argument.kind  = ArgumentKindDeclaration
-			argument.value = Declaration {
-				location: argument.location,
-				name:     identifier.trail[0],
-				what:     what,
-			}
+			argument.value = declaration
+			
 		} else {
 			argument.kind  = ArgumentKindIdentifier
 			argument.value = identifier

parser/body.go

@@ -8,63 +8,45 @@ func (parser *ParsingOperation) parseBody () (err error) {
 	for {
 		err = parser.expect(lexer.TokenKindName)
 		if err != nil { return }
-
 		sectionType := parser.token.Value().(string)
+
 		switch sectionType {
 		case "data":
-			var section *DataSection
-			section, err = parser.parseDataSection()
-			if parser.tree.dataSections == nil {
-				parser.tree.dataSections =
-					make(map[string] *DataSection)
-			}
-			parser.tree.dataSections[section.name] = section
+			section, parseErr := parser.parseDataSection()
+			err = parser.tree.addSection(section)
 			if err      != nil { return }
+			if parseErr != nil { return }
+			
 		case "type":
-			var section *TypeSection
-			section, err = parser.parseTypeSection()
-			if parser.tree.typeSections == nil {
-				parser.tree.typeSections =
-					make(map[string] *TypeSection)
-			}
-			parser.tree.typeSections[section.name] = section
+			section, parseErr := parser.parseTypeSection()
+			err = parser.tree.addSection(section)
 			if err      != nil { return }
+			if parseErr != nil { return }
+			
 		case "objt":
-			var section *ObjtSection
-			section, err = parser.parseObjtSection()
-			if parser.tree.objtSections == nil {
-				parser.tree.objtSections =
-					make(map[string] *ObjtSection)
-			}
-			parser.tree.objtSections[section.name] = section
+			section, parseErr := parser.parseObjtSection()
+			err = parser.tree.addSection(section)
 			if err      != nil { return }
+			if parseErr != 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
+			section, parseErr := parser.parseFaceSection()
+			err = parser.tree.addSection(section)
 			if err      != nil { return }
+			if parseErr != nil { return }
+			
 		case "enum":
-			var section *EnumSection
-			section, err = parser.parseEnumSection()
-			if parser.tree.enumSections == nil {
-				parser.tree.enumSections =
-					make(map[string] *EnumSection)
-			}
-			parser.tree.enumSections[section.name] = section
+			section, parseErr := parser.parseEnumSection()
+			err = parser.tree.addSection(section)
 			if err      != nil { return }
+			if parseErr != nil { return }
+			
 		case "func":
-			var section *FuncSection
-			section, err = parser.parseFuncSection()
-			if parser.tree.funcSections == nil {
-				parser.tree.funcSections =
-					make(map[string] *FuncSection)
-			}
-			parser.tree.funcSections[section.name] = section
+			section, parseErr := parser.parseFuncSection()
+			err = parser.tree.addSection(section)
 			if err      != nil { return }
+			if parseErr != nil { return }
+			
 		default:
 			err = parser.token.NewError (
 				"unknown section type \"" + sectionType + "\"",
@@ -73,3 +55,18 @@ func (parser *ParsingOperation) parseBody () (err error) {
 		}
 	}
 }
+
+// addSection adds a section to the tree, ensuring it has a unique name within
+// the module.
+func (tree *SyntaxTree) addSection (section Section) (err error) {
+	_, exists := tree.sections[section.Name()]
+	if exists {
+		err = section.NewError (
+			"cannot have multiple sections with the same name",
+			infoerr.ErrorKindError)
+		return
+	}
+
+	tree.sections[section.Name()] = section
+	return
+}

parser/data.go

@@ -5,13 +5,13 @@ import "git.tebibyte.media/arf/arf/lexer"
 
 // parseData parses a data section.
 func (parser *ParsingOperation) parseDataSection () (
-	section *DataSection,
+	section DataSection,
 	err     error,
 ) {
 	err = parser.expect(lexer.TokenKindName)
 	if err != nil { return }
 	
-	section = &DataSection { location: parser.token.Location() }
+	section.location = parser.token.Location()
 
 	err = parser.nextToken(lexer.TokenKindPermission)
 	if err != nil { return }

parser/enum.go

@@ -4,14 +4,15 @@ import "git.tebibyte.media/arf/arf/types"
 import "git.tebibyte.media/arf/arf/lexer"
 import "git.tebibyte.media/arf/arf/infoerr"
 
+// parseEnumSection parses an enumerated type section.
 func (parser *ParsingOperation) parseEnumSection () (
-	section *EnumSection,
+	section EnumSection,
 	err     error,
 ) {
 	err = parser.expect(lexer.TokenKindName)
 	if err != nil { return }
 	
-	section = &EnumSection { location: parser.token.Location() }
+	section.location = parser.token.Location()
 
 	// get permission
 	err = parser.nextToken(lexer.TokenKindPermission)
@@ -36,7 +37,7 @@ func (parser *ParsingOperation) parseEnumSection () (
 	if err != nil { return }
 
 	// parse members
-	err = parser.parseEnumMembers(section)
+	err = parser.parseEnumMembers(&section)
 	if err != nil { return }
 	
 	if len(section.members) == 0 {

parser/face.go

@@ -6,16 +6,14 @@ import "git.tebibyte.media/arf/arf/infoerr"
 
 // parseFaceSection parses an interface section.
 func (parser *ParsingOperation) parseFaceSection () (
-	section *FaceSection,
+	section FaceSection,
 	err     error,
 ) {
 	err = parser.expect(lexer.TokenKindName)
 	if err != nil { return }
 	
-	section = &FaceSection {
-		location: parser.token.Location(),
-		behaviors:  make(map[string] FaceBehavior),
-	}
+	section.behaviors = make(map[string] FaceBehavior)
+	section.location  = parser.token.Location()
 
 	// get permission
 	err = parser.nextToken(lexer.TokenKindPermission)

parser/func.go

@@ -6,13 +6,13 @@ import "git.tebibyte.media/arf/arf/infoerr"
 
 // parseFunc parses a function section.
 func (parser *ParsingOperation) parseFuncSection () (
-	section *FuncSection,
+	section FuncSection,
 	err     error,
 ) {
 	err = parser.expect(lexer.TokenKindName)
 	if err != nil { return }
 	
-	section = &FuncSection { location: parser.token.Location() }
+	section.location = parser.token.Location()
 
 	// get permission
 	err = parser.nextToken(lexer.TokenKindPermission)
@@ -29,7 +29,7 @@ func (parser *ParsingOperation) parseFuncSection () (
 	if err != nil { return }
 	err = parser.nextToken()
 	if err != nil { return }
-	err = parser.parseFuncArguments(section)
+	err = parser.parseFuncArguments(&section)
 	if err != nil { return }
 
 	// check to see if the function is external
@@ -185,12 +185,12 @@ func (parser *ParsingOperation) parseFuncArguments (
 				err = parser.nextToken()
 				if err != nil { return }
 
-				output.defaultValue, err =
+				output.value, err =
 					parser.parseInitializationValues(1)
 				into.outputs = append(into.outputs, output)
 				if err != nil { return }
 			} else {
-				output.defaultValue, err =
+				output.value, err =
 					parser.parseArgument()
 				into.outputs = append(into.outputs, output)
 				if err != nil { return }

parser/misc.go

@@ -3,6 +3,29 @@ package parser
 import "git.tebibyte.media/arf/arf/lexer"
 import "git.tebibyte.media/arf/arf/infoerr"
 
+// TODO: need to come up with another syntax for bitfields, and use that syntax
+// for fixed-length arrays. the problem is, we cant use {} for those kinds of
+// arrays because they aren't pointers under the hood and that goes against the
+// arf design goals in a nasty ugly way, and not only that. but the :mut type
+// qualifier is meaningless on fixed length arrays now. the bit field syntax
+// solves both of these problems very gracefully. but now, the problem is coming
+// up with new bit field syntax. implementing this change is extremely
+// necessary, for it will supercharge the coherency of the language and make it
+// way more awesome.
+//
+// this new syntax cannot conflict with arguments, so it cannot have any
+// tokens that begin those. basically all symbol tokens are on the table here.
+// some ideas:
+//
+// ro member:Type ~ 4
+// ro member:Type & 4    <- i like this one because binary &. so intuitive.
+// ro member:Type % 4
+// ro member:Type | 4
+// ro member:Type ! 4
+// ro member:Type (4)    <- this looks phenomenal, but it needs new tokens not
+//                          used anywhere else, and it would be mildly annoying
+//                          to parse.
+
 // parseType parses a type notation of the form Name, {Name}, etc.
 func (parser *ParsingOperation) parseType () (what Type, err error) {
 	err = parser.expect(lexer.TokenKindName, lexer.TokenKindLBrace)
@@ -34,7 +57,7 @@ func (parser *ParsingOperation) parseType () (what Type, err error) {
 			err = parser.nextToken(lexer.TokenKindRBrace)
 			if err != nil { return }
 		} else if parser.token.Is(lexer.TokenKindElipsis) {
-			what.kind = TypeKindArray
+			what.kind = TypeKindVariableArray
 		
 			err = parser.nextToken(lexer.TokenKindRBrace)
 			if err != nil { return }

parser/node-traits.go

@@ -0,0 +1,70 @@
+package parser
+
+import "git.tebibyte.media/arf/arf/file"
+import "git.tebibyte.media/arf/arf/types"
+import "git.tebibyte.media/arf/arf/infoerr"
+
+// locatable allows a tree node to have a location.
+type locatable struct {
+	location file.Location
+}
+
+// Location returns the location of the node.
+func (trait locatable) Location () (location file.Location) {
+	location = trait.location
+	return
+}
+
+// NewError creates a new error at the node's location.
+func (trait locatable) NewError (
+	message string,
+	kind    infoerr.ErrorKind,
+) (
+	err error,
+) {
+	err = infoerr.NewError(trait.location, message, kind)
+	return
+}
+
+// nameable allows a tree node to have a name.
+type nameable struct {
+	name string
+}
+
+// Name returns the name of the node.
+func (trait nameable) Name () (name string) {
+	name = trait.name
+	return
+}
+// typeable allows a node to have a type.
+type typeable struct {
+	what Type
+}
+
+// Type returns the type of the node.
+func (trait typeable) Type () (what Type) {
+	what =  trait.what
+	return
+}
+
+// permissionable allows a node to have a permission.
+type permissionable struct {
+	permission types.Permission
+}
+
+// Permission returns the permision of the node.
+func (trait permissionable) Permission () (permission types.Permission) {
+	permission = trait.permission
+	return
+}
+
+// valuable allows a node to have an argument value.
+type valuable struct {
+	value Argument
+}
+
+// Value returns the value argument of the node.
+func (trait valuable) Value () (value Argument) {
+	value = trait.value
+	return
+}

parser/objt.go

@@ -7,13 +7,13 @@ import "git.tebibyte.media/arf/arf/infoerr"
 // parseObjtSection parses an object type definition. This allows for structured
 // types to be defined, and for member variables to be added and overridden.
 func (parser *ParsingOperation) parseObjtSection () (
-	section *ObjtSection,
+	section ObjtSection,
 	err     error,
 ) {
 	err = parser.expect(lexer.TokenKindName)
 	if err != nil { return }
 	
-	section = &ObjtSection { location: parser.token.Location() }
+	section.location = parser.token.Location()
 
 	// get permission
 	err = parser.nextToken(lexer.TokenKindPermission)
@@ -38,7 +38,7 @@ func (parser *ParsingOperation) parseObjtSection () (
 	if err != nil { return }
 
 	// parse members
-	err = parser.parseObjtMembers(section)
+	err = parser.parseObjtMembers(&section)
 	if err != nil { return }
 	
 	if len(section.members) == 0 {
@@ -108,11 +108,11 @@ func (parser *ParsingOperation) parseObjtMember () (
 		err = parser.nextToken()
 		if err != nil { return }
 
-		member.defaultValue,
+		member.value,
 		err = parser.parseInitializationValues(1)
 		if err != nil { return }
 	} else {
-		member.defaultValue, err = parser.parseArgument()
+		member.value, err = parser.parseArgument()
 		if err != nil { return }
 
 		err = parser.expect(lexer.TokenKindNewline)

parser/parser.go

@@ -14,13 +14,25 @@ type ParsingOperation struct {
 	tokens     []lexer.Token
 	tokenIndex int
 
-	tree *SyntaxTree
+	tree SyntaxTree
 }
 
+// TODO:
+// - implement parser cache
+// - have this try to hit the cache, and actually parse on miss
+// - rename this to Fetch
+// - add `skim bool` argument. when this is true, don't parse any code or data
+//   section initialization values, just definitions and their default values.
+
 // Parse reads the files located in the module specified by modulePath, and
 // converts them into an abstract syntax tree.
-func Parse (modulePath string) (tree *SyntaxTree, err error) {
-	parser := ParsingOperation { modulePath: modulePath }
+func Parse (modulePath string) (tree SyntaxTree, err error) {
+	parser := ParsingOperation {
+		modulePath: modulePath,
+		tree: SyntaxTree {
+			sections: make(map[string] Section),			
+		},
+	}
 
 	if parser.modulePath[len(parser.modulePath) - 1] != '/' {
 		parser.modulePath += "/"
@@ -54,9 +66,6 @@ func (parser *ParsingOperation) parse (sourceFile *file.File) (err error) {
 	if err != nil { return }
 
 	// reset the parser
-	if parser.tree == nil {
-		parser.tree = &SyntaxTree { }
-	}
 	if len(tokens) == 0 { return }
 	parser.tokens = tokens
 	parser.token  = tokens[0]

parser/test-common.go

@@ -7,15 +7,6 @@ import "testing"
 
 func checkTree (modulePath string, correct string, test *testing.T) {
 	tree, err := Parse(modulePath)
-	if tree == nil {
-		test.Log("TREE IS NIL!")
-		if err != io.EOF && err != nil {
-			test.Log("returned error:")
-			test.Log(err)
-		}
-		test.Fail()
-		return
-	}
 	
 	treeString := tree.ToString(0)
 	treeRunes  := []rune(treeString)

parser/tree-tostring.go

@@ -30,7 +30,7 @@ func sortMapKeysAlphabetically[KEY_TYPE any] (
 	return
 }
 
-func (tree *SyntaxTree) ToString (indent int) (output string) {
+func (tree SyntaxTree) ToString (indent int) (output string) {
 	output += doIndent(indent, ":arf\n")
 
 	if tree.author != "" {
@@ -47,35 +47,11 @@ func (tree *SyntaxTree) ToString (indent int) (output string) {
 	
 	output += doIndent(indent, "---\n")
 
-	typeSectionKeys := sortMapKeysAlphabetically(tree.typeSections)
-	for _, name := range typeSectionKeys {
-		output += tree.typeSections[name].ToString(indent)
+	sectionKeys := sortMapKeysAlphabetically(tree.sections)
+	for _, name := range sectionKeys {
+		output += tree.sections[name].ToString(indent)
 	}
 
-	objtSectionKeys := sortMapKeysAlphabetically(tree.objtSections)
-	for _, name := range objtSectionKeys {
-		output += tree.objtSections[name].ToString(indent)
-	}
-
-	enumSectionKeys := sortMapKeysAlphabetically(tree.enumSections)
-	for _, name := range enumSectionKeys {
-		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)
-	}
-
-	funcSectionKeys := sortMapKeysAlphabetically(tree.funcSections)
-	for _, name := range funcSectionKeys {
-		output += tree.funcSections[name].ToString(indent)
-	}
 	return
 }
 
@@ -90,7 +66,7 @@ func (identifier Identifier) ToString () (output string) {
 	return
 }
 
-func (what *Type) ToString () (output string) {
+func (what Type) ToString () (output string) {
 	if what.kind == TypeKindBasic {
 		output += what.name.ToString()
 	} else {
@@ -98,12 +74,9 @@ func (what *Type) ToString () (output string) {
 		output += what.points.ToString()
 
 		if what.kind == TypeKindArray {
-			output += " "
-			if what.length == 0 {
-				output += ".."
-			} else {
-				output += fmt.Sprint(what.length)
-			}
+			output += fmt.Sprint(" ", what.length)
+		} else if what.kind == TypeKindVariableArray {
+			output += " .."
 		}
 		
 		output += "}"
@@ -154,7 +127,7 @@ func (values ArrayInitializationValues) ToString (
 	return
 }
 
-func (argument *Argument) ToString (indent int, breakLine bool) (output string) {
+func (argument Argument) ToString (indent int, breakLine bool) (output string) {
 	if !breakLine { indent = 0 }
 	if argument.kind == ArgumentKindNil {
 		output += "NIL-ARGUMENT"
@@ -279,7 +252,7 @@ func (argument *Argument) ToString (indent int, breakLine bool) (output string)
 	return
 }
 
-func (section *DataSection) ToString (indent int) (output string) {
+func (section DataSection) ToString (indent int) (output string) {
 	output += doIndent (
 		indent,
 		"data ",
@@ -303,25 +276,25 @@ func (section *DataSection) ToString (indent int) (output string) {
 	return
 }
 
-func (section *TypeSection) ToString (indent int) (output string) {
+func (section TypeSection) ToString (indent int) (output string) {
 	output += doIndent (
 		indent,
 		"type ",
 		section.permission.ToString(), " ",
 		section.name, ":",
-		section.inherits.ToString())
+		section.what.ToString())
 
 	isComplexInitialization :=
-		section.defaultValue.kind == ArgumentKindObjectInitializationValues ||
-		section.defaultValue.kind == ArgumentKindArrayInitializationValues
+		section.value.kind == ArgumentKindObjectInitializationValues ||
+		section.value.kind == ArgumentKindArrayInitializationValues
 
-	if section.defaultValue.value == nil {
+	if section.value.value == nil {
 		output += "\n"
 	} else if isComplexInitialization {
 		output += "\n"
-		output += section.defaultValue.ToString(indent + 1, true)
+		output += section.value.ToString(indent + 1, true)
 	} else {
-		output += " " + section.defaultValue.ToString(0, false)
+		output += " " + section.value.ToString(0, false)
 		output += "\n"
 	}
 	return
@@ -339,23 +312,23 @@ func (member ObjtMember) ToString (indent int) (output string) {
 	}
 	
 	isComplexInitialization :=
-		member.defaultValue.kind == ArgumentKindObjectInitializationValues ||
-		member.defaultValue.kind == ArgumentKindArrayInitializationValues
+		member.value.kind == ArgumentKindObjectInitializationValues ||
+		member.value.kind == ArgumentKindArrayInitializationValues
 	
-	if member.defaultValue.value == nil {
+	if member.value.value == nil {
 		output += "\n"
 	} else if isComplexInitialization {
 		output += "\n"
-		output += member.defaultValue.ToString(indent + 1, true)
+		output += member.value.ToString(indent + 1, true)
 	} else {
-		output += " " + member.defaultValue.ToString(0, false)
+		output += " " + member.value.ToString(0, false)
 		output += "\n"
 	}
 
 	return
 }
 
-func (section *ObjtSection) ToString (indent int) (output string) {
+func (section ObjtSection) ToString (indent int) (output string) {
 	output += doIndent (
 		indent,
 		"objt ",
@@ -369,7 +342,7 @@ func (section *ObjtSection) ToString (indent int) (output string) {
 	return
 }
 
-func (section *EnumSection) ToString (indent int) (output string) {
+func (section EnumSection) ToString (indent int) (output string) {
 	output += doIndent (
 		indent,
 		"enum ",
@@ -397,7 +370,7 @@ func (section *EnumSection) ToString (indent int) (output string) {
 	return
 }
 
-func (section *FaceSection) ToString (indent int) (output string) {
+func (section FaceSection) ToString (indent int) (output string) {
 	output += doIndent (
 		indent,
 		"face ",
@@ -412,7 +385,7 @@ func (section *FaceSection) ToString (indent int) (output string) {
 	return
 }
 
-func (behavior *FaceBehavior) ToString (indent int) (output string) {
+func (behavior FaceBehavior) ToString (indent int) (output string) {
 	output += doIndent(indent, behavior.name, "\n")
 	
 	for _, inputItem := range behavior.inputs {
@@ -473,13 +446,13 @@ func (block Block) ToString (indent int) (output string) {
 
 func (funcOutput FuncOutput) ToString () (output string) {
 	output += funcOutput.Declaration.ToString()
-	if funcOutput.defaultValue.kind != ArgumentKindNil {
-		output += " " + funcOutput.defaultValue.ToString(0, false)
+	if funcOutput.value.kind != ArgumentKindNil {
+		output += " " + funcOutput.value.ToString(0, false)
 	}
 	return
 }
 
-func (section *FuncSection) ToString (indent int) (output string) {
+func (section FuncSection) ToString (indent int) (output string) {
 	output += doIndent (
 		indent,
 		"func ",

parser/tree.go

@@ -2,6 +2,7 @@ package parser
 
 import "git.tebibyte.media/arf/arf/file"
 import "git.tebibyte.media/arf/arf/types"
+import "git.tebibyte.media/arf/arf/infoerr"
 
 // SyntaxTree represents an abstract syntax tree. It covers an entire module. It
 // can be expected to be syntactically correct, but it might not be semantically
@@ -11,21 +12,39 @@ type SyntaxTree struct {
 	author  string
 
 	requires []string
-	typeSections map[string] *TypeSection
-	objtSections map[string] *ObjtSection
-	enumSections map[string] *EnumSection
-	faceSections map[string] *FaceSection
-	dataSections map[string] *DataSection
-	funcSections map[string] *FuncSection
+	sections map[string] Section
 }
 
-// Identifier represents a chain of arguments separated by a dot.
+// SectionKind differentiates Section interfaces.
+type SectionKind int
+
+const (
+	SectionKindType = iota
+	SectionKindObjt
+	SectionKindEnum
+	SectionKindFace
+	SectionKindData
+	SectionKindFunc
+)
+
+// Section can be any kind of section. You can find out what type of section it
+// is with the Kind method.
+type Section interface {
+	Location   () (location file.Location)
+	Kind       () (kind SectionKind)
+	Permission () (permission types.Permission)
+	Name       () (name string)
+	NewError   (message string, kind infoerr.ErrorKind) (err error)
+	ToString   (indent int) (output string)
+}
+
+// Identifier represents a chain of names separated by a dot.
 type Identifier struct {
-	location file.Location
+	locatable
 	trail []string
 }
 
-// TypeKind represents what kind of type a type is
+// TypeKind represents what kind of type a type is.
 type TypeKind int
 
 const (
@@ -36,19 +55,21 @@ const (
 	// TypeKindPointer means it's a pointer
 	TypeKindPointer
 
-	// TypeKindArray means it's an array.
+	// TypeKindArray means it's a fixed length array.
 	TypeKindArray
+
+	// TypeKindVariableArray means it's an array of variable length.
+	TypeKindVariableArray
 )
 
 // Type represents a type specifier
 type Type struct {
-	location file.Location
+	locatable
 
 	mutable bool
 	kind TypeKind
 
-	// only applicable for arrays. a value of zero means it has an
-	// undefined/dynamic length.
+	// only applicable for fixed length arrays.
 	length uint64
 
 	// only applicable for basic.
@@ -60,22 +81,22 @@ type Type struct {
 
 // Declaration represents a variable declaration.
 type Declaration struct {
-	location file.Location
-	name     string
-	what     Type
+	locatable
+	nameable
+	typeable
 }
 
 // ObjectInitializationValues represents a list of object member initialization
 // attributes.
 type ObjectInitializationValues struct {
-	location   file.Location
+	locatable
 	attributes map[string] Argument
 }
 
 // ArrayInitializationValues represents a list of attributes initializing an
 // array.
 type ArrayInitializationValues struct {
-	location file.Location
+	locatable
 	values []Argument
 }
 
@@ -139,7 +160,7 @@ const (
 // Argument represents a value that can be placed anywhere a value goes. This
 // allows things like phrases being arguments to other phrases.
 type Argument struct {
-	location file.Location
+	locatable
 	kind  ArgumentKind
 	value any
 	// TODO: if there is an argument expansion operator its existence should
@@ -148,66 +169,64 @@ type Argument struct {
 
 // DataSection represents a global variable.
 type DataSection struct {
-	location file.Location
-	name     string
-	
-	what       Type
-	permission types.Permission
-	value      Argument
+	locatable
+	nameable
+	typeable
+	permissionable
+	valuable
 }
 
 // TypeSection represents a blind type definition.
 type TypeSection struct {
-	location file.Location
-	name     string
-	
-	inherits     Type
-	permission   types.Permission
-	defaultValue Argument
+	locatable
+	nameable
+	typeable
+	permissionable
+	valuable
 }
 
 // ObjtMember represents a part of an object type definition.
 type ObjtMember struct {
-	location file.Location
-	name     string
+	locatable
+	nameable
+	typeable
+	permissionable
+	valuable
 	
-	what         Type
 	bitWidth uint64
-	permission   types.Permission
-	defaultValue Argument
 }
 
 // ObjtSection represents an object type definition.
 type ObjtSection struct {
-	location file.Location
-	name     string
-
+	locatable
+	nameable
+	permissionable
 	inherits Identifier
-	permission   types.Permission
+
 	members []ObjtMember
 }
 
 // EnumMember represents a member of an enum section.
 type EnumMember struct {
-	location file.Location
-	name     string
-	value    Argument
+	locatable
+	nameable
+	valuable
 }
 
 // EnumSection represents an enumerated type section.
 type EnumSection struct {
-	location file.Location
-	name     string
+	locatable
+	nameable
+	typeable
+	permissionable
 
-	what       Type
-	permission types.Permission
 	members []EnumMember
 }
 
 // FaceBehavior represents a behavior of an interface section.
 type FaceBehavior struct {
-	location file.Location
-	name string
+	locatable
+	nameable
 
 	inputs  []Declaration
 	outputs []Declaration
@@ -215,11 +234,11 @@ type FaceBehavior struct {
 
 // FaceSection represents an interface type section.
 type FaceSection struct {
-	location file.Location
-	name     string
+	locatable
+	nameable
+	permissionable
 	inherits Identifier
 	
-	permission types.Permission
 	behaviors map[string] FaceBehavior
 }
 
@@ -248,6 +267,8 @@ type Phrase struct {
 	location  file.Location
 	command   Argument
 	arguments []Argument
+	// TODO: this is wack. it should be named after a plural noun like,
+	// returnees or something. accessor methods should beupdated to match.
 	returnsTo []Argument
 
 	kind PhraseKind
@@ -263,14 +284,14 @@ type Block []Phrase
 // that it can have a default value.
 type FuncOutput struct {
 	Declaration
-	defaultValue Argument
+	valuable
 }
 
 // FuncSection represents a function section.
 type FuncSection struct {
-	location   file.Location
-	name       string
-	permission types.Permission
+	locatable
+	nameable
+	permissionable
 	
 	receiver *Declaration
 	inputs   []Declaration

parser/type.go

@@ -2,18 +2,17 @@ package parser
 
 import "git.tebibyte.media/arf/arf/types"
 import "git.tebibyte.media/arf/arf/lexer"
-// import "git.tebibyte.media/arf/arf/infoerr"
 
 // parseTypeSection parses a blind type definition, meaning it can inherit from
 // anything including primitives, but cannot define structure.
 func (parser *ParsingOperation) parseTypeSection () (
-	section *TypeSection,
+	section TypeSection,
 	err     error,
 ) {
 	err = parser.expect(lexer.TokenKindName)
 	if err != nil { return }
 	
-	section = &TypeSection { location: parser.token.Location() }
+	section.location = parser.token.Location()
 
 	// get permission
 	err = parser.nextToken(lexer.TokenKindPermission)
@@ -30,7 +29,7 @@ func (parser *ParsingOperation) parseTypeSection () (
 	if err != nil { return }
 	err = parser.nextToken()
 	if err != nil { return }
-	section.inherits, err = parser.parseType()
+	section.what, err = parser.parseType()
 	if err != nil { return }
 
 	// parse default values
@@ -38,10 +37,10 @@ func (parser *ParsingOperation) parseTypeSection () (
 		err = parser.nextToken()
 		if err != nil { return }
 
-		section.defaultValue, err = parser.parseInitializationValues(0)
+		section.value, err = parser.parseInitializationValues(0)
 		if err != nil { return }
 	} else {
-		section.defaultValue, err = parser.parseArgument()
+		section.value, err = parser.parseArgument()
 		if err != nil { return }
 
 		err = parser.expect(lexer.TokenKindNewline)

types/iterator.go

@@ -0,0 +1,50 @@
+package types
+
+// Iterator is an object capable of iterating over any string-indexed map, while
+// protecting its data.
+type Iterator[VALUE_TYPE any] struct {
+	index      int
+	keys       []string
+	underlying map[string] VALUE_TYPE
+}
+
+// NewIterator creates a new iterator that iterates over the specified map.
+func NewIterator[VALUE_TYPE any] (
+	underlying map[string] VALUE_TYPE,
+) (
+	iterator Iterator[VALUE_TYPE],
+) {
+	iterator.underlying = underlying
+	iterator.keys = make([]string, len(underlying))
+
+	index := 0
+	for key, _ := range underlying {
+		iterator.keys[index] = key
+		index ++
+	}
+	
+	return
+}
+
+// Key returns the current key the iterator is on.
+func (iterator Iterator[VALUE_TYPE]) Key () (key string) {
+	key = iterator.keys[iterator.index]
+	return
+}
+
+// Value returns the current value the iterator is on.
+func (iterator Iterator[VALUE_TYPE]) Value () (value VALUE_TYPE) {
+	value = iterator.underlying[iterator.keys[iterator.index]]
+	return
+}
+
+// Next advances the iterator by 1.
+func (iterator Iterator[VALUE_TYPE]) Next () {
+	iterator.index ++
+}
+
+// End returns whether the iterator has reached the end of the map.
+func (iterator Iterator[VALUE_TYPE]) End () (atEnd bool) {
+	atEnd = iterator.index >= len(iterator.keys) || iterator.index < 0
+	return
+}