feat: tokenizer accepts braces, line terminator, and equal sign

pkg/saccharine/ast/expression.go

@@ -20,9 +20,15 @@ type Atom struct {
 	Name string
 }
 
+type Clause struct {
+	Statements []Statement
+	Returns    Expression
+}
+
 func (Abstraction) IsExpression() {}
 func (Application) IsExpression() {}
 func (Atom) IsExpression()        {}
+func (Clause) IsExpression()      {}
 
 /** ------------------------------------------------------------------------- */
 
@@ -37,3 +43,7 @@ func NewApplication(abstraction Expression, arguments []Expression) *Application
 func NewAtom(name string) *Atom {
 	return &Atom{Name: name}
 }
+
+func NewClause(statements []Statement, returns Expression) *Clause {
+	return &Clause{Statements: statements, Returns: returns}
+}

pkg/saccharine/ast/program.go

@@ -1,5 +0,0 @@
-package ast
-
-type Program struct {
-	Statements []Statement
-}

pkg/saccharine/ast/statement.go

@@ -7,11 +7,6 @@ type Statement interface {
 /** ------------------------------------------------------------------------- */
 
 type LetStatement struct {
-	Variable string
-	Value    Expression
-}
-
-type MethodStatement struct {
 	Name       string
 	Parameters []string
 	Body       Expression
@@ -22,7 +17,6 @@ type DeclareStatement struct {
 }
 
 func (LetStatement) IsStatement()     {}
-func (MethodStatement) IsStatement()  {}
 func (DeclareStatement) IsStatement() {}
 
 /** ------------------------------------------------------------------------- */

pkg/saccharine/ast/visit.go

@@ -1,22 +0,0 @@
-package ast
-
-import "fmt"
-
-type Visitor[T any] interface {
-	VisitAtom(*Atom) T
-	VisitAbstraction(*Abstraction) T
-	VisitApplication(*Application) T
-}
-
-func Visit[T any](visitor Visitor[T], node Expression) T {
-	switch node := node.(type) {
-	case *Atom:
-		return visitor.VisitAtom(node)
-	case *Abstraction:
-		return visitor.VisitAbstraction(node)
-	case *Application:
-		return visitor.VisitApplication(node)
-	default:
-		panic(fmt.Sprintf("unknown node %t", node))
-	}
-}