Improved code layout

src/build/Build.go

@@ -19,8 +19,8 @@ func New(files ...string) *Build {
 
 // Run parses the input files and generates an executable file.
 func (build *Build) Run() (map[string]*Function, error) {
-	functions, errors := Scan(build.Files)
-	return Compile(functions, errors)
+	functions, errors := scan(build.Files)
+	return compile(functions, errors)
 }
 
 // Executable returns the path to the executable.

src/build/Function.go

@@ -73,25 +73,6 @@ func (f *Function) Compile() {
 	f.Assembler.Return()
 }
 
-// PrintAsm shows the assembly instructions.
-func (f *Function) PrintAsm() {
-	ansi.Bold.Println(f.Name)
-	ansi.Dim.Println("╭────────────────────────────────────────────────────────────")
-
-	for _, x := range f.Assembler.Instructions {
-		ansi.Dim.Print("│ ")
-		fmt.Print(x.Mnemonic.String())
-
-		if x.Data != nil {
-			fmt.Print(" " + x.Data.String())
-		}
-
-		fmt.Print("\n")
-	}
-
-	ansi.Dim.Println("╰────────────────────────────────────────────────────────────")
-}
-
 // CompileInstruction compiles a single instruction.
 func (f *Function) CompileInstruction(line token.List) error {
 	if len(line) == 0 {
@@ -99,6 +80,30 @@ func (f *Function) CompileInstruction(line token.List) error {
 	}
 
 	if line[0].Kind == token.Keyword {
+		return f.CompileKeyword(line)
+	}
+
+	expr := expression.Parse(line)
+
+	if expr == nil {
+		return nil
+	}
+
+	defer expr.Close()
+
+	if isVariableDefinition(expr) {
+		return f.CompileVariableDefinition(expr)
+	}
+
+	if isFunctionCall(expr) {
+		return f.CompileFunctionCall(expr)
+	}
+
+	return errors.New(&errors.InvalidInstruction{Instruction: expr.Token.Text()}, f.File, expr.Token.Position)
+}
+
+// CompileKeyword compiles an instruction that starts with a keyword.
+func (f *Function) CompileKeyword(line token.List) error {
 	switch line[0].Text() {
 	case "return":
 		if len(line) > 1 {
@@ -112,21 +117,12 @@ func (f *Function) CompileInstruction(line token.List) error {
 	default:
 		return errors.New(&errors.KeywordNotImplemented{Keyword: line[0].Text()}, f.File, line[0].Position)
 	}
-	}
 
-	expr := expression.Parse(line)
-
-	if expr == nil {
 	return nil
 }
 
-	defer expr.Close()
-
-	if expr.Token.Kind == token.Number || expr.Token.Kind == token.Identifier || expr.Token.Kind == token.String {
-		return errors.New(&errors.InvalidInstruction{Instruction: expr.Token.Text()}, f.File, expr.Token.Position)
-	}
-
-	if expr.Token.Text() == ":=" {
+// CompileVariableDefinition compiles a variable definition.
+func (f *Function) CompileVariableDefinition(expr *expression.Expression) error {
 	if len(expr.Children) < 2 {
 		return errors.New(errors.MissingAssignValue, f.File, expr.LastChild().Token.After())
 	}
@@ -141,7 +137,7 @@ func (f *Function) CompileInstruction(line token.List) error {
 	value := expr.Children[1]
 
 	// All expressions are returned to the memory pool.
-		// To avoid losing variable values, we will remove it from the expression.
+	// To avoid losing variable values, we will detach it from the expression.
 	expr.RemoveChild(value)
 
 	f.Variables[name] = &Variable{
@@ -153,7 +149,8 @@ func (f *Function) CompileInstruction(line token.List) error {
 	return nil
 }
 
-	if expr.Token.Text() == "λ" {
+// CompileFunctionCall compiles a function call.
+func (f *Function) CompileFunctionCall(expr *expression.Expression) error {
 	funcName := expr.Children[0].Token.Text()
 	parameters := expr.Children[1:]
 
@@ -193,10 +190,36 @@ func (f *Function) CompileInstruction(line token.List) error {
 	return nil
 }
 
-	return nil
+// PrintAsm shows the assembly instructions.
+func (f *Function) PrintAsm() {
+	ansi.Bold.Println(f.Name)
+	ansi.Dim.Println("╭────────────────────────────────────────────────────────────")
+
+	for _, x := range f.Assembler.Instructions {
+		ansi.Dim.Print("│ ")
+		fmt.Print(x.Mnemonic.String())
+
+		if x.Data != nil {
+			fmt.Print(" " + x.Data.String())
+		}
+
+		fmt.Print("\n")
+	}
+
+	ansi.Dim.Println("╰────────────────────────────────────────────────────────────")
 }
 
 // String returns the function name.
 func (f *Function) String() string {
 	return f.Name
 }
+
+// isVariableDefinition returns true if the expression is a variable definition.
+func isVariableDefinition(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Text() == ":="
+}
+
+// isFunctionCall returns true if the expression is a function call.
+func isFunctionCall(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Text() == "λ"
+}

src/build/compile.go

@@ -4,8 +4,8 @@ import (
 	"sync"
 )
 
-// Compile compiles all the functions.
-func Compile(functions <-chan *Function, errors <-chan error) (map[string]*Function, error) {
+// compile waits for all functions to finish compilation.
+func compile(functions <-chan *Function, errors <-chan error) (map[string]*Function, error) {
 	allFunctions := map[string]*Function{}
 
 	for functions != nil || errors != nil {

src/build/scan.go

@@ -11,8 +11,8 @@ import (
 	"git.akyoto.dev/cli/q/src/errors"
 )
 
-// Scan scans the directory.
-func Scan(files []string) (<-chan *Function, <-chan error) {
+// scan scans the directory.
+func scan(files []string) (<-chan *Function, <-chan error) {
 	functions := make(chan *Function)
 	errors := make(chan error)