Cli now handles printing stuff

cli/cli.go

@@ -1,6 +1,7 @@
 package cli
 
 import "os"
+import "io"
 import "fmt"
 import "sort"
 import "errors"
@@ -11,6 +12,8 @@ import "strconv"
 // possible to create multiple Cli's to have so many sub-commands in one
 // program.
 type Cli struct {
+	Logger
+
 	// Description describes the application.
 	Description string
 
@@ -49,12 +52,13 @@ func New (description string, flags ...*Flag) *Cli {
 }
 
 // AddSub adds a sub-command to this command. It automatically fills out the
-// sub-command's Super field.
+// sub-command's Super field, and alters the prefix of its Logger to match.
 func (this *Cli) AddSub (name string, sub *Cli) {
 	super := this.Super
 	if super != "" { super += " " }
 	super += name
-	sub.Super = super
+	sub.Super  = super
+	sub.Prefix = os.Args[0] + " " + super
 	this.Sub[name] = sub
 }
 
@@ -67,7 +71,7 @@ func (this *Cli) AddSub (name string, sub *Cli) {
 // command that did the parsing.
 func (this *Cli) Parse (args []string) (*Cli, error) {
 	// try to find a sub-command
-	if this.Sub != nil && len(args) > 0 {
+	if this.Sub != nil && len(args) > 1 {
 		if sub, ok := this.Sub[args[1]]; ok {
 			return sub.Parse(args[1:])
 		}
@@ -153,7 +157,7 @@ func (this *Cli) Parse (args []string) (*Cli, error) {
 func (this *Cli) ParseOrExit (args []string) *Cli {
 	command, err := this.Parse(args)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%s: %v\n\n", os.Args[0], err)
+		fmt.Fprintf(this, "%s: %v\n\n", os.Args[0], err)
 		this.Usage()
 		os.Exit(2)
 	}
@@ -183,25 +187,25 @@ func (this *Cli) LongFlag (long string) (*Flag, bool) {
 // Usage prints out usage/help information.
 func (this *Cli) Usage () {
 	// syntax
-	fmt.Fprint(os.Stderr, "Usage:")
-	fmt.Fprint(os.Stderr, " ", os.Args[0])
+	fmt.Fprint(this, "Usage:")
+	fmt.Fprint(this, " ", os.Args[0])
 	if this.Super != "" {
-		fmt.Fprint(os.Stderr, " ", this.Super)
+		fmt.Fprint(this, " ", this.Super)
 	}
 	hasSubCommands := this.Sub != nil && len(this.Sub) > 0
 	if hasSubCommands {
-		fmt.Fprint(os.Stderr, " [COMMAND]")
+		fmt.Fprint(this, " [COMMAND]")
 	}
 	if this.Syntax == "" {
-		fmt.Fprint(os.Stderr, " [OPTION]...")
+		fmt.Fprint(this, " [OPTION]...")
 	} else {
-		fmt.Fprint(os.Stderr, " ", this.Syntax)
+		fmt.Fprint(this, " ", this.Syntax)
 	}
-	fmt.Fprint(os.Stderr, "\n\n")
+	fmt.Fprint(this, "\n\n")
 
 	// description
 	if this.Description != "" {
-		fmt.Fprintf(os.Stderr, "%s\n\n", this.Description)
+		fmt.Fprintf(this, "%s\n\n", this.Description)
 	}
 
 	// fit the longest flag
@@ -228,12 +232,12 @@ func (this *Cli) Usage () {
 			shortLong += "--" + flag.Long
 		}
 
-		fmt.Fprintf(os.Stderr, format, shortLong, flag.Help)
+		fmt.Fprintf(this, format, shortLong, flag.Help)
 	}
 
 	// commands
 	if hasSubCommands {
-		fmt.Fprint(os.Stderr, "\nCommands:\n\n")
+		fmt.Fprint(this, "\nCommands:\n\n")
 		names := sortMapKeys(this.Sub)
 
 		// fit the longest command
@@ -246,11 +250,65 @@ func (this *Cli) Usage () {
 		format := fmt.Sprint("\t%-", longest + 2, "s%s\n")
 		
 		for _, name := range names {
-			fmt.Fprintf(os.Stderr, format, name, this.Sub[name].Description)
+			fmt.Fprintf(this, format, name, this.Sub[name].Description)
 		}
 	}
 }
 
+// Logger prints messages to an output writer.
+type Logger struct {
+	// Writer specifies the writer to output to. If it is nil, the Logger
+	// will output to os.Stderr. If you wish to silence the output, set it
+	// to io.Discard.
+	io.Writer
+
+	// Debug determines whether or not debug messages will be logged.
+	Debug bool
+
+	// Prefix is printed before all messages. If this is an empty string,
+	// os.Args[0] will be used.
+	Prefix string
+}
+
+// Println logs a normal message.
+func (this *Logger) Println (v ...any) {
+	fmt.Fprintf(this, "%s: %s", this.prefix(), fmt.Sprintln(v...))
+}
+
+// Errorln logs an error message.
+func (this *Logger) Errorln (v ...any) {
+	fmt.Fprintf(this, "%s: %s", this.prefix(), fmt.Sprintln(v...))
+}
+
+// Warnln logs a warning.
+func (this *Logger) Warnln (v ...any) {
+	fmt.Fprintf(this, "%s: warning: %s", this.prefix(), fmt.Sprintln(v...))
+}
+
+// Debugln logs debugging information. It will only print the message if the
+// Debug field is set to true.
+func (this *Logger) Debugln (v ...any) {
+	if !this.Debug { return }
+	fmt.Fprintf(this, "%s: debug: %s", this.prefix(), fmt.Sprintln(v...))
+}
+
+func (this *Logger) prefix () string {
+	if this.Prefix == "" {
+		return os.Args[0]
+	} else {
+		return this.Prefix
+	}
+}
+
+// Write writes to the Logger's writer. If it is nil, it writes to os.Stderr.
+func (this *Logger) Write (data []byte) (n int, err error) {
+	if this.Writer == nil {
+		return os.Stderr.Write(data)
+	} else {
+		return this.Writer.Write(data)
+	}
+}
+
 // Flag is a command line option.
 type Flag struct {
 	Short rune   // The short form of the flag (-l)

cmd/fsplc/main.go

@@ -1,6 +1,7 @@
 package main
 
 import "os"
+import "io"
 import "path/filepath"
 import "git.tebibyte.media/fspl/fspl/cli"
 import "git.tebibyte.media/fspl/fspl/entity"
@@ -11,7 +12,7 @@ func main () {
 	// instantiate the compiler
 	// FIXME: perhaps we want different paths on Windows?
 	comp := new(compiler.Compiler)
-	comp.Stderr   = os.Stderr
+	comp.Writer   = os.Stderr
 	comp.Resolver = compiler.NewResolver (
 		"/usr/local/src/fspl",
 		"/usr/src/fspl",
@@ -68,7 +69,7 @@ func main () {
 	comp.Optimization = optimization.Value
 	comp.Format       = format.Value
 	comp.Debug        = debug.Value != ""
-	comp.Quiet        = quiet.Value != ""
+	if quiet.Value != "" { comp.Writer = io.Discard }
 
 	err = comp.CompileUnit(entity.Address(application.Args[0]))
 	if err != nil {

compiler/compiler.go

@@ -1,6 +1,5 @@
 package compiler
 
-import "io"
 import "os"
 import "fmt"
 import "sort"
@@ -8,6 +7,7 @@ import "errors"
 import "os/exec"
 import "path/filepath"
 import "github.com/google/uuid"
+import "git.tebibyte.media/fspl/fspl/cli"
 import "git.tebibyte.media/fspl/fspl/llvm"
 import "git.tebibyte.media/fspl/fspl/lexer"
 import "git.tebibyte.media/fspl/fspl/entity"
@@ -19,12 +19,11 @@ import "git.tebibyte.media/fspl/fspl/generator/native"
 
 type Compiler struct {
 	Resolver
+	cli.Logger
+	
 	Output       string
 	Optimization string
 	Format       string
-	Stderr       io.Writer
-	Debug        bool
-	Quiet        bool
 }
 
 func (this *Compiler) CompileUnit (address entity.Address) error {
@@ -353,25 +352,6 @@ func (this *Compiler) FindBackend (filetype string) (string, []string, error) {
 		"or 'clang' are accessable from your PATH")
 }
 
-func (this *Compiler) Errorln (v ...any) {
-	if this.Quiet         { return }
-	if this.Stderr == nil { return }
-	fmt.Fprintf(this.Stderr, "%s: %s", os.Args[0], fmt.Sprintln(v...))
-}
-
-func (this *Compiler) Warnln (v ...any) {
-	if this.Quiet         { return }
-	if this.Stderr == nil { return }
-	fmt.Fprintf(this.Stderr, "%s: warning: %s", os.Args[0], fmt.Sprintln(v...))
-}
-
-func (this *Compiler) Debugln (v ...any) {
-	if this.Quiet         { return }
-	if !this.Debug        { return }
-	if this.Stderr == nil { return }
-	fmt.Fprintf(this.Stderr, "%s: debug: %s", os.Args[0], fmt.Sprintln(v...))
-}
-
 func sortMapKeys[T any] (unsorted map[string] T) []string {
 	keys := make([]string, len(unsorted))
 	index := 0