Do not show username at interpreter startup.

Now Monk not monkey
Formatting and code clarity


git-svn-id: https://svn.tlawal.org/svn/monkey@9 f6afcba9-9ef1-4bdd-9b72-7484f5705bac

lexer/lexer.go

@@ -9,128 +9,128 @@ type Lexer struct {
 	current_char  byte
 }
 
-func New(input string) *Lexer {
-	l := &Lexer{input: input}
-	l.read_char()
-	return l
-}
-
 func new_token(TokenType token.TokenType, ch byte) token.Token {
 	return token.Token{Type: TokenType, Literal: string(ch)}
 }
 
-func (lexer *Lexer) read_char() {
+func (l_lexer *Lexer) read_char() {
-	if lexer.read_position >= len(lexer.input) {
+	if l_lexer.read_position >= len(l_lexer.input) {
-		lexer.current_char = 0
+		l_lexer.current_char = 0
 	} else {
-		lexer.current_char = lexer.input[lexer.read_position]
+		l_lexer.current_char = l_lexer.input[l_lexer.read_position]
 	}
-	lexer.position = lexer.read_position
+	l_lexer.position = l_lexer.read_position
-	lexer.read_position += 1
+	l_lexer.read_position += 1
 }
 
-func (lexer *Lexer) peek_char() byte {
+func (l_lexer *Lexer) peek_char() byte {
-	if lexer.read_position >= len(lexer.input) {
+	if l_lexer.read_position >= len(l_lexer.input) {
 		return 0
 	} else {
-		return lexer.input[lexer.read_position]
+		return l_lexer.input[l_lexer.read_position]
 	}
 }
 
-func (lexer *Lexer) read_identifier() string {
+func (l_lexer *Lexer) read_identifier() string {
-	position := lexer.position
+	position := l_lexer.position
-	for is_letter(lexer.current_char) {
+	for is_letter(l_lexer.current_char) {
-		lexer.read_char()
+		l_lexer.read_char()
 	}
-	return lexer.input[position:lexer.position]
+	return l_lexer.input[position:l_lexer.position]
 }
 
 func is_letter(ch byte) bool {
 	return 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' || ch == '_'
 }
 
-func (lexer *Lexer) skip_whitespace() {
+func (l_lexer *Lexer) skip_whitespace() {
-	for lexer.current_char == ' ' || lexer.current_char == '\t' || lexer.current_char == '\n' || lexer.current_char == '\r' {
+	for l_lexer.current_char == ' ' || l_lexer.current_char == '\t' || l_lexer.current_char == '\n' || l_lexer.current_char == '\r' {
-		lexer.read_char()
+		l_lexer.read_char()
 	}
 }
 
-func (lexer *Lexer) read_number() string {
+func (l_lexer *Lexer) read_number() string {
-	position := lexer.position
+	position := l_lexer.position
-	for is_digit(lexer.current_char) {
+	for is_digit(l_lexer.current_char) {
-		lexer.read_char()
+		l_lexer.read_char()
 	}
-	return lexer.input[position:lexer.position]
+	return l_lexer.input[position:l_lexer.position]
 }
 
 func is_digit(ch byte) bool {
 	return '0' <= ch && ch <= '9'
 }
 
-func (lexer *Lexer) NextToken() token.Token {
+func New(input string) *Lexer {
-	var tok token.Token
+	l := &Lexer{input: input}
-	lexer.skip_whitespace()
+	l.read_char()
+	return l
+} 
 
-	switch lexer.current_char {
+func (l_lexer *Lexer) NextToken() token.Token {
+	var tok token.Token
+	l_lexer.skip_whitespace()
+
+	switch l_lexer.current_char {
 	case '=':
-		if lexer.peek_char() == '=' {
+		if l_lexer.peek_char() == '=' {
-			ch := lexer.current_char
+			ch := l_lexer.current_char
-			lexer.read_char()
+			l_lexer.read_char()
-			literal := string(ch) + string(lexer.current_char)
+			literal := string(ch) + string(l_lexer.current_char)
 			tok = token.Token{Type: token.EQ, Literal: literal}
 		} else {
-			tok = new_token(token.ASSIGN, lexer.current_char)
+			tok = new_token(token.ASSIGN, l_lexer.current_char)
 		}
 	case '!':
-		if lexer.peek_char() == '=' {
+		if l_lexer.peek_char() == '=' {
-			ch := lexer.current_char
+			ch := l_lexer.current_char
-			lexer.read_char()
+			l_lexer.read_char()
-			literal := string(ch) + string(lexer.current_char)
+			literal := string(ch) + string(l_lexer.current_char)
 			tok = token.Token{Type: token.NOT_EQ, Literal: literal}
 		} else {
-			tok = new_token(token.BANG, lexer.current_char)
+			tok = new_token(token.BANG, l_lexer.current_char)
 		}
 	case ';':
-		tok = new_token(token.SEMICOLON, lexer.current_char)
+		tok = new_token(token.SEMICOLON, l_lexer.current_char)
 	case '(':
-		tok = new_token(token.LPAREN, lexer.current_char)
+		tok = new_token(token.LPAREN, l_lexer.current_char)
 	case ')':
-		tok = new_token(token.RPAREN, lexer.current_char)
+		tok = new_token(token.RPAREN, l_lexer.current_char)
 	case '{':
-		tok = new_token(token.LBRACE, lexer.current_char)
+		tok = new_token(token.LBRACE, l_lexer.current_char)
 	case '}':
-		tok = new_token(token.RBRACE, lexer.current_char)
+		tok = new_token(token.RBRACE, l_lexer.current_char)
 	case ',':
-		tok = new_token(token.COMMA, lexer.current_char)
+		tok = new_token(token.COMMA, l_lexer.current_char)
 	case '+':
-		tok = new_token(token.PLUS, lexer.current_char)
+		tok = new_token(token.PLUS, l_lexer.current_char)
 	case '-':
-		tok = new_token(token.MINUS, lexer.current_char)
+		tok = new_token(token.MINUS, l_lexer.current_char)
 	case '/':
-		tok = new_token(token.SLASH, lexer.current_char)
+		tok = new_token(token.SLASH, l_lexer.current_char)
 	case '*':
-		tok = new_token(token.ASTERISK, lexer.current_char)
+		tok = new_token(token.ASTERISK, l_lexer.current_char)
 	case '<':
-		tok = new_token(token.LT, lexer.current_char)
+		tok = new_token(token.LT, l_lexer.current_char)
 	case '>':
-		tok = new_token(token.GT, lexer.current_char)
+		tok = new_token(token.GT, l_lexer.current_char)
 	case 0:
 		tok.Literal = ""
 		tok.Type = token.EOF
 
 	default:
-		if is_letter(lexer.current_char) {
+		if is_letter(l_lexer.current_char) {
-			tok.Literal = lexer.read_identifier()
+			tok.Literal = l_lexer.read_identifier()
 			tok.Type = token.LookupIdentifier(tok.Literal)
 			return tok
-		} else if is_digit(lexer.current_char) {
+		} else if is_digit(l_lexer.current_char) {
 			tok.Type = token.INT
-			tok.Literal = lexer.read_number()
+			tok.Literal = l_lexer.read_number()
 			return tok
 		} else {
-			tok = new_token(token.ILLEGAL, lexer.current_char)
+			tok = new_token(token.ILLEGAL, l_lexer.current_char)
 		}
 	}
-	lexer.read_char()
+	l_lexer.read_char()
 	return tok
 }

main.go

@@ -11,17 +11,16 @@ package main
 import (
 	"fmt"
 	"os"
-	"os/user"
 
 	"monkey/repl"
 )
 
 func main() {
-	user, err := user.Current()
+	// user, err := user.Current()
-	if err != nil {
+	// if err != nil {
-		panic(err)
+	// 	panic(err)
-	}
+	// }
 
-	fmt.Printf("Hello %s! Welcome to the Monkey programming language!\n", user.Username)
+	fmt.Printf("Welcome to the Monk programming language!\n")
 	repl.Start(os.Stdin, os.Stdout)
 }