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Do not show username at interpreter startup.

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Now Monk not monkey
Formatting and code clarity


git-svn-id: https://svn.tlawal.org/svn/monkey@9 f6afcba9-9ef1-4bdd-9b72-7484f5705bac
This commit is contained in:
Tijani Lawal 2022-05-23 14:18:27 +00:00
parent 0aa17eeee4
commit 69ffeb209c
2 changed files with 65 additions and 66 deletions
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120
lexer/lexer.go
View File

@ -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() {
if lexer.read_position >= len(lexer.input) {
lexer.current_char = 0
func (l_lexer *Lexer) read_char() {
if l_lexer.read_position >= len(l_lexer.input) {
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
lexer.read_position += 1
l_lexer.position = l_lexer.read_position
l_lexer.read_position += 1
}
func (lexer *Lexer) peek_char() byte {
if lexer.read_position >= len(lexer.input) {
func (l_lexer *Lexer) peek_char() byte {
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 {
position := lexer.position
for is_letter(lexer.current_char) {
lexer.read_char()
func (l_lexer *Lexer) read_identifier() string {
position := l_lexer.position
for is_letter(l_lexer.current_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() {
for lexer.current_char == ' ' || lexer.current_char == '\t' || lexer.current_char == '\n' || lexer.current_char == '\r' {
lexer.read_char()
func (l_lexer *Lexer) skip_whitespace() {
for l_lexer.current_char == ' ' || l_lexer.current_char == '\t' || l_lexer.current_char == '\n' || l_lexer.current_char == '\r' {
l_lexer.read_char()
}
}
func (lexer *Lexer) read_number() string {
position := lexer.position
for is_digit(lexer.current_char) {
lexer.read_char()
func (l_lexer *Lexer) read_number() string {
position := l_lexer.position
for is_digit(l_lexer.current_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 {
var tok token.Token
lexer.skip_whitespace()
func New(input string) *Lexer {
l := &Lexer{input: input}
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() == '=' {
ch := lexer.current_char
lexer.read_char()
literal := string(ch) + string(lexer.current_char)
if l_lexer.peek_char() == '=' {
ch := l_lexer.current_char
l_lexer.read_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() == '=' {
ch := lexer.current_char
lexer.read_char()
literal := string(ch) + string(lexer.current_char)
if l_lexer.peek_char() == '=' {
ch := l_lexer.current_char
l_lexer.read_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) {
tok.Literal = lexer.read_identifier()
if is_letter(l_lexer.current_char) {
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
}

11
main.go
View File

@ -11,17 +11,16 @@ package main
import (
"fmt"
"os"
"os/user"
"monkey/repl"
)
func main() {
user, err := user.Current()
if err != nil {
panic(err)
}
// user, err := user.Current()
// if err != nil {
// 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)
}