RENAME THIS COMMIT: Move lexer and Error into separate packages

pj1-go/lexer/lexer.go

@@ -1,4 +1,4 @@
-package main
+package lexer
 
 import (
 	"fmt"
@@ -6,6 +6,8 @@ import (
 	"strconv"
 	"strings"
 	"unicode/utf8"
+
+	"git.bonsai.cool/kayprish/pj1/pj1-go/util"
 )
 
 type TokenType int
@@ -102,7 +104,7 @@ func (t Token) String() string {
 
 type Lexer struct {
 	source string
-	tokens []Token
+	Tokens []Token
 
 	startByte   int
 	currentByte int
@@ -123,7 +125,7 @@ func (l *Lexer) ScanTokens() {
 		l.scanToken()
 	}
 
-	l.tokens = append(l.tokens, NewToken(EOF, "", nil, l.line))
+	l.Tokens = append(l.Tokens, NewToken(EOF, "", nil, l.line))
 }
 
 func (l Lexer) atEnd() bool {
@@ -226,7 +228,7 @@ func (l *Lexer) scanToken() {
 		} else {
 			// TODO: if there are multiple bad characters
 			// coalesce similar errors into one
-			error(l.line, fmt.Sprintf("Unexpected character, %v.", c))
+			util.Error(l.line, fmt.Sprintf("Unexpected character, %v.", c))
 		}
 	}
 }
@@ -351,7 +353,7 @@ func (l *Lexer) str() {
 			case 'e':
 				c = '\x1b'
 			default:
-				error(l.line, fmt.Sprintf("Invalid escape sequence \\%v.", l.peek()))
+				util.Error(l.line, fmt.Sprintf("Invalid escape sequence \\%v.", l.peek()))
 				return
 			}
 		}
@@ -360,7 +362,7 @@ func (l *Lexer) str() {
 	}
 
 	if l.atEnd() {
-		error(l.line, "Unterminated string.")
+		util.Error(l.line, "Unterminated string.")
 		return
 	}
 
@@ -378,5 +380,5 @@ func (l *Lexer) addSimpleToken(ttype TokenType) {
 
 func (l *Lexer) addToken(ttype TokenType, literal interface{}) {
 	text := l.source[l.startByte:l.currentByte]
-	l.tokens = append(l.tokens, NewToken(ttype, text, literal, l.line))
+	l.Tokens = append(l.Tokens, NewToken(ttype, text, literal, l.line))
 }

pj1-go/lexer/tokentype_string.go

@@ -1,6 +1,6 @@
 // Code generated by "stringer -type=TokenType"; DO NOT EDIT.
 
-package main
+package lexer
 
 import "strconv"
 

pj1-go/pj1.go

@@ -5,10 +5,9 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-)
 
-var (
+	"git.bonsai.cool/kayprish/pj1/pj1-go/lexer"
-	hadError bool = false
+	"git.bonsai.cool/kayprish/pj1/pj1-go/util"
 )
 
 func main() {
@@ -30,7 +29,7 @@ func runFile(path string) {
 	}
 	run(string(bytes[:]))
 
-	if hadError {
+	if util.HadError {
 		os.Exit(65)
 	}
 }
@@ -46,7 +45,7 @@ func runPrompt() {
 		fmt.Println(line)
 		run(line)
 
-		hadError = false
+		util.HadError = false
 	}
 	if err := scanner.Err(); err != nil {
 		fmt.Fprintln(os.Stderr, "reading standard input:", err)
@@ -54,21 +53,11 @@ func runPrompt() {
 }
 
 func run(source string) {
-	lexer := NewLexer(source)
+	l := lexer.NewLexer(source)
-	lexer.ScanTokens()
+	l.ScanTokens()
-	var tokens []Token = lexer.tokens
+	var tokens []lexer.Token = l.Tokens
 
 	for _, token := range tokens {
 		fmt.Println(token)
 	}
 }
-
-// TODO: might have to rename
-func error(line int, msg string) {
-	report(line, "", msg)
-	hadError = true
-}
-
-func report(line int, where string, msg string) {
-	fmt.Fprintln(os.Stderr, "[line "+fmt.Sprint(line)+"] Error"+where+": "+msg)
-}

pj1-go/util/error.go

@@ -0,0 +1,19 @@
+package util
+
+import (
+	"fmt"
+	"os"
+)
+
+var (
+	HadError bool = false
+)
+
+func Error(line int, msg string) {
+	report(line, "", msg)
+	HadError = true
+}
+
+func report(line int, where string, msg string) {
+	fmt.Fprintln(os.Stderr, "[line "+fmt.Sprint(line)+"] Error"+where+": "+msg)
+}