feat: finish tokenizer

internal/tokenizer/tokenizer.go

@@ -4,6 +4,9 @@ import (
 	"bufio"
 	"regexp"
 	"slices"
+	"strings"
+
+	"github.com/hazemKrimi/jack-compiler/internal/utils"
 )
 
 type TokenType int
@@ -25,6 +28,7 @@ var KEYWORDS = []string{
 	"static",
 	"var",
 	"int",
+	"char",
 	"read",
 	"boolean",
 	"void",
@@ -67,62 +71,215 @@ type Token struct {
 	Type  TokenType
 }
 
-func ExtractTokens(tokens *[]Token, reader *bufio.Reader) error {
-	read := ""
-	buf := []byte{}
+func isDigit(text string) (bool, error) {
+	if match, err := regexp.MatchString("^[[:digit:]]$", text); err != nil {
+		return false, err
+	} else if match {
+		return true, nil
+	}
 
-	for {
-		_, err := reader.Read(buf)
-		read += string(buf)
+	return false, nil
+}
+
+func isWhiteSpace(text string) (bool, error) {
+	if match, err := regexp.MatchString("^[[:space:]]$", text); err != nil {
+		return false, err
+	} else if match {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func isComment(text string, reader *bufio.Reader) (bool, error) {
+	if text == "/" {
+		n, err := reader.ReadByte()
+		next := string(n)
 
 		if err != nil {
+			return false, err
+		}
+
+		switch next {
+		case "/":
+			_, err := reader.ReadBytes('\n')
+
+			if err != nil {
+				return false, err
+			}
+
+			return true, nil
+		case "*":
+			_, err := reader.ReadBytes('*')
+
+			if err != nil {
+				return false, err
+			}
+
+			p, err := reader.Peek(1)
+
+			if err != nil {
+				return false, err
+			}
+
+			for string(p) != "/" {
+				_, err := reader.ReadBytes('*')
+
+				if err != nil {
+					return false, err
+				}
+
+				p, err = reader.Peek(1)
+			}
+
+			_, err = reader.ReadBytes('/')
+
+			if err != nil {
+				return false, err
+			}
+
+			return true, nil
+		default:
+			err = reader.UnreadByte()
+
+			if err != nil {
+				return false, err
+			}
+
+			return false, nil
+		}
+	}
+
+	return false, nil
+}
+
+func ExtractTokens(tokens *[]Token, reader *bufio.Reader) error {
+	buf := make([]byte, 0)
+
+	for {
+		b, err := reader.ReadByte()
+
+		if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+			break
+		} else if isErr {
 			return err
 		}
 
-		if match, _ := regexp.MatchString("^[[:space:]]$", read); match {
+		text := string(b)
+		comment, err := isComment(text, reader)
+
+		if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+			break
+		} else if isErr {
+			return err
+		} else if comment {
 			continue
 		}
 
-		if read == "/" {
-			next, err := reader.ReadByte()
+		whitespace, err := isWhiteSpace(text)
 
-			if err != nil {
-				return err
+		if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+			break
+		} else if isErr {
+			return err
+		} else if whitespace {
+			if len(buf) > 0 {
+
+				read := string(buf)
+
+				if slices.Contains(KEYWORDS, read) {
+					*tokens = append(*tokens, Token{Value: read, Type: KEYWORD})
+				} else {
+					*tokens = append(*tokens, Token{Value: read, Type: IDENTIFIER})
+				}
+
+				buf = nil
 			}
 
-			if string(next) == "/" || string(next) == "*" {
-				_, err := reader.ReadBytes('/')
+			continue
+		}
 
-				if err != nil {
-					return err
-				}
-			} else {
-				*tokens = append(*tokens, Token{Value: read, Type: SYMBOL})
-				read = ""
+		digit, err := isDigit(text)
 
-				err := reader.UnreadByte()
+		if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+			break
+		} else if isErr {
+			return err
+		} else if digit {
+			if len(buf) == 0 {
+				var integerConstant strings.Builder
 
-				if err != nil {
-					return err
+				integerConstant.WriteString(text)
+
+				for {
+					b, err := reader.ReadByte()
+
+					if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+						break
+					} else if isErr {
+						return err
+					}
+
+					anotherDigit, err := isDigit(string(b))
+
+					if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+						break
+					} else if isErr {
+						return err
+					}
+
+					if !anotherDigit {
+						err := reader.UnreadByte()
+
+						if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+							break
+						} else if isErr {
+							return err
+						}
+
+						break
+					} else {
+						integerConstant.WriteString(string(b))
+					}
 				}
 
+				*tokens = append(*tokens, Token{Value: integerConstant.String(), Type: INT_CONST})
 				continue
 			}
 		}
 
-		if slices.Contains(SYMBOLS, read) {
-			*tokens = append(*tokens, Token{Value: read, Type: SYMBOL})
-			read = ""
+		if text == "\"" {
+			b, err := reader.ReadBytes('"')
+
+			if isErr, isEOF := utils.CheckReaderError(err); isEOF {
+				break
+			} else if isErr {
+				return err
+			}
+
+			*tokens = append(*tokens, Token{Value: string(b[:len(b)-1]), Type: STR_CONST})
+			continue
+		}
+
+		if slices.Contains(SYMBOLS, text) {
+			if len(buf) > 0 {
+				read := string(buf)
+
+				if slices.Contains(KEYWORDS, read) {
+					*tokens = append(*tokens, Token{Value: read, Type: KEYWORD})
+				} else {
+					*tokens = append(*tokens, Token{Value: read, Type: IDENTIFIER})
+				}
+
+				buf = nil
+			}
+
+			*tokens = append(*tokens, Token{Value: text, Type: SYMBOL})
 
 			continue
 		}
 
-		if slices.Contains(KEYWORDS, read) {
-			*tokens = append(*tokens, Token{Value: read, Type: KEYWORD})
-			read = ""
-
-			continue
-		}
+		buf = append(buf, b)
 	}
 
 	return nil