fixed folder structure + lab4 less hardcode, cleanup

2024-04-28 20:24:11 +03:00
parent b6ae645808
commit c0efefa1a1
17 changed files with 86 additions and 73 deletions
--- a/src/Lab3/Lexer.java
+++ b/src/Lab3/Lexer.java
@@ -0,0 +1,104 @@
+package Lab3;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Stack;
+
+public class Lexer {
+    public enum TokenType {
+        NUMBER,
+        OPERATOR,
+        LPAREN,
+        RPAREN,
+        FUNCTION,
+        COMMA,
+        EOF
+    }
+
+    public static class Token {
+        public TokenType type;
+        public String value;
+
+        public Token(TokenType type, String value) {
+            this.type = type;
+            this.value = value;
+        }
+    }
+
+    public static List<Token> tokenize(String input) {
+        List<Token> tokens = new ArrayList<>();
+        input = input.replaceAll("\\s", "");
+        int i = 0;
+        while (i < input.length()) {
+            char ch = input.charAt(i);
+            if (Character.isDigit(ch)) {
+                StringBuilder sb = new StringBuilder();
+                while (i < input.length() && (Character.isDigit(input.charAt(i)) || input.charAt(i) == '.')) {
+                    sb.append(input.charAt(i));
+                    i++;
+                }
+                tokens.add(new Token(TokenType.NUMBER, sb.toString()));
+            } else if (Character.isLetter(ch)) {
+                StringBuilder sb = new StringBuilder();
+                while (i < input.length() && Character.isLetter(input.charAt(i))) {
+                    sb.append(input.charAt(i));
+                    i++;
+                }
+                tokens.add(new Token(TokenType.FUNCTION, sb.toString()));
+            } else {
+                switch (ch) {
+                    case '(':
+                        tokens.add(new Token(TokenType.LPAREN, "("));
+                        i++;
+                        break;
+                    case ')':
+                        tokens.add(new Token(TokenType.RPAREN, ")"));
+                        i++;
+                        break;
+                    case ',':
+                        tokens.add(new Token(TokenType.COMMA, ","));
+                        i++;
+                        break;
+                    default:
+                        tokens.add(new Token(TokenType.OPERATOR, String.valueOf(ch)));
+                        i++;
+                        break;
+                }
+            }
+        }
+
+        tokens.add(new Token(TokenType.EOF, ""));
+
+        if (!areParenthesesBalanced(tokens)) {
+            throw new RuntimeException("Parentheses are not balanced.");
+        }
+
+        return tokens;
+    }
+
+    private static boolean areParenthesesBalanced(List<Token> tokens) {
+        Stack<TokenType> stack = new Stack<>();
+        for (Token token : tokens) {
+            if (token.type == TokenType.LPAREN) {
+                stack.push(TokenType.LPAREN);
+            } else if (token.type == TokenType.RPAREN) {
+                if (stack.isEmpty() || stack.pop() != TokenType.LPAREN) {
+                    return false;
+                }
+            }
+        }
+        return stack.isEmpty();
+    }
+
+    public static void main(String[] args) {
+        String input = "(3 + 5) * loge(16)";
+        try {
+            List<Token> tokens = tokenize(input);
+            for (Token token : tokens) {
+                System.out.println(token.type + " : " + token.value);
+            }
+        } catch (RuntimeException e) {
+            System.err.println(e.getMessage());
+        }
+    }
+}