Foxsaurus & Khaelen
Foxsaurus Foxsaurus
Khaelen Khaelen
Khaelen Khaelen
Language is essentially a data protocol—every rule a function, every clause a packet. Want to analyze its structure for a more efficient network stack?
Foxsaurus Foxsaurus
Sounds like a code‑review of the cosmos—just make sure the grammar doesn’t throw a buffer overflow. Give me the syntax, and I’ll riff on the protocol.
Khaelen Khaelen
Here’s a concise EBNF‑style grammar for a basic programming language: ``` <program> ::= { <statement> } <statement> ::= <assignment> | <function_call> | <if_statement> | <while_statement> <assignment> ::= <identifier> '=' <expression> ';' <function_call> ::= <identifier> '(' [ <expression> { ',' <expression> } ] ')' ';' <if_statement> ::= 'if' '(' <expression> ')' '{' <program> '}' [ 'else' '{' <program> '}' ] <while_statement> ::= 'while' '(' <expression> ')' '{' <program> '}' <expression> ::= <term> { ('+' | '-') <term> } <term> ::= <factor> { ('*' | '/') <factor> } <factor> ::= <number> | <identifier> | '(' <expression> ')' <identifier>::= letter { letter | digit | '_' } <number> ::= digit { digit } ``` Feel free to parse it, find the vulnerabilities, and riff on the protocol.
Foxsaurus Foxsaurus
That looks pretty tight—just the usual suspects: if, while, assignment, function calls. No left‑recursion to choke a recursive descent parser, so you can get rolling with a hand‑written lexer. The only thing that might bite you is the lack of explicit precedence for unary minus, and you’ll need to remember that <identifier> can clash with <number> if you don’t separate them with a delimiter. What’s the next move? Want me to sketch a parser or poke holes in the design?
Khaelen Khaelen
Alright, let’s map the exact steps. First, lock down the lexer: tokenize identifiers, numbers, operators, and punctuation, each with a distinct token type; no ambiguity. Next, generate an AST by a hand‑written recursive descent, paying attention to precedence—binary ops via a shunting‑yard or manual precedence levels, unary minus handled in the factor rule. Then walk the tree to build a bytecode stream; keep a symbol table for variables, a function table for calls, and a stack for runtime values. While parsing, record any unreachable code, duplicate labels, or self‑referencing definitions; that’s where the “holes” show up. If you want a full parser sketch, I can dump the exact function signatures and error handling patterns. Or you can start by writing a minimal lexer and we’ll iterate. What do you prefer?
Foxsaurus Foxsaurus
Kick it off with a lexer that spits out distinct token types—ids, nums, ops, punct, no overlap. Then hand‑write a recursive descent: precedence tiers for +/-, */; let the factor rule swallow unary minus. Build the AST, walk it into bytecode, keep symbol and function tables, a stack at runtime. While parsing flag unreachable blocks, duplicate labels, circular defs. Sound good? Or you want the exact function outlines to jump right in?
Khaelen Khaelen
Sound good. Give me the skeletons for lex, parse, and bytecode emit, and I’ll line them up, flag the unreachable blocks, and keep the tables tight. If you need more detail, just name the functions.
Foxsaurus Foxsaurus
Lex: tokenizer() -> list[Token] loop over input, emit ID, NUM, OP, PUNC tokens, skip whitespace Parse: parse_program(tokens) -> ASTProgram parse_statement() parse_assignment() parse_function_call() parse_if_statement() parse_while_statement() parse_expression(precedence) -> ASTExpr parse_term() parse_factor() Bytecode Emit: emit_program(ast) -> bytecode list emit_statement(stmt) emit_assignment(assign) emit_function_call(call) emit_if(ifstmt) emit_while(whilestmt) Also: build_symbol_table(ast), build_function_table(ast), detect_unreachable(ast)
Khaelen Khaelen
Tokenizer: tokenizer(source) -> list of Token   cursor = 0   while cursor < len(source):     if whitespace: skip     elif letter: read id, append Token(ID, value)     elif digit: read number, append Token(NUM, value)     elif char in '+-*/=': append Token(OP, char)     elif char in '();{}': append Token(PUNC, char)     else: raise error Parser: parse_program(tokens) -> ASTProgram   pointer = 0   statements = []   while pointer < len(tokens):     statements.append(parse_statement())   return ASTProgram(statements) parse_statement() -> ASTNode   if current token is ID and next is '=': return parse_assignment()   elif current token is ID and next is '(': return parse_function_call()   elif current token is 'if': return parse_if_statement()   elif current token is 'while': return parse_while_statement()   else: error parse_expression(precedence) -> ASTExpr   left = parse_factor()   while next token OP with precedence >= current precedence:     op = consume()     right = parse_expression(precedence_of(op)+1)     left = ASTBinary(op, left, right)   return left parse_factor() -> ASTExpr   if token is '-': consume; return ASTUnary('-', parse_factor())   elif token is '(' : consume; expr = parse_expression(0); expect ')'; return expr   elif token is NUM: consume; return ASTNumber(value)   elif token is ID: consume; return ASTVariable(name) Bytecode emission: emit_program(ast) -> list of Instruction   instrs = []   for stmt in ast.statements:     instrs.extend(emit_statement(stmt))   return instrs emit_statement(stmt)   if Assignment: return emit_assignment(stmt)   elif FunctionCall: return emit_function_call(stmt)   elif If: return emit_if(stmt)   elif While: return emit_while(stmt) emit_assignment(assign)   return [LOAD_CONST assign.value, STORE_VAR assign.name] emit_function_call(call)   return [PUSH_ARG call.args..., CALL_FUNC call.name] emit_if(ifstmt)   else_label = new_label()   end_label = new_label()   return [EVAL ifstmt.condition, JUMP_IF_FALSE else_label] + emit_statement(ifstmt.then) + [JUMP end_label, LABEL else_label] + emit_statement(ifstmt.else) + [LABEL end_label] emit_while(whilestmt)   start = new_label()   end = new_label()   return [LABEL start, EVAL whilestmt.condition, JUMP_IF_FALSE end] + emit_statement(whilestmt.body) + [JUMP start, LABEL end] Symbol and function tables: build_symbol_table(ast) – traverse, record variable names, scopes, detect redeclarations build_function_table(ast) – record function names, parameter counts, detect circular definitions Detect unreachable: after building CFG, run reachability analysis, flag blocks never hit. That’s the skeleton; you can fill in token classes, instruction set, and error handling.
Foxsaurus Foxsaurus
Token struct tokenizer(source) → list[Token] cursor = 0 while cursor < len(source): if source[cursor] is whitespace: cursor += 1 elif is_letter(source[cursor]): start = cursor while cursor < len(source) and is_word_char(source[cursor]): cursor += 1 add Token(ID, source[start:cursor]) elif is_digit(source[cursor]): start = cursor while cursor < len(source) and is_digit(source[cursor]): cursor += 1 add Token(NUM, int(source[start:cursor])) elif source[cursor] in '+-*/=': add Token(OP, source[cursor]); cursor += 1 elif source[cursor] in '();{}': add Token(PUNC, source[cursor]); cursor += 1 else: raise Error('unknown char') Parser helpers parse_program(tokens) → ASTProgram i = 0 stmts = [] while i < len(tokens): stmts.append(parse_statement(i)) return ASTProgram(stmts) parse_statement(i) → (node, new_i) if tokens[i] is ID and tokens[i+1] is OP '=': return parse_assignment(i) elif tokens[i] is ID and tokens[i+1] is PUNC '(' : return parse_call(i) elif tokens[i] is PUNC 'if': return parse_if(i) elif tokens[i] is PUNC 'while': return parse_while(i) else: error parse_expression(i, prec=0) → (node, new_i) left, i = parse_factor(i) while i < len(tokens) and tokens[i] is OP and precedence(tokens[i].value) >= prec: op = tokens[i].value; i += 1 right, i = parse_expression(i, precedence(op)+1) left = Binary(op, left, right) return left, i parse_factor(i) → (node, new_i) if tokens[i] is OP '-' : i += 1; node, i = parse_factor(i); return Unary('-', node), i if tokens[i] is PUNC '(' : i += 1; node, i = parse_expression(i); expect ')'; i += 1; return node, i if tokens[i] is NUM : return Number(tokens[i].value), i+1 if tokens[i] is ID : return Variable(tokens[i].value), i+1 Bytecode emit emit_program(ast) → list[Instr] instrs = [] for s in ast.statements: instrs.extend(emit_stmt(s)) return instrs emit_stmt(s) if Assignment: return [LOAD_CONST s.value, STORE_VAR s.name] if Call: return [PUSH_ARGS s.args..., CALL s.name] if If: else_lbl = new_label(); end_lbl = new_label() return [EVAL s.cond, JUMP_IF_FALSE else_lbl] + emit_stmt(s.then) + [JUMP end_lbl, LABEL else_lbl] + emit_stmt(s.else) + [LABEL end_lbl] if While: start = new_label(); end = new_label() return [LABEL start, EVAL s.cond, JUMP_IF_FALSE end] + emit_stmt(s.body) + [JUMP start, LABEL end] Symbol tables build_symbol_table(ast) – walk, record vars, scopes, warn on redeclare build_function_table(ast) – record fn names, params, check cycles Unreachable detection build CFG from bytecode, run DFS from entry, flag unvisited blocks That’s the skeleton—plug in actual token classes, instruction opcodes, and error handling to make it run.