Add intial lexer back again, fix docs

Makefile

@@ -86,11 +86,13 @@ ifeq ($(BUILD_MODE), release)
 	PLATFORM_SOURCE := $(ARCH_DIR)/main.c \
 		$(ARCH_DIR)/devices.c\
         $(SRC_DIR)/tools/parser.c \
+        $(SRC_DIR)/tools/lexer.c \
 		$(SRC_DIR)/tools/assembler.c
 else
 	PLATFORM_SOURCE := $(ARCH_DIR)/main.c \
 		$(ARCH_DIR)/devices.c \
         $(SRC_DIR)/tools/parser.c \
+        $(SRC_DIR)/tools/lexer.c \
 		$(SRC_DIR)/tools/assembler.c
 endif
 

README.org

@@ -58,14 +58,26 @@ The Undâr compiler will be written in Sċieppan, as well as core VM tests.
 #+BEGIN_SRC lisp
 ((code 
 	(label main	
-		(load-immediate $0 &terminal-namespace) ; load terminal namespace
 		(load-immediate $1 &hello-str) ; load hello string ptr
-    	(string-length $2 $1)                   ; get length to write to stdout
+		(push $1)
-		(syscall WRITE $0 $1 $2)                ; do the write syscall
+    	(call &pln)
-		(halt)))                                ; done
+		(halt)) ; done
+  	(label pln 
+		(load-immediate $0 &terminal-namespace) ; get terminal device
+		(load-immediate $11 0)
+		(syscall OPEN $0 $0 $11)	
+		(load-immediate $3 &new-line)
+		(pop $1)
+    	(load-offset-32 $7 $0 4) ; load handle
+		(string-length $2 $1)
+		(syscall WRITE $7 $1 $2)
+		(string-length $4 $3)
+		(syscall WRITE $7 $3 $4)
+		(return)))
 (data 
 	(label terminal-namespace "/dev/term/0")
-    (label hello-str "nuqneH 'u'?\n")))
+	(label new-line "\n")
+    (label hello-str "nuqneH 'u'?")))
 #+END_SRC
 
 #+BEGIN_SRC sh
@@ -82,36 +94,38 @@ heap allocations using the internal malloc opcode push pointers within this fram
 
 #+BEGIN_SRC lisp
 ((code 
-	(label main                  ; this example adds 2 numbers together
+	(label main
-		(load-immediate $0 1)    ; pushes 1 onto the stack for the function call
+		(load-immediate $0 &terminal-namespace) ; get terminal device
+		(load-immediate $11 0)
+		(syscall OPEN $0 $0 $11)
+
+		(load-immediate $1 &help) ; print help message
 		(push $0)
-		(load-immediate $0 1) 
+        (push $1)
+		(call &pln)
+
+		(load-immediate $1 32) ; read in a string of max 32 char length 
+		(malloc $4 $1) ; allocate memory for the string
+		(load-offset-32 $7 $0 4) ; load handle
+		(syscall READ $7 $2 $1 $4) ; read the string
+
 		(push $0)
-		(call &add)              ; here a new frame is generated
+		(push $4)
-		(pop $0)                 ; the element is returned and the memory for the pln is "freed" automatically because the child frame is done
+		(call &pln) ; print the string
 		(halt))
-	
-	(label add 
-		(pop $0)
-		(pop $1)
-		(add-int $2 $1 $0)      ; add the arguments
-		(int-to-string $3 $2)   ; convert to a string (heap allocation)
-		(push $3)
-		(call &pln)         ; call print function
-		(push $2)
-		(return))               ; return to main function
-
   	(label pln 
-		(load-immediate $0 &terminal-namespace) ; load the namespace for the terminal
+		(load-immediate $3 &new-line)
-		(load-immediate $3 &new-line)           ; and a newline char
+		(pop $1)
-		(pop $1)                                ; pointer to string
+    	(pop $0)
-		(string-length $2 $1)                   ; get the length
+    	(load-offset-32 $7 $0 4) ; load handle
-		(syscall WRITE $0 $1 $2)                ; write the string
+		(string-length $2 $1)
+		(syscall WRITE $7 $1 $2)
 		(string-length $4 $3)
-		(syscall WRITE $0 $3 $4)
+		(syscall WRITE $7 $3 $4)
-		(return)))                              ; return back to add function
+		(return)))
-(data                                           ; allocates strings at compile time
+(data 
 	(label terminal-namespace "/dev/term/0")
+    (label help "Enter a string: ")
 	(label new-line "\n")))
 #+END_SRC
 

src/arch/linux/main.c

@@ -1,5 +1,6 @@
 #include "../../tools/assembler.h"
 #include "../../tools/parser.h"
+#include "../../tools/lexer.h"
 #include "../../vm/vm.h"
 #include "devices.h"
 #include <SDL2/SDL.h>
@@ -122,6 +123,50 @@ bool loadVM(const char *filename, VM *vm) {
 
 // Function to compile and optionally save
 bool compileAndSave(const char *source_file, const char *output_file, VM *vm) {
+  USED(vm);
+  USED(output_file);
+  FILE *f = fopen(source_file, "rb");
+  if (!f) {
+    perror("fopen");
+    return false;
+  }
+
+  static char source[MAX_SRC_SIZE + 1];
+
+  fseek(f, 0, SEEK_END);
+  long len = ftell(f);
+  fseek(f, 0, SEEK_SET);
+  if (len >= MAX_SRC_SIZE) {
+    fprintf(stderr, "Source is larger than buffer\n");
+    fclose(f);
+    return false;
+  }
+  size_t read = fread(source, 1, len, f);
+  source[read] = '\0';
+  fclose(f);
+
+  initLexer(source);
+  Token token;
+  do {
+    token = nextToken();
+    if (token.type == TOKEN_ERROR) {
+      printf("ERROR at line %d: %.*s\n", token.line, token.length, token.start);
+      break; // Stop on error, or continue if you want to see more
+    }
+    if (token.type != TOKEN_EOF) {
+      printf("Line %d [%s]: %.*s\n", 
+            token.line, 
+            tokenTypeToString(token.type), 
+            token.length, 
+            token.start);
+    }
+  } while (token.type != TOKEN_EOF);
+
+  return true;
+}
+
+// Function to assemble and optionally save
+bool assembleAndSave(const char *source_file, const char *output_file, VM *vm) {
   FILE *f = fopen(source_file, "rb");
   if (!f) {
     perror("fopen");
@@ -377,7 +422,7 @@ i32 main(i32 argc, char *argv[]) {
   bool dump_rom = false;
   char *input_file = nil;
   char *output_file = nil;
-  bool is_rom = false;
+  bool is_rom, is_assembly = false;
 
   // Parse command line arguments
   for (i32 i = 1; i < argc; i++) {
@@ -395,6 +440,9 @@ i32 main(i32 argc, char *argv[]) {
       if (ext && (strcmp(ext, ".rom") == 0)) {
         is_rom = true;
       }
+      if (ext && (strcmp(ext, ".asm.lisp") == 0)) {
+        is_assembly = true;
+      }
     } else if (output_file == nil && dump_rom) {
       // This is the output file for -o flag
       output_file = argv[i];
@@ -408,8 +456,14 @@ i32 main(i32 argc, char *argv[]) {
     if (is_rom) {
       // Load ROM file directly
       compilation_success = loadVM(input_file, &vm);
-    } else {
+    } else if (is_assembly) {
       // Compile Lisp file
+      if (dump_rom && output_file) {
+        compilation_success = assembleAndSave(input_file, output_file, &vm);
+      } else {
+        compilation_success = assembleAndSave(input_file, nil, &vm);
+      }
+    } else {
       if (dump_rom && output_file) {
         compilation_success = compileAndSave(input_file, output_file, &vm);
       } else {

src/tools/lexer.c

@@ -0,0 +1,324 @@
+#include <string.h>
+
+#include "../vm/common.h"
+#include "lexer.h"
+
+typedef struct {
+  const char *start;
+  const char *current;
+  int line;
+} Lexer;
+
+Lexer lexer;
+
+void initLexer(const char *source) {
+  lexer.start = source;
+  lexer.current = source;
+  lexer.line = 1;
+}
+
+static bool isAlpha(char c) {
+  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_';
+}
+
+static bool isDigit(char c) { return c >= '0' && c <= '9'; }
+
+static bool isAtEnd() { return *lexer.current == '\0'; }
+
+static char advance() {
+  lexer.current++;
+  return lexer.current[-1];
+}
+
+static char peek() { return *lexer.current; }
+
+static char peekNext() {
+  if (isAtEnd())
+    return '\0';
+  return lexer.current[1];
+}
+
+static bool match(char expected) {
+  if (isAtEnd())
+    return false;
+  if (*lexer.current != expected)
+    return false;
+  lexer.current++;
+  return true;
+}
+
+static Token makeToken(TokenType type) {
+  Token token;
+  token.type = type;
+  token.start = lexer.start;
+  token.length = (int)(lexer.current - lexer.start);
+  token.line = lexer.line;
+  return token;
+}
+
+static Token errorToken(const char *message) {
+  Token token;
+  token.type = TOKEN_ERROR;
+  token.start = message;
+  token.length = (int)strlen(message);
+  token.line = lexer.line;
+  return token;
+}
+
+static void skipWhitespace() {
+  for (;;) {
+    char c = peek();
+    switch (c) {
+    case ' ':
+    case '\r':
+    case '\t':
+      advance();
+      break;
+    case '\n':
+      lexer.line++;
+      advance();
+      break;
+    case '/':
+      if (peekNext() == '/') {
+        // Single-line comment: skip until newline or end of file
+        advance(); 
+        while (peek() != '\n' && !isAtEnd())
+          advance();
+      } else if (peekNext() == '*') {
+        // Multi-line comment: skip until '*/' or end of file
+        advance(); 
+        advance(); 
+        while (!isAtEnd()) {
+          if (peek() == '*' && peekNext() == '/') {
+            advance(); 
+            advance(); 
+            break;     // Exit loop, comment ended
+          }
+          advance();
+        }
+      } else {
+        return; // Not a comment, let tokenization handle it
+      }
+      break;
+    default:
+      return;
+    }
+  }
+}
+
+static TokenType checkKeyword(int start, int length, const char *rest,
+                              TokenType type) {
+  if (lexer.current - lexer.start == start + length &&
+      memcmp(lexer.start + start, rest, length) == 0) {
+    return type;
+  }
+
+  return TOKEN_IDENTIFIER;
+}
+
+static TokenType identifierType() {
+  switch (lexer.start[0]) {
+  case 'a':
+    return checkKeyword(1, 2, "nd", TOKEN_OPERATOR_AND);
+  case 'e':
+    return checkKeyword(1, 3, "lse", TOKEN_KEYWORD_ELSE);
+  case 'f':
+    if (lexer.current - lexer.start > 1) {
+      switch (lexer.start[1]) {
+      case 'a':
+        return checkKeyword(2, 3, "lse", TOKEN_KEYWORD_FALSE);
+      case 'o':
+        return checkKeyword(2, 1, "r", TOKEN_KEYWORD_FOR);
+      }
+      return checkKeyword(1, 7, "unction", TOKEN_KEYWORD_FN);
+    }
+    break;
+  case 'i':
+    return checkKeyword(1, 1, "f", TOKEN_KEYWORD_IF);
+  case 'n':
+    return checkKeyword(1, 2, "il", TOKEN_KEYWORD_NIL);
+  case 'o':
+    return checkKeyword(1, 1, "r", TOKEN_OPERATOR_OR);
+  case 'p':
+    if (lexer.current - lexer.start > 1) {
+      switch (lexer.start[1]) {
+      case 'l':
+        return checkKeyword(2, 2, "ex", TOKEN_KEYWORD_PLEX);
+      case 'r':
+        return checkKeyword(2, 3, "int", TOKEN_KEYWORD_PRINT);
+      }
+    }
+    break;
+  case 'r':
+    return checkKeyword(1, 5, "eturn", TOKEN_KEYWORD_RETURN);
+  case 't':
+    if (lexer.current - lexer.start > 1) {
+      switch (lexer.start[1]) {
+      case 'h':
+        return checkKeyword(2, 2, "is", TOKEN_KEYWORD_THIS);
+      case 'r':
+        return checkKeyword(2, 2, "ue", TOKEN_KEYWORD_TRUE);
+      }
+    }
+    break;
+  case 'l':
+    return checkKeyword(1, 2, "et", TOKEN_KEYWORD_LET);
+  case 'w':
+    return checkKeyword(1, 4, "hile", TOKEN_KEYWORD_WHILE);
+  }
+
+  return TOKEN_IDENTIFIER;
+}
+
+static Token identifier() {
+  while (isAlpha(peek()) || isDigit(peek()))
+    advance();
+  return makeToken(identifierType());
+}
+
+static Token number() {
+  while (isDigit(peek()))
+    advance();
+
+  /*  Look for a fractional part. */
+  if (peek() == '.' && isDigit(peekNext())) {
+    /*  Consume the ".". */
+    advance();
+
+    while (isDigit(peek()))
+      advance();
+
+    return makeToken(TOKEN_FLOAT_LITERAL);
+  }
+
+  return makeToken(TOKEN_INT_LITERAL);
+}
+
+static Token string() {
+  while (peek() != '"' && !isAtEnd()) {
+    if (peek() == '\n')
+      lexer.line++;
+    advance();
+  }
+
+  if (isAtEnd())
+    return errorToken("Unterminated string.");
+
+  /*  The closing quote. */
+  advance();
+  return makeToken(TOKEN_STRING_LITERAL);
+}
+
+Token nextToken() {
+  skipWhitespace();
+  lexer.start = lexer.current;
+
+  if (isAtEnd())
+    return makeToken(TOKEN_EOF);
+
+  char c = advance();
+  if (isAlpha(c))
+    return identifier();
+  if (isDigit(c))
+    return number();
+
+  switch (c) {
+  case '(':
+    return makeToken(TOKEN_LPAREN);
+  case ')':
+    return makeToken(TOKEN_RPAREN);
+  case '{':
+    return makeToken(TOKEN_LBRACE);
+  case '}':
+    return makeToken(TOKEN_RBRACE);
+  case '[':
+    return makeToken(TOKEN_LBRACKET);
+  case ']':
+    return makeToken(TOKEN_RBRACKET);
+  case ';':
+    return makeToken(TOKEN_SEMICOLON);
+  case ',':
+    return makeToken(TOKEN_COMMA);
+  case '.':
+    return makeToken(TOKEN_DOT);
+  case '-':
+    return makeToken(TOKEN_MINUS);
+  case '+':
+    return makeToken(TOKEN_PLUS);
+  case '/':
+    return makeToken(TOKEN_SLASH);
+  case '*':
+    return makeToken(TOKEN_STAR);
+  case '!':
+    return makeToken(match('=') ? TOKEN_BANG_EQ : TOKEN_BANG);
+  case '=':
+    return makeToken(match('=') ? TOKEN_EQ_EQ : TOKEN_EQ);
+  case '<':
+    return makeToken(match('=') ? TOKEN_LTE : TOKEN_LT);
+  case '>':
+    return makeToken(match('=') ? TOKEN_GTE : TOKEN_GT);
+  case '"':
+    return string();
+  }
+
+  return errorToken("Unexpected character.");
+}
+
+const char* tokenTypeToString(TokenType type) {
+  switch (type) {
+    case TOKEN_EOF: return "EOF";
+    case TOKEN_IDENTIFIER: return "IDENTIFIER";
+    case TOKEN_INT_LITERAL: return "INT_LITERAL";
+    case TOKEN_UINT_LITERAL: return "UINT_LITERAL";
+    case TOKEN_FLOAT_LITERAL: return "FLOAT_LITERAL";
+    case TOKEN_STRING_LITERAL: return "STRING_LITERAL";
+    case TOKEN_TYPE_INT: return "TYPE_INT";
+    case TOKEN_TYPE_NAT: return "TYPE_NAT";
+    case TOKEN_TYPE_REAL: return "TYPE_REAL";
+    case TOKEN_TYPE_STR: return "TYPE_STR";
+    case TOKEN_KEYWORD_PLEX: return "KEYWORD_PLEX";
+    case TOKEN_KEYWORD_FN: return "KEYWORD_FN";
+    case TOKEN_KEYWORD_LET: return "KEYWORD_LET";
+    case TOKEN_KEYWORD_CONST: return "KEYWORD_CONST";
+    case TOKEN_KEYWORD_IF: return "KEYWORD_IF";
+    case TOKEN_KEYWORD_ELSE: return "KEYWORD_ELSE";
+    case TOKEN_KEYWORD_WHILE: return "KEYWORD_WHILE";
+    case TOKEN_KEYWORD_FOR: return "KEYWORD_FOR";
+    case TOKEN_KEYWORD_RETURN: return "KEYWORD_RETURN";
+    case TOKEN_KEYWORD_USE: return "KEYWORD_USE";
+    case TOKEN_KEYWORD_INIT: return "KEYWORD_INIT";
+    case TOKEN_KEYWORD_THIS: return "KEYWORD_THIS";
+    case TOKEN_KEYWORD_PRINT: return "KEYWORD_PRINT";
+    case TOKEN_KEYWORD_NIL: return "KEYWORD_NIL";
+    case TOKEN_KEYWORD_TRUE: return "KEYWORD_TRUE";
+    case TOKEN_KEYWORD_FALSE: return "KEYWORD_FALSE";
+    case TOKEN_OPERATOR_IS: return "OPERATOR_IS";
+    case TOKEN_OPERATOR_NOT: return "OPERATOR_NOT";
+    case TOKEN_OPERATOR_AND: return "OPERATOR_AND";
+    case TOKEN_OPERATOR_OR: return "OPERATOR_OR";
+    case TOKEN_BANG: return "BANG";
+    case TOKEN_BANG_EQ: return "BANG_EQ";
+    case TOKEN_EQ: return "EQ";
+    case TOKEN_EQ_EQ: return "EQ_EQ";
+    case TOKEN_GT: return "GT";
+    case TOKEN_LT: return "LT";
+    case TOKEN_GTE: return "GTE";
+    case TOKEN_LTE: return "LTE";
+    case TOKEN_DOT: return "DOT";
+    case TOKEN_COMMA: return "COMMA";
+    case TOKEN_COLON: return "COLON";
+    case TOKEN_SEMICOLON: return "SEMICOLON";
+    case TOKEN_PLUS: return "PLUS";
+    case TOKEN_MINUS: return "MINUS";
+    case TOKEN_STAR: return "STAR";
+    case TOKEN_SLASH: return "SLASH";
+    case TOKEN_LPAREN: return "LPAREN";
+    case TOKEN_RPAREN: return "RPAREN";
+    case TOKEN_LBRACE: return "LBRACE";
+    case TOKEN_RBRACE: return "RBRACE";
+    case TOKEN_LBRACKET: return "LBRACKET";
+    case TOKEN_RBRACKET: return "RBRACKET";
+    case TOKEN_ERROR: return "ERROR";
+    default: return "UNKNOWN_TOKEN";
+  }
+}

src/tools/lexer.h

@@ -0,0 +1,71 @@
+#ifndef UNDAR_LEXER_H
+#define UNDAR_LEXER_H
+
+typedef enum {
+  TOKEN_EOF,
+  TOKEN_IDENTIFIER,
+  TOKEN_INT_LITERAL,
+  TOKEN_UINT_LITERAL,
+  TOKEN_FLOAT_LITERAL,
+  TOKEN_STRING_LITERAL,
+  TOKEN_TYPE_INT,
+  TOKEN_TYPE_NAT,
+  TOKEN_TYPE_REAL,
+  TOKEN_TYPE_STR,
+  TOKEN_KEYWORD_PLEX,
+  TOKEN_KEYWORD_FN,
+  TOKEN_KEYWORD_LET,
+  TOKEN_KEYWORD_CONST,
+  TOKEN_KEYWORD_IF,
+  TOKEN_KEYWORD_ELSE,
+  TOKEN_KEYWORD_WHILE,
+  TOKEN_KEYWORD_FOR,
+  TOKEN_KEYWORD_RETURN,
+  TOKEN_KEYWORD_USE,
+  TOKEN_KEYWORD_INIT,
+  TOKEN_KEYWORD_THIS,
+  TOKEN_KEYWORD_PRINT,
+  TOKEN_KEYWORD_NIL,
+  TOKEN_KEYWORD_TRUE,
+  TOKEN_KEYWORD_FALSE,
+  TOKEN_OPERATOR_IS,
+  TOKEN_OPERATOR_NOT,
+  TOKEN_OPERATOR_AND,
+  TOKEN_OPERATOR_OR,
+  TOKEN_BANG,
+  TOKEN_BANG_EQ,
+  TOKEN_EQ,
+  TOKEN_EQ_EQ,
+  TOKEN_GT,
+  TOKEN_LT,
+  TOKEN_GTE,
+  TOKEN_LTE,
+  TOKEN_DOT,
+  TOKEN_COMMA,
+  TOKEN_COLON,
+  TOKEN_SEMICOLON,
+  TOKEN_PLUS,
+  TOKEN_MINUS,
+  TOKEN_STAR,
+  TOKEN_SLASH,
+  TOKEN_LPAREN,
+  TOKEN_RPAREN,
+  TOKEN_LBRACE,
+  TOKEN_RBRACE,
+  TOKEN_LBRACKET,
+  TOKEN_RBRACKET,
+  TOKEN_ERROR
+} TokenType;
+
+typedef struct {
+  TokenType type;
+  const char *start;
+  int length;
+  int line;
+} Token;
+
+void initLexer(const char *source);
+Token nextToken();
+const char* tokenTypeToString(TokenType type);
+
+#endif