The uBASIC 0.1 source code

Makefile

@@ -0,0 +1 @@
+use-ubasic: use-ubasic.o ubasic.o tokenizer.o

tokenizer.c

@@ -0,0 +1,243 @@
+/*
+ * Copyright (c) 2006, Adam Dunkels
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#define DEBUG 0
+
+#if DEBUG
+#define DEBUG_PRINTF(...)  printf(__VA_ARGS__)
+#else
+#define DEBUG_PRINTF(...)
+#endif
+
+#include "tokenizer.h"
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+static char const *ptr, *nextptr;
+
+#define MAX_NUMLEN 5
+
+struct keyword_token {
+  char *keyword;
+  int token;
+};
+
+static int current_token = TOKENIZER_ERROR;
+
+static const struct keyword_token keywords[] = {
+  {"let", TOKENIZER_LET},
+  {"print", TOKENIZER_PRINT},
+  {"if", TOKENIZER_IF},
+  {"then", TOKENIZER_THEN},
+  {"else", TOKENIZER_ELSE},
+  {"for", TOKENIZER_FOR},
+  {"to", TOKENIZER_TO},
+  {"next", TOKENIZER_NEXT},
+  {"goto", TOKENIZER_GOTO},
+  {"gosub", TOKENIZER_GOSUB},
+  {"return", TOKENIZER_RETURN},
+  {"call", TOKENIZER_CALL},
+  {"end", TOKENIZER_END},
+  {NULL, TOKENIZER_ERROR}
+};
+
+/*---------------------------------------------------------------------------*/
+static int
+singlechar(void)
+{
+  if(*ptr == '\n') {
+    return TOKENIZER_CR;
+  } else if(*ptr == ',') {
+    return TOKENIZER_COMMA;
+  } else if(*ptr == ';') {
+    return TOKENIZER_SEMICOLON;
+  } else if(*ptr == '+') {
+    return TOKENIZER_PLUS;
+  } else if(*ptr == '-') {
+    return TOKENIZER_MINUS;
+  } else if(*ptr == '&') {
+    return TOKENIZER_AND;
+  } else if(*ptr == '|') {
+    return TOKENIZER_OR;
+  } else if(*ptr == '*') {
+    return TOKENIZER_ASTR;
+  } else if(*ptr == '/') {
+    return TOKENIZER_SLASH;
+  } else if(*ptr == '%') {
+    return TOKENIZER_MOD;
+  } else if(*ptr == '(') {
+    return TOKENIZER_LEFTPAREN;
+  } else if(*ptr == ')') {
+    return TOKENIZER_RIGHTPAREN;
+  } else if(*ptr == '<') {
+    return TOKENIZER_LT;
+  } else if(*ptr == '>') {
+    return TOKENIZER_GT;
+  } else if(*ptr == '=') {
+    return TOKENIZER_EQ;
+  }
+  return 0;
+}
+/*---------------------------------------------------------------------------*/
+static int
+get_next_token(void)
+{
+  struct keyword_token const *kt;
+  int i;
+
+  DEBUG_PRINTF("get_next_token(): '%s'\n", ptr);
+
+  if(*ptr == 0) {
+    return TOKENIZER_ENDOFINPUT;
+  }
+
+  if(isdigit(*ptr)) {
+    for(i = 0; i < MAX_NUMLEN; ++i) {
+      if(!isdigit(ptr[i])) {
+	if(i > 0) {
+	  nextptr = ptr + i;
+	  return TOKENIZER_NUMBER;
+	} else {
+	  DEBUG_PRINTF("get_next_token: error due to too short number\n");
+	  return TOKENIZER_ERROR;
+	}
+      }
+      if(!isdigit(ptr[i])) {
+	DEBUG_PRINTF("get_next_token: error due to malformed number\n");
+	return TOKENIZER_ERROR;
+      }
+    }
+    DEBUG_PRINTF("get_next_token: error due to too long number\n");
+    return TOKENIZER_ERROR;
+  } else if(singlechar()) {
+    nextptr = ptr + 1;
+    return singlechar();
+  } else if(*ptr == '"') {
+    nextptr = ptr;
+    do {
+      ++nextptr;
+    } while(*nextptr != '"');
+    ++nextptr;
+    return TOKENIZER_STRING;
+  } else {
+    for(kt = keywords; kt->keyword != NULL; ++kt) {
+      if(strncmp(ptr, kt->keyword, strlen(kt->keyword)) == 0) {
+	nextptr = ptr + strlen(kt->keyword);
+	return kt->token;
+      }
+    }
+  }
+
+  if(*ptr >= 'a' && *ptr <= 'z') {
+    nextptr = ptr + 1;
+    return TOKENIZER_VARIABLE;
+  }
+
+
+  return TOKENIZER_ERROR;
+}
+/*---------------------------------------------------------------------------*/
+void
+tokenizer_init(const char *program)
+{
+  ptr = program;
+  current_token = get_next_token();
+}
+/*---------------------------------------------------------------------------*/
+int
+tokenizer_token(void)
+{
+  return current_token;
+}
+/*---------------------------------------------------------------------------*/
+void
+tokenizer_next(void)
+{
+
+  if(tokenizer_finished()) {
+    return;
+  }
+
+  DEBUG_PRINTF("tokenizer_next: %p\n", nextptr);
+  ptr = nextptr;
+  while(*ptr == ' ') {
+    ++ptr;
+  }
+  current_token = get_next_token();
+  DEBUG_PRINTF("tokenizer_next: '%s' %d\n", ptr, current_token);
+  return;
+}
+/*---------------------------------------------------------------------------*/
+int
+tokenizer_num(void)
+{
+  return atoi(ptr);
+}
+/*---------------------------------------------------------------------------*/
+void
+tokenizer_string(char *dest, int len)
+{
+  char *string_end;
+  int string_len;
+
+  if(tokenizer_token() != TOKENIZER_STRING) {
+    return;
+  }
+  string_end = strchr(ptr + 1, '"');
+  if(string_end == NULL) {
+    return;
+  }
+  string_len = string_end - ptr - 1;
+  if(len < string_len) {
+    string_len = len;
+  }
+  memcpy(dest, ptr + 1, string_len);
+  dest[string_len] = 0;
+}
+/*---------------------------------------------------------------------------*/
+void
+tokenizer_error_print(void)
+{
+  DEBUG_PRINTF("tokenizer_error_print: '%s'\n", ptr);
+}
+/*---------------------------------------------------------------------------*/
+int
+tokenizer_finished(void)
+{
+  return *ptr == 0 || current_token == TOKENIZER_ENDOFINPUT;
+}
+/*---------------------------------------------------------------------------*/
+int
+tokenizer_variable_num(void)
+{
+  return *ptr - 'a';
+}
+/*---------------------------------------------------------------------------*/

tokenizer.h

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2006, Adam Dunkels
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+#ifndef __TOKENIZER_H__
+#define __TOKENIZER_H__
+
+enum {
+  TOKENIZER_ERROR,
+  TOKENIZER_ENDOFINPUT,
+  TOKENIZER_NUMBER,
+  TOKENIZER_STRING,
+  TOKENIZER_VARIABLE,
+  TOKENIZER_LET,
+  TOKENIZER_PRINT,
+  TOKENIZER_IF,
+  TOKENIZER_THEN,
+  TOKENIZER_ELSE,
+  TOKENIZER_FOR,
+  TOKENIZER_TO,
+  TOKENIZER_NEXT,
+  TOKENIZER_GOTO,
+  TOKENIZER_GOSUB,
+  TOKENIZER_RETURN,
+  TOKENIZER_CALL,
+  TOKENIZER_END,
+  TOKENIZER_COMMA,
+  TOKENIZER_SEMICOLON,
+  TOKENIZER_PLUS,
+  TOKENIZER_MINUS,
+  TOKENIZER_AND,
+  TOKENIZER_OR,
+  TOKENIZER_ASTR,
+  TOKENIZER_SLASH,
+  TOKENIZER_MOD,
+  TOKENIZER_LEFTPAREN,
+  TOKENIZER_RIGHTPAREN,
+  TOKENIZER_LT,
+  TOKENIZER_GT,
+  TOKENIZER_EQ,
+  TOKENIZER_CR,
+};
+
+void tokenizer_init(const char *program);
+void tokenizer_next(void);
+int tokenizer_token(void);
+int tokenizer_num(void);
+int tokenizer_variable_num(void);
+void tokenizer_string(char *dest, int len);
+
+int tokenizer_finished(void);
+void tokenizer_error_print(void);
+
+#endif /* __TOKENIZER_H__ */