Add NEW; report line number of error.

This commit is contained in:
Lawrence Kesteloot 2018-08-03 12:02:14 -07:00
parent e3f29f7dc5
commit 109a0af072
3 changed files with 51 additions and 23 deletions

61
main.c
View File

@ -25,6 +25,7 @@ uint8_t title_length = 9;
#define T_LIST 0x82
#define T_POKE 0x83
#define T_RUN 0x84
#define T_NEW 0x85
// Line number used for "no line number".
#define INVALID_LINE_NUMBER 0xFFFF
@ -36,6 +37,7 @@ static uint8_t *TOKEN[] = {
"LIST",
"POKE",
"RUN",
"NEW",
};
static int16_t TOKEN_COUNT = sizeof(TOKEN)/sizeof(TOKEN[0]);
@ -111,6 +113,14 @@ static uint8_t *get_end_of_program(uint8_t *line) {
return line + 2;
}
/**
* Clear the stored program.
*/
static void new_statement() {
g_program[0] = '\0';
g_program[1] = '\0';
}
/**
* List the stored program.
*/
@ -184,6 +194,16 @@ static uint16_t parse_uint16(uint8_t **s_ptr) {
return value;
}
/**
* Generate code to put the value into AX.
*/
static void compile_load_ax(uint16_t value) {
g_compiled[g_compiled_length++] = I_LDX;
g_compiled[g_compiled_length++] = value >> 8;
g_compiled[g_compiled_length++] = I_LDA;
g_compiled[g_compiled_length++] = value & 0xFF;
}
/**
* Parse an expression, generating code to compute it, leaving the
* result in AX.
@ -203,10 +223,7 @@ static uint8_t *compile_expression(uint8_t *s) {
}
value = parse_uint16(&s);
g_compiled[g_compiled_length++] = I_LDX;
g_compiled[g_compiled_length++] = value >> 8;
g_compiled[g_compiled_length++] = I_LDA;
g_compiled[g_compiled_length++] = value & 0xFF;
compile_load_ax(value);
have_value_in_ax = 1;
} else if (*s == '+') {
plus_count += 1;
@ -301,7 +318,7 @@ static void set_up_compile(void) {
/**
* Compile the tokenized line of BASIC, adding it to the g_compiled binary.
*/
static void compile_buffer(uint8_t *buffer) {
static void compile_buffer(uint8_t *buffer, uint16_t line_number) {
uint8_t *s = buffer;
uint8_t done;
@ -366,8 +383,13 @@ static void compile_buffer(uint8_t *buffer) {
}
if (error) {
if (line_number != INVALID_LINE_NUMBER) {
compile_load_ax(line_number);
add_call(syntax_error_in_line);
} else {
add_call(syntax_error);
}
}
} while (!done);
}
@ -405,12 +427,14 @@ static void compile_stored_program(void) {
uint8_t *line = g_program;
uint8_t *next_line;
set_up_compile();
while ((next_line = get_next_line(line)) != 0) {
uint16_t line_number = get_line_number(line);
compile_buffer(line + 4);
compile_buffer(line + 4, line_number);
line = next_line;
}
complete_compile_and_execute();
}
/**
@ -427,15 +451,18 @@ static void process_input_buffer() {
if (line_number == INVALID_LINE_NUMBER) {
// Immediate mode.
set_up_compile();
// See if it's the "RUN" command, which we don't compile.
if (g_input_buffer[0] == T_RUN) {
// We don't compile "RUN".
compile_stored_program();
} else if (g_input_buffer[0] == T_NEW) {
// We don't compile "NEW".
new_statement();
} else {
// Compile the immediate mode line.
compile_buffer(g_input_buffer);
}
set_up_compile();
compile_buffer(g_input_buffer, INVALID_LINE_NUMBER);
complete_compile_and_execute();
}
} else {
// Stored mode. Add line to program.
@ -502,18 +529,8 @@ int16_t main(void)
{
int16_t blink;
/*
int16_t i, j, k;
i = 2;
j = 3;
k = 4;
i = i*j;
*/
// Blank program.
g_program[0] = '\0';
g_program[1] = '\0';
// Clear stored program.
new_statement();
// Initialize UI.
home();

View File

@ -184,3 +184,13 @@ void syntax_error(void) {
print("\n?SYNTAX ERROR");
// No linefeed, assume prompt will do it.
}
/**
* Display a syntax error message for stored program.
*/
void syntax_error_in_line(uint16_t line_number) {
print("\n?SYNTAX ERROR IN ");
print_int(line_number);
// No linefeed, assume prompt will do it.
}

View File

@ -23,5 +23,6 @@ void print_int(uint16_t i);
void print_newline(void);
void syntax_error(void);
void syntax_error_in_line(uint16_t line_number);
#endif // __RUNTIME_H__