/*
* Tiny BASIC
* Token handling functions
*
* Copyright (C) Damian Walker 2019
* Created: 15-Aug-2019
*/
/* includes */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "token.h"
/*
* Internal data structures
*/
/* Private data */
typedef struct {
TokenClass class; /* class of token */
int line; /* line on which token was found */
int pos; /* position within the line on which token was found */
char *content; /* representation of token */
} Private;
/*
* Internal Data
*/
/* Convenience variables */
static Token *this; /* the token object */
static Private *data; /* the private data */
/*
* Public methods
*/
/*
* Return the class of the token
* params:
* Token* token the token object
* returns:
* TokenClass the class of the token
*/
static TokenClass get_class (Token *token) {
this = token;
data = token->data;
return data->class;
}
/*
* Return the line on which the token begins
* params:
* Token* token the token object
* returns:
* int the line on which the token begins
*/
static int get_line (Token *token) {
this = token;
data = token->data;
return data->line;
}
/*
* Return the character position on which the token begins
* params:
* Token* token the token object
* returns:
* int the position on which the token begins
*/
static int get_pos (Token *token) {
this = token;
data = token->data;
return data->pos;
}
/*
* Return the content of the token begins
* params:
* Token* token the token object
* returns:
* char* the text content of the token
*/
static char *get_content (Token *token) {
this = token;
data = token->data;
return data->content;
}
/*
* Set the token class
* params:
* Token* token the token to set
* TokenClass class the class
*/
static void set_class (Token *token, TokenClass class) {
this = token;
data = this->data;
data->class = class;
}
/*
* Set the token line and position
* params:
* Token* token the token to set
* int line the line on which the token began
* int pos the position on which the token began
*/
static void set_line_pos (Token *token, int line, int pos) {
this = token;
data = this->data;
data->line = line;
data->pos = pos;;
}
/*
* Set the token's text content
* params:
* Token* token the token to alter
* char* content the text content to set
*/
static void set_content (Token *token, char *content) {
this = token;
data = this->data;
if (data->content)
strcpy (data
->content
, content
); }
/*
* Set all of the values of an existing token in a single function call.
* params:
* Token* token the token to update
* TokenClass class class of token to initialise
* int line line on which the token occurred
* int pos character position on which the token occurred
* char* content the textual content of the token
*/
static void initialise (Token *token, TokenClass class, int line, int pos,
char *content) {
/* set convenience variables */
this = token;
data = this->data;
/* initialise the easy members */
data->class = class ? class : TOKEN_NONE;
data->line = line ? line : 0;
data->pos = pos ? pos : 0;
/* initialise the content */
if (content)
set_content (this, content);
}
/*
* Token destructor
* params:
* Token* token the doomed token
*/
static void destroy (Token *token) {
if ((this = token)) {
data = this->data;
if (data->content)
}
}
/*
* Constructors
*/
/*
* Token constructor without values to initialise
* returns:
* Token* the created token
*/
Token *new_Token (void) {
/* create the structure */
this
= malloc (sizeof (Token
)); this
->data
= data
= malloc (sizeof (Private
));
/* initialise properties */
data->class = TOKEN_NONE;
data->line = data->pos = 0;
data->content = NULL;
/* set up methods */
this->initialise = initialise;
this->get_class = get_class;
this->get_line = get_line;
this->get_pos = get_pos;
this->get_content = get_content;
this->set_class = set_class;
this->set_line_pos = set_line_pos;
this->set_content = set_content;
this->destroy = destroy;
/* return the created structure */
return this;
}
/*
* Token constructor with values to initialise
* params:
* TokenClass class class of token to initialise
* int line line on which the token occurred
* int pos character position on which the token occurred
* char* content the textual content of the token
* returns:
* Token* the created token
*/
Token *new_Token_init (TokenClass class, int line, int pos, char *content) {
/* create a blank token */
this = new_Token ();
this->initialise (this, class, line, pos, content);
/* return the new token */
return this;
}