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/*
Copyright (C) 2021- The University of Notre Dame
This software is distributed under the GNU General Public License.
See the file COPYING for details.
*/
/*
This is a program to explore the jx library.
It reads in a JX expression, evaluates it, prints out the result, then saves it to the context.
Results of previous expressions can be referenced via the `out_%d` symbol, and their query via `in_%d`
The program exits once EOF is reached or after the user enters the `quit` or `exit` command
*/
#include "jx.h"
#include "jx_sub.h"
#include "jx_eval.h"
#include "jx_function.h"
#include "jx_parse.h"
#include "jx_print.h"
#include "jx_pretty_print.h"
#include <stdio.h>
#include <string.h>
#ifdef HAS_LIBREADLINE
#include "readline/readline.h"
#include "readline/history.h"
#endif
#define CATALOG_URL "http://catalog.cse.nd.edu:9097/query.json"
#define MAX_LINE 4096
const char * MSG_WELCOME =
"Welcome to the JX Language Explorer.\n"
"\n"
"Type 'help' for help\n"
"\n";
const char * MSG_HELP =
"\n"
" help display this message\n"
" functions display a list of functions supported by the JX language\n"
" values display a list of values supported by the JX language\n"
" operators display a list of operators supported by the JX language\n"
" in_# the #'th input query\n"
" out_# result of in_#\n"
" catalog alias to fetch catalog data\n"
" quit|exit exit program\n"
"\n";
const char * MSG_VALUES =
"\n"
" string \"string\"\n"
" integer 42\n"
" float 3.14159\n"
" boolean true | false\n"
" array [ 1, 2, 3 ]\n"
" objects { \"temp\": 32, \"name\": \"fred\" }\n"
"\n";
const char * MSG_OPERATORS =
"\n"
" lookup obj[\"a\"], arr[0], arr[0:10]\n"
" concatenation \"abc\" + \"def\" -> \"abcdef\"\n"
" arithmetic * / + - %\n"
" logic and or not\n"
" comparison == != < <= > >=\n"
" comprehensions expr for x in [1,2,3], [x*x for x in range(10) if x % 2 == 0]\n"
"\n";
void insert_constants(struct jx *context) {
jx_insert(context, jx_string("catalog"), jx_parse_string("fetch(\"" CATALOG_URL "\")"));
jx_insert(context, jx_string("help"), jx_string("help"));
jx_insert(context, jx_string("functions"), jx_string("functions"));
jx_insert(context, jx_string("values"), jx_string("values"));
jx_insert(context, jx_string("operators"), jx_string("operators"));
jx_insert(context, jx_string("quit"), jx_string("exit"));
jx_insert(context, jx_string("exit"), jx_string("exit"));
}
char *sub_to_string(struct jx *j, struct jx *context) {
// expand symbols
struct jx *expanded = jx_sub(j, context);
// convert to string
char *str = jx_print_string(expanded);
jx_delete(expanded);
return str;
}
struct jx * parse_line(char *line) {
struct jx_parser *p = jx_parser_create(false);
jx_parser_read_string(p, line);
struct jx *j = jx_parse(p);
if(jx_parser_errors(p)) {
printf("jx parse error: %s\n", jx_parser_error_string(p));
jx_delete(j);
jx_parser_delete(p);
return NULL;
}
jx_parser_delete(p);
return j;
}
int main(int argc, char *argv[]) {
char in[14];
char out[15];
char in_prompt[18];
char out_prompt[18];
char line[MAX_LINE];
struct jx *context = jx_object(0);
insert_constants(context);
printf("%s", MSG_WELCOME);
for (unsigned int i=0; ; i++) {
if (i > 0) {
printf("--------------------\n");
}
sprintf(in, "in_%d", i);
sprintf(out, "out_%d", i);
sprintf(in_prompt, "%s : ", in);
sprintf(out_prompt, "%s : ", out);
#ifdef HAS_LIBREADLINE
char *temp = readline(in_prompt);
if(!temp)
break;
if (*temp) {
add_history(temp);
}
strcpy(line, temp);
free(temp);
#else
printf("%s", in_prompt);
fflush(stdout);
if(!fgets(line, MAX_LINE, stdin))
break;
#endif
struct jx *parsed = parse_line(line);
if (!parsed) {
continue;
}
// insert fully-expanded expression into context
char *expr_str = sub_to_string(parsed, context);
jx_insert(context, jx_string(in), jx_string(expr_str));
free(expr_str);
struct jx *res = jx_eval(parsed, context);
if (!res) {
continue;
}
if (jx_istype(res, JX_ERROR)) {
printf("error %s\n", res->u.err->u.string_value);
jx_delete(res);
continue;
}
if (jx_istype(res, JX_STRING)) {
if (strcmp(res->u.string_value, "exit") == 0) {
jx_delete(res);
break;
} else if (strcmp(res->u.string_value, "help") == 0) {
printf("%s", MSG_HELP);
} else if (strcmp(res->u.string_value, "functions") == 0) {
jx_function_help(stdout);
} else if (strcmp(res->u.string_value, "operators") == 0) {
printf("%s", MSG_OPERATORS);
} else if (strcmp(res->u.string_value, "values") == 0) {
printf("%s", MSG_VALUES);
} else if (strcmp(res->u.string_value, "help") == 0) {
printf("%s", MSG_HELP);
} else {
printf("%s%s\n", out_prompt, res->u.string_value);
}
} else {
printf("%s", out_prompt);
jx_pretty_print_stream(res, stdout);
printf("\n");
}
jx_delete(res);
jx_insert(context, jx_string(out), parsed);
}
jx_delete(context);
return 0;
}
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