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#include <stdio.h>
#include <stdlib.h>
#include "vendor/mpc.h"
#include "template.h"
char *read_file(char *filename) {
char *input = malloc(BUFSIZ);
unsigned int size = 0;
FILE *f = fopen(filename, "r");
if (!f) {
printf("Could not open \"%s\" for reading", filename);
exit(1);
}
unsigned int read = 0;
while ( (read = fread(input, 1, BUFSIZ, f)) > 0) {
size += read;
input = realloc(input, size + BUFSIZ);
}
fclose(f);
input[size] = '\0';
return input;
}
char *trim_trailing_whitespace(char *str) {
for (int i=strlen(str)-1; isspace(str[i]); i--) {
str[i] = '\0';
}
return str;
}
char *trim_leading_whitespace(char *str) {
while (isspace(*str)) {
str++;
}
return str;
}
char *eval_expression(mpc_ast_t* node, struct hashmap *ctx) {
if (strstr(node->tag, "symbol")) {
/* Return empty string if no context was passed. Should probably signal error here. */
if (ctx == NULL) {
return "";
}
char *key = node->contents;
/* TODO: Handle unexisting symbols (returns NULL currently) */
return hashmap_resolve(ctx, key);
} else if(strstr(node->tag, "number")) {
return node->contents;
} else if(strstr(node->tag, "string")) {
return node->children[1]->contents;
}
return NULL;
}
int eval(char *dest, mpc_ast_t* t, struct hashmap *ctx) {
static int trim_whitespace = 0;
char buf[64];
// eval expression
if (strstr(t->tag, "content|expression|")) {
// maybe eat whitespace going backward
if (strstr(t->children[1]->contents, "-")) {
dest = trim_trailing_whitespace(dest);
}
/* set flag for next eval() to trim leading whitespace from text */
if (strstr(t->children[3]->contents, "-")) {
trim_whitespace = 1;
}
mpc_ast_t *left_node = t->children[2];
char *lvalue = eval_expression(left_node, ctx);
mpc_ast_t *op = t->children[4];
if (op != NULL && strstr(op->tag, "op")) {
mpc_ast_t *right_node = t->children[6];
char *rvalue = eval_expression(right_node, ctx);
/* if operator is + and either left or right node is of type string: concat */
if (op->contents[0] == '+' && (strstr(left_node->tag, "string") || strstr(right_node->tag, "string"))) {
sprintf(buf, "%s%s", lvalue, rvalue);
} else {
/* eval int infix expression */
int result;
switch (op->contents[0]) {
case '+': result = atoi(lvalue) + atoi(rvalue); break;
case '-': result = atoi(lvalue) - atoi(rvalue); break;
case '/': result = atoi(lvalue) / atoi(rvalue); break;
case '*': result = atoi(lvalue) * atoi(rvalue); break;
case '>': result = atoi(lvalue) > atoi(rvalue); break;
case '<': result = atoi(lvalue) < atoi(rvalue); break;
}
sprintf(buf, "%d", result);
}
strcat(dest, buf);
return 0;
}
strcat(dest, lvalue);
return 0;
}
if (strstr(t->tag, "content|statement|for")) {
char *tmp_key = t->children[2]->contents;
char *iterator_key = t->children[4]->contents;
struct vector *list = hashmap_resolve(ctx, iterator_key);
for (int i=0; i < list->size; i++) {
hashmap_insert(ctx, tmp_key, list->values[i]);
eval(dest, t->children[6], ctx);
}
return 0;
}
if (strstr(t->tag, "content|text")) {
char *str = t->contents;
if (trim_whitespace) {
str = trim_leading_whitespace(str);
trim_whitespace = 0;
}
strcat(dest, str);
return 0;
}
for (int i=0; i < t->children_num; i++) {
eval(dest, t->children[i], ctx);
}
return 0;
}
mpc_parser_t *parser_init() {
mpc_parser_t *symbol = mpc_new("symbol");
mpc_parser_t *number = mpc_new("number");
mpc_parser_t *string = mpc_new("string");
mpc_parser_t *op = mpc_new("op");
mpc_parser_t *text = mpc_new("text");
mpc_parser_t *expression = mpc_new("expression");
mpc_parser_t *comment = mpc_new("comment");
mpc_parser_t *statement = mpc_new("statement");
mpc_parser_t *statement_open = mpc_new("statement_open");
mpc_parser_t *statement_close = mpc_new("statement_close");
mpc_parser_t *statement_for = mpc_new("for");
mpc_parser_t *statement_if = mpc_new("if");
mpc_parser_t *statement_block = mpc_new("block");
mpc_parser_t *statement_extends = mpc_new("extends");
mpc_parser_t *body = mpc_new("body");
mpc_parser_t *content = mpc_new("content");
mpc_parser_t *template = mpc_new("template");
mpca_lang(MPCA_LANG_WHITESPACE_SENSITIVE,
" symbol : /[a-zA-Z_.]+/ ;"
" number : /[0-9]+/ ;"
" string : '\"' /([^\"])*/ '\"' ;"
" op : '+' | '-' | '*' | '/' | '>' | '<';"
" text : /[^{][^{%#]*/ ;"
" expression : \"{{\" /-? */ (<symbol> | <number> | <string> ) (/ */ <op> / */ (<symbol> | <number> | <string> ))? / *-?/ \"}}\" ;"
" comment : \"{#\" /[^#][^#}]*/ \"#}\" ;"
" statement_open: \"{%\" /-? */;"
" statement_close: / *-?/ \"%}\";"
" for : <statement_open> \"for \" <symbol> \" in \" <symbol> <statement_close> <body> <statement_open> \"endfor\" <statement_close> ;"
" block : <statement_open> \"block \" <statement_close> <statement_open> \"endblock\" <statement_close>;"
" extends : <statement_open> \"extends \" <statement_close>;"
/* TODO: Extend parser to include expression */
" if : <statement_open> \"if \" <statement_close> <body> <statement_open> \"endif\" <statement_close> ;"
" statement : <for> | <block> | <extends> | <if> ;"
" content : <expression> | <statement> | <text> | <comment>;"
" body : <content>* ;"
" template : /^/ <body> /$/ ;",
symbol,
op,
number,
string,
expression,
text,
comment,
statement_open,
statement_close,
statement,
statement_if,
statement_for,
statement_block,
statement_extends,
content,
body,
template,
NULL);
return template;
}
char *template(char *tmpl, struct hashmap *ctx) {
mpc_parser_t *parser = parser_init();
mpc_result_t r;
if (!mpc_parse("input", tmpl, parser, &r)) {
mpc_err_print(r.error);
mpc_err_delete(r.error);
return NULL;
}
#if DEBUG
printf("Template: %s\n", tmpl);
printf("AST: ");
mpc_ast_print(r.output);
printf("\n");
#endif
// FIXME: Allocate precisely
char *output = malloc(strlen(tmpl) * 2);
output[0] = '\0';
eval(output, r.output, ctx);
mpc_ast_delete(r.output);
return output;
}
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