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#include <stdio.h>
#include <stdlib.h>
#include <err.h>
#include <unistd.h>
#include <dirent.h>
#include "vendor/mpc.h"
#include "template.h"
enum unja_object_type {
OBJ_NULL,
OBJ_INT,
OBJ_STRING,
};
struct unja_object {
enum unja_object_type type;
int integer;
char *string;
};
struct unja_object null_object = {
.type = OBJ_NULL,
};
struct buffer {
int size;
int cap;
char *string;
};
struct env {
struct hashmap *templates;
};
struct template {
char *name;
mpc_ast_t *ast;
struct hashmap *blocks;
char *parent;
};
/* ensure buffer has room for a string sized l, grows buffer capacity if needed */
void buffer_reserve(struct buffer *buf, int l) {
int req_size = buf->size + l;
if (req_size >= buf->cap) {
while (req_size >= buf->cap) {
buf->cap *= 2;
}
buf->string = realloc(buf->string, buf->cap * sizeof *buf->string);
if (!buf->string) {
err(EXIT_FAILURE, "out of memory");
}
}
}
mpc_parser_t *parser_init() {
static mpc_parser_t *template;
if (template != NULL) {
return template;
}
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 *print = mpc_new("print");
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");
template = mpc_new("template");
mpca_lang(MPCA_LANG_DEFAULT,
" symbol : /[a-zA-Z][a-zA-Z0-9_.]*/ ;"
" number : /[0-9]+/ ;"
" string : '\"' /([^\"])*/ '\"' ;"
" op : '+' | '-' | '*' | '/' | '>' | '<';"
" text : /[^{][^{%#]*/ ;"
" expression: (<symbol> | <number> | <string>) (<op> (<symbol> | <number> | <string>))* ;"
" print : \"{{\" /-? */ <expression> / *-?/ \"}}\" ;"
" comment : \"{#\" /[^#][^#}]*/ \"#}\" ;"
" statement_open: \"{%\" /-? */;"
" statement_close: / *-?/ \"%}\";"
" for : <statement_open> \"for \" <symbol> \"in\" <symbol> <statement_close> <body> <statement_open> \"endfor\" <statement_close> ;"
" block : <statement_open> \"block \" <symbol> <statement_close> <body> <statement_open> \"endblock\" <statement_close>;"
" extends : <statement_open> \"extends \" <string> <statement_close>;"
" if : <statement_open> \"if \" <expression> <statement_close> <body> (<statement_open> \"else\" <statement_close> <body>)? <statement_open> \"endif\" <statement_close> ;"
" statement : <for> | <block> | <extends> | <if> ;"
" content : <print> | <statement> | <text> | <comment>;"
" body : <content>* ;"
" template : /^/ <body> /$/ ;",
symbol,
op,
number,
string,
print,
expression,
text,
comment,
statement_open,
statement_close,
statement,
statement_if,
statement_for,
statement_block,
statement_extends,
content,
body,
template,
NULL);
return template;
}
mpc_ast_t *parse(char *tmpl) {
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;
}
return r.output;
}
struct hashmap *find_blocks_in_ast(mpc_ast_t *node, struct hashmap *map) {
if (strstr(node->tag, "content|statement|block")) {
char *name = node->children[2]->contents;
hashmap_insert(map, name, node);
}
for (int i=0; i < node->children_num; i++) {
find_blocks_in_ast(node->children[i], map);
}
}
struct env *env_new(char *dirname) {
DIR *dr = opendir(dirname);
if (dr == NULL) {
err(EXIT_FAILURE, "could not open directory %s", dirname);
}
struct env *env = malloc(sizeof *env);
env->templates = hashmap_new();
chdir(dirname);
struct dirent *de;
while ((de = readdir(dr)) != NULL) {
// skip files starting with a dot
if (de->d_name[0] == '.') {
continue;
}
char *name = de->d_name;
char *tmpl = read_file(name);
mpc_ast_t *ast = parse(tmpl);
struct template *t = malloc(sizeof *t);
t->ast = ast;
t->name = name;
t->blocks = find_blocks_in_ast(ast, hashmap_new());
t->parent = NULL;
if (ast->children_num > 1 && ast->children[1]->children_num > 0 && strstr(ast->children[1]->children[0]->tag, "content|statement|extends")) {
t->parent = ast->children[1]->children[0]->children[2]->children[1]->contents;
}
hashmap_insert(env->templates, name, t);
}
closedir(dr);
return env;
}
void env_free(struct env *env) {
// TODO: Free template strings
free(env);
}
char *read_file(char *filename) {
char *input = malloc(BUFSIZ);
unsigned int size = 0;
FILE *f = fopen(filename, "r");
if (!f) {
err(EXIT_FAILURE, "Could not open \"%s\" for reading", filename);
}
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;
}
struct unja_object *make_string_object(char *value, char *value2) {
struct unja_object *obj = malloc(sizeof *obj);
obj->type = OBJ_STRING;
int l = strlen(value) + 1;
if (value2) {
l += strlen(value2);
}
obj->string = malloc(l);
strcpy(obj->string, value);
if(value2) {
strcat(obj->string, value2);
}
return obj;
}
struct unja_object *make_int_object(int value) {
struct unja_object *obj = malloc(sizeof *obj);
obj->type = OBJ_INT;
obj->integer = value;
return obj;
}
void eval_object(struct buffer *buf, struct unja_object *obj) {
char tmp[64];
switch (obj->type) {
case OBJ_NULL:
break;
case OBJ_STRING:
buffer_reserve(buf, strlen(obj->string));
strcat(buf->string, obj->string);
break;
case OBJ_INT:
sprintf(tmp, "%d", obj->integer);
buffer_reserve(buf, strlen(tmp));
strcat(buf->string, tmp);
break;
}
}
int object_to_int(struct unja_object *obj) {
switch (obj->type) {
case OBJ_NULL: return 0;
case OBJ_STRING: return atoi(obj->string);
case OBJ_INT: return obj->integer;
}
return 0;
}
void object_free(struct unja_object *obj) {
switch(obj->type) {
case OBJ_NULL: return;
case OBJ_STRING:
free(obj->string);
break;
case OBJ_INT: break;
}
free(obj);
}
int object_is_truthy(struct unja_object *obj) {
switch (obj->type) {
case OBJ_NULL: return 0;
case OBJ_STRING: return strlen(obj->string) > 0;
case OBJ_INT: return obj->integer > 0;
}
return 0;
}
struct unja_object *eval_expression_value(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 &null_object;
}
char *key = node->contents;
char *value = hashmap_resolve(ctx, key);
/* TODO: Handle unexisting symbols (returns NULL currently) */
if (value == NULL) {
return &null_object;
}
return make_string_object(value, NULL);
} else if(strstr(node->tag, "number|")) {
return make_int_object(atoi(node->contents));
} else if(strstr(node->tag, "string|")) {
return make_string_object(node->children[1]->contents, NULL);
}
return &null_object;
}
struct unja_object *eval_expression(mpc_ast_t* expr, struct hashmap *ctx) {
if (expr->children_num >= 2 && strstr(expr->children[1]->tag, "op")) {
mpc_ast_t *left_node = expr->children[0];
mpc_ast_t *op = expr->children[1];
mpc_ast_t *right_node = expr->children[2];
struct unja_object *left = eval_expression_value(left_node, ctx);
struct unja_object *right = eval_expression_value(right_node, ctx);
/* if operator is + and either left or right node is of type string: concat */
if (op->contents[0] == '+' && (left->type == OBJ_STRING && right->type == OBJ_STRING)) {
struct unja_object *result = make_string_object(left->string, right->string);
object_free(left);
object_free(right);
return result;
}
/* eval int infix expression */
int result;
switch (op->contents[0]) {
case '+': result = object_to_int(left) + object_to_int(right); break;
case '-': result = object_to_int(left) - object_to_int(right); break;
case '/': result = object_to_int(left) / object_to_int(right); break;
case '*': result = object_to_int(left) * object_to_int(right); break;
case '>': result = object_to_int(left) > object_to_int(right); break;
case '<': result = object_to_int(left) < object_to_int(right); break;
}
object_free(left);
object_free(right);
return make_int_object(result);
}
mpc_ast_t *left_node = expr;
return eval_expression_value(left_node, ctx);
}
int eval(struct buffer *buf, mpc_ast_t* t, struct hashmap *ctx) {
static int trim_whitespace = 0;
if (strstr(t->tag, "content|statement|extends")) {
char *template_name = t->children[2]->children[1]->contents;
// TODO: Render given template instead
// but replace blocks with blocks in current template
return 0;
}
if (strstr(t->tag, "content|statement|block")) {
char *block_name = t->children[2]->contents;
return eval(buf, t->children[4], ctx);
}
// eval print statement
if (strstr(t->tag, "content|print")) {
// maybe eat whitespace going backward
if (strstr(t->children[1]->contents, "-")) {
buf->string = trim_trailing_whitespace(buf->string);
}
/* set flag for next eval() to trim leading whitespace from text */
if (strstr(t->children[3]->contents, "-")) {
trim_whitespace = 1;
}
mpc_ast_t *expr = t->children[2];
struct unja_object *obj = eval_expression(expr, ctx);
eval_object(buf, obj);
object_free(obj);
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(buf, t->children[6], ctx);
}
return 0;
}
if (strstr(t->tag, "content|statement|if")) {
mpc_ast_t *expr = t->children[2];
struct unja_object *result = eval_expression(expr, ctx);
if (object_is_truthy(result)) {
eval(buf, t->children[4], ctx);
} else {
if (t->children_num > 8) {
eval(buf, t->children[8], ctx);
}
}
object_free(result);
return 0;
}
if (strstr(t->tag, "content|text")) {
char *str = t->contents;
if (trim_whitespace) {
str = trim_leading_whitespace(str);
trim_whitespace = 0;
}
buffer_reserve(buf, strlen(str));
strcat(buf->string, str);
return 0;
}
for (int i=0; i < t->children_num; i++) {
eval(buf, t->children[i], ctx);
}
return 0;
}
char *render_ast(mpc_ast_t *ast, struct hashmap *ctx) {
#if DEBUG
printf("AST: \n");
mpc_ast_print(ast);
printf("\n");
#endif
struct buffer buf;
buf.size = 0;
buf.cap = 256;
buf.string = malloc(buf.cap);
buf.string[0] = '\0';
eval(&buf, ast, ctx);
return buf.string;
}
char *template_string(char *tmpl, struct hashmap *ctx) {
#if DEBUG
printf("Template: %s\n", tmpl);
#endif
mpc_ast_t *ast = parse(tmpl);
char *output = render_ast(ast, ctx);
mpc_ast_delete(ast);
return output;
}
char *template(struct env *env, char *template_name, struct hashmap *ctx) {
struct template *t = hashmap_get(env->templates, template_name);
#if DEBUG
printf("Template name: %s\n", t->name);
printf("Parent: %s\n", t->parent ? t->parent : "None");
#endif
return render_ast(t->ast, ctx);
}
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