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|
#include <stdio.h>
#include <stdlib.h>
#include <err.h>
#include <unistd.h>
#include <dirent.h>
#include <string.h>
#include <assert.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;
char *string_ptr;
};
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) {
errx(EXIT_FAILURE, "out of memory");
}
}
}
mpc_parser_t *parser_init() {
static mpc_parser_t *template;
if (template != NULL) {
return template;
}
mpc_parser_t *spaces = mpc_new("spaces");
mpc_parser_t *symbol = mpc_new("symbol");
mpc_parser_t *number = mpc_new("number");
mpc_parser_t *string = mpc_new("string");
mpc_parser_t *text = mpc_new("text");
mpc_parser_t *print = mpc_new("print");
mpc_parser_t *lexp = mpc_new("lexp");
mpc_parser_t *exp = 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 *factor = mpc_new("factor");
mpc_parser_t *term = mpc_new("term");
mpc_parser_t *filter = mpc_new("filter");
template = mpc_new("template");
mpca_lang(MPCA_LANG_WHITESPACE_SENSITIVE,
" spaces : / */ ;"
" symbol : /[a-zA-Z][a-zA-Z0-9_.]*/ ;"
" number : /[0-9]+/ ;"
" text : /[^{][^{%#]*/;"
" string : '\"' /([^\"])*/ '\"' ;"
" factor : <symbol> | <number> | <string> ;"
" filter : <spaces> '|' <spaces> <symbol>; "
" term : <factor> (<spaces> ('*' | '/' | '%') <spaces> <factor>)* <filter>?;"
" lexp : <term> (<spaces> ('+' | '-') <spaces> <term>)* ;"
" expression: <lexp> <spaces> '>' <spaces> <lexp> "
" | <lexp> <spaces> '<' <spaces> <lexp> "
" | <lexp> <spaces> \">=\" <spaces> <lexp> "
" | <lexp> <spaces> \"<=\" <spaces> <lexp> "
" | <lexp> <spaces> \"!=\" <spaces> <lexp> "
" | <lexp> <spaces> \"==\" <spaces> <lexp> "
" | \"not\" <spaces> <lexp> "
" | <lexp> ;"
" print : /{{2}-? */ <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> /$/ ;",
spaces,
filter,
factor,
term,
symbol,
text,
number,
string,
print,
lexp,
exp,
comment,
statement_open,
statement_close,
statement,
statement_if,
statement_for,
statement_block,
statement_extends,
content,
body,
template);
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)) {
puts(tmpl);
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);
}
return map;
}
struct env *env_new(char *dirname) {
/* store current working dir so we can revert to it after reading templates */
char working_dir[256];
getcwd(working_dir, 255);
DIR *dr = opendir(dirname);
if (dr == NULL) {
errx(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;
}
// copy template name as closedir free's it otherwise
char *name = malloc(strlen(de->d_name) + 1);
strcpy(name, de->d_name);
char *tmpl = read_file(name);
#if DEBUG
printf("Parsing template from file %s: %s\n", name, tmpl);
#endif
mpc_ast_t *ast = parse(tmpl);
free(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);
chdir(working_dir);
return env;
}
void template_free(void *v) {
struct template *t = (struct template *)v;
hashmap_free(t->blocks);
mpc_ast_delete(t->ast);
free(t->name);
free(t);
}
void env_free(struct env *env) {
hashmap_walk(env->templates, template_free);
hashmap_free(env->templates);
free(env);
}
char *read_file(char *filename) {
char *input = malloc(BUFSIZ);
unsigned int size = 0;
FILE *f = fopen(filename, "r");
if (!f) {
errx(EXIT_FAILURE, "could not open \"%s\" for reading", filename);
}
unsigned int read = 0;
while ( (read = fread(input + read, 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; i >= 0 && 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);
obj->string_ptr = obj->string;
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_ptr);
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 && strcmp(obj->string, "0") != 0;
case OBJ_INT: return obj->integer > 0;
}
return 0;
}
struct context {
struct hashmap *vars;
struct hashmap *filters;
struct env *env;
struct template *current_template;
};
struct unja_object *eval_expression_value(mpc_ast_t* node, struct context *ctx) {
if (strstr(node->tag, "symbol|")) {
/* Return empty string if no vars were passed. Should probably signal error here. */
if (ctx->vars == NULL) {
return &null_object;
}
char *key = node->contents;
char *value = hashmap_resolve(ctx->vars, 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_string_infix_expression(struct unja_object *left, char *op, struct unja_object *right) {
struct unja_object *result;
if (strcmp(op, "+") == 0) {
result = make_string_object(left->string, right->string);
} else if (strcmp(op, "==") == 0) {
result = make_int_object(strcmp(left->string, right->string) == 0);
} else if(strcmp(op, "!=") == 0) {
result = make_int_object(strcmp(left->string, right->string) != 0);
} else {
errx(EXIT_FAILURE, "invalid string operator: %s", op);
}
object_free(left);
object_free(right);
return result;
}
struct unja_object *eval_infix_expression(struct unja_object *left, char *op, struct unja_object *right) {
/* if operator is + and either left or right node is of type string: concat */
if (left->type == OBJ_STRING && right->type == OBJ_STRING) {
return eval_string_infix_expression(left, op, right);
}
int result;
switch (op[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 '>':
if (op[1] == '=') {
result = object_to_int(left) >= object_to_int(right);
} else {
result = object_to_int(left) > object_to_int(right);
}
break;
case '<':
if (op[1] == '=') {
result = object_to_int(left) <= object_to_int(right);
} else {
result = object_to_int(left) < object_to_int(right);
}
break;
case '!':
if (op[1] == '=') {
result = object_to_int(left) != object_to_int(right);
} else {
errx(EXIT_FAILURE, "invalid int operator: %s", op);
}
break;
case '=':
if (op[1] == '=') {
result = object_to_int(left) == object_to_int(right);
} else {
errx(EXIT_FAILURE, "invalid int operator: %s", op);
}
break;
}
object_free(left);
object_free(right);
return make_int_object(result);
}
struct unja_object *eval_expression(mpc_ast_t* expr, struct context *ctx) {
/* singular term */
if (expr->children_num == 0 || strstr(expr->tag, "string|")) {
return eval_expression_value(expr, ctx);
}
struct unja_object *result;
/* singular negated term */
if (strcmp(expr->children[0]->contents, "not") == 0) {
result = eval_expression_value(expr->children[2], ctx);
struct unja_object *negated = make_int_object(!object_to_int(result));
object_free(result);
return negated;
}
/* otherwise: with operator */
unsigned int offset = 0;
mpc_ast_t *left_node = expr->children[0];
struct unja_object *left = eval_expression(left_node, ctx);
result = left;
while (offset < (expr->children_num - 1)) {
/* Check if we arrived at a filter (guaranteed to be last in expression list) */
if (strstr(expr->children[offset+1]->tag, "filter")) {
char *filter_name = expr->children[offset+1]->children[3]->contents;
struct unja_object *(*filter_fn)(struct unja_object *) = hashmap_get(ctx->filters, filter_name);
if (NULL == filter_fn) {
errx(EXIT_FAILURE, "unknown filter: %s", filter_name);
}
result = filter_fn(result);
break;
}
mpc_ast_t *op = expr->children[offset+2];
mpc_ast_t *right_node = expr->children[offset+4];
struct unja_object *right = eval_expression(right_node, ctx);
result = eval_infix_expression(left, op->contents, right);
left = result;
offset += 4;
}
return result;
}
int eval(struct buffer *buf, mpc_ast_t* t, struct context *ctx) {
static int trim_whitespace = 0;
// maybe eat whitespace going backward
if (t->children_num > 0 && strstr(t->children[0]->contents, "-")) {
buf->string = trim_trailing_whitespace(buf->string);
}
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;
}
if (strstr(t->tag, "content|statement|block")) {
trim_whitespace = strstr(t->children[3]->contents, "-") ? 1 : 0;
char *block_name = t->children[2]->contents;
// find block in "lowest" template
struct template *templ = ctx->current_template;
mpc_ast_t *block = hashmap_get(templ->blocks, block_name);
while (templ != NULL && block == NULL) {
templ = hashmap_get(ctx->env->templates, templ->parent);
block = hashmap_get(templ->blocks, block_name);
}
if (block) {
eval(buf, block->children[4], ctx);
} else {
/* block not found in any lower template, so just render the one we got */
eval(buf, t->children[4], ctx);
}
trim_whitespace = strstr(t->children[7]->contents, "-") ? 1 : 0;
return 0;
}
// eval print statement
if (strstr(t->tag, "content|print")) {
trim_whitespace = strstr(t->children[2]->contents, "-") ? 1 : 0;
mpc_ast_t *expr = t->children[1];
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->vars, iterator_key);
/* add "loop" variable to context */
struct hashmap *loop = hashmap_new();
char index[8], first[2], last[2];
hashmap_insert(loop, "index", index);
hashmap_insert(loop, "first", first);
hashmap_insert(loop, "last", last);
hashmap_insert(ctx->vars, "loop", loop);
/* loop over values in vector */
for (int i=0; i < list->size; i++) {
/* set loop variable values */
sprintf(index, "%d", i);
sprintf(first, "%d", i == 0);
sprintf(last, "%d", i == (list->size - 1));
hashmap_insert(ctx->vars, tmp_key, list->values[i]);
trim_whitespace = strstr(t->children[5]->contents, "-") ? 1 : 0;
/* evaluate body */
eval(buf, t->children[6], ctx);
}
/* remove "loop" variable from context */
hashmap_remove(ctx->vars, "loop");
hashmap_free(loop);
/* trim trailing whitespace if closing tag has minus sign */
if (strstr(t->children[7]->contents, "-")) {
buf->string = trim_trailing_whitespace(buf->string);
}
trim_whitespace = strstr(t->children[9]->contents, "-") ? 1 : 0;
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)) {
trim_whitespace = strstr(t->children[3]->contents, "-") ? 1 : 0;
eval(buf, t->children[4], ctx);
/* trim trailing whitespace if closing tag has minus sign */
if (strstr(t->children[5]->contents, "-")) {
buf->string = trim_trailing_whitespace(buf->string);
}
trim_whitespace = strstr(t->children[7]->contents, "-") ? 1 : 0;
} else {
if (t->children_num > 8) {
trim_whitespace = strstr(t->children[7]->contents, "-") ? 1 : 0;
eval(buf, t->children[8], ctx);
/* trim trailing whitespace if closing tag has minus sign */
if (strstr(t->children[9]->contents, "-")) {
buf->string = trim_trailing_whitespace(buf->string);
}
trim_whitespace = strstr(t->children[11]->contents, "-") ? 1 : 0;
}
}
object_free(result);
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 context *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;
}
struct unja_object *filter_trim(struct unja_object *obj) {
assert(obj->type == OBJ_STRING);
obj->string = trim_leading_whitespace(obj->string);
trim_trailing_whitespace(obj->string);
return obj;
}
struct unja_object *filter_lower(struct unja_object *obj) {
assert(obj->type == OBJ_STRING);
int len = strlen(obj->string);
for (int i=0; i < len; i++) {
obj->string[i] = tolower(obj->string[i]);
}
return obj;
}
struct unja_object *filter_wordcount(struct unja_object *obj) {
assert(obj->type == OBJ_STRING);
int len = strlen(obj->string);
int word_count = 1;
for (int i=0; i < len; i++) {
if (isspace(obj->string[i])) {
word_count++;
}
}
object_free(obj);
return make_int_object(word_count);
}
struct unja_object *filter_length(struct unja_object *obj) {
assert(obj->type == OBJ_STRING);
int len = strlen(obj->string);
object_free(obj);
return make_int_object(len);
}
struct hashmap *default_filters() {
struct hashmap *filters = hashmap_new();
hashmap_insert(filters, "trim", filter_trim);
hashmap_insert(filters, "lower", filter_lower);
hashmap_insert(filters, "wordcount", filter_wordcount);
hashmap_insert(filters, "length", filter_length);
return filters;
}
struct context context_new(struct hashmap *vars, struct env *env, struct template *current_tmpl) {
struct context ctx;
ctx.filters = default_filters();
ctx.vars = vars;
ctx.env = env;
ctx.current_template = current_tmpl;
return ctx;
}
void context_free(struct context ctx) {
hashmap_free(ctx.filters);
}
char *template_string(char *tmpl, struct hashmap *vars) {
#if DEBUG
printf("Template: %s\n", tmpl);
#endif
struct mpc_ast_t *ast = parse(tmpl);
struct context ctx = context_new(vars, NULL, NULL);
char *output = render_ast(ast, &ctx);
mpc_ast_delete(ast);
context_free(ctx);
return output;
}
char *template(struct env *env, char *template_name, struct hashmap *vars) {
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
struct context ctx = context_new(vars, env, t);
// find root template
while (t->parent != NULL) {
char *parent_name = t->parent;
t = hashmap_get(env->templates, parent_name);
if (t == NULL) {
errx(EXIT_FAILURE, "template tried to extend unexisting parent \"%s\"", parent_name);
break;
}
}
char *output = render_ast(t->ast, &ctx);
context_free(ctx);
return output;
}
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