feat(ltm): initial full template compiler/parser

ltm/src/_include/ltm/template_internal.h

@@ -37,11 +37,10 @@ typedef enum ltm_template_block_type {
  */
 typedef struct ltm_template_block {
   ltm_template_block_type type;
-  union {
+  struct {
-    ltm_template *template;
+    void *ptr;
-    const char *s;
-  } data;
     size_t len;
+  } data;
 } ltm_template_block;
 
 typedef struct ltm_template_block_name {
@@ -69,4 +68,11 @@ struct ltm_template {
 
 ltm_err ltm_template_init(ltm_template **out);
 
+ltm_err ltm_template_name_append(ltm_template *template, const char *s,
+                                 size_t len, size_t index);
+
+ltm_err ltm_template_block_append(ltm_template *template,
+                                  ltm_template_block_type type, void *data,
+                                  size_t len);
+
 #endif

ltm/src/ltm_template.c

@@ -0,0 +1,69 @@
+#include "ltm/template.h"
+#include "ltm/template_internal.h"
+
+ltm_err ltm_template_init(ltm_template **out) {
+  ltm_template *template = calloc(1, sizeof(ltm_template));
+
+  if (template == NULL) {
+    return ltm_err_failed_alloc;
+  }
+
+  *out = template;
+
+  return ltm_err_ok;
+}
+
+ltm_err ltm_template_name_append(ltm_template *template, const char *s,
+                                 size_t len, size_t index) {
+  ltm_template_block_name *names =
+      realloc(template->names.arr,
+              (template->names.len + 1) * sizeof(ltm_template_block_name));
+
+  if (names == NULL) {
+    return ltm_err_failed_alloc;
+  }
+
+  ltm_template_block_name *name = &names[template->names.len];
+
+  name->name.s = s;
+  name->name.len = len;
+  name->index = index;
+
+  template->names.arr = names;
+  template->names.len++;
+
+  return ltm_err_ok;
+}
+
+ltm_err ltm_template_block_append(ltm_template *template,
+                                  ltm_template_block_type type, void *data,
+                                  size_t len) {
+  ltm_template_block *blocks =
+      realloc(template->blocks.arr,
+              (template->blocks.len + 1) * sizeof(ltm_template_block));
+
+  if (blocks == NULL) {
+    return ltm_err_failed_alloc;
+  }
+
+  ltm_template_block *block = &blocks[template->blocks.len];
+
+  block->type = type;
+
+  switch (type) {
+  case ltm_template_block_type_literal:
+    block->data.ptr = data;
+    block->data.len = len;
+    break;
+  case ltm_template_block_type_loop:
+    block->data.ptr = data;
+    break;
+  // For the other cases, we explicitely ignore the data and len arguments
+  default:;
+  }
+
+  template->blocks.arr = blocks;
+  template->blocks.len++;
+
+  return ltm_err_ok;
+}

ltm/src/ltm_template_compile.c

@@ -6,19 +6,7 @@
 #include "ltm/template.h"
 #include "ltm/template_internal.h"
 
-ltm_err ltm_template_init(ltm_template **out) {
+static bool ltm_template_next_placeholder(ltm_placeholder *ph, const char *s,
-  ltm_template *template = calloc(1, sizeof(ltm_template));
-
-  if (template == NULL) {
-    return ltm_err_failed_alloc;
-  }
-
-  *out = template;
-
-  return ltm_err_ok;
-}
-
-bool ltm_template_next_placeholder(ltm_placeholder *ph, const char *s,
                                           size_t len) {
   if (len == 0) {
     return false;
@@ -26,9 +14,19 @@ bool ltm_template_next_placeholder(ltm_placeholder *ph, const char *s,
 
   ph->start = memchr(s, '{', len - 1);
 
-  if ((ph->start != NULL) && (ph->start[1] == '{')) {
+  if ((ph->start == NULL) || (ph->start[1] != '{')) {
+    return false;
+  }
+
   size_t new_len = len - (ph->start - s);
 
+  // A template can never be valid without at least 5 characters
+  if (new_len < 5) {
+    ph->type = ltm_placeholder_type_invalid;
+
+    return true;
+  }
+
   ph->end = memchr(ph->start + 2, '}', new_len - 3);
 
   // Non-terminated placeholders aren't valid
@@ -63,6 +61,7 @@ bool ltm_template_next_placeholder(ltm_placeholder *ph, const char *s,
 
   ph->name.len = ident - ph->name.s;
 
+  // Skip whitespace over to next word
   while ((*ident == ' ') && (ident != ph->end - 1)) {
     ident++;
   }
@@ -79,7 +78,7 @@ bool ltm_template_next_placeholder(ltm_placeholder *ph, const char *s,
 
     size_t ident_len = temp - ident;
 
-      if (strncmp("loop", ident, ident_len) == 0) {
+    if (strncmp("start", ident, ident_len) == 0) {
       ph->type = ltm_placeholder_type_loop_start;
     } else if (strncmp("end", ident, ident_len) == 0) {
       ph->type = ltm_placeholder_type_loop_end;
@@ -91,79 +90,48 @@ bool ltm_template_next_placeholder(ltm_placeholder *ph, const char *s,
   return true;
 }
 
-  return false;
-}
-
 ltm_err ltm_template_compile_n(ltm_template **out, const char *s, size_t len) {
   ltm_template *template;
   LTM_RES(ltm_template_init(&template));
 
   ltm_placeholder ph;
   bool in_loop = false;
-  const char *loop_start = NULL;
+  const char *loop_start = NULL, *loop_name = NULL;
-  size_t loop_depth = 0;
+  size_t loop_depth = 0, loop_name_len = 0;
 
   size_t cur_loop_depth = 0;
 
   while (ltm_template_next_placeholder(&ph, s, len)) {
     // Add part before placeholder as literal
     if (!in_loop && (ph.start != s)) {
-      ltm_template_block *blocks =
+      LTM_RES(ltm_template_block_append(
-          realloc(template->blocks.arr,
+          template, ltm_template_block_type_literal, (void *)s, ph.start - s));
-                  (template->blocks.len + 1) * sizeof(ltm_template_block));
-
-      if (blocks == NULL) {
-        return ltm_err_failed_alloc;
-      }
-
-      blocks[template->blocks.len].type = ltm_template_block_type_literal;
-      blocks[template->blocks.len].data.s = s;
-      blocks[template->blocks.len].len = ph.start - s;
-
-      template->blocks.arr = blocks;
-      template->blocks.len++;
     }
 
     switch (ph.type) {
+    // Invalid placeholders can be detected as early as possible
     case ltm_placeholder_type_invalid:
       return ltm_err_invalid_template;
-    case ltm_placeholder_type_var: {
+    case ltm_placeholder_type_var:
-      ltm_template_block *blocks =
+      if (!in_loop) {
-          realloc(template->blocks.arr,
+        LTM_RES(ltm_template_block_append(template, ltm_template_block_type_var,
-                  (template->blocks.len + 1) * sizeof(ltm_template_block));
+                                          NULL, 0));
-
+        LTM_RES(ltm_template_name_append(template, ph.name.s, ph.name.len,
-      if (blocks == NULL) {
+                                         template->blocks.len - 1));
-        return ltm_err_failed_alloc;
       }
-
+      break;
-      blocks[template->blocks.len].type = ltm_template_block_type_var;
-      template->blocks.arr = blocks;
-
-      ltm_template_block_name *names =
-          realloc(template->names.arr,
-                  (template->names.len + 1) * sizeof(ltm_template_block_name));
-
-      if (names == NULL) {
-        return ltm_err_failed_alloc;
-      }
-
-      names[template->names.len].name.s = ph.name.s;
-      names[template->names.len].name.len = ph.name.len;
-      names[template->names.len].index = template->blocks.len;
-      template->names.arr = names;
-
-      template->blocks.len++;
-      template->names.len++;
-    } break;
     case ltm_placeholder_type_loop_start:
       if (!in_loop) {
         loop_start = ph.end + 1;
-        in_loop = true;
         loop_depth = cur_loop_depth;
+        loop_name = ph.name.s;
+        loop_name_len = ph.name.len;
+        in_loop = true;
       }
       cur_loop_depth++;
       break;
     case ltm_placeholder_type_loop_end:
+      // This means there's more loop end placeholders than loop starts
       if (cur_loop_depth == 0) {
         return ltm_err_invalid_template;
       }
@@ -171,13 +139,18 @@ ltm_err ltm_template_compile_n(ltm_template **out, const char *s, size_t len) {
       cur_loop_depth--;
 
       if (in_loop && (cur_loop_depth == loop_depth)) {
-        size_t loop_len = ph.end - loop_start;
+        size_t loop_len = ph.start - loop_start;
-        // TODO recursive call to compile
+        ltm_template *loop_template;
+        LTM_RES(ltm_template_compile_n(&loop_template, loop_start, loop_len));
+        LTM_RES(ltm_template_block_append(
+            template, ltm_template_block_type_loop, loop_template, 0));
+        LTM_RES(ltm_template_name_append(template, loop_name, loop_name_len,
+                                         template->blocks.len - 1));
 
         in_loop = false;
       }
       // We encountered a loop end without a start
-      else {
+      else if (!in_loop) {
         return ltm_err_invalid_template;
       }
       break;
@@ -194,20 +167,8 @@ ltm_err ltm_template_compile_n(ltm_template **out, const char *s, size_t len) {
 
   // Add remaining trailing literal
   if (len > 0) {
-    ltm_template_block *blocks =
+    LTM_RES(ltm_template_block_append(template, ltm_template_block_type_literal,
-        realloc(template->blocks.arr,
+                                      (void *)s, len));
-                (template->blocks.len + 1) * sizeof(ltm_template_block));
-
-    if (blocks == NULL) {
-      return ltm_err_failed_alloc;
-    }
-
-    blocks[template->blocks.len].type = ltm_template_block_type_literal;
-    blocks[template->blocks.len].data.s = s;
-    blocks[template->blocks.len].len = len;
-
-    template->blocks.arr = blocks;
-    template->blocks.len++;
   }
 
   *out = template;

ltm/test/compile.c

@@ -1,3 +1,4 @@
+#include "ltm/common.h"
 #include "test.h"
 
 #include "ltm/template.h"
@@ -12,8 +13,8 @@ void test_single_placeholder() {
   TEST_CHECK(template->blocks.len == 2);
 
   TEST_CHECK(template->blocks.arr[0].type == ltm_template_block_type_literal);
-  TEST_CHECK(template->blocks.arr[0].data.s == s);
+  TEST_CHECK(template->blocks.arr[0].data.ptr == s);
-  TEST_CHECK(template->blocks.arr[0].len == 7);
+  TEST_CHECK(template->blocks.arr[0].data.len == 7);
 
   TEST_CHECK(template->blocks.arr[1].type == ltm_template_block_type_var);
 
@@ -33,14 +34,14 @@ void test_single_placeholder_trailing() {
   TEST_CHECK(template->blocks.len == 3);
 
   TEST_CHECK(template->blocks.arr[0].type == ltm_template_block_type_literal);
-  TEST_CHECK(template->blocks.arr[0].data.s == s);
+  TEST_CHECK(template->blocks.arr[0].data.ptr == s);
-  TEST_CHECK(template->blocks.arr[0].len == 7);
+  TEST_CHECK(template->blocks.arr[0].data.len == 7);
 
   TEST_CHECK(template->blocks.arr[1].type == ltm_template_block_type_var);
 
   TEST_CHECK(template->blocks.arr[2].type == ltm_template_block_type_literal);
-  TEST_CHECK(template->blocks.arr[2].data.s == s + 18);
+  TEST_CHECK(template->blocks.arr[2].data.ptr == s + 18);
-  TEST_CHECK(template->blocks.arr[2].len == 1);
+  TEST_CHECK(template->blocks.arr[2].data.len == 1);
 
   TEST_CHECK(template->names.len == 1);
 
@@ -49,8 +50,63 @@ void test_single_placeholder_trailing() {
   TEST_CHECK(template->names.arr[0].index == 1);
 }
 
+void test_single_loop() {
+  const char *s = "abc {{ l start }}some content {{ var }} {{ l end }}";
+
+  ltm_template *template;
+  TEST_CHECK(ltm_template_compile(&template, s) == ltm_err_ok);
+
+  TEST_CHECK(template->names.len == 1);
+  TEST_CHECK(template->names.arr[0].name.s == s + 7);
+  TEST_CHECK(template->names.arr[0].name.len == 1);
+  TEST_CHECK(template->names.arr[0].index == 1);
+
+  TEST_CHECK(template->blocks.len == 2);
+
+  TEST_CHECK(template->blocks.arr[0].type == ltm_template_block_type_literal);
+  TEST_CHECK(template->blocks.arr[0].data.ptr == s);
+  TEST_CHECK(template->blocks.arr[0].data.len == 4);
+
+  TEST_CHECK(template->blocks.arr[1].type == ltm_template_block_type_loop);
+  ltm_template *loop_template = template->blocks.arr[1].data.ptr;
+
+  TEST_CHECK(loop_template->blocks.len == 3);
+  TEST_CHECK(loop_template->blocks.arr[0].type == ltm_template_block_type_literal);
+  TEST_CHECK(loop_template->blocks.arr[0].data.ptr == s + 17);
+  TEST_CHECK(loop_template->blocks.arr[0].data.len == 13);
+  TEST_CHECK(loop_template->blocks.arr[1].type == ltm_template_block_type_var);
+  TEST_CHECK(loop_template->blocks.arr[2].type == ltm_template_block_type_literal);
+  TEST_CHECK(loop_template->blocks.arr[2].data.ptr == s + 39);
+  TEST_CHECK(loop_template->blocks.arr[2].data.len == 1);
+
+  TEST_CHECK(loop_template->names.len == 1);
+  TEST_CHECK(loop_template->names.arr[0].name.s == s + 33);
+  TEST_CHECK(loop_template->names.arr[0].name.len == 3);
+  TEST_CHECK(loop_template->names.arr[0].index == 1);
+}
+
+void test_unclosed_placeholder() {
+  ltm_template *template;
+
+  const char *s = "abc {{ var }";
+  TEST_CHECK(ltm_template_compile(&template, s) == ltm_err_invalid_template);
+
+  s = "abc {{ var ";
+  TEST_CHECK(ltm_template_compile(&template, s) == ltm_err_invalid_template);
+}
+
+void test_unclosed_loop() {
+  ltm_template *template;
+
+  const char *s = "abc {{ var start }} {{ hello }}";
+  TEST_CHECK(ltm_template_compile(&template, s) == ltm_err_invalid_template);
+}
+
 TEST_LIST = {
   { "template single placeholder", test_single_placeholder },
   { "template single placeholder trailing", test_single_placeholder_trailing },
+  { "template single loop", test_single_loop },
+  { "template unclosed placeholder", test_unclosed_placeholder },
+  { "template unclosed loop", test_unclosed_loop },
   { NULL, NULL }
 };