1 files changed, 152 insertions, 0 deletions
diff --git a/src/parser.c b/src/parser.c
new file mode 100644
index 0000000..855b94e
--- /dev/null
+++ b/src/parser.c
@@ -0,0 +1,152 @@
+#include "all.h"
+#include "ivec.h"
+#include "node_vec.h"
+#include <stdint.h>
+#include <stdlib.h>
+
+static inline lex_tok_e peek(parser_t *p) {
+  return iv_get(&p->lx->tokens, p->pos);
+}
+
+static inline lex_tok_e advance(parser_t *p) {
+  return iv_get(&p->lx->tokens, p->pos++);
+}
+
+static ast_node_t *new_node(ast_type_e type, int val) {
+  ast_node_t *n = malloc(sizeof(ast_node_t));
+  n->type = type;
+  n->val = val;
+  n->next = NULL;
+  n->children = (node_vec){0};
+  return n;
+}
+
+static ast_node_t *parse_block(parser_t *p);
+
+static ast_node_t *parse_single(parser_t *p) {
+  lex_tok_e t = peek(p);
+
+  switch (t) {
+
+  case LEX_PINC: {
+    int count = 0;
+    while (peek(p) == LEX_PINC) {
+      advance(p);
+      count++;
+    }
+    return new_node(AST_INC, count);
+  }
+
+  case LEX_PDEC: {
+    int count = 0;
+    while (peek(p) == LEX_PDEC) {
+      advance(p);
+      count++;
+    }
+    return new_node(AST_DEC, count);
+  }
+
+  case LEX_VINC: {
+    int count = 0;
+    while (peek(p) == LEX_VINC) {
+      advance(p);
+      count++;
+    }
+    return new_node(AST_PTR_INC, count);
+  }
+
+  case LEX_VDEC: {
+    int count = 0;
+    while (peek(p) == LEX_VDEC) {
+      advance(p);
+      count++;
+    }
+    return new_node(AST_PTR_DEC, count);
+  }
+
+  case LEX_OUT:
+    advance(p);
+    return new_node(AST_OUT, 1);
+
+  case LEX_IN:
+    advance(p);
+    return new_node(AST_IN, 1);
+
+  case LEX_LB:
+    advance(p); // consume '['
+    return parse_block(p);
+
+  case LEX_RB:
+    return NULL;
+
+  case LEX_EOF:
+    return NULL;
+
+  default:
+    advance(p);
+    return NULL;
+  }
+}
+
+static ast_node_t *parse_block(parser_t *p) {
+  ast_node_t *loop = new_node(AST_LOOP, 1);
+
+  while (1) {
+    lex_tok_e t = peek(p);
+
+    if (t == LEX_EOF) {
+      break;
+    }
+
+    if (t == LEX_RB) {
+      advance(p); // consume ']'
+      break;
+    }
+
+    ast_node_t *child = parse_single(p);
+    if (child) {
+      node_vec_push(&loop->children, child);
+    }
+  }
+
+  return loop;
+}
+
+parser_t parser_init(lexer_t *lx) { return (parser_t){.lx = lx, .pos = 0}; }
+
+ast_node_t *parse_program(parser_t *p) {
+  ast_node_t *head = NULL;
+  ast_node_t *tail = NULL;
+
+  while (peek(p) != LEX_EOF) {
+
+    ast_node_t *node = parse_single(p);
+    if (!node)
+      continue;
+
+    if (!head) {
+      head = tail = node;
+    } else {
+      tail->next = node;
+      tail = node;
+    }
+  }
+
+  return head;
+}
+
+void ast_free(ast_node_t *node) {
+  if (!node)
+    return;
+
+  if (node->next)
+    ast_free(node->next);
+
+  for (size_t i = 0; i < node->children.len; i++) {
+    ast_free(node->children._data[i]);
+  }
+
+  node_vec_free(&node->children);
+
+  free(node);
+}