From 460d4f4259153ff3fffb2618c4e5e385b5b29f24 Mon Sep 17 00:00:00 2001
From: lquint <leo.quintrand@gmail.com>
Date: Fri, 6 Aug 2021 01:39:54 +0200
Subject: [PATCH] adding new files

---
 peg-engine.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++
 peg-nodes.h  |  44 +++++++++++++++++++++
 2 files changed, 150 insertions(+)
 create mode 100644 peg-engine.c
 create mode 100644 peg-nodes.h

diff --git a/peg-engine.c b/peg-engine.c
new file mode 100644
index 0000000..0322f86
--- /dev/null
+++ b/peg-engine.c
@@ -0,0 +1,106 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+Node *_checktype(Node *object, enum op type)
+{
+    if (object->type == type) return object;
+    fprintf(stderr, "\naccesing type %i as if it were a %i\n", object->type, type);
+    exit(1);
+    return 0;
+}
+
+#define get(object, type, member)	(_checktype(object, type)->type.member)
+
+void setBit(char *bits, int n)
+{
+    bits[n/8] |= (1 << n%8);
+}
+
+int testBit(char *bits, int n)
+{
+    return bits[n/8] & (1 << n%8);
+}
+
+int execute(Node *node, InputBuffer *in)
+{
+    switch (node->type) {
+      case String: {
+	  if (strncmp(currentText(in), get(node,String,string), get(node,String,len))) {
+	      return 0;
+	  }
+	  advance(in, get(node,String,len));
+	  return 1;
+      }
+      case And: {
+	  int pos= getPosition(in);
+	  if (!execute(get(node,And,children[0]), in)) //si il y a eu une erreur
+	  {
+	      return 0;
+	  } //si ça s'est bien passé
+	  if (!execute(get(node,And,children[1]), in)) {
+	      setPosition(in, pos);
+	      return 0;
+	  }
+	  return 1;
+      }
+      case Or: {
+	  if (execute(get(node,Or,children[0]), in)) {
+	      return 1;
+	  }
+	  return execute(get(node,Or,children[1]), in);
+      }
+      case Star: {
+	  while (execute(get(node,Star,children[0]), in));
+	  return 1;
+      }
+      case Plus: {
+	  if (!execute(get(node,Plus,children[0]), in)) {
+	      return 0;
+	  }
+	  while (execute(get(node,Plus,children[0]), in));
+	  return 1;
+      }
+      case Class: {
+	  if (testBit(get(node,Class,array),currentChar(in))) {
+          advance(in, 1);
+	      return 1;
+	  }
+	  return 0;
+      }
+      case Query: {
+	  execute(get(node,Query,children[0]), in);
+	  return 1;
+      }
+      case Exc: {
+	  int pos= getPosition(in);
+	  if (!execute(get(node,Exc,children[0]), in)) {
+	      return 1;
+	  }
+	  setPosition(in, pos);
+	  return 0;
+      }
+      case Et: {
+	  int pos= getPosition(in);
+	  if (!execute(get(node,Et,children[0]), in)) {
+	      return 0;
+	  }
+	  setPosition(in, pos);
+	  return 1;
+      }
+      case Dot: {
+	  if (atEnd(in)) {
+	      return 0;
+	  }
+	  advance(in, 1);
+	  return 1;
+      }
+      case Id: {
+	  Symbol *symbol= get(node, Id, symbol);
+	  if (0 == symbol->rule) { printf("undefined rule: %s\n", symbol->name); }
+	  return execute(symbol->rule, in);
+      }
+    }
+    printf("this cannot happen\n");
+    abort();
+}
\ No newline at end of file
diff --git a/peg-nodes.h b/peg-nodes.h
new file mode 100644
index 0000000..4432da4
--- /dev/null
+++ b/peg-nodes.h
@@ -0,0 +1,44 @@
+enum op { String, Query, Star, Plus, Or, And, Class, Dot, Exc, Et, Id} ;
+
+
+typedef union Node Node;
+typedef struct Symbol Symbol;
+typedef struct SymbolTable SymbolTable;
+typedef struct NodeCount NodeCount;
+
+
+struct String  { enum op type;  char *string; int len; };
+struct Query   { enum op type;  Node *children[1]; };
+struct Star    { enum op type;  Node *children[1]; };
+struct Plus    { enum op type;  Node *children[1]; };
+struct Or      { enum op type;  Node *children[2]; };
+struct And     { enum op type;  Node *children[2]; };
+struct Class   { enum op type;  char *array; };
+struct Dot     { enum op type; };
+struct Exc     { enum op type;  Node *children[1]; };
+struct Et      { enum op type;  Node *children[1]; };
+struct Id      { enum op type; Symbol *symbol; };
+
+union Node {
+    enum op type;
+    struct String String;
+    struct Query Query;
+    struct Star Star;
+    struct Plus Plus;
+    struct Or Or;
+    struct And And;
+    struct Class Class;
+    struct Dot Dot;
+    struct Exc Exc;
+    struct Et Et;
+    struct Id Id;
+};
+
+struct Symbol{
+  char* name;
+  Node *rule;
+  int number;
+};
+
+
+