[ADD/WIP] Add corresponding source code for parser

src/Parser.c

@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2022-2023 Jordan Bancino <@jordan:bancino.net>
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <Parser.h>
+
+#include <Cytoplasm/Memory.h>
+#include <Cytoplasm/Str.h>
+
+#include <string.h>
+#include <sys/types.h>
+
+struct Parser {
+    char *string;
+    size_t idx;
+
+    ssize_t mark;
+
+    int eof;
+};
+
+Parser *
+ParserCreate(char * str)
+{
+    Parser * ret;
+    if (!str)
+    {
+        return NULL;
+    }
+
+    ret = Malloc(sizeof(Parser));
+
+    ret->string = StrDuplicate(str);
+    ret->idx = 0;
+    ret->eof = 0;
+    ret->mark = -1;
+
+    return ret;
+}
+
+void
+ParserStartCopy(Parser * p)
+{
+    if (!p)
+    {
+        return;
+    }
+    p->mark = p->idx;
+}
+char *
+ParserEndCopy(Parser * p)
+{
+    char *ret;
+    size_t len;
+    if (!p || p->mark >= 0)
+    {
+        return NULL;
+    }
+
+    len = p->idx - p->mark;
+
+    ret = Malloc(len + 1);
+    memcpy(ret, p->string + p->mark, len);
+    ret[len] = '\0';
+
+    return ret;
+}
+
+int
+ParserExcept(Parser * p, char c)
+{
+    char strc;
+    if (!p || p->eof)
+    {
+        return 0;
+    }
+
+    strc = p->string[p->idx++];
+    if (!strc)
+    {
+        p->eof = 1;
+        p->idx--; /* Avoid overflows */
+    }
+    return strc == c;
+}
+int
+ParserExceptOneOf(Parser * p, const char * str)
+{
+    char strc;
+    if (!p || !str || p->eof)
+    {
+        return 0;
+    }
+
+    strc = p->string[p->idx++];
+    if (!strc)
+    {
+        p->eof = 1;
+        p->idx--; /* Avoid overflows */
+    }
+    return !!strchr(str, strc);
+}
+
+void
+ParserEnd(Parser * p)
+{
+    if (!p)
+    {
+        return;
+    }
+    Free(p->string);
+    Free(p);
+}

src/include/Parser.h

@@ -52,6 +52,13 @@ extern Parser * ParserCreate(char *);
  */
 extern int ParserExcept(Parser *, char);
 
+/**
+ * Returns true if the character at the current position in 
+ * the parsing process is one of the characters in the inputted 
+ * string, and advances by one character eitherway.
+ */
+extern int ParserExceptOneOf(Parser *, const char *);
+
 /**
  * Starts a clipping session. This stores an index into the 
  * parser, until