Initial upload

lex.h

@@ -0,0 +1,55 @@
+/* vim: set filetype=c: */
+
+#ifndef _LEX_H_
+#define _LEX_H_
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include "token.h"
+#include "token_list.h"
+#include "ptr_stack.h"
+#include "error.h"
+
+#define LEX_MAX_CONTEXT_SIZE 256
+
+typedef struct Lex Lex;
+struct Lex {
+    /** Output **/
+    TokenList tokens;
+    /* Stats */
+    size_t out_written_total; /* Total number of tokens put out */
+    size_t out_read_total; /* Total number of read chars */
+
+    /** Internal **/
+    /* Stores a stack of pointers to LParen TokenListItems. Using this,
+     * we can always know where each paren's matching paren is located,
+     * which allows for a fast operator precedence implementation. */
+    PtrStack ptr_stack_;
+    /* Holds chars of text that haven't completely been lexed yet */
+    char context_[LEX_MAX_CONTEXT_SIZE];
+    size_t context_size_;
+};
+
+extern void Lex_init(Lex* obj);
+
+extern Result Lex_lex_char(Lex* obj, char in);
+
+extern Result Lex_finish_lex(Lex* obj);
+
+/* This function MUST be called exactly once for every operator , as it transforms the
+ * expression into a representation which allows for an easy creation of a tertiary tree.
+ * The order of calls to this function is what dictates the actual precedence.
+ * Usage: Call this function once for each operator precedence:
+ * opsym is a string with the operator characters to apply precedence to, for example "+-";
+ * right_to_left specifies the direction. For most math operators, this should be false, but
+ * for pow for example, it should be true.
+ * You should call this function for the operators with highest priority, i.e. pow first.
+ * An example setup would be:
+ * Lex_apply_op_precedence(&lex, "^", true);
+ * Lex_apply_op_precedence(&lex, "*:", false);
+ * Lex_apply_op_precedence(&lex, "+-", false); */
+extern Result Lex_apply_op_precedence(Lex* obj, const char* opsyms, bool right_to_left);
+
+extern void Lex_uninit(Lex* obj);
+
+#endif /* _LEX_H_ */