1 files changed, 81 insertions, 0 deletions
diff --git a/lex.h b/lex.h
new file mode 100644
index 0000000..460636a
--- /dev/null
+++ b/lex.h
@@ -0,0 +1,81 @@
+#ifndef LEX_H
+#define LEX_H
+
+#include "str.h"
+
+#define LEX_TOK_LIST\
+	X(TOK_EOF, "end-of-file")\
+	X(TOK_IDENT, "identifier")\
+	X(TOK_PROC, "proc")\
+	X(TOK_LET, "let")\
+	X(TOK_VAR, "var")\
+	X(TOK_CONST, "const")\
+	X(TOK_RETURN, "return")\
+	X(TOK_LBRACE, "{")\
+	X(TOK_RBRACE, "}")\
+	X(TOK_LPAREN, "(")\
+	X(TOK_RPAREN, ")")\
+	X(TOK_PLUS, "+")\
+	X(TOK_MINUS, "-")\
+	X(TOK_ASTERISK, "*")\
+	X(TOK_SLASH, "/")\
+	X(TOK_EQUALS, "=")\
+	X(TOK_COLON, ":")\
+	X(TOK_COMMA, ",")\
+	X(TOK_LIT_STR, "string literal")\
+	X(TOK_LIT_CHAR, "character literal")\
+	X(TOK_LIT_NUM, "numeric literal")
+
+#define LEX_TOK_CHAR_LIST\
+	X(TOK_LBRACE, '{')\
+	X(TOK_RBRACE, '}')\
+	X(TOK_LPAREN, '(')\
+	X(TOK_RPAREN, ')')\
+	X(TOK_PLUS, '+')\
+	X(TOK_MINUS, '-')\
+	X(TOK_ASTERISK, '*')\
+	X(TOK_SLASH, '/')\
+	X(TOK_EQUALS, '=')\
+	X(TOK_COLON, ':')\
+	X(TOK_COMMA, ',')
+
+typedef enum {
+#define X(n, s) n,
+	LEX_TOK_LIST
+#undef X
+	TOK_MAX,
+} Token;
+
+static const char *lex_tok_str[TOK_MAX] = {
+#define X(n, s) s,
+	LEX_TOK_LIST
+#undef X
+};
+
+#define TMASK(t) (1L << t)
+typedef unsigned long TokMask;
+
+typedef struct {
+	Token tok;
+	Str ident;
+	Str filename, buf;
+	Arena arena;
+	int ofs;
+} Lexer;
+
+typedef enum {
+	LE_WARN,
+	LE_ERROR
+} LexErr;
+
+void lex_start(Lexer *l, const char *path);
+void lex_free(Lexer *l);
+void lex_expected(Lexer *l, TokMask t);
+void lex_expected_not(Lexer *l, TokMask t);
+void lex_expect(Lexer *l, TokMask t); /* next -> expected */
+void lex_expect_not(Lexer *l, TokMask t); /* next -> expected_not */
+void lex_error(Lexer *l, LexErr e, Str msg);
+void lex_pos(Lexer *l, int *line, int *col);
+void lex_next(Lexer *l);
+
+#endif