q66 pushed a commit to branch master.
http://git.enlightenment.org/core/efl.git/commit/?id=5c3cc82bddfda8ec7889b75c8dc1e6c55e3452a3
commit 5c3cc82bddfda8ec7889b75c8dc1e6c55e3452a3
Author: Daniel Kolesa <d.kol...@samsung.com>
Date: Tue Jul 15 10:09:50 2014 +0100
eolian: comment eo_lexer.h
---
src/lib/eolian/eo_lexer.h | 53 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/src/lib/eolian/eo_lexer.h b/src/lib/eolian/eo_lexer.h
index 277df41..56077cb 100644
--- a/src/lib/eolian/eo_lexer.h
+++ b/src/lib/eolian/eo_lexer.h
@@ -7,6 +7,8 @@
#include <Eolian.h>
#include "eo_definitions.h"
+/* a token is an int, custom tokens start at this - single-char tokens are
+ * simply represented by their ascii */
#define START_CUSTOM 257
enum Tokens
@@ -14,6 +16,8 @@ enum Tokens
TOK_COMMENT = START_CUSTOM, TOK_EOF, TOK_VALUE
};
+/* all keywords in eolian, they can still be used as names (they're TOK_VALUE)
+ * they just fill in the "kw" field of the token */
#define KEYWORDS KW(class), KW(const), KW(private), KW(protected), \
KW(return), KW(signed), KW(struct), KW(unsigned), KW(virtual), \
\
@@ -42,6 +46,7 @@ enum Tokens
\
KW(true), KW(false), KW(null)
+/* "regular" keyword and @ prefixed keyword */
#define KW(x) KW_##x
#define KWAT(x) KW_at_##x
@@ -54,6 +59,9 @@ enum Keywords
#undef KW
#undef KWAT
+/* a token - "token" is the actual token id, "value" is the value of a token
+ * if needed - NULL otherwise - for example the value of a TOK_VALUE, "kw"
+ * is the keyword id if this is a keyword, it's 0 when not a keyword */
typedef struct _Eo_Token
{
int token;
@@ -68,6 +76,9 @@ enum Nodes
NODE_STRUCT
};
+/* represents a node, aka a result of parsing - currently class, typedef
+ * or struct, they're all stored in a list in lexer state and their type
+ * is determined by enum Nodes above */
typedef struct _Eo_Node
{
unsigned char type;
@@ -79,21 +90,49 @@ typedef struct _Eo_Node
};
} Eo_Node;
+/* keeps all lexer state */
typedef struct _Eo_Lexer
{
+ /* current character being tested */
int current;
+ /* column is token aware column number, for example when lexing a keyword
+ * it points to the beginning of it after the lexing is done, icolumn is
+ * token unaware, always pointing to current column */
int column, icolumn;
+ /* the current line number */
int line_number;
+ /* t: "normal" - token to lex into, "lookahead" - a lookahead token, used
+ * to look one token past "t", when we need to check for a token after the
+ * current one and use it in a conditional without consuming the current
+ * token - used in pretty few cases - because we have one extra lookahead
+ * token, that makes our grammar LL(2) - two tokens in total */
Eo_Token t, lookahead;
+ /* a string buffer used to keep contents of token currently being read,
+ * if needed at all */
Eina_Strbuf *buff;
+ /* a handle pointing to a memory mapped file representing the file we're
+ * currently lexing */
Eina_File *handle;
+ /* the source file name */
const char *source;
+ /* points to the current character in our mmapped file being lexed, just
+ * incremented until the end */
const char *stream;
+ /* end pointer - required to check if we've reached past the file, as
+ * mmapped data will give us no EOF */
const char *stream_end;
+ /* points to the current line being lexed, used by error messages to
+ * display the current line with a caret at the respective column */
const char *stream_line;
+ /* this is jumped to when an error happens */
jmp_buf err_jmp;
+ /* represents the results of parsing */
Eina_List *nodes;
+ /* represents the temporaries, every object that is allocated by the
+ * parser is temporarily put here so the resources can be reclaimed in
+ * case of error - and it's nulled when it's written into a more permanent
+ * position (e.g. as part of another struct, or into nodes */
Eo_Lexer_Temps tmp;
} Eo_Lexer;
@@ -101,17 +140,31 @@ int eo_lexer_init (void);
int eo_lexer_shutdown (void);
Eo_Lexer *eo_lexer_new (const char *source);
void eo_lexer_free (Eo_Lexer *ls);
+/* gets a TOK_VALUE balanced token, aka keeps lexing everything until the
+ * "end" character, but keeps it balanced, so if it hits "beg" during lexing,
+ * it won't end at the next "end", useful for lexing between () or [] */
int eo_lexer_get_balanced (Eo_Lexer *ls, char beg, char end);
+/* gets a TOK_VALUE until the "end" character */
int eo_lexer_get_until (Eo_Lexer *ls, char end);
+/* gets a regular token, singlechar or one of TOK_something */
int eo_lexer_get (Eo_Lexer *ls);
+/* like above, but allows you to specify a list of custom characters that can
+ * be used as part of identifiers */
int eo_lexer_get_ident (Eo_Lexer *ls, const char *chars);
+/* lookahead token - see Eo_Lexer */
int eo_lexer_lookahead (Eo_Lexer *ls);
int eo_lexer_lookahead_ident(Eo_Lexer *ls, const char *chars);
+/* "throws" an error, with a custom message and custom token */
void eo_lexer_lex_error (Eo_Lexer *ls, const char *msg, int token);
+/* like above, but uses the lexstate->t.token, aka current token */
void eo_lexer_syntax_error (Eo_Lexer *ls, const char *msg);
+/* turns the token into a string, writes into the given buffer */
void eo_lexer_token_to_str (int token, char *buf);
+/* returns the string representation of a keyword */
const char *eo_lexer_keyword_str_get(int kw);
+/* checks if the given keyword is a builtin type */
Eina_Bool eo_lexer_is_type_keyword(int kw);
+/* gets the C type name for a builtin type name - e.g. uchar -> unsigned char
*/
const char *eo_lexer_get_c_type (int kw);
extern int _eo_lexer_log_dom;
--
