{
char *p = s;
char *q = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l)
- #define YYMARKER q
- #define YYFILL(n)
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l)
+#define YYMARKER q
+#define YYFILL(n)
for(;;)
{
in this lesson. In the next example we see one way to get rid of it.
. We use a 'for(;;)'-loop around the scanner block. We could have used a
'while(1)'-loop instead but some compilers generate a warning for it.
- . To make the output more readable we use 're2c:indent:top' scanenr
+ . To make the output more readable we use 're2c:indent:top' scanner
configuration that configures re2c to prepend a single tab (the default)
to the beginning of each output line.
. The following lines are expressions and for each expression we output the
token name and continue the scanner loop.
. The second last token detects the end of our input, the terminating zero in
- out input string. In other scanners detecting the end of input may vary.
+ our input string. In other scanners detecting the end of input may vary.
For example binary code may contain \0 as valid input.
. The last expression accepts any input character. It tells re2c to accept
the opposit of the empty range. This includes numbers and our tokens but
{
char *p = s;
char *q = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l)
- #define YYMARKER q
- #define YYFILL(n)
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l)
+#define YYMARKER q
+#define YYFILL(n)
for(;;)
{
char *p = s;
char *l = s;
char *q = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT l
- #define YYMARKER q
- #define YYFILL(n) { if (!fill(p, n, &l)) break; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT l
+#define YYMARKER q
+#define YYFILL(n) { if (!fill(p, n, &l)) break; }
for(;;)
{
char *p = s;
char *l = s;
char *q = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT l
- #define YYMARKER q
- #define YYFILL(n) { if (!fill(p, n, &l)) break; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT l
+#define YYMARKER q
+#define YYFILL(n) { if (!fill(p, n, &l)) break; }
for(;;)
{
{
char *p = s;
char *q = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l+2)
- #define YYMARKER q
- #define YYFILL(n) { printf("OOD\n"); return 2; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l+2)
+#define YYMARKER q
+#define YYFILL(n) { printf("OOD\n"); return 2; }
for(;;)
{
{
char *p = s;
char *q = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l+2)
- #define YYMARKER q
- #define YYFILL(n) { printf("OOD\n"); return 2; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l+2)
+#define YYMARKER q
+#define YYFILL(n) { printf("OOD\n"); return 2; }
for(;;)
{
char *p = s;
char *q = 0;
char *t;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l+2)
- #define YYMARKER q
- #define YYFILL(n) { printf("OOD\n"); return 2; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l+2)
+#define YYMARKER q
+#define YYFILL(n) { printf("OOD\n"); return 2; }
for(;;)
{
char *p = s;
char *q = 0;
char *t;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l+2)
- #define YYMARKER q
- #define YYFILL(n) { printf("OOD\n"); return 2; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l+2)
+#define YYMARKER q
+#define YYFILL(n) { printf("OOD\n"); return 2; }
for(;;)
{
char *t;
int res = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l+1)
- #define YYMARKER q
- #define YYFILL(n) { return depth == 1 ? 0 : 2; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l+1)
+#define YYMARKER q
+#define YYFILL(n) { return depth == 1 ? 0 : 2; }
while(!res)
{
. We are going to write an UPN calculator so we need an additional rule to
ignore white space.
. Then we need to store the scanned input somewhere and do our math on it.
- . Also we need to scann all arguments since the main c code gets the input
+ . Also we need to scan all arguments since the main c code gets the input
split up into chunks.
. In contrast to what we did before we now add a variable res that holds the
scanner state. We initialize that variable to 0 and quit the loop when it
char *t;
int res = 0;
- #define YYCTYPE char
- #define YYCURSOR p
- #define YYLIMIT (s+l+1)
- #define YYMARKER q
- #define YYFILL(n) { return depth == 1 ? 0 : 2; }
+#define YYCTYPE char
+#define YYCURSOR p
+#define YYLIMIT (s+l+1)
+#define YYMARKER q
+#define YYFILL(n) { return depth == 1 ? 0 : 2; }
while(!res)
{
char *t;
int res = 0;
- #define YYCTYPE char
- #define YYCURSOR p
+#define YYCTYPE char
+#define YYCURSOR p
while(!res)
{
char *t;
int res = 0;
- #define YYCTYPE char
- #define YYCURSOR p
+#define YYCTYPE char
+#define YYCURSOR p
while(!res)
{
char *t;
int res = 0;
- #define YYCTYPE char
- #define YYCURSOR p
+#define YYCTYPE char
+#define YYCURSOR p
while(!res)
{
char *t;
int res = 0;
- #define YYCTYPE char
- #define YYCURSOR p
+#define YYCTYPE char
+#define YYCURSOR p
while(!res)
{
{
char *pzCurScanPos = pzStrToScan;
char *pzBacktrackInfo = 0;
- #define YYCTYPE char
- #define YYCURSOR pzCurScanPos
- #define YYLIMIT (pzStrToScan+lenStrToScan)
- #define YYMARKER pzBacktrackInfo
- #define YYFILL(n)
+#define YYCTYPE char
+#define YYCURSOR pzCurScanPos
+#define YYLIMIT (pzStrToScan+lenStrToScan)
+#define YYMARKER pzBacktrackInfo
+#define YYFILL(n)
for(;;)
{
{
char *pzCurScanPos = pzStrToScan;
char *pzBacktrackInfo = 0;
- #define YYCTYPE char
- #define YYCURSOR pzCurScanPos
- #define YYLIMIT (pzStrToScan+lenStrToScan)
- #define YYMARKER pzBacktrackInfo
- #define YYFILL(n)
+#define YYCTYPE char
+#define YYCURSOR pzCurScanPos
+#define YYLIMIT (pzStrToScan+lenStrToScan)
+#define YYMARKER pzBacktrackInfo
+#define YYFILL(n)
for(;;)
{
in this lesson. In the next example we see one way to get rid of it.
. We use a 'for(;;)'-loop around the scanner block. We could have used a
'while(1)'-loop instead but some compilers generate a warning for it.
- . To make the output more readable we use 're2c:indent:top' scanenr
+ . To make the output more readable we use 're2c:indent:top' scanner
configuration that configures re2c to prepend a single tab (the default)
to the beginning of each output line.
. The following lines are expressions and for each expression we output the
token name and continue the scanner loop.
. The second last token detects the end of our input, the terminating zero in
- out input string. In other scanners detecting the end of input may vary.
+ our input string. In other scanners detecting the end of input may vary.
For example binary code may contain \0 as valid input.
. The last expression accepts any input character. It tells re2c to accept
the opposit of the empty range. This includes numbers and our tokens but
{
char *pzCurScanPos = pzStrToScan;
char *pzBacktrackInfo = 0;
- #define YYCTYPE char
- #define YYCURSOR pzCurScanPos
- #define YYLIMIT (pzStrToScan+lenStrToScan)
- #define YYMARKER pzBacktrackInfo
- #define YYFILL(n)
+#define YYCTYPE char
+#define YYCURSOR pzCurScanPos
+#define YYLIMIT (pzStrToScan+lenStrToScan)
+#define YYMARKER pzBacktrackInfo
+#define YYFILL(n)
for(;;)
{
{
char *pzCurScanPos = pzStrToScan;
char *pzBacktrackInfo = 0;
- #define YYCTYPE char
- #define YYCURSOR pzCurScanPos
- #define YYLIMIT (pzStrToScan+lenStrToScan)
- #define YYMARKER pzBacktrackInfo
- #define YYFILL(n)
+#define YYCTYPE char
+#define YYCURSOR pzCurScanPos
+#define YYLIMIT (pzStrToScan+lenStrToScan)
+#define YYMARKER pzBacktrackInfo
+#define YYFILL(n)
for(;;)
{
- multiple scanner blocks
. We use a main scanner block that outputs every input character unless the
- input is two /s or a / followed by a *. In the lattertwo cases we switch
+ input is two /s or a / followed by a *. In the latter two cases we switch
to a special c++ comment and a comment block respectively.
. Both special blocks simply detect their end ignore any other character.
. The c++ block is a bit special. Since the terminating new line needs to
/*!ignore:re2c
- complexity
- . When a comemnt is preceeded by a new line and followed by whitespace and a
+ . When a comment is preceeded by a new line and followed by whitespace and a
new line then we can drop the trailing whitespace and new line.
. Additional to what we strip out already what about two consequtive comment
blocks? When two comments are only separated by whitespace we want to drop
- formatting
. Until now we only used single line expression code and we always had the
opening { on the same line as the rule itself. If we have multiline rule
- code and care for formatting we can nolonger rely on re2c. Now we have
+ code and care for formatting we can no longer rely on re2c. Now we have
to indent the rule code ourself. Also we need to take care of the opening
{. If we keep it on the same line as the rule then re2c will indent it
correctly and the emitted #line informations will be correct. If we place
- it on the next line then the #line directivy will also point to that line
+ it on the next line then the #line directive will also point to that line
and not to the rule.
*/
001_upn_calculator
- This lesson gets you started with re2c. In the end you will have an easy UPN
- calculator for use at command line.
+ This lesson gets you started with re2c. In the end you will have an easy
+ RPN calculator for use at command line.
- You will learn about the basic interface of re2c when scanning input strings.
- How to detect the end of the input and use that to stop scanning in order to
- avoid problems.
+ You will learn about the basic interface of re2c when scanning input
+ strings. How to detect the end of the input and use that to stop scanning
+ in order to avoid problems.
The lesson also contains a windows subdirectory to get you started in the
Microsoft world.
002_strip_comments
- In this lesson you will learn how to use multiple scanner blocks and how to
- read the input from a file instead of a zero terminated string. In the end you
- will have a scanner that filters comments out of c source files but keeps re2c
- comments.
+ In this lesson you will learn how to use multiple scanner blocks and how
+ to read the input from a file instead of a zero terminated string. In the
+ end you will have a scanner that filters comments out of c source files
+ but keeps re2c comments.
projects / re2c / commitdiff