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-rw-r--r--doc/specs/parse_y.y297
1 files changed, 297 insertions, 0 deletions
diff --git a/doc/specs/parse_y.y b/doc/specs/parse_y.y
new file mode 100644
index 0000000..b195f5d
--- /dev/null
+++ b/doc/specs/parse_y.y
@@ -0,0 +1,297 @@
+
+%{
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAXLINE 1000
+#define INDENT_STRING " "
+#define PAPER_WIDTH 74
+
+ int indent=0;
+ int line=1;
+ char *last_label=NULL;
+
+ extern int yylex(void);
+ extern char *yytext;
+ extern void yyerror(const char *x);
+ extern char *get_label(const char *label);
+ extern void set_label(const char *label, const char *target);
+ char *new_counter(const char *key);
+%}
+
+%union {
+ int def;
+ char *string;
+}
+
+%token NEW_COUNTER LABEL HASH CHAR NEWLINE NO_INDENT RIGHT
+%type <string> stuff text
+
+%start doc
+
+%%
+
+doc:
+| doc NEWLINE {
+ printf("\n");
+ ++line;
+}
+| doc stuff NEWLINE {
+ if (strlen($2) > (PAPER_WIDTH-(indent ? strlen(INDENT_STRING):0))) {
+ yyerror("line too long");
+ }
+ printf("%s%s\n", indent ? INDENT_STRING:"", $2);
+ free($2);
+ indent = 1;
+ ++line;
+}
+| doc stuff RIGHT stuff NEWLINE {
+ char fixed[PAPER_WIDTH+1];
+ int len;
+
+ len = PAPER_WIDTH-(strlen($2)+strlen($4));
+
+ if (len >= 0) {
+ memset(fixed, ' ', len);
+ fixed[len] = '\0';
+ } else {
+ yyerror("line too wide");
+ fixed[0] = '\0';
+ }
+ printf("%s%s%s\n", $2, fixed, $4);
+ free($2);
+ free($4);
+ indent = 1;
+ ++line;
+}
+| doc stuff RIGHT stuff RIGHT stuff NEWLINE {
+ char fixed[PAPER_WIDTH+1];
+ int len, l;
+
+ len = PAPER_WIDTH-(strlen($2)+strlen($4));
+
+ if (len < 0) {
+ len = 0;
+ yyerror("line too wide");
+ }
+
+ l = len/2;
+ memset(fixed, ' ', l);
+ fixed[l] = '\0';
+ printf("%s%s%s", $2, fixed, $4);
+ free($2);
+ free($4);
+
+ l = (len+1)/2;
+ memset(fixed, ' ', l);
+ fixed[l] = '\0';
+ printf("%s%s\n", fixed, $6);
+ free($6);
+
+ indent = 1;
+ ++line;
+}
+| doc stuff RIGHT stuff RIGHT stuff NEWLINE {
+ char fixed[PAPER_WIDTH+1];
+ int len, l;
+
+ len = PAPER_WIDTH-(strlen($2)+strlen($4));
+
+ if (len < 0) {
+ len = 0;
+ yyerror("line too wide");
+ }
+
+ l = len/2;
+ memset(fixed, ' ', l);
+ fixed[l] = '\0';
+ printf("%s%s%s", $2, fixed, $4);
+ free($2);
+ free($4);
+
+ l = (len+1)/2;
+ memset(fixed, ' ', l);
+ fixed[l] = '\0';
+ printf("%s%s\n", fixed, $6);
+ free($6);
+
+ indent = 1;
+ ++line;
+}
+;
+
+stuff: {
+ $$ = strdup("");
+}
+| stuff text {
+ $$ = malloc(strlen($1)+strlen($2)+1);
+ sprintf($$,"%s%s", $1, $2);
+ free($1);
+ free($2);
+}
+;
+
+text: CHAR {
+ $$ = strdup(yytext);
+}
+| text CHAR {
+ $$ = malloc(strlen($1)+2);
+ sprintf($$,"%s%s", $1, yytext);
+ free($1);
+}
+| NO_INDENT {
+ $$ = strdup("");
+ indent = 0;
+}
+| HASH {
+ $$ = strdup("#");
+}
+| LABEL {
+ if (($$ = get_label(yytext)) == NULL) {
+ set_label(yytext, last_label);
+ $$ = strdup("");
+ }
+}
+| NEW_COUNTER {
+ $$ = new_counter(yytext);
+}
+;
+
+%%
+
+typedef struct node_s {
+ struct node_s *left, *right;
+ const char *key;
+ char *value;
+} *node_t;
+
+node_t label_root = NULL;
+node_t counter_root = NULL;
+
+static const char *find_key(node_t root, const char *key)
+{
+ while (root) {
+ int cmp = strcmp(key, root->key);
+
+ if (cmp > 0) {
+ root = root->right;
+ } else if (cmp) {
+ root = root->left;
+ } else {
+ return root->value;
+ }
+ }
+ return NULL;
+}
+
+static node_t set_key(node_t root, const char *key, const char *value)
+{
+ if (root) {
+ int cmp = strcmp(key, root->key);
+ if (cmp > 0) {
+ root->right = set_key(root->right, key, value);
+ } else if (cmp) {
+ root->left = set_key(root->left, key, value);
+ } else {
+ free(root->value);
+ root->value = strdup(value);
+ }
+ } else {
+ root = malloc(sizeof(struct node_s));
+ root->right = root->left = NULL;
+ root->key = strdup(key);
+ root->value = strdup(value);
+ }
+ return root;
+}
+
+void yyerror(const char *x)
+{
+ fprintf(stderr, "line %d: %s\n", line, x);
+}
+
+char *get_label(const char *label)
+{
+ const char *found = find_key(label_root, label);
+
+ if (found) {
+ return strdup(found);
+ }
+ return NULL;
+}
+
+void set_label(const char *label, const char *target)
+{
+ if (target == NULL) {
+ yyerror("no hanging value for label");
+ target = "<??" ">"; /* avoid trigraph warning */
+ }
+ label_root = set_key(label_root, label, target);
+}
+
+char *new_counter(const char *key)
+{
+ int i=0, j, ndollars = 0;
+ const char *old;
+ char *new;
+
+ if (key[i++] != '#') {
+ yyerror("bad index");
+ return strdup("<???" ">"); /* avoid trigraph warning */
+ }
+
+ while (key[i] == '$') {
+ ++ndollars;
+ ++i;
+ }
+
+ key += i;
+ old = find_key(counter_root, key);
+ new = malloc(20*ndollars);
+
+ if (old) {
+ for (j=0; ndollars > 1 && old[j]; ) {
+ if (old[j++] == '.' && --ndollars <= 0) {
+ break;
+ }
+ }
+ if (j) {
+ strncpy(new, old, j);
+ }
+ if (old[j]) {
+ i = atoi(old+j);
+ } else {
+ new[j++] = '.';
+ i = 0;
+ }
+ } else {
+ j=0;
+ while (--ndollars > 0) {
+ new[j++] = '0';
+ new[j++] = '.';
+ }
+ i = 0;
+ }
+ new[j] = '\0';
+ sprintf(new+j, "%d", ++i);
+
+ counter_root = set_key(counter_root, key, new);
+
+ if (last_label) {
+ free(last_label);
+ }
+ last_label = strdup(new);
+
+ return new;
+}
+
+int
+main(void)
+{
+ return yyparse();
+}