ref: 02c6058f5d529e41afb0208c69f0cbf694b02b18
dir: /sys/src/cmd/eqn/lex.c/
#include "e.h" #include "y.tab.h" #include <ctype.h> #include <errno.h> #define SSIZE 1000 char token[SSIZE]; int sp; void space(void); void dodef(tbl *); void define(int); void ifdef(void); void include(void); void delim(void); yylex(void) { register int c; tbl *tp; begin: while ((c = input()) == ' ' || c == '\n' || c == '\t') ; yylval = c; switch (c) { case EOF: ERROR "unexpected end of input inside equation" WARNING; return(EOF); case '~': return(SPACE); case '^': return(THIN); /* case '\t': return(TAB); */ case '{': return('{'); case '}': return('}'); case '"': for (sp = 0; (c=input())!='"' && c != '\n'; ) { if (c == '\\') if ((c = input()) != '"') token[sp++] = '\\'; token[sp++] = c; if (sp >= SSIZE) ERROR "quoted string %.20s... too long", token FATAL; } token[sp] = '\0'; yylval = (int) &token[0]; if (c == '\n') ERROR "missing \" in %.20s", token WARNING; return(QTEXT); } if (!display && c == righteq) return(EOF); unput(c); getstr(token, SSIZE); dprintf(".\tlex token = |%s|\n", token); if ((tp = lookup(deftbl, token)) != NULL) { /* defined term */ c = input(); unput(c); if (c == '(') /* macro with args */ dodef(tp); else { /* no args */ unput(' '); pbstr(tp->cval); dprintf(".\tfound %s|=%s|\n", token, tp->cval); } goto begin; } if ((tp = lookup(keytbl, token)) == NULL) /* not a keyword */ return CONTIG; switch (tp->ival) { /* some kind of keyword */ case DEFINE: case TDEFINE: case NDEFINE: define(tp->ival); break; case IFDEF: ifdef(); break; case DELIM: delim(); break; case GSIZE: globsize(); break; case GFONT: globfont(); break; case INCLUDE: include(); break; case SPACE: space(); break; case DOTEQ: /* .EQ inside equation -- should warn if at bottom level */ break; case DOTEN: if (curfile == infile) return EOF; /* else ignore nested .EN */ break; default: return tp->ival; } goto begin; } void getstr(char *s, int n) { register int c; register char *p; p = s; while ((c = input()) == ' ' || c == '\n') ; if (c == EOF) { *s = 0; return; } while (c != ' ' && c != '\t' && c != '\n' && c != '{' && c != '}' && c != '"' && c != '~' && c != '^') { if (!display && c == righteq) break; if (c == '(' && p > s) { /* might be defined(...) */ *p = '\0'; if (lookup(deftbl, s) != NULL) break; } if (c == '\\') if ((c = input()) != '"') *p++ = '\\'; *p++ = c; if (--n <= 0) ERROR "token %.20s... too long", s FATAL; c = input(); } unput(c); *p = '\0'; yylval = (int) s; } cstr(char *s, int quote, int maxs) { int del, c, i; s[0] = 0; while ((del=input()) == ' ' || del == '\t') ; if (quote) for (i=0; (c=input()) != del && c != EOF;) { s[i++] = c; if (i >= maxs) return(1); /* disaster */ } else { if (del == '\n') return(1); s[0] = del; for (i=1; (c=input())!=' ' && c!= '\t' && c!='\n' && c!=EOF;) { s[i++] = c; if (i >= maxs) return(1); /* disaster */ } } s[i] = '\0'; if (c == EOF) ERROR "Unexpected end of input at %.20s", s FATAL; return(0); } void define(int type) { char *p1, *p2; extern int ftune(char *, char *); getstr(token, SSIZE); /* get name */ if (type != DEFINE) { cstr(token, 1, SSIZE); /* skip the definition too */ return; } p1 = strsave(token); if (cstr(token, 1, SSIZE)) ERROR "Unterminated definition at %.20s", token FATAL; if (lookup(ftunetbl, p1) != NULL) { /* double tuning param */ dprintf(".\ttune %s %s\n", p1, token); ftune(p1, token); } else { p2 = strsave(token); install(deftbl, p1, p2, 0); dprintf(".\tname %s defined as %s\n", p1, p2); } } void ifdef(void) /* do body if name is defined */ { char name[100], *p; getstr(name, sizeof(name)); /* get name */ cstr(token, 1, SSIZE); /* and body */ if (lookup(deftbl, name) != NULL) { /* found it */ p = strsave(token); pushsrc(Free, p); pushsrc(String, p); } } char *spaceval = NULL; void space(void) /* collect line of form "space amt" to replace \x in output */ { getstr(token, SSIZE); spaceval = strsave(token); dprintf(".\tsetting spaceval to %s\n", token); } char *strsave(char *s) { register char *q; q = malloc(strlen(s)+1); if (q == NULL) ERROR "out of space in strsave on %s", s FATAL; strcpy(q, s); return(q); } void include(void) { char name[100]; FILE *fin; int c; while ((c = input()) == ' ') ; unput(c); cstr(name, c == '"', sizeof(name)); /* gets it quoted or not */ if ((fin = fopen(name, "r")) == NULL) ERROR "can't open file %s", name FATAL; errno = 0; curfile++; curfile->fin = fin; curfile->fname = strsave(name); curfile->lineno = 0; printf(".lf 1 %s\n", curfile->fname); pushsrc(File, curfile->fname); } void delim(void) { yyval = eqnreg = 0; if (cstr(token, 0, SSIZE)) ERROR "Bizarre delimiters" FATAL; lefteq = token[0]; righteq = token[1]; if (!isprint(lefteq) || !isprint(righteq)) ERROR "Bizarre delimiters" FATAL; if (lefteq == 'o' && righteq == 'f') lefteq = righteq = '\0'; }