%{ /* * R : A Computer Langage for Statistical Data Analysis * Copyright (C) 1995, 1996, 1997 Robert Gentleman and Ross Ihaka * Copyright (C) 1997--1999 Robert Gentleman, Ross Ihaka and the * R Development Core Team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifdef HAVE_CONFIG_H #include #endif #ifdef HAVE_ALLOCA_H #include #endif #include "IOStuff.h" /*-> Defn.h */ #include "Fileio.h" #include "Parse.h" /* Useful defines so editors don't get confused ... */ #define LBRACE '{' #define RBRACE '}' /* Functions used in the parsing process */ static void CheckFormalArgs(SEXP, SEXP); static SEXP FirstArg(SEXP, SEXP); static SEXP GrowList(SEXP, SEXP); static void IfPush(void); static int KeywordLookup(char*); static SEXP NewList(void); static SEXP NextArg(SEXP, SEXP, SEXP); static SEXP TagArg(SEXP, SEXP); /* These routines allocate constants */ SEXP mkComplex(char *); SEXP mkFalse(void); SEXP mkFloat(char *); SEXP mkInteger(char *); SEXP mkNA(void); SEXP mkString(const char *); SEXP mkTrue(void); /* Internal lexer / parser state variables */ static int EatLines = 0; static int GenerateCode = 0; static int EndOfFile = 0; static int xxgetc(); static int xxungetc(); static int xxcharcount, xxcharsave; /* Handle function source */ /* FIXME: These arrays really ought to be dynamically extendable */ #define MAXFUNSIZE 65536 #define MAXLINESIZE 1024 #define MAXNEST 265 static unsigned char FunctionSource[MAXFUNSIZE]; static unsigned char SourceLine[MAXLINESIZE]; static unsigned char *FunctionStart[MAXNEST], *SourcePtr; static int FunctionLevel = 0; static int KeepSource; /* Soon to be defunct entry points */ void R_SetInput(int); int R_fgetc(FILE*); /* Routines used to build the parse tree */ static SEXP xxnullformal(void); static SEXP xxfirstformal0(SEXP); static SEXP xxfirstformal1(SEXP, SEXP); static SEXP xxaddformal0(SEXP, SEXP); static SEXP xxaddformal1(SEXP, SEXP, SEXP); static SEXP xxexprlist0(); static SEXP xxexprlist1(SEXP); static SEXP xxexprlist2(SEXP, SEXP); static SEXP xxsub0(void); static SEXP xxsub1(SEXP); static SEXP xxsymsub0(SEXP); static SEXP xxsymsub1(SEXP, SEXP); static SEXP xxnullsub0(); static SEXP xxnullsub1(SEXP); static SEXP xxsublist1(SEXP); static SEXP xxsublist2(SEXP, SEXP); static SEXP xxcond(SEXP); static SEXP xxifcond(SEXP); static SEXP xxif(SEXP, SEXP, SEXP); static SEXP xxifelse(SEXP, SEXP, SEXP, SEXP); static SEXP xxforcond(SEXP, SEXP); static SEXP xxfor(SEXP, SEXP, SEXP); static SEXP xxwhile(SEXP, SEXP, SEXP); static SEXP xxrepeat(SEXP, SEXP); static SEXP xxnxtbrk(SEXP); static SEXP xxfuncall(SEXP, SEXP); static SEXP xxdefun(SEXP, SEXP, SEXP); static SEXP xxunary(SEXP, SEXP); static SEXP xxbinary(SEXP, SEXP, SEXP); static SEXP xxparen(SEXP, SEXP); static SEXP xxsubscript(SEXP, SEXP, SEXP); static SEXP xxexprlist(SEXP, SEXP); static int xxvalue(SEXP, int); #define YYSTYPE SEXP %} %token END_OF_INPUT ERROR %token STR_CONST NUM_CONST NULL_CONST SYMBOL FUNCTION %token LEFT_ASSIGN RIGHT_ASSIGN LBB %token FOR IN IF ELSE WHILE NEXT BREAK REPEAT %token GT GE LT LE EQ NE AND OR %left '?' %left LOW WHILE FOR REPEAT %right IF %left ELSE %right LEFT_ASSIGN %left RIGHT_ASSIGN %left '~' TILDE %left OR %left AND %left UNOT NOT %left GT GE LT LE EQ NE %left '+' '-' %left '*' '/' '%' %left SPECIAL %left ':' %left UMINUS UPLUS %right '^' %left '$' %nonassoc '(' '[' LBB %% prog : END_OF_INPUT { return 0; } | '\n' { return xxvalue(NULL,2); } | expr '\n' { return xxvalue($1,3); } | expr ';' { return xxvalue($1,4); } | error { YYABORT; } ; expr : NUM_CONST { $$ = $1; } | STR_CONST { $$ = $1; } | NULL_CONST { $$ = $1; } | SYMBOL { $$ = $1; } | '{' exprlist '}' { $$ = xxexprlist($1,$2); } | '(' expr ')' { $$ = xxparen($1,$2); } | '-' expr %prec UMINUS { $$ = xxunary($1,$2); } | '+' expr %prec UMINUS { $$ = xxunary($1,$2); } | '!' expr %prec UNOT { $$ = xxunary($1,$2); } | '~' expr %prec TILDE { $$ = xxunary($1,$2); } | '?' expr { $$ = xxunary($1,$2); } | expr ':' expr { $$ = xxbinary($2,$1,$3); } | expr '+' expr { $$ = xxbinary($2,$1,$3); } | expr '-' expr { $$ = xxbinary($2,$1,$3); } | expr '*' expr { $$ = xxbinary($2,$1,$3); } | expr '/' expr { $$ = xxbinary($2,$1,$3); } | expr '^' expr { $$ = xxbinary($2,$1,$3); } | expr SPECIAL expr { $$ = xxbinary($2,$1,$3); } | expr '%' expr { $$ = xxbinary($2,$1,$3); } | expr '~' expr { $$ = xxbinary($2,$1,$3); } | expr LT expr { $$ = xxbinary($2,$1,$3); } | expr LE expr { $$ = xxbinary($2,$1,$3); } | expr EQ expr { $$ = xxbinary($2,$1,$3); } | expr NE expr { $$ = xxbinary($2,$1,$3); } | expr GE expr { $$ = xxbinary($2,$1,$3); } | expr GT expr { $$ = xxbinary($2,$1,$3); } | expr AND expr { $$ = xxbinary($2,$1,$3); } | expr OR expr { $$ = xxbinary($2,$1,$3); } | expr LEFT_ASSIGN expr { $$ = xxbinary($2,$1,$3); } | expr RIGHT_ASSIGN expr { $$ = xxbinary($2,$3,$1); } | FUNCTION '(' formlist ')' cr expr %prec LOW { $$ = xxdefun($1,$3,$6); } | expr '(' sublist ')' { $$ = xxfuncall($1,$3); } | IF ifcond expr { $$ = xxif($1,$2,$3); } | IF ifcond expr ELSE expr { $$ = xxifelse($1,$2,$3,$5); } | FOR forcond expr %prec FOR { $$ = xxfor($1,$2,$3); } | WHILE cond expr { $$ = xxwhile($1,$2,$3); } | REPEAT expr { $$ = xxrepeat($1,$2); } | expr LBB sublist ']' ']' { $$ = xxsubscript($1,$2,$3); } | expr '[' sublist ']' { $$ = xxsubscript($1,$2,$3); } | expr '$' SYMBOL { $$ = xxbinary($2,$1,$3); } | expr '$' STR_CONST { $$ = xxbinary($2,$1,$3); } | NEXT { $$ = xxnxtbrk($1); } | BREAK { $$ = xxnxtbrk($1); } ; cond : '(' expr ')' { $$ = xxcond($2); } ; ifcond : '(' expr ')' { $$ = xxifcond($2); } ; forcond : '(' SYMBOL IN expr ')' { $$ = xxforcond($2,$4); } ; exprlist: { $$ = xxexprlist0(); } | expr { $$ = xxexprlist1($1); } | exprlist ';' expr { $$ = xxexprlist2($1,$3); } | exprlist ';' { $$ = $1; } | exprlist '\n' expr { $$ = xxexprlist2($1,$3); } | exprlist '\n' { $$ = $1;} ; sublist : sub { $$ = xxsublist1($1); } | sublist cr ',' sub { $$ = xxsublist2($1,$4); } ; sub : { $$ = xxsub0(); } | expr { $$ = xxsub1($1); } | SYMBOL '=' { $$ = xxsymsub0($1); } | SYMBOL '=' expr { $$ = xxsymsub1($1,$3); } | STR_CONST '=' { $$ = xxsymsub0($1); } | STR_CONST '=' expr { $$ = xxsymsub1($1,$3); } | NULL_CONST '=' { $$ = xxnullsub0(); } | NULL_CONST '=' expr { $$ = xxnullsub1($3); } ; formlist: { $$ = xxnullformal(); } | SYMBOL { $$ = xxfirstformal0($1); } | SYMBOL '=' expr { $$ = xxfirstformal1($1,$3); } | formlist ',' SYMBOL { $$ = xxaddformal0($1,$3); } | formlist ',' SYMBOL '=' expr { $$ = xxaddformal1($1,$3,$5); } ; cr : { EatLines = 1; } ; %% /*----------------------------------------------------------------------------*/ static int (*ptr_getc)(void); static int (*ptr_ungetc)(int); static int xxgetc(void) { int c = ptr_getc(); if (c == EOF) { EndOfFile = 1; return R_EOF; } if (c == '\n') R_ParseError += 1; /* FIXME: check for overrun in SourcePtr */ if ( GenerateCode && FunctionLevel > 0 ) *SourcePtr++ = c; xxcharcount++; return c; } static int xxungetc(int c) { if (c == '\n') R_ParseError -= 1; if ( GenerateCode && FunctionLevel > 0 ) SourcePtr--; xxcharcount--; return ptr_ungetc(c); } static int xxvalue(SEXP v, int k) { if (k > 2) UNPROTECT_PTR(v); R_CurrentExpr = v; return k; } static SEXP xxnullformal() { SEXP ans; PROTECT(ans = R_NilValue); return ans; } static SEXP xxfirstformal0(SEXP sym) { SEXP ans; UNPROTECT_PTR(sym); if (GenerateCode) PROTECT(ans = FirstArg(R_MissingArg, sym)); else PROTECT(ans = R_NilValue); return ans; } static SEXP xxfirstformal1(SEXP sym, SEXP expr) { SEXP ans; if (GenerateCode) PROTECT(ans = FirstArg(expr, sym)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); UNPROTECT_PTR(sym); return ans; } static SEXP xxaddformal0(SEXP formlist, SEXP sym) { SEXP ans; if (GenerateCode) { CheckFormalArgs(formlist ,sym); PROTECT(ans = NextArg(formlist, R_MissingArg, sym)); } else PROTECT(ans = R_NilValue); UNPROTECT_PTR(sym); UNPROTECT_PTR(formlist); return ans; } static SEXP xxaddformal1(SEXP formlist, SEXP sym, SEXP expr) { SEXP ans; if (GenerateCode) { CheckFormalArgs(formlist, sym); PROTECT(ans = NextArg(formlist, expr, sym)); } else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); UNPROTECT_PTR(sym); UNPROTECT_PTR(formlist); return ans; } static SEXP xxexprlist0() { SEXP ans; if (GenerateCode) PROTECT(ans = NewList()); else PROTECT(ans = R_NilValue); return ans; } static SEXP xxexprlist1(SEXP expr) { SEXP ans,tmp; if (GenerateCode) { PROTECT(tmp = NewList()); PROTECT(ans = GrowList(tmp, expr)); UNPROTECT(1); } else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); return ans; } static SEXP xxexprlist2(SEXP exprlist, SEXP expr) { SEXP ans; if (GenerateCode) PROTECT(ans = GrowList(exprlist, expr)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); UNPROTECT_PTR(exprlist); return ans; } static SEXP xxsub0(void) { SEXP ans; if (GenerateCode) PROTECT(ans = lang2(R_MissingArg,R_NilValue)); else PROTECT(ans = R_NilValue); return ans; } static SEXP xxsub1(SEXP expr) { SEXP ans; if (GenerateCode) PROTECT(ans = TagArg(expr, R_NilValue)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); return ans; } static SEXP xxsymsub0(SEXP sym) { SEXP ans; if (GenerateCode) PROTECT(ans = TagArg(R_MissingArg, sym)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(sym); return ans; } static SEXP xxsymsub1(SEXP sym, SEXP expr) { SEXP ans; if (GenerateCode) PROTECT(ans = TagArg(expr, sym)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); UNPROTECT_PTR(sym); return ans; } static SEXP xxnullsub0() { SEXP ans; UNPROTECT_PTR(R_NilValue); if (GenerateCode) PROTECT(ans = TagArg(R_MissingArg, install("NULL"))); else PROTECT(ans = R_NilValue); return ans; } static SEXP xxnullsub1(SEXP expr) { SEXP ans = install("NULL"); UNPROTECT_PTR(R_NilValue); if (GenerateCode) PROTECT(ans = TagArg(expr, ans)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); return ans; } static SEXP xxsublist1(SEXP sub) { SEXP ans; if (GenerateCode) PROTECT(ans = FirstArg(CAR(sub),CADR(sub))); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(sub); return ans; } static SEXP xxsublist2(SEXP sublist, SEXP sub) { SEXP ans; if (GenerateCode) PROTECT(ans = NextArg(sublist, CAR(sub), CADR(sub))); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(sub); UNPROTECT_PTR(sublist); return ans; } static SEXP xxcond(SEXP expr) { EatLines = 1; return expr; } static SEXP xxifcond(SEXP expr) { EatLines = 1; return expr; } static SEXP xxif(SEXP ifsym, SEXP cond, SEXP expr) { SEXP ans; if (GenerateCode) PROTECT(ans = lang3(ifsym, cond, expr)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); UNPROTECT_PTR(cond); return ans; } static SEXP xxifelse(SEXP ifsym, SEXP cond, SEXP ifexpr, SEXP elseexpr) { SEXP ans; if( GenerateCode) PROTECT(ans = lang4(ifsym, cond, ifexpr, elseexpr)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(elseexpr); UNPROTECT_PTR(ifexpr); UNPROTECT_PTR(cond); return ans; } static SEXP xxforcond(SEXP sym, SEXP expr) { SEXP ans; EatLines = 1; if (GenerateCode) PROTECT(ans = LCONS(sym, expr)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(expr); UNPROTECT_PTR(sym); return ans; } static SEXP xxfor(SEXP forsym, SEXP forcond, SEXP body) { SEXP ans; if (GenerateCode) PROTECT(ans = lang4(forsym, CAR(forcond), CDR(forcond), body)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(body); UNPROTECT_PTR(forcond); return ans; } static SEXP xxwhile(SEXP whilesym, SEXP cond, SEXP body) { SEXP ans; if (GenerateCode) PROTECT(ans = lang3(whilesym, cond, body)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(body); UNPROTECT_PTR(cond); return ans; } static SEXP xxrepeat(SEXP repeatsym, SEXP body) { SEXP ans; if (GenerateCode) PROTECT(ans = lang2(repeatsym, body)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(body); return ans; } static SEXP xxnxtbrk(SEXP keyword) { if (GenerateCode) PROTECT(keyword = lang1(keyword)); else PROTECT(keyword = R_NilValue); return keyword; } static SEXP xxfuncall(SEXP expr, SEXP args) { SEXP ans, sav_expr = expr; if(GenerateCode) { if (isString(expr)) expr = install(CHAR(STRING(expr)[0])); PROTECT(expr); if (length(CDR(args)) == 1 && CADR(args) == R_MissingArg && TAG(CDR(args)) == R_NilValue ) ans = lang1(expr); else ans = LCONS(expr, CDR(args)); UNPROTECT(1); PROTECT(ans); } else { PROTECT(ans = R_NilValue); } UNPROTECT_PTR(args); UNPROTECT_PTR(sav_expr); return ans; } static SEXP xxdefun(SEXP fname, SEXP formals, SEXP body) { SEXP ans; SEXP source; if (GenerateCode) { if (!KeepSource) PROTECT(source = R_NilValue); else { unsigned char *p, *p0, *end; int lines = 0, nc; /* If the function ends with an endline comment, e.g. function() print("Hey") # This comment we need some special handling to keep it from getting chopped off. Normally, we will have read one token too far, which is what xxcharcount and xxcharsave keeps track of. */ end = SourcePtr - (xxcharcount - xxcharsave); for (p = end ; p < SourcePtr && (*p == ' ' || *p == '\t') ; p++) ; if (*p == '#') { while (p < SourcePtr && *p != '\n') p++; end = p; } for (p = FunctionStart[FunctionLevel]; p < end ; p++) if (*p == '\n') lines++; if ( *(end - 1) != '\n' ) lines++; PROTECT(source = allocVector(STRSXP, lines)); p0 = FunctionStart[FunctionLevel]; lines = 0; for (p = FunctionStart[FunctionLevel]; p < end ; p++) if (*p == '\n' || p == end - 1) { nc = p - p0; if (*p != '\n') nc++; strncpy(SourceLine, p0, nc); SourceLine[nc] = '\0'; STRING(source)[lines++] = mkChar(SourceLine); p0 = p + 1; } /* PrintValue(source); */ } PROTECT(ans = lang4(fname, CDR(formals), body, source)); UNPROTECT_PTR(source); } else PROTECT(ans = R_NilValue); UNPROTECT_PTR(body); UNPROTECT_PTR(formals); FunctionLevel--; return ans; } static SEXP xxunary(SEXP op, SEXP arg) { SEXP ans; if (GenerateCode) PROTECT(ans = lang2(op, arg)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(arg); return ans; } static SEXP xxbinary(SEXP n1, SEXP n2, SEXP n3) { SEXP ans; if (GenerateCode) PROTECT(ans = lang3(n1, n2, n3)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(n2); UNPROTECT_PTR(n3); return ans; } static SEXP xxparen(SEXP n1, SEXP n2) { SEXP ans; if (GenerateCode) PROTECT(ans = lang2(n1, n2)); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(n2); return ans; } static SEXP xxsubscript(SEXP a1, SEXP a2, SEXP a3) { SEXP ans; if (GenerateCode) PROTECT(ans = LCONS(a2, LCONS(a1, CDR(a3)))); else PROTECT(ans = R_NilValue); UNPROTECT_PTR(a3); UNPROTECT_PTR(a1); return ans; } static SEXP xxexprlist(SEXP a1, SEXP a2) { SEXP ans; EatLines = 0; if (GenerateCode) { TYPEOF(a2) = LANGSXP; CAR(a2) = a1; PROTECT(ans = a2); } else PROTECT(ans = R_NilValue); UNPROTECT_PTR(a2); return ans; } /*--------------------------------------------------------------------------*/ static SEXP TagArg(SEXP arg, SEXP tag) { switch (TYPEOF(tag)) { case STRSXP: tag = install(CHAR(STRING(tag)[0])); case NILSXP: case SYMSXP: return lang2(arg, tag); default: error("incorrect tag type\n"); return R_NilValue/* -Wall */; } } /* Stretchy List Structures : Lists are created and grown using a special */ /* dotted pair. The CAR of the list points to the last cons-cell in the */ /* list and the CDR points to the first. The list can be extracted from */ /* the pair by taking its CDR, while the CAR gives fast access to the end */ /* of the list. */ /* Create a stretchy-list dotted pair */ static SEXP NewList(void) { SEXP s = CONS(R_NilValue, R_NilValue); CAR(s) = s; return s; } /* Add a new element at the end of a stretchy list */ static SEXP GrowList(SEXP l, SEXP s) { SEXP tmp; PROTECT(s); tmp = CONS(s, R_NilValue); UNPROTECT(1); SETCDR(CAR(l), tmp); CAR(l) = tmp; return l; } #if 0 /* Comment Handling :R_CommentSxp is of the same form as an expression */ /* list, each time a new { is encountered a new element is placed in the */ /* R_CommentSxp and when a } is encountered it is removed. */ static void ResetComment(void) { R_CommentSxp = CONS(R_NilValue, R_NilValue); } static void PushComment(void) { if (GenerateCode) R_CommentSxp = CONS(R_NilValue, R_CommentSxp); } static void PopComment(void) { if (GenerateCode) R_CommentSxp = CDR(R_CommentSxp); } #ifdef NOT_used int IsComment(SEXP l) { if (isList(l) && isString(CAR(l)) && !strncmp(CHAR(STRING(CAR(l))[0]), "#", 1)) return 1; else return 0; } #endif static void AddComment(SEXP l) { SEXP tcmt, cmt; int i, ncmt; if(GenerateCode) { tcmt = CAR(R_CommentSxp); /* Return if there are no comments */ if (tcmt == R_NilValue || l == R_NilValue) return; /* Attach the comments as a comment attribute */ ncmt = length(tcmt); cmt = allocVector(STRSXP, ncmt); for(i=0 ; i= 0) { PROTECT(rval = allocVector(EXPRSXP, n)); for (i = 0 ; i < n ; i++) { try_again: ParseInit(); t = R_Parse1(status); switch(*status) { case PARSE_NULL: goto try_again; break; case PARSE_OK: VECTOR(rval)[i] = t; break; case PARSE_INCOMPLETE: case PARSE_ERROR: case PARSE_EOF: rval = R_NilValue; break; } } UNPROTECT(1); return rval; } else { PROTECT(t = NewList()); for(;;) { ParseInit(); rval = R_Parse1(status); switch(*status) { case PARSE_NULL: break; case PARSE_OK: t = GrowList(t, rval); break; case PARSE_INCOMPLETE: case PARSE_ERROR: UNPROTECT(1); return R_NilValue; break; case PARSE_EOF: t = CDR(t); rval = allocVector(EXPRSXP, length(t)); for (n = 0 ; n < LENGTH(rval) ; n++) { VECTOR(rval)[n] = CAR(t); t = CDR(t); } UNPROTECT(1); *status = PARSE_OK; return rval; break; } } } } SEXP R_ParseFile(FILE *fp, int n, int *status) { GenerateCode = 1; R_ParseError = 1; fp_parse = fp; ptr_getc = file_getc; ptr_ungetc = file_ungetc; return R_Parse(n, status); } SEXP R_ParseVector(SEXP text, int n, int *status) { SEXP rval; TextBuffer textb; R_TextBufferInit(&textb, text); txtb = &textb; GenerateCode = 1; R_ParseError = 1; ptr_getc = text_getc; ptr_ungetc = text_ungetc; rval = R_Parse(n, status); R_TextBufferFree(&textb); return rval; } #ifdef GENERAL SEXP R_ParseGeneral(int (*ggetc)(), int (*gungetc)(), int n, int *status) { GenerateCode = 1; R_ParseError = 1; ptr_getc = ggetc; ptr_ungetc = gungetc; return R_Parse(n, status); } #endif static char *Prompt(SEXP prompt, int type) { if(type == 1) { if(length(prompt) <= 0) { return (char*)CHAR(STRING(GetOption(install("prompt"), R_NilValue))[0]); } else return CHAR(STRING(prompt)[0]); } else { return (char*)CHAR(STRING(GetOption(install("continue"), R_NilValue))[0]); } } SEXP R_ParseBuffer(IoBuffer *buffer, int n, int *status, SEXP prompt) { SEXP rval, t; char *bufp, buf[1024]; int c, i, prompt_type = 1; R_IoBufferWriteReset(buffer); buf[0] = '\0'; bufp = buf; if (n >= 0) { PROTECT(rval = allocVector(EXPRSXP, n)); for (i = 0 ; i < n ; i++) { try_again: if(!*bufp) { if(R_ReadConsole(Prompt(prompt, prompt_type), buf, 1024, 1) == 0) return R_NilValue; bufp = buf; } while ((c = *bufp++)) { R_IoBufferPutc(c, buffer); if (c == ';' || c == '\n') { break; } } t = R_Parse1Buffer(buffer, 1, status); switch(*status) { case PARSE_NULL: goto try_again; break; case PARSE_OK: VECTOR(rval)[i] = t; break; case PARSE_INCOMPLETE: case PARSE_ERROR: case PARSE_EOF: rval = R_NilValue; break; } } UNPROTECT(1); R_IoBufferWriteReset(buffer); return rval; } else { PROTECT(t = NewList()); for (;;) { if (!*bufp) { if(R_ReadConsole(Prompt(prompt, prompt_type), buf, 1024, 1) == 0) return R_NilValue; bufp = buf; } while ((c = *bufp++)) { R_IoBufferPutc(c, buffer); if (c == ';' || c == '\n') { break; } } rval = R_Parse1Buffer(buffer, 1, status); switch(*status) { case PARSE_NULL: break; case PARSE_OK: t = GrowList(t, rval); break; case PARSE_INCOMPLETE: case PARSE_ERROR: R_IoBufferWriteReset(buffer); UNPROTECT(1); return R_NilValue; break; case PARSE_EOF: R_IoBufferWriteReset(buffer); t = CDR(t); rval = allocVector(EXPRSXP, length(t)); for (n = 0 ; n < LENGTH(rval) ; n++) { VECTOR(rval)[n] = CAR(t); t = CDR(t); } UNPROTECT(1); *status = PARSE_OK; return rval; break; } } } } /*---------------------------------------------------------------------------- * * The Lexical Analyzer: * * Basic lexical analysis is performed by the following * routines. Input is read a line at a time, and, if the * program is in batch mode, each input line is echoed to * standard output after it is read. * * The function yylex() scans the input, breaking it into * tokens which are then passed to the parser. The lexical * analyser maintains a symbol table (in a very messy fashion). * * The fact that if statements need to parse differently * depending on whether the statement is being interpreted or * part of the body of a function causes the need for ifpop * and IfPush. When an if statement is encountered an 'i' is * pushed on a stack (provided there are parentheses active). * At later points this 'i' needs to be popped off of the if * stack. * */ static void IfPush(void) { if (*contextp==LBRACE || *contextp=='[' || *contextp=='(' || *contextp == 'i') *++contextp = 'i'; } static void ifpop(void) { if (*contextp=='i') *contextp-- = 0; } static int typeofnext(void) { int k, c; c = xxgetc(); if (isdigit(c)) k = 1; else if (isalpha(c) || c == '.') k = 2; else k = 3; xxungetc(c); return k; } static int nextchar(int expect) { int c = xxgetc(); if (c == expect) return 1; else xxungetc(c); return 0; } /* Special Symbols */ /* Syntactic Keywords + Symbolic Constants */ struct { char *name; int token; } keywords[] = { { "NULL", NULL_CONST }, { "NA", NUM_CONST }, { "TRUE", NUM_CONST }, { "FALSE", NUM_CONST }, { "GLOBAL.ENV", NUM_CONST }, { "Inf", NUM_CONST }, { "NaN", NUM_CONST }, { "function", FUNCTION }, { "while", WHILE }, { "repeat", REPEAT }, { "for", FOR }, { "if", IF }, { "in", IN }, { "else", ELSE }, { "next", NEXT }, { "break", BREAK }, { "...", SYMBOL }, { 0, 0 } }; /* KeywordLookup has side effects, it sets yylval */ static int KeywordLookup(char *s) { int i; for (i = 0; keywords[i].name; i++) { if (strcmp(keywords[i].name, s) == 0) { switch (keywords[i].token) { case NULL_CONST: PROTECT(yylval = R_NilValue); break; case NUM_CONST: switch(i) { case 1: PROTECT(yylval = mkNA()); break; case 2: PROTECT(yylval = mkTrue()); break; case 3: PROTECT(yylval = mkFalse()); break; case 4: PROTECT(yylval = R_GlobalEnv); break; case 5: PROTECT(yylval = allocVector(REALSXP, 1)); REAL(yylval)[0] = R_PosInf; break; case 6: PROTECT(yylval = allocVector(REALSXP, 1)); REAL(yylval)[0] = R_NaN; break; } break; case FUNCTION: case WHILE: case REPEAT: case FOR: case IF: case NEXT: case BREAK: yylval = install(s); break; case IN: case ELSE: break; case SYMBOL: PROTECT(yylval = install(s)); break; } return keywords[i].token; } } return 0; } SEXP mkString(const char *s) { SEXP t; PROTECT(t = allocVector(STRSXP, 1)); STRING(t)[0] = mkChar(s); UNPROTECT(1); return t; } SEXP mkFloat(char *s) { SEXP t = allocVector(REALSXP, 1); REAL(t)[0] = atof(s); return t; } SEXP mkComplex(char *s) { SEXP t = allocVector(CPLXSXP, 1); COMPLEX(t)[0].r = 0; COMPLEX(t)[0].i = atof(s); return t; } SEXP mkNA(void) { SEXP t = allocVector(LGLSXP, 1); LOGICAL(t)[0] = NA_LOGICAL; return t; } SEXP mkTrue(void) { SEXP s = allocVector(LGLSXP, 1); LOGICAL(s)[0] = 1; return s; } SEXP mkFalse(void) { SEXP s = allocVector(LGLSXP, 1); LOGICAL(s)[0] = 0; return s; } void yyerror(char *s) { } static void CheckFormalArgs(SEXP formlist, SEXP new) { while (formlist != R_NilValue) { if (TAG(formlist) == new) { error("Repeated formal argument.\n"); } formlist = CDR(formlist); } } static char yytext[MAXELTSIZE]; static int SkipSpace(void) { int c; while ((c = xxgetc()) == ' ' || c == '\t' || c == '\f') /* nothing */; return c; } /* Note that with interactive use, EOF cannot occur inside */ /* a comment. However, semicolons inside comments make it */ /* appear that this does happen. For this reason we use the */ /* special assignment EndOfFile=2 to indicate that this is */ /* going on. This is detected and dealt with in Parse1Buffer. */ static int SkipComment(void) { char *p; int c; p = yytext; *p++ = '#'; while ((c = xxgetc()) != '\n' && c != R_EOF) *p++ = c; *p = '\0'; if (c == R_EOF) EndOfFile = 2; return c; } static int NumericValue(int c) { int seendot = (c == '.'); int seenexp = 0; char *p = yytext; *p++ = c; while (isdigit(c = xxgetc()) || c == '.' || c == 'e' || c == 'E') { if (c == 'E' || c == 'e') { if (seenexp) break; seenexp = 1; seendot = 1; *p++ = c; c = xxgetc(); if (!isdigit(c) && c != '+' && c != '-') break; } if (c == '.') { if (seendot) break; seendot = 1; } *p++ = c; } *p = '\0'; if(c == 'i') { yylval = mkComplex(yytext); } else { xxungetc(c); yylval = mkFloat(yytext); } PROTECT(yylval); return NUM_CONST; } /* Strings may contain the standard ANSI escapes and octal */ /* specifications of the form \o, \oo or \ooo, where 'o' */ /* is an octal digit. */ static int StringValue(int c) { int quote = c; char *p = yytext; while ((c = xxgetc()) != R_EOF && c != quote) { if (c == '\n') { xxungetc(c); return ERROR; } if (c == '\\') { c = xxgetc(); if ('0' <= c && c <= '8') { int octal = c - '0'; if ('0' <= (c = xxgetc()) && c <= '8') { octal = 8 * octal + c - '0'; if ('0' <= (c = xxgetc()) && c <= '8') { octal = 8 * octal + c - '0'; } else xxungetc(c); } else xxungetc(c); c = octal; } else { switch (c) { case 'a': c = '\a'; break; case 'b': c = '\b'; break; case 'f': c = '\f'; break; case 'n': c = '\n'; break; case 'r': c = '\r'; break; case 't': c = '\t'; break; case 'v': c = '\v'; break; case '\\': c = '\\'; break; } } } *p++ = c; } *p = '\0'; PROTECT(yylval = mkString(yytext)); return STR_CONST; } static int SpecialValue(int c) { char *p = yytext; *p++ = c; while ((c = xxgetc()) != R_EOF && c != '%') { if (c == '\n') { xxungetc(c); return ERROR; } *p++ = c; } if (c == '%') *p++ = c; *p++ = '\0'; yylval = install(yytext); return SPECIAL; } /* return 1 if name is a valid name 0 otherwise */ int isValidName(char *name) { char *p; int c, i; p = name; c = *p++; if( c != '.' && !isalpha(c) ) return 0; for (i = 0; keywords[i].name; i++) if (strcmp(keywords[i].name, name) == 0 && !(strcmp(name, "...")==0)) return 0; if (c == '.' ) { if( strlen(name)==1 ) return 1; while ( (c = *p++) ) if( !isdigit(c) ) { if( !isalpha(c) ) return 0; else break; }; if( c == '\0' ) return 0; } while ( c = *p++, (isalnum(c) || c=='.') ); if (c == '\0') return 1; else return 0; } static int SymbolValue(int c) { int kw; char *p = yytext; do { *p++ = c; } while ((c = xxgetc()) != R_EOF && (isalnum(c) || c == '.')); xxungetc(c); *p = '\0'; /* FIXME: check overrun conditions */ if ((kw = KeywordLookup(yytext))) { if ( kw == FUNCTION ) { if ( FunctionLevel++ == 0 && GenerateCode) { strcpy(FunctionSource, "function"); SourcePtr = FunctionSource + 8; } FunctionStart[FunctionLevel] = SourcePtr - 8; #if 0 printf("%d,%d\n",SourcePtr - FunctionSource, FunctionLevel); #endif } return kw; } PROTECT(yylval = install(yytext)); return SYMBOL; } /* Split the input stream into tokens. */ /* This is the lowest of the parsing levels. */ static int token() { int c, kw; if (SavedToken) { c = SavedToken; yylval = SavedLval; SavedLval = R_NilValue; SavedToken = 0; return c; } xxcharsave = xxcharcount; /* want to be able to go back one token */ c = SkipSpace(); if (c == '#') c = SkipComment(); if (c == R_EOF) return END_OF_INPUT; /* Either digits or symbols can start with a "." */ /* so we need to decide which it is and jump to */ /* the correct spot. */ if (c == '.') { kw = typeofnext(); if (kw >= 2) goto symbol; } /* literal numbers */ if (c == '.' || isdigit(c)) return NumericValue(c); /* literal strings */ if (c == '\"' || c == '\'') return StringValue(c); /* special functions */ if (c == '%') return SpecialValue(c); /* functions, constants and variables */ symbol: if (c == '.' || isalpha(c)) return SymbolValue(c); /* gag, barf, but the punters want it */ if (c == '_') { yylval = install("<-"); return LEFT_ASSIGN; } /* compound tokens */ switch (c) { case '<': if (nextchar('=')) { yylval = install("<="); return LE; } if (nextchar('-')) { yylval = install("<-"); return LEFT_ASSIGN; } if (nextchar('<')) { if (nextchar('-')) { yylval = install("<<-"); return LEFT_ASSIGN; } else return ERROR; } yylval = install("<"); return LT; case '-': if (nextchar('>')) { if (nextchar('>')) { yylval = install("<<-"); return RIGHT_ASSIGN; } else { yylval = install("<-"); return RIGHT_ASSIGN; } } yylval = install("-"); return '-'; case '>': if (nextchar('=')) { yylval = install(">="); return GE; } yylval = install(">"); return GT; case '!': if (nextchar('=')) { yylval = install("!="); return NE; } yylval = install("!"); return '!'; case '=': if (nextchar('=')) { yylval = install("=="); return EQ; } return '='; case ':': if (nextchar('=')) { yylval = install(":="); return LEFT_ASSIGN; } yylval = install(":"); return ':'; case '&': if (nextchar('&')) { yylval = install("&&"); return AND; } yylval = install("&"); return AND; case '|': if (nextchar('|')) { yylval = install("||"); return OR; } yylval = install("|"); return OR; case LBRACE: yylval = install("{"); return c; case RBRACE: return c; case '(': yylval = install("("); return c; case ')': return c; case '[': if (nextchar('[')) { yylval = install("[["); return LBB; } yylval = install("["); return c; case ']': return c; case '?': strcpy(yytext, "help"); yylval = install(yytext); return c; case '*': if (nextchar('*')) c='^'; yytext[0] = c; yytext[1] = '\0'; yylval = install(yytext); return c; case '+': case '/': case '^': case '~': case '$': yytext[0] = c; yytext[1] = '\0'; yylval = install(yytext); return c; default: return c; } } int yylex(void) { int tok; again: tok = token(); /* Newlines must be handled in a context */ /* sensitive way. The following block of */ /* deals directly with newlines in the */ /* body of "if" statements. */ if (tok == '\n') { if (EatLines || *contextp == '[' || *contextp == '(') goto again; /* The essence of this is that in the body of */ /* an "if", any newline must be checked to */ /* see if it is followed by an "else". */ /* such newlines are discarded. */ if (*contextp == 'i') { /* Find the next non-newline token */ while(tok == '\n') tok = token(); /* If we enounter "}", ")" or "]" then */ /* we know that all immediately preceding */ /* "if" bodies have been terminated. */ /* The corresponding "i" values are */ /* popped off the context stack. */ if (tok == RBRACE || tok == ')' || tok == ']' ) { while (*contextp == 'i') ifpop(); *contextp-- = 0; return tok; } /* When a "," is encountered, it terminates */ /* just the immediately preceding "if" body */ /* so we pop just a single "i" of the */ /* context stack. */ if (tok == ',') { ifpop(); return tok; } /* Tricky! If we find an "else" we must */ /* ignore the preceding newline. Any other */ /* token means that we must return the newline */ /* to terminate the "if" and "push back" that */ /* token so that we will obtain it on the next */ /* call to token. In either case sensitivity */ /* is lost, so we pop the "i" from the context */ /* stack. */ if(tok == ELSE) { EatLines = 1; ifpop(); return ELSE; } else { ifpop(); SavedToken = tok; SavedLval = yylval; return '\n'; } } else return '\n'; } /* Additional context sensitivities */ switch(tok) { /* Any newlines immediately following the */ /* the following tokens are discarded. The */ /* expressions are clearly incomplete. */ case '+': case '-': case '*': case '/': case '^': case LT: case LE: case GE: case GT: case EQ: case OR: case AND: case SPECIAL: case FUNCTION: case WHILE: case REPEAT: case FOR: case IN: case '?': case '!': case '=': case ':': case '~': case '$': case LEFT_ASSIGN: case RIGHT_ASSIGN: EatLines = 1; break; /* Push any "if" statements found and */ /* discard any immediately following newlines. */ case IF: IfPush(); EatLines = 1; break; /* Terminate any immediately preceding "if" */ /* statements and discard any immediately */ /* following newlines. */ case ELSE: ifpop(); EatLines = 1; break; /* These tokens terminate any immediately */ /* preceding "if" statements. */ case ';': case ',': ifpop(); break; /* Any newlines following these tokens can */ /* indicate the end of an expression. */ case SYMBOL: case STR_CONST: case NUM_CONST: case NULL_CONST: case NEXT: case BREAK: EatLines = 0; break; /* Handle brackets, braces and parentheses */ case LBB: *++contextp = '['; *++contextp = '['; break; case '[': *++contextp = tok; break; case LBRACE: *++contextp = tok; EatLines = 1; break; case '(': *++contextp = tok; break; case ']': while (*contextp == 'i') ifpop(); *contextp-- = 0; EatLines = 0; break; case RBRACE: while (*contextp == 'i') ifpop(); *contextp-- = 0; break; case ')': while (*contextp == 'i') ifpop(); *contextp-- = 0; EatLines = 0; break; } return tok; }