| char *rcs_lex = "$Id: lex.c,v 2.38 1996/11/08 12:49:35 roberto Exp roberto $"; |
| |
| |
| #include <ctype.h> |
| #include <string.h> |
| |
| #include "mem.h" |
| #include "tree.h" |
| #include "table.h" |
| #include "lex.h" |
| #include "inout.h" |
| #include "luadebug.h" |
| #include "parser.h" |
| |
| #define MINBUFF 260 |
| |
| #define next() (current = input()) |
| #define save(x) (yytext[tokensize++] = (x)) |
| #define save_and_next() (save(current), next()) |
| |
| |
| static int current; /* look ahead character */ |
| static Input input; /* input function */ |
| |
| |
| void lua_setinput (Input fn) |
| { |
| current = '\n'; |
| lua_linenumber = 0; |
| input = fn; |
| } |
| |
| void luaI_syntaxerror (char *s) |
| { |
| char msg[256]; |
| char *token = luaI_buffer(1); |
| if (token[0] == 0) |
| token = "<eof>"; |
| sprintf (msg,"%s;\n> last token read: \"%s\" at line %d in file %s", |
| s, token, lua_linenumber, lua_parsedfile); |
| lua_error (msg); |
| } |
| |
| |
| static struct |
| { |
| char *name; |
| int token; |
| } reserved [] = { |
| {"and", AND}, |
| {"do", DO}, |
| {"else", ELSE}, |
| {"elseif", ELSEIF}, |
| {"end", END}, |
| {"function", FUNCTION}, |
| {"if", IF}, |
| {"local", LOCAL}, |
| {"nil", NIL}, |
| {"not", NOT}, |
| {"or", OR}, |
| {"repeat", REPEAT}, |
| {"return", RETURN}, |
| {"then", THEN}, |
| {"until", UNTIL}, |
| {"while", WHILE} }; |
| |
| |
| #define RESERVEDSIZE (sizeof(reserved)/sizeof(reserved[0])) |
| |
| |
| void luaI_addReserved (void) |
| { |
| int i; |
| for (i=0; i<RESERVEDSIZE; i++) |
| { |
| TaggedString *ts = lua_createstring(reserved[i].name); |
| ts->marked = reserved[i].token; /* reserved word (always > 255) */ |
| } |
| } |
| |
| static int inclinenumber (int pragma_allowed) |
| { |
| ++lua_linenumber; |
| if (pragma_allowed && current == '$') { /* is a pragma? */ |
| char *buff = luaI_buffer(MINBUFF+1); |
| int i = 0; |
| next(); /* skip $ */ |
| while (isalnum(current)) { |
| if (i >= MINBUFF) luaI_syntaxerror("pragma too long"); |
| buff[i++] = current; |
| next(); |
| } |
| buff[i] = 0; |
| if (strcmp(buff, "debug") == 0) |
| lua_debug = 1; |
| else if (strcmp(buff, "nodebug") == 0) |
| lua_debug = 0; |
| else luaI_syntaxerror("invalid pragma"); |
| } |
| return lua_linenumber; |
| } |
| |
| static int read_long_string (char *yytext, int buffsize) |
| { |
| int cont = 0; |
| int tokensize = 2; /* '[[' already stored */ |
| while (1) |
| { |
| if (buffsize-tokensize <= 2) /* may read more than 1 char in one cicle */ |
| yytext = luaI_buffer(buffsize *= 2); |
| switch (current) |
| { |
| case 0: |
| save(0); |
| return WRONGTOKEN; |
| case '[': |
| save_and_next(); |
| if (current == '[') |
| { |
| cont++; |
| save_and_next(); |
| } |
| continue; |
| case ']': |
| save_and_next(); |
| if (current == ']') |
| { |
| if (cont == 0) goto endloop; |
| cont--; |
| save_and_next(); |
| } |
| continue; |
| case '\n': |
| save_and_next(); |
| inclinenumber(0); |
| continue; |
| default: |
| save_and_next(); |
| } |
| } endloop: |
| save_and_next(); /* pass the second ']' */ |
| yytext[tokensize-2] = 0; /* erases ']]' */ |
| luaY_lval.vWord = luaI_findconstantbyname(yytext+2); |
| yytext[tokensize-2] = ']'; /* restores ']]' */ |
| save(0); |
| return STRING; |
| } |
| |
| int luaY_lex (void) |
| { |
| static int linelasttoken = 0; |
| double a; |
| int buffsize = MINBUFF; |
| char *yytext = luaI_buffer(buffsize); |
| yytext[1] = yytext[2] = yytext[3] = 0; |
| if (lua_debug) |
| luaI_codedebugline(linelasttoken); |
| linelasttoken = lua_linenumber; |
| while (1) |
| { |
| int tokensize = 0; |
| switch (current) |
| { |
| case '\n': |
| next(); |
| linelasttoken = inclinenumber(1); |
| continue; |
| |
| case ' ': case '\t': case '\r': /* CR: to avoid problems with DOS */ |
| next(); |
| continue; |
| |
| case '-': |
| save_and_next(); |
| if (current != '-') return '-'; |
| do { next(); } while (current != '\n' && current != 0); |
| continue; |
| |
| case '[': |
| save_and_next(); |
| if (current != '[') return '['; |
| else |
| { |
| save_and_next(); /* pass the second '[' */ |
| return read_long_string(yytext, buffsize); |
| } |
| |
| case '=': |
| save_and_next(); |
| if (current != '=') return '='; |
| else { save_and_next(); return EQ; } |
| |
| case '<': |
| save_and_next(); |
| if (current != '=') return '<'; |
| else { save_and_next(); return LE; } |
| |
| case '>': |
| save_and_next(); |
| if (current != '=') return '>'; |
| else { save_and_next(); return GE; } |
| |
| case '~': |
| save_and_next(); |
| if (current != '=') return '~'; |
| else { save_and_next(); return NE; } |
| |
| case '"': |
| case '\'': |
| { |
| int del = current; |
| save_and_next(); |
| while (current != del) |
| { |
| if (buffsize-tokensize <= 2) /* may read more than 1 char in one cicle */ |
| yytext = luaI_buffer(buffsize *= 2); |
| switch (current) |
| { |
| case 0: |
| case '\n': |
| save(0); |
| return WRONGTOKEN; |
| case '\\': |
| next(); /* do not save the '\' */ |
| switch (current) |
| { |
| case 'n': save('\n'); next(); break; |
| case 't': save('\t'); next(); break; |
| case 'r': save('\r'); next(); break; |
| case '\n': save_and_next(); inclinenumber(0); break; |
| default : save_and_next(); break; |
| } |
| break; |
| default: |
| save_and_next(); |
| } |
| } |
| next(); /* skip delimiter */ |
| save(0); |
| luaY_lval.vWord = luaI_findconstantbyname(yytext+1); |
| tokensize--; |
| save(del); save(0); /* restore delimiter */ |
| return STRING; |
| } |
| |
| case 'a': case 'b': case 'c': case 'd': case 'e': |
| case 'f': case 'g': case 'h': case 'i': case 'j': |
| case 'k': case 'l': case 'm': case 'n': case 'o': |
| case 'p': case 'q': case 'r': case 's': case 't': |
| case 'u': case 'v': case 'w': case 'x': case 'y': |
| case 'z': |
| case 'A': case 'B': case 'C': case 'D': case 'E': |
| case 'F': case 'G': case 'H': case 'I': case 'J': |
| case 'K': case 'L': case 'M': case 'N': case 'O': |
| case 'P': case 'Q': case 'R': case 'S': case 'T': |
| case 'U': case 'V': case 'W': case 'X': case 'Y': |
| case 'Z': |
| case '_': |
| { |
| TaggedString *ts; |
| do { save_and_next(); } while (isalnum(current) || current == '_'); |
| save(0); |
| ts = lua_createstring(yytext); |
| if (ts->marked > 2) |
| return ts->marked; /* reserved word */ |
| luaY_lval.pTStr = ts; |
| ts->marked = 2; /* avoid GC */ |
| return NAME; |
| } |
| |
| case '.': |
| save_and_next(); |
| if (current == '.') |
| { |
| save_and_next(); |
| if (current == '.') |
| { |
| save_and_next(); |
| return DOTS; /* ... */ |
| } |
| else return CONC; /* .. */ |
| } |
| else if (!isdigit(current)) return '.'; |
| /* current is a digit: goes through to number */ |
| a=0.0; |
| goto fraction; |
| |
| case '0': case '1': case '2': case '3': case '4': |
| case '5': case '6': case '7': case '8': case '9': |
| a=0.0; |
| do { |
| a=10.0*a+(current-'0'); |
| save_and_next(); |
| } while (isdigit(current)); |
| if (current == '.') { |
| save_and_next(); |
| if (current == '.') |
| luaI_syntaxerror( |
| "ambiguous syntax (decimal point x string concatenation)"); |
| } |
| fraction: |
| { double da=0.1; |
| while (isdigit(current)) |
| { |
| a+=(current-'0')*da; |
| da/=10.0; |
| save_and_next(); |
| } |
| if (current == 'e' || current == 'E') |
| { |
| int e=0; |
| int neg; |
| double ea; |
| save_and_next(); |
| neg=(current=='-'); |
| if (current == '+' || current == '-') save_and_next(); |
| if (!isdigit(current)) { save(0); return WRONGTOKEN; } |
| do { |
| e=10.0*e+(current-'0'); |
| save_and_next(); |
| } while (isdigit(current)); |
| for (ea=neg?0.1:10.0; e>0; e>>=1) |
| { |
| if (e & 1) a*=ea; |
| ea*=ea; |
| } |
| } |
| luaY_lval.vFloat = a; |
| save(0); |
| return NUMBER; |
| } |
| |
| default: /* also end of program (0) */ |
| { |
| save_and_next(); |
| return yytext[0]; |
| } |
| } |
| } |
| } |
| |