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#include "lie.h"
#include "parser.h"
#define local static
#define STRBLSIZE 500
#define hash_mod 1997
#define shift (c= backed_up ? backed_up=false, next_c : fetch_char())
#define unput(c) (backed_up=true,next_c=c)
#define first_semi_keyword HELP
#define first_type_id (HELP-6)
#define keyword_limit array_size(keyword)
#define subject_name_limit 64
int lineno=1;
local char* char_point=NULL;
local int chars_left=0;
char* name_tab[hash_mod]; /* actual names of identifiers */
local short hash_tab[hash_mod];
/* non-negative entries point into |name_tab| array */
local short hash_count=0;
symblst symbol_tab[hash_mod];
local char* tok_buf; /* points to currently recorded string */
local int tok_len,tok_buf_size;
local int c, next_c;
local boolean backed_up=false; /* whether we should use |next_c| next */
local boolean start_of_command;
local enum { normal, help, edit, learn, ended } command_type;
local boolean ignore_nl; /* whether |'\n'| is treated as space */
local int nesting; /* number of pending opening symbols */
local boolean short_ints;
char* keyword[]=
{ "",
"if", "then", "else", "fi",
"for", "to", "downto", "in", "row", "while", "do", "od",
"loc", "return", "break",
"make", "iapply", "vapply", "mapply",
"on", "off", "setdefault", "savestate", "restorestate",
"mat", "vec", "int", "grp", "tex", "pol",
"help", "type",
"edit", "read", "write", "monfil",
"learn", "exec", "quit", "exit",
"listvars", "listfuns", "listops",
"maxnodes", "maxobjects"
};
char subject_name[subject_name_limit];
local char* store(char* s,int len)
{ int n= ++len>STRBLSIZE ? len : STRBLSIZE; /* size of new block if needed */
char* result=char_point;
if (len>chars_left)
result=char_point=alloc_array(char,chars_left=n);
char_point+=len; chars_left-=len; return strncpy(result,s,len);
}
local short hash(char* s) /* |s| is a non-empty string */
{ char c; long r=*s++; while ((c=*s++)!='\0') r=(c+(r<<8))%hash_mod;
return (short)r;
}
strtype match(char* str, boolean copy)
{ short i,h=hash(str);
while ((i=hash_tab[h])>=0)
if (strcmp(name_tab[i],str)==0) return i; /* identifier found in table */
else if (++h==hash_mod) h=0; /* move past occupied slot */
if (hash_count>=hash_mod-1) fatal("Hash table overflow");
hash_tab[h]= hash_count; /* this number represents the new identifier */
name_tab[hash_count]=copy ? store(str,(int)strlen(str)): str;
return hash_count++;
}
short creatmapname(char *a)
{ char *s=strcat(strcpy(alloc_array(char,strlen(a)+2),"."),a);
short result=match(s,true); free(s); return result;
}
void clear_symbol_tab(void)
{ int i; for (i=0; i<hash_mod; ++i) symbol_tab[i]=NULL; }
local void app_c(char c)
{ if (tok_len==tok_buf_size)
{ char* p=tok_buf;
tok_buf=strncpy(alloc_array(char,tok_buf_size*=2),tok_buf,tok_len);
freearr(p);
}
tok_buf[tok_len++]=c;
}
void init_scanner(void) {
{ int i; for(i=0; i<hash_mod; ++i) hash_tab[i]=-1; }
clear_symbol_tab();
tok_buf=alloc_array(char,tok_buf_size=8);
{ int i; for (i=0; i<keyword_limit; i++) match(keyword[i],false);
}
}
void init_command(void)
{ start_of_command=true; command_type=normal; ignore_nl=false; nesting=0;
short_ints=false; fetch_line(promptlabel);
}
void clear_input(void)
{ if (command_type!=ended) do shift; while(c!='\n' && c!=EOF); }
local void skip_space(void)
{ do
{ if (c=='\\') ignore_nl=true;
else if (c=='\n')
{ ++lineno;
if (ignore_nl || nesting>0)
{ ignore_nl=false; fetch_line(PROMPT2); }
else break; /* stop at non-ignored newline */
}
else if (c=='#')
{ do shift; while (c!='#' && c!='\n' && c!=EOF);
if (c!='#') continue;
/* |'\n'| requires action, |EOF| must not be skipped */
}
else if (!isspace(c)) break;
shift;
} while(true);
}
int yylex(void)
{ short code;
if (command_type==ended) return 0;
restart: shift; skip_space(); ignore_nl=false;
if (c==EOF || c=='\n')
{ if (c==EOF && cur_in==stdin) stop=true;
command_type=ended; return ENTER;
}
if (command_type!=normal)
if (c=='>' && command_type==help)
{ code= shift!='>' ? unput(c),WRITEHELP : APPENDHELP; command_type=edit; }
else
{ code=ANY_STRING; tok_len=0;
do app_c(c),shift;
while (c!='\n' && c!=EOF &&
!(command_type!=learn &&
(isspace(c) || command_type==help && c=='>'))
);
if (command_type==learn) /* then strip trailing spaces */
while (tok_len>0 && isspace(tok_buf[tok_len-1])) --tok_len;
app_c('\0'); unput(c);
if (command_type!=help) yylval.text=tok_buf;
else
{ sprintf(subject_name,"%.*s",subject_name_limit-1,tok_buf);
yylval.text=subject_name;
}
}
else
{ if (isupper(c))
{ char type=c; int next=shift; unput(next); c=type;
if (!isalpha(next) && next!='_')
/* else fall through for multi-letter identifier */
{ if (strchr("ABCDEFGT",type)!=NULL)
{ code=GROUPID; yylval.sub=type; short_ints=true; }
else if (type=='X' || type=='Y') code=X;
else error ("Lone `%c' not legal as identifier.\n",type);
goto finish;
}
}
if (isalpha(c))
{ tok_len=0;
do app_c(c), shift; while(isalpha(c) || isdigit(c) || c=='_');
app_c('\0'); unput(c);
code=match(tok_buf,true);
if (code>= (start_of_command ? keyword_limit : first_semi_keyword))
{ yylval.sub=code; code=IDENT; }
else if (code>=first_type_id && code<first_semi_keyword)
{ yylval.sub=code-first_type_id; code=TYPEID; }
else switch(code)
{ case IF: case FOR: case WHILE: ++nesting;
break; case FI: case OD: --nesting;
break; case APPLY: case APPLY+1: case APPLY+2:
yylval.sub=code-APPLY; code=APPLY;
break; case LISTCOMMAND: case LISTCOMMAND+1: case LISTCOMMAND+2:
yylval.sub=code-LISTCOMMAND; code=LISTCOMMAND;
break; case QUIT+1: --code; /* \.{exit} $\to$ \.{quit} */
break; case HELP: yylval.sub=0; command_type=help;
break; case MAXNODES: case MAXOBJECTS: case ON:
short_ints=true; goto finish;
break; case EDIT: case READ: case WRITE: case MONFIL: command_type=edit;
break; case LEARN: case EXEC: command_type=learn;
}
}
else if (isdigit(c))
{ tok_len=0; do app_c(c),shift; while (isdigit(c));
app_c('\0'); unput(c);
if (short_ints) { code=INT; yylval.val=atol(tok_buf); }
else { code=NUMBER; yylval.num=str2bigint(tok_buf); }
}
else
switch(c)
{
default: printf("Unrecognised character `%c'\n",c); goto restart;
case '"':
{ tok_len=0;
do
{ while (shift!='"' && c!='\n' && c!=EOF) app_c(c);
if (c!='"')
{ printf("Unclosed string denotation on line %d.\n"
"\t(for multi-line strings use string-break.)\n", lineno);
break;
}
if (shift=='"') app_c(c); else skip_space();
} while (c=='"'); /* continue after quote-image or string-break */
app_c('\0'); unput(c); yylval.sym=addtekstnode(tok_buf); code=TEXT;
}
break; case '?': code=HELP; yylval.sub=1; command_type=help;
break; case '@': code=QUIT;
break; case ';': code=SEMICOLON; ignore_nl=true;
break; case ',': code=COMMA;
break; case '(': code=LPAR; ++nesting;
break; case ')': code=RPAR; --nesting;
break; case '{': code=LBRACE; ++nesting;
break; case '}': code=RBRACE; --nesting;
break; case '[': code=LBRACK; ++nesting;
break; case ']': code=RBRACK; --nesting;
break; case '|': if (shift=='|') code=OR; else { unput(c); code=BAR;}
ignore_nl=true;
break; case '&': if (shift!='&') unput(c); code=AND; ignore_nl=true;
break; case '!': if (shift=='=') { code=RELOP; yylval.sub=1; }
else { unput(c); code=NOT; }
break; case '=': if (shift=='=') { code=RELOP; yylval.sub=0; }
else { unput(c); code=BECOMES; }
ignore_nl=true;
break; case '<': code=RELOP; yylval.sub= shift=='=' ? 4 : (unput(c),2);
ignore_nl=true;
break; case '>': code=RELOP; yylval.sub= shift=='=' ? 5 : (unput(c),3);
ignore_nl=true;
break; case '+': if (shift=='=') code=PLUSAB;
else { unput(c); code=ADDOP; yylval.sub=0; }
ignore_nl=true;
break; case '-': code=ADDOP; yylval.sub=1; ignore_nl=true;
break; case '*': code=TIMES; ignore_nl=true;
break; case '/': code=DIVOP; yylval.sub=0; ignore_nl=true;
break; case '%': code=DIVOP; yylval.sub=1; ignore_nl=true;
break; case '^': code=POWER; ignore_nl=true;
break; case '$': code=DOLLAR; tok_len=0;
do app_c(c),shift; while(isdigit(c));
app_c('\0'); unput(c);
yylval.sub=match(tok_buf,true);
break; case ':': code=COLON; command_type=learn;
}
}
short_ints=false; /* flag lasts for one token only */
finish: start_of_command=false; return code;
}
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