%option reentrant bison-bridge bison-locations %option noyywrap %option never-interactive %option stack %option nodefault %option nounput noyy_top_state %x STRING %x IND_STRING %x INSIDE_DOLLAR_CURLY %{ #include "nixexpr.hh" #include "parser-tab.hh" using namespace nix; namespace nix { static void initLoc(YYLTYPE * loc) { loc->first_line = loc->last_line = 1; loc->first_column = loc->last_column = 1; } static void adjustLoc(YYLTYPE * loc, const char * s, size_t len) { loc->first_line = loc->last_line; loc->first_column = loc->last_column; while (len--) { switch (*s++) { case '\r': if (*s == '\n') /* cr/lf */ s++; /* fall through */ case '\n': ++loc->last_line; loc->last_column = 1; break; default: ++loc->last_column; } } } static Expr * unescapeStr(SymbolTable & symbols, const char * s, size_t length) { string t; t.reserve(length); char c; while ((c = *s++)) { if (c == '\\') { assert(*s); c = *s++; if (c == 'n') t += '\n'; else if (c == 'r') t += '\r'; else if (c == 't') t += '\t'; else t += c; } else if (c == '\r') { /* Normalise CR and CR/LF into LF. */ t += '\n'; if (*s == '\n') s++; /* cr/lf */ } else t += c; } return new ExprString(symbols.create(t)); } } #define YY_USER_INIT initLoc(yylloc) #define YY_USER_ACTION adjustLoc(yylloc, yytext, yyleng); #define PUSH_STATE(state) yy_push_state(state, yyscanner) #define POP_STATE() yy_pop_state(yyscanner) %} ANY .|\n ID [a-zA-Z\_][a-zA-Z0-9\_\'\-]* INT [0-9]+ FLOAT (([1-9][0-9]*\.[0-9]*)|(0?\.[0-9]+))([Ee][+-]?[0-9]+)? PATH [a-zA-Z0-9\.\_\-\+]*(\/[a-zA-Z0-9\.\_\-\+]+)+\/? HPATH \~(\/[a-zA-Z0-9\.\_\-\+]+)+\/? SPATH \<[a-zA-Z0-9\.\_\-\+]+(\/[a-zA-Z0-9\.\_\-\+]+)*\> URI [a-zA-Z][a-zA-Z0-9\+\-\.]*\:[a-zA-Z0-9\%\/\?\:\@\&\=\+\$\,\-\_\.\!\~\*\']+ %% <INITIAL,INSIDE_DOLLAR_CURLY>{ if { return IF; } then { return THEN; } else { return ELSE; } assert { return ASSERT; } with { return WITH; } let { return LET; } in { return IN; } rec { return REC; } inherit { return INHERIT; } or { return OR_KW; } \.\.\. { return ELLIPSIS; } \=\= { return EQ; } \!\= { return NEQ; } \<\= { return LEQ; } \>\= { return GEQ; } \&\& { return AND; } \|\| { return OR; } \-\> { return IMPL; } \/\/ { return UPDATE; } \+\+ { return CONCAT; } {ID} { yylval->id = strdup(yytext); return ID; } {INT} { errno = 0; yylval->n = strtol(yytext, 0, 10); if (errno != 0) throw ParseError(format("invalid integer '%1%'") % yytext); return INT; } {FLOAT} { errno = 0; yylval->nf = strtod(yytext, 0); if (errno != 0) throw ParseError(format("invalid float '%1%'") % yytext); return FLOAT; } \$\{ { PUSH_STATE(INSIDE_DOLLAR_CURLY); return DOLLAR_CURLY; } } \} { return '}'; } <INSIDE_DOLLAR_CURLY>\} { POP_STATE(); return '}'; } \{ { return '{'; } <INSIDE_DOLLAR_CURLY>\{ { PUSH_STATE(INSIDE_DOLLAR_CURLY); return '{'; } <INITIAL,INSIDE_DOLLAR_CURLY>\" { PUSH_STATE(STRING); return '"'; } <STRING>([^\$\"\\]|\$[^\{\"\\]|\\{ANY}|\$\\{ANY})*\$/\" | <STRING>([^\$\"\\]|\$[^\{\"\\]|\\{ANY}|\$\\{ANY})+ { /* It is impossible to match strings ending with '$' with one regex because trailing contexts are only valid at the end of a rule. (A sane but undocumented limitation.) */ yylval->e = unescapeStr(data->symbols, yytext, yyleng); return STR; } <STRING>\$\{ { PUSH_STATE(INSIDE_DOLLAR_CURLY); return DOLLAR_CURLY; } <STRING>\" { POP_STATE(); return '"'; } <STRING>\$|\\|\$\\ { /* This can only occur when we reach EOF, otherwise the above (...|\$[^\{\"\\]|\\.|\$\\.)+ would have triggered. This is technically invalid, but we leave the problem to the parser who fails with exact location. */ return STR; } <INITIAL,INSIDE_DOLLAR_CURLY>\'\'(\ *\n)? { PUSH_STATE(IND_STRING); return IND_STRING_OPEN; } <IND_STRING>([^\$\']|\$[^\{\']|\'[^\'\$])+ { yylval->e = new ExprIndStr(yytext); return IND_STR; } <IND_STRING>\'\'\$ | <IND_STRING>\$ { yylval->e = new ExprIndStr("$"); return IND_STR; } <IND_STRING>\'\'\' { yylval->e = new ExprIndStr("''"); return IND_STR; } <IND_STRING>\'\'\\{ANY} { yylval->e = unescapeStr(data->symbols, yytext + 2, yyleng - 2); return IND_STR; } <IND_STRING>\$\{ { PUSH_STATE(INSIDE_DOLLAR_CURLY); return DOLLAR_CURLY; } <IND_STRING>\'\' { POP_STATE(); return IND_STRING_CLOSE; } <IND_STRING>\' { yylval->e = new ExprIndStr("'"); return IND_STR; } <INITIAL,INSIDE_DOLLAR_CURLY>{ {PATH} { if (yytext[yyleng-1] == '/') throw ParseError("path '%s' has a trailing slash", yytext); yylval->path = strdup(yytext); return PATH; } {HPATH} { if (yytext[yyleng-1] == '/') throw ParseError("path '%s' has a trailing slash", yytext); yylval->path = strdup(yytext); return HPATH; } {SPATH} { yylval->path = strdup(yytext); return SPATH; } {URI} { yylval->uri = strdup(yytext); return URI; } [ \t\r\n]+ /* eat up whitespace */ \#[^\r\n]* /* single-line comments */ \/\*([^*]|\*+[^*/])*\*+\/ /* long comments */ {ANY} return yytext[0]; } <<EOF>> { data->atEnd = true; return 0; } %%