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Diffstat (limited to 'mixlib/mix_eval_scanner.l')
| -rw-r--r-- | mixlib/mix_eval_scanner.l | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/mixlib/mix_eval_scanner.l b/mixlib/mix_eval_scanner.l new file mode 100644 index 0000000..443654d --- /dev/null +++ b/mixlib/mix_eval_scanner.l @@ -0,0 +1,246 @@ +/* -*-c-*- ------------------ mix_eval_scanner.l : + * scanner used by mix_eval_t + * ------------------------------------------------------------------ + * Last change: Time-stamp: <00/12/02 22:48:00 jose> + * ------------------------------------------------------------------ + * Copyright (C) 2000 jose antonio ortega ruiz <jaortega@acm.org> + * + * 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. + * + */ + +%{ +#include "mix.h" +#include "xmix_eval.h" + +#define YY_DECL \ + mix_eval_result_t mix_eval_expr (mix_eval_data_ *data) + +#define RETURN_STATE(err) \ + do { \ + done = TRUE; \ + state = err; \ + BEGIN (INITIAL); \ + } while (FALSE) + +#define CLEAN_UP() \ + do { \ + yy_delete_buffer (buffer); \ + g_free (expr_cp); \ + } while (FALSE) + +static mix_word_t + eval_binop_ (const gchar *op, mix_word_t x, mix_word_t y); + +static void + unput_word_ (mix_word_t word); + +%} + +%option nomain +%option caseless +%option pointer +%option stack +%option noyywrap +%option noyy_top_state +%option noreject +%option outfile="lex.yy.c" + +%s EVAL +%s WEVAL + +ws [ \t]+ +digit [0-9] +letter [A-Z] +number [+-]?{digit}+ +mixchar [0-9A-Z .,'')(+*/=$<>@;:\-] +locsymbol {digit}H +flocsymbol {digit}F +blocsymbol {digit}B +symbol {digit}*{letter}+[A-Z0-9]* +binop "+"|"-"|"*"|"/"|"//"|":" +atexpr {digit}+|{symbol}|\* +expr [+-]?{atexpr}({binop}{1}{atexpr})* +fpart \({expr}\) +wexpr {expr}({fpart})?(,{expr}({fpart})?)* + + +%% + +%{ + YY_BUFFER_STATE buffer; + mix_word_t expr_val = MIX_WORD_ZERO, wexpr_val = MIX_WORD_ZERO; + mix_word_t wexpr_val_tmp = MIX_WORD_ZERO; + mix_eval_result_t state = MIX_EVAL_OK; + gchar *expr_cp; + gboolean is_fp = FALSE, done = FALSE; + g_assert (data != NULL && data->expr != NULL); + /* make room enough to unput computed values */ + expr_cp = g_strdup_printf (" %s", data->expr); + buffer = yy_scan_string (expr_cp); +%} + + +<*><<EOF>> { + CLEAN_UP (); + return MIX_EVAL_INTERN; +} + +<INITIAL>{ + {ws} /* eat whitespace */ + . { + if (!done && state == MIX_EVAL_OK) { + yyless (0); + yy_push_state (WEVAL); + } else { + CLEAN_UP (); + if (state == MIX_EVAL_OK) return (MIX_EVAL_SYNTAX); + return state; + } + } + "\n" { + CLEAN_UP(); + if (state == MIX_EVAL_OK) + data->value = wexpr_val; + return state; + } +} + +<WEVAL>{ + {number}"(" { + is_fp = TRUE; + wexpr_val_tmp = mix_word_new (atol (yytext)); + } + {number}")" { + glong val = atol (yytext); + if ( !is_fp ) { + RETURN_STATE (MIX_EVAL_MIS_PAREN); + } else if ( val < 0 || val > MIX_BYTE_MAX + || !mix_fspec_is_valid (mix_byte_new (val)) ) { + RETURN_STATE (MIX_EVAL_INV_FSPEC); + } else { + is_fp = FALSE; + wexpr_val = mix_word_store_field (mix_byte_new (val), + wexpr_val_tmp, + wexpr_val); + } + } + {number} { + wexpr_val = mix_word_new (atol (yytext)); + } + {expr} yyless (0); yy_push_state (EVAL); + ,/{expr} /* eat comma if followed by expression */ + [\t\n ] { /* ok if not inside an f-part */ + if ( is_fp ) { + RETURN_STATE (MIX_EVAL_MIS_PAREN); + } + unput (yytext[yyleng-1]); + done = TRUE; + yy_pop_state (); + } + . RETURN_STATE (MIX_EVAL_SYNTAX); +} + +<EVAL>{ + {binop}{digit}+ { + const gchar *s = ( yytext[1] == '/' ) ? yytext+2 : yytext+1; + mix_word_t value = mix_word_new (atol (s)); + expr_val = eval_binop_ (yytext, expr_val, value); + } + {binop}{symbol} { + const gchar *s = ( yytext[1] == '/' ) ? yytext+2 : yytext+1; + if ( !mix_symbol_table_is_defined (data->table, s) ) { + RETURN_STATE (MIX_EVAL_UNDEF_SYM); + } + expr_val = eval_binop_ (yytext, expr_val, + mix_symbol_table_value (data->table, s)); + } + "***" { + mix_word_t loc = mix_short_to_word_fast (data->loc); + (void)mix_word_mul (loc, loc, NULL, &loc); + unput_word_ (loc); + } + {binop}"*" { + expr_val = eval_binop_ (yytext, expr_val, + mix_short_to_word_fast (data->loc)); + } + "*" unput_word_ (mix_short_to_word_fast (data->loc)); + {number} expr_val = mix_word_new (atol (yytext)); + {symbol} { + if ( !mix_symbol_table_is_defined (data->table, yytext) ) { + RETURN_STATE (MIX_EVAL_UNDEF_SYM); + } + expr_val = mix_symbol_table_value (data->table, yytext); + } + [,)(\n\t ] { + unput (yytext[0]); + unput_word_ (expr_val); + yy_pop_state (); + } + + . RETURN_STATE (MIX_EVAL_SYNTAX); +} + + +%% + +static mix_word_t +eval_binop_ (const gchar *op, mix_word_t x, mix_word_t y) +{ + mix_word_t result = MIX_WORD_ZERO; + switch (op[0]) + { + case '+': + result = mix_word_add (x,y); + break; + case '-': + result = mix_word_sub (x,y); + break; + case '*': + mix_word_mul (x, y, NULL, &result); + break; + case ':': + { + mix_word_t a; + mix_word_mul (x, 8, NULL, &a); + result = mix_word_add (a, y); + break; + } + case '/': + if ( strlen (op) > 1 && op[1] == '/' ) { + mix_word_div (x,MIX_WORD_ZERO,y, &result, NULL); + } else { + mix_word_div (MIX_WORD_ZERO, x, y, &result, NULL); + } + break; + default: + g_assert_not_reached (); + } + return result; +} + + +static void +unput_word_ (mix_word_t word) +{ + gchar *value; + gint k; + value = g_strdup_printf ("%s%ld", + mix_word_is_negative (word)? "-":"+", + mix_word_magnitude (word)); + for (k = strlen (value) - 1; k >= 0; --k) + unput (value[k]); + g_free (value); +} |