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Diffstat (limited to 'contrib/bc/dc/stack.c')
| -rw-r--r-- | contrib/bc/dc/stack.c | 457 |
1 files changed, 457 insertions, 0 deletions
diff --git a/contrib/bc/dc/stack.c b/contrib/bc/dc/stack.c new file mode 100644 index 0000000..c8cd195 --- /dev/null +++ b/contrib/bc/dc/stack.c @@ -0,0 +1,457 @@ +/* + * implement stack functions for dc + * + * Copyright (C) 1994, 1997 Free Software Foundation, Inc. + * + * 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, 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, you can either send email to this + * program's author (see below) or write to: The Free Software Foundation, + * Inc.; 675 Mass Ave. Cambridge, MA 02139, USA. + */ + +/* This module is the only one that knows what stacks (both the + * regular evaluation stack and the named register stacks) + * look like. + */ + +#include "config.h" + +#include <stdio.h> +#ifdef HAVE_STDLIB_H +# include <stdlib.h> +#endif +#include "dc.h" +#include "dc-proto.h" +#include "dc-regdef.h" + +/* an oft-used error message: */ +#define Empty_Stack fprintf(stderr, "%s: stack empty\n", progname) + + +/* simple linked-list implementaion suffices: */ +struct dc_list { + dc_data value; + struct dc_list *link; +}; +typedef struct dc_list dc_list; + +/* the anonymous evaluation stack */ +static dc_list *dc_stack=NULL; + +/* the named register stacks */ +static dc_list *dc_register[DC_REGCOUNT]; + + +/* allocate a new dc_list item */ +static dc_list * +dc_alloc DC_DECLVOID() +{ + dc_list *result; + + result = dc_malloc(sizeof *result); + result->value.dc_type = DC_UNINITIALIZED; + result->link = NULL; + return result; +} + + +/* check that there are two numbers on top of the stack, + * then call op with the popped numbers. Construct a dc_data + * value from the dc_num returned by op and push it + * on the stack. + * If the op call doesn't return DC_SUCCESS, then leave the stack + * unmodified. + */ +void +dc_binop DC_DECLARG((op, kscale)) + int (*op)DC_PROTO((dc_num, dc_num, int, dc_num *)) DC_DECLSEP + int kscale DC_DECLEND +{ + dc_data a; + dc_data b; + dc_data r; + + if (!dc_stack || !dc_stack->link){ + Empty_Stack; + return; + } + if (dc_stack->value.dc_type!=DC_NUMBER + || dc_stack->link->value.dc_type!=DC_NUMBER){ + fprintf(stderr, "%s: non-numeric value\n", progname); + return; + } + (void)dc_pop(&b); + (void)dc_pop(&a); + if ((*op)(a.v.number, b.v.number, kscale, &r.v.number) == DC_SUCCESS){ + r.dc_type = DC_NUMBER; + dc_push(r); + dc_free_num(&a.v.number); + dc_free_num(&b.v.number); + }else{ + /* op failed; restore the stack */ + dc_push(a); + dc_push(b); + } +} + +/* check that there are two numbers on top of the stack, + * then call op with the popped numbers. Construct two dc_data + * values from the dc_num's returned by op and push them + * on the stack. + * If the op call doesn't return DC_SUCCESS, then leave the stack + * unmodified. + */ +void +dc_binop2 DC_DECLARG((op, kscale)) + int (*op)DC_PROTO((dc_num, dc_num, int, dc_num *, dc_num *)) DC_DECLSEP + int kscale DC_DECLEND +{ + dc_data a; + dc_data b; + dc_data r1; + dc_data r2; + + if (!dc_stack || !dc_stack->link){ + Empty_Stack; + return; + } + if (dc_stack->value.dc_type!=DC_NUMBER + || dc_stack->link->value.dc_type!=DC_NUMBER){ + fprintf(stderr, "%s: non-numeric value\n", progname); + return; + } + (void)dc_pop(&b); + (void)dc_pop(&a); + if ((*op)(a.v.number, b.v.number, kscale, + &r1.v.number, &r2.v.number) == DC_SUCCESS){ + r1.dc_type = DC_NUMBER; + dc_push(r1); + r2.dc_type = DC_NUMBER; + dc_push(r2); + dc_free_num(&a.v.number); + dc_free_num(&b.v.number); + }else{ + /* op failed; restore the stack */ + dc_push(a); + dc_push(b); + } +} + +/* check that there are two numbers on top of the stack, + * then call dc_compare with the popped numbers. + * Return negative, zero, or positive based on the ordering + * of the two numbers. + */ +int +dc_cmpop DC_DECLVOID() +{ + int result; + dc_data a; + dc_data b; + + if (!dc_stack || !dc_stack->link){ + Empty_Stack; + return 0; + } + if (dc_stack->value.dc_type!=DC_NUMBER + || dc_stack->link->value.dc_type!=DC_NUMBER){ + fprintf(stderr, "%s: non-numeric value\n", progname); + return 0; + } + (void)dc_pop(&b); + (void)dc_pop(&a); + result = dc_compare(b.v.number, a.v.number); + dc_free_num(&a.v.number); + dc_free_num(&b.v.number); + return result; +} + +/* check that there are three numbers on top of the stack, + * then call op with the popped numbers. Construct a dc_data + * value from the dc_num returned by op and push it + * on the stack. + * If the op call doesn't return DC_SUCCESS, then leave the stack + * unmodified. + */ +void +dc_triop DC_DECLARG((op, kscale)) + int (*op)DC_PROTO((dc_num, dc_num, dc_num, int, dc_num *)) DC_DECLSEP + int kscale DC_DECLEND +{ + dc_data a; + dc_data b; + dc_data c; + dc_data r; + + if (!dc_stack || !dc_stack->link || !dc_stack->link->link){ + Empty_Stack; + return; + } + if (dc_stack->value.dc_type!=DC_NUMBER + || dc_stack->link->value.dc_type!=DC_NUMBER + || dc_stack->link->link->value.dc_type!=DC_NUMBER){ + fprintf(stderr, "%s: non-numeric value\n", progname); + return; + } + (void)dc_pop(&c); + (void)dc_pop(&b); + (void)dc_pop(&a); + if ((*op)(a.v.number, b.v.number, c.v.number, + kscale, &r.v.number) == DC_SUCCESS){ + r.dc_type = DC_NUMBER; + dc_push(r); + dc_free_num(&a.v.number); + dc_free_num(&b.v.number); + dc_free_num(&c.v.number); + }else{ + /* op failed; restore the stack */ + dc_push(a); + dc_push(b); + dc_push(c); + } +} + + +/* initialize the register stacks to their initial values */ +void +dc_register_init DC_DECLVOID() +{ + int i; + + for (i=0; i<DC_REGCOUNT; ++i) + dc_register[i] = NULL; +} + +/* clear the evaluation stack */ +void +dc_clear_stack DC_DECLVOID() +{ + dc_list *n; + dc_list *t; + + for (n=dc_stack; n; n=t){ + t = n->link; + if (n->value.dc_type == DC_NUMBER) + dc_free_num(&n->value.v.number); + else if (n->value.dc_type == DC_STRING) + dc_free_str(&n->value.v.string); + else + dc_garbage("in stack", -1); + free(n); + } + dc_stack = NULL; +} + +/* push a value onto the evaluation stack */ +void +dc_push DC_DECLARG((value)) + dc_data value DC_DECLEND +{ + dc_list *n = dc_alloc(); + + if (value.dc_type!=DC_NUMBER && value.dc_type!=DC_STRING) + dc_garbage("in data being pushed", -1); + n->value = value; + n->link = dc_stack; + dc_stack = n; +} + +/* push a value onto the named register stack */ +void +dc_register_push DC_DECLARG((stackid, value)) + int stackid DC_DECLSEP + dc_data value DC_DECLEND +{ + dc_list *n = dc_alloc(); + + stackid = regmap(stackid); + n->value = value; + n->link = dc_register[stackid]; + dc_register[stackid] = n; +} + +/* set *result to the value on the top of the evaluation stack */ +/* The caller is responsible for duplicating the value if it + * is to be maintained as anything more than a transient identity. + * + * DC_FAIL is returned if the stack is empty (and *result unchanged), + * DC_SUCCESS is returned otherwise + */ +int +dc_top_of_stack DC_DECLARG((result)) + dc_data *result DC_DECLEND +{ + if (!dc_stack){ + Empty_Stack; + return DC_FAIL; + } + if (dc_stack->value.dc_type!=DC_NUMBER + && dc_stack->value.dc_type!=DC_STRING) + dc_garbage("at top of stack", -1); + *result = dc_stack->value; + return DC_SUCCESS; +} + +/* set *result to a dup of the value on the top of the named register stack */ +/* + * DC_FAIL is returned if the named stack is empty (and *result unchanged), + * DC_SUCCESS is returned otherwise + */ +int +dc_register_get DC_DECLARG((regid, result)) + int regid DC_DECLSEP + dc_data *result DC_DECLEND +{ + dc_list *r; + + regid = regmap(regid); + r = dc_register[regid]; + if ( ! r ){ + fprintf(stderr, "%s: register ", progname); + dc_show_id(stderr, regid, " is empty\n"); + return DC_FAIL; + } + *result = dc_dup(r->value); + return DC_SUCCESS; +} + +/* set the top of the named register stack to the indicated value */ +/* If the named stack is empty, craft a stack entry to enter the + * value into. + */ +void +dc_register_set DC_DECLARG((regid, value)) + int regid DC_DECLSEP + dc_data value DC_DECLEND +{ + dc_list *r; + + regid = regmap(regid); + r = dc_register[regid]; + if ( ! r ) + dc_register[regid] = dc_alloc(); + else if (r->value.dc_type == DC_NUMBER) + dc_free_num(&r->value.v.number); + else if (r->value.dc_type == DC_STRING) + dc_free_str(&r->value.v.string); + else + dc_garbage("", regid); + dc_register[regid]->value = value; +} + +/* pop from the evaluation stack + * + * DC_FAIL is returned if the stack is empty (and *result unchanged), + * DC_SUCCESS is returned otherwise + */ +int +dc_pop DC_DECLARG((result)) + dc_data *result DC_DECLEND +{ + dc_list *r; + + r = dc_stack; + if (!r){ + Empty_Stack; + return DC_FAIL; + } + if (r->value.dc_type!=DC_NUMBER && r->value.dc_type!=DC_STRING) + dc_garbage("at top of stack", -1); + *result = r->value; + dc_stack = r->link; + free(r); + return DC_SUCCESS; +} + +/* pop from the named register stack + * + * DC_FAIL is returned if the named stack is empty (and *result unchanged), + * DC_SUCCESS is returned otherwise + */ +int +dc_register_pop DC_DECLARG((stackid, result)) + int stackid DC_DECLSEP + dc_data *result DC_DECLEND +{ + dc_list *r; + + stackid = regmap(stackid); + r = dc_register[stackid]; + if (!r){ + fprintf(stderr, "%s: stack register ", progname); + dc_show_id(stderr, stackid, " is empty\n"); + return DC_FAIL; + } + if (r->value.dc_type!=DC_NUMBER && r->value.dc_type!=DC_STRING) + dc_garbage(" stack", stackid); + *result = r->value; + dc_register[stackid] = r->link; + free(r); + return DC_SUCCESS; +} + + +/* tell how many entries are currently on the evaluation stack */ +int +dc_tell_stackdepth DC_DECLVOID() +{ + dc_list *n; + int depth=0; + + for (n=dc_stack; n; n=n->link) + ++depth; + return depth; +} + + +/* return the length of the indicated data value; + * if discard_flag is true, the deallocate the value when done + * + * The definition of a datum's length is deligated to the + * appropriate module. + */ +int +dc_tell_length DC_DECLARG((value, discard_flag)) + dc_data value DC_DECLSEP + dc_boolean discard_flag DC_DECLEND +{ + int length; + + if (value.dc_type == DC_NUMBER){ + length = dc_numlen(value.v.number); + if (discard_flag == DC_TRUE) + dc_free_num(&value.v.number); + } else if (value.dc_type == DC_STRING) { + length = dc_strlen(value.v.string); + if (discard_flag == DC_TRUE) + dc_free_str(&value.v.string); + } else { + dc_garbage("in tell_length", -1); + /*NOTREACHED*/ + length = 0; /*just to suppress spurious compiler warnings*/ + } + return length; +} + + + +/* print out all of the values on the evaluation stack */ +void +dc_printall DC_DECLARG((obase)) + int obase DC_DECLEND +{ + dc_list *n; + + for (n=dc_stack; n; n=n->link) + dc_print(n->value, obase); +} |
