gnuplot/src/parse.c at branch-5-4-stable · gnuplot/gnuplot · GitHub

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/* GNUPLOT - parse.c */

/*[

* Permission to use, copy, and distribute this software and its

* documentation for any purpose with or without fee is hereby granted,

* provided that the above copyright notice appear in all copies and

* that both that copyright notice and this permission notice appear

* in supporting documentation.

* Permission to modify the software is granted, but not the right to

* distribute the complete modified source code. Modifications are to

* be distributed as patches to the released version. Permission to

* distribute binaries produced by compiling modified sources is granted,

* provided you

* 1. distribute the corresponding source modifications from the

* released version in the form of a patch file along with the binaries,

* 2. add special version identification to distinguish your version

* in addition to the base release version number,

* 3. provide your name and address as the primary contact for the

* support of your modified version, and

* 4. retain our contact information in regard to use of the base

* software.

* Permission to distribute the released version of the source code along

* with corresponding source modifications in the form of a patch file is

* granted with same provisions 2 through 4 for binary distributions.

* This software is provided "as is" without express or implied warranty

* to the extent permitted by applicable law.

]*/

#include "parse.h"

#include "alloc.h"

#include "command.h"

#include "datablock.h"

#include "eval.h"

#include "help.h"

#include "util.h"

/* Protection mechanism for trying to parse a string followed by a + or - sign.

* Also suppresses an undefined variable message if an unrecognized token

* is encountered during try_to_get_string().

TBOOLEAN string_result_only = FALSE;

static int parse_recursion_level;

/* Exported globals: the current 'dummy' variable names */

char c_dummy_var[MAX_NUM_VAR][MAX_ID_LEN+1];

char set_dummy_var[MAX_NUM_VAR][MAX_ID_LEN+1] = { "x", "y" };

int fit_dummy_var[MAX_NUM_VAR];

TBOOLEAN scanning_range_in_progress = FALSE;

/* This is used by plot_option_using() */

int at_highest_column_used = -1;

/* This is checked by df_readascii() */

TBOOLEAN parse_1st_row_as_headers = FALSE;

/* This is used by df_open() and df_readascii() */

udvt_entry *df_array = NULL;

/* Iteration structures used for bookkeeping */

t_iterator * plot_iterator = NULL;

t_iterator * set_iterator = NULL;

/* Internal prototypes: */

static void convert(struct value *, int);

static void extend_at(void);

static union argument *add_action(enum operators sf_index);

static void parse_expression(void);

static void accept_logical_OR_expression(void);

static void accept_logical_AND_expression(void);

static void accept_inclusive_OR_expression(void);

static void accept_exclusive_OR_expression(void);

static void accept_AND_expression(void);

static void accept_equality_expression(void);

static void accept_relational_expression(void);

static void accept_bitshift_expression(void);

static void accept_additive_expression(void);

static void accept_multiplicative_expression(void);

static void parse_primary_expression(void);

static void parse_conditional_expression(void);

static void parse_logical_OR_expression(void);

static void parse_logical_AND_expression(void);

static void parse_inclusive_OR_expression(void);

static void parse_exclusive_OR_expression(void);

static void parse_AND_expression(void);

static void parse_equality_expression(void);

static void parse_relational_expression(void);

static void parse_bitshift_expression(void);

static void parse_additive_expression(void);

static void parse_multiplicative_expression(void);

static void parse_unary_expression(void);

static void parse_sum_expression(void);

static int parse_assignment_expression(void);

static int parse_array_assignment_expression(void);

static void set_up_columnheader_parsing(struct at_entry *previous );

static TBOOLEAN no_iteration(t_iterator *);

static void reevaluate_iteration_limits(t_iterator *iter);

static void reset_iteration(t_iterator *iter);

/* Internal variables: */

static struct at_type *at = NULL;

static int at_size = 0;

static void

convert(struct value *val_ptr, int t_num)

{

*val_ptr = token[t_num].l_val;

}

intgr_t

int_expression()

{

return (intgr_t)real_expression();

}

double

real_expression()

{

double result;

struct value a;

result = real(const_express(&a));

gpfree_string(&a);

return result;

}

void

parse_reset_after_error()

{

string_result_only = FALSE;

parse_recursion_level = 0;

}

/* JW 20051126:

* Wrapper around const_express() called by try_to_get_string().

* Disallows top level + and - operators.

* This enables things like set xtics ('-\pi' -pi, '-\pi/2' -pi/2.)

struct value *

const_string_express(struct value *valptr)

{

string_result_only = TRUE;

const_express(valptr);

string_result_only = FALSE;

return (valptr);

}

struct value *

const_express(struct value *valptr)

{

int tkn = c_token;

if (END_OF_COMMAND)

int_error(c_token, "constant expression required");

/* div - no dummy variables in a constant expression */

dummy_func = NULL;

evaluate_at(temp_at(), valptr); /* run it and send answer back */

if (undefined) {

int_error(tkn, "undefined value");

}

if (valptr->type == ARRAY) {

/* Make sure no one tries to free it later */

valptr->type = NOTDEFINED;

int_error(NO_CARET, "const_express: unsupported array operation");

}

return (valptr);

}

/* Used by plot2d/plot3d/stats/fit:

* Parse an expression that may return a filename string, a datablock name,

* a constant, or a dummy function using dummy variables x, y, ...

* If any dummy variables are present, set (*atptr) to point to an action table

* corresponding to the parsed expression, and return NULL.

* Otherwise evaluate the expression and return a string if there is one.

* The return value "str" and "*atptr" both point to locally-managed memory,

* which must not be freed by the caller!

char*

string_or_express(struct at_type **atptr)

{

int i;

TBOOLEAN has_dummies;

static char *array_placeholder = "@@";

static char* str = NULL;

free(str);

str = NULL;

df_array = NULL;

if (atptr)

*atptr = NULL;

if (END_OF_COMMAND)

int_error(c_token, "expression expected");

/* parsing for datablocks */

if (equals(c_token,"$"))

return parse_datablock_name();

/* special keywords */

if (equals(c_token,"keyentry"))

return NULL;

if (isstring(c_token) && (str = try_to_get_string()))

return str;

/* If this is a bare array name for an existing array, store a pointer */

/* for df_open() to use. "@@" is a magic pseudo-filename passed to */

/* df_open() that tells it to use the stored pointer. */

if (type_udv(c_token) == ARRAY && !equals(c_token+1, "[")) {

df_array = add_udv(c_token++);

return array_placeholder;

}

/* parse expression */

temp_at();

/* check if any dummy variables are used */

has_dummies = FALSE;

for (i = 0; i < at->a_count; i++) {

enum operators op_index = at->actions[i].index;

if ( op_index == PUSHD1 || op_index == PUSHD2 || op_index == PUSHD

|| op_index == SUM ) {

has_dummies = TRUE;

break;

}

if (!has_dummies) {

/* no dummy variables: evaluate expression */

struct value val;

evaluate_at(at, &val);

if (!undefined && val.type == STRING) {

/* prevent empty string variable from treated as special file '' or "" */

if (*val.v.string_val == '\0') {

free(val.v.string_val);

str = strdup(" ");

} else {

str = val.v.string_val;

}

/* prepare return */

if (atptr)

*atptr = at;

return str;

}

/* build an action table and return its pointer, but keep a pointer in at

* so that we can free it later if the caller hasn't taken over management

* of this table.

struct at_type *

temp_at()

{

if (at != NULL)

free_at(at);

at = (struct at_type *) gp_alloc(sizeof(struct at_type), "action table");

memset(at, 0, sizeof(*at)); /* reset action table !!! */

at_size = MAX_AT_LEN;

parse_recursion_level = 0;

parse_expression();

return (at);

}

/* build an action table, put it in dynamic memory, and return its pointer */

struct at_type *

perm_at()

{

struct at_type *at_ptr;

size_t len;

(void) temp_at();

len = sizeof(struct at_type)

+ (at->a_count - MAX_AT_LEN) * sizeof(struct at_entry);

at_ptr = (struct at_type *) gp_realloc(at, len, "perm_at");

at = NULL; /* invalidate at pointer */

return (at_ptr);

}

/* Create an action table that describes a call to column("string"). */

/* This is used by plot_option_using() to handle 'plot ... using "string"' */

struct at_type *

create_call_column_at(char *string)

{

struct at_type *at = gp_alloc(sizeof(int) + 2*sizeof(struct at_entry),"");

at->a_count = 2;

at->actions[0].index = PUSHC;

at->actions[0].arg.j_arg = 3; /* FIXME - magic number! */

at->actions[0].arg.v_arg.type = STRING;

at->actions[0].arg.v_arg.v.string_val = string;

at->actions[1].index = COLUMN;

at->actions[1].arg.j_arg = 0;

return (at);

}

/* Create an action table that describes a call to columnhead(-1). */

/* This is substituted for the bare keyword "colummhead" */

struct at_type *

create_call_columnhead()

{

struct at_type *at = gp_alloc(sizeof(int) + 2*sizeof(struct at_entry),"");

at->a_count = 2;

at->actions[0].index = PUSHC;

at->actions[0].arg.j_arg = 3; /* FIXME - magic number! */

at->actions[0].arg.v_arg.type = INTGR;

at->actions[0].arg.v_arg.v.int_val = -1;

at->actions[1].index = COLUMNHEAD;

at->actions[1].arg.j_arg = 0;

return (at);

}

static void

extend_at()

{

size_t newsize = sizeof(struct at_type) + at_size * sizeof(struct at_entry);

at = gp_realloc(at, newsize, "extend_at");

at_size += MAX_AT_LEN;

FPRINTF((stderr, "Extending at size to %d\n", at_size));

}

/* Add function number <sf_index> to the current action table */

static union argument *

add_action(enum operators sf_index)

{

if (at->a_count >= at_size) {

extend_at();

}

at->actions[at->a_count].index = sf_index;

return (&(at->actions[at->a_count++].arg));

}

/* For external calls to parse_expressions()

* parse_recursion_level is expected to be 0 */

static void

parse_expression()

{ /* full expressions */

if (parse_assignment_expression())

return;

parse_recursion_level++;

accept_logical_OR_expression();

parse_conditional_expression();

parse_recursion_level--;

}

static void

accept_logical_OR_expression()

{ /* ? : expressions */

accept_logical_AND_expression();

parse_logical_OR_expression();

}

static void

accept_logical_AND_expression()

{

accept_inclusive_OR_expression();

parse_logical_AND_expression();

}

static void

accept_inclusive_OR_expression()

{

accept_exclusive_OR_expression();

parse_inclusive_OR_expression();

}

static void

accept_exclusive_OR_expression()

{

accept_AND_expression();

parse_exclusive_OR_expression();

}

static void

accept_AND_expression()

{

accept_equality_expression();

parse_AND_expression();

}

static void

accept_equality_expression()

{

accept_relational_expression();

parse_equality_expression();

}

static void

accept_relational_expression()

{

accept_bitshift_expression();

parse_relational_expression();

}

static void

accept_bitshift_expression()

{

accept_additive_expression();

parse_bitshift_expression();

}

static void

accept_additive_expression()

{

accept_multiplicative_expression();

parse_additive_expression();

}

static void

accept_multiplicative_expression()

{

parse_unary_expression(); /* - things */

parse_multiplicative_expression(); /* * / % */

}

static int

parse_assignment_expression()

{

/* Check for assignment operator Var = <expr> */

if (isletter(c_token) && equals(c_token + 1, "=")) {

/* push the variable name */

union argument *foo = add_action(PUSHC);

char *varname = NULL;

m_capture(&varname,c_token,c_token);

foo->v_arg.type = STRING;

foo->v_arg.v.string_val = varname;

/* push a dummy variable that would be the index if this were an array */

/* FIXME: It would be nice to hide this from "show at" */

foo = add_action(PUSHC);

foo->v_arg.type = NOTDEFINED;

/* push the expression whose value it will get */

c_token += 2;

parse_expression();

/* push the actual assignment operation */

(void) add_action(ASSIGN);

return 1;

}

/* Check for assignment to an array element Array[<expr>] = <expr> */

if (parse_array_assignment_expression())

return 1;

return 0;

}

* If an array assignment is the first thing on a command line it is handled by

* the separate routine array_assignment().

* Here we catch assignments that are embedded in an expression.

* Examples:

* print A[2] = foo

* A[1] = A[2] = A[3] = 0

static int

parse_array_assignment_expression()

{

/* Check for assignment to an array element Array[<expr>] = <expr> */

if (isletter(c_token) && equals(c_token+1, "[")) {

char *varname = NULL;

union argument *foo;

int save_action, save_token;

/* Quick check for the most common false positives */

/* i.e. other constructs that begin with "name[" */

/* FIXME: quicker than the full test below, but do we care? */

if (equals(c_token+3, "]") && !equals(c_token+4, "="))

return 0;

if (equals(c_token+3, ":")) /* substring s[foo:baz] */

return 0;

/* Is this really a known array name? */

if (type_udv(c_token) != ARRAY)

return 0;

/* Save state of the action table and the command line */

save_action = at->a_count;

save_token = c_token;

/* push the array name */

m_capture(&varname,c_token,c_token);

foo = add_action(PUSHC);

foo->v_arg.type = STRING;

foo->v_arg.v.string_val = varname;

/* push the index */

c_token += 2;

parse_expression();

/* If this wasn't really an array element assignment, back out. */

/* NB: Depending on what we just parsed, this may leak memory. */

if (!equals(c_token, "]") || !equals(c_token+1, "=")) {

c_token = save_token;

at->a_count = save_action;

free(varname);

return 0;

}

/* Now we evaluate the expression whose value it will get */

c_token += 2;

parse_expression();

/* push the actual assignment operation */

(void) add_action(ASSIGN);

return 1;

}

return 0;

}

/* add action table entries for primary expressions, i.e. either a

* parenthesized expression, a variable name, a numeric constant, a

* function evaluation, a power operator or postfix '!' (factorial)

* expression.

* Sep 2016 cardinality expression |Array| */

static void

parse_primary_expression()

{

if (equals(c_token, "(")) {

c_token++;

parse_expression();

/* Expressions may be separated by a comma */

while (equals(c_token,",")) {

c_token++;

(void) add_action(POP);

parse_expression();

}

if (!equals(c_token, ")"))

int_error(c_token, "')' expected");

c_token++;

} else if (equals(c_token, "$")) {

struct value a;

c_token++;

if (!isanumber(c_token)) {

if (equals(c_token+1, "[")) {

struct udvt_entry *datablock_udv;

c_token--;

datablock_udv = get_udv_by_name(parse_datablock_name());

if (!datablock_udv)

int_error(c_token-2,"No such datablock");

add_action(PUSH)->udv_arg = datablock_udv;

} else

int_error(c_token, "Column number or datablock line expected");

} else {

convert(&a, c_token++);

if (a.type != INTGR || a.v.int_val < 0)

int_error(c_token, "Positive integer expected");

if (at_highest_column_used < a.v.int_val)

at_highest_column_used = a.v.int_val;

add_action(DOLLARS)->v_arg = a;

}

} else if (equals(c_token, "$#")) {

struct value a = {INTGR, {DOLLAR_NCOLUMNS}};

c_token++;

add_action(DOLLARS)->v_arg = a;

} else if (equals(c_token, "|")) {

struct udvt_entry *udv;

c_token++;

if (equals(c_token,"$")) {

udv = get_udv_by_name(parse_datablock_name());

if (!udv)

int_error(c_token-1, "no such datablock");

} else {

udv = add_udv(c_token++);

if (udv->udv_value.type != ARRAY)

int_error(c_token-1, "not an array");

}

add_action(PUSH)->udv_arg = udv;

if (!equals(c_token, "|"))

int_error(c_token, "'|' expected");

c_token++;

add_action(CARDINALITY);

} else if (isanumber(c_token)) {

union argument *foo = add_action(PUSHC);

convert(&(foo->v_arg), c_token);

c_token++;

} else if (isletter(c_token)) {

/* Found an identifier --- check whether its a function or a

* variable by looking for the parentheses of a function

* argument list */

if (equals(c_token + 1, "(")) {

enum operators whichfunc = is_builtin_function(c_token);

struct value num_params;

num_params.type = INTGR;

if (whichfunc) {

c_token += 2; /* skip fnc name and '(' */

parse_expression(); /* parse fnc argument */

num_params.v.int_val = 1;

while (equals(c_token, ",")) {

c_token++;

num_params.v.int_val++;

parse_expression();

}

if (!equals(c_token, ")"))

int_error(c_token, "')' expected");

c_token++;

/* So far sprintf is the only built-in function */

/* with a variable number of arguments. */

if (!strcmp(ft[whichfunc].f_name,"sprintf"))

add_action(PUSHC)->v_arg = num_params;

/* v4 timecolumn only had 1 param; v5 has 2. Accept either */

if (!strcmp(ft[whichfunc].f_name,"timecolumn"))

add_action(PUSHC)->v_arg = num_params;

/* These functions have an optional 3rd parameter */

if (!strncmp(ft[whichfunc].f_name,"weekdate_",9))

add_action(PUSHC)->v_arg = num_params;

/* The column() function has side effects requiring special handling */

if (!strcmp(ft[whichfunc].f_name,"column")) {

set_up_columnheader_parsing( &(at->actions[at->a_count-1]) );

}

(void) add_action(whichfunc);

} else {

/* it's a call to a user-defined function */

enum operators call_type = (int) CALL;

int tok = c_token;

c_token += 2; /* skip func name and '(' */

parse_expression();

if (equals(c_token, ",")) { /* more than 1 argument? */

num_params.v.int_val = 1;

while (equals(c_token, ",")) {

num_params.v.int_val += 1;

c_token += 1;

parse_expression();

}

add_action(PUSHC)->v_arg = num_params;

call_type = (int) CALLN;

}

if (!equals(c_token, ")"))

int_error(c_token, "')' expected");

c_token++;

add_action(call_type)->udf_arg = add_udf(tok);

}

} else if (equals(c_token, "sum") && equals(c_token+1, "[")) {

parse_sum_expression();

/* dummy_func==NULL is a flag to say no dummy variables active */

} else if (dummy_func) {

if (equals(c_token, c_dummy_var[0])) {

c_token++;

add_action(PUSHD1)->udf_arg = dummy_func;

fit_dummy_var[0]++;

} else if (equals(c_token, c_dummy_var[1])) {

c_token++;

add_action(PUSHD2)->udf_arg = dummy_func;

fit_dummy_var[1]++;

} else {

int i, param = 0;

for (i = 2; i < MAX_NUM_VAR; i++) {

if (equals(c_token, c_dummy_var[i])) {

struct value num_params;

num_params.type = INTGR;

num_params.v.int_val = i;

param = 1;

c_token++;

add_action(PUSHC)->v_arg = num_params;

add_action(PUSHD)->udf_arg = dummy_func;

fit_dummy_var[i]++;

break;

}

if (!param) { /* defined variable */

add_action(PUSH)->udv_arg = add_udv(c_token);

c_token++;

}

/* its a variable, with no dummies active - div */

} else {

add_action(PUSH)->udv_arg = add_udv(c_token);

c_token++;

}

/* end if letter */

/* Maybe it's a string constant */

else if (isstring(c_token)) {

union argument *foo = add_action(PUSHC);

foo->v_arg.type = STRING;

foo->v_arg.v.string_val = NULL;

/* this dynamically allocated string will be freed by free_at() */

m_quote_capture(&(foo->v_arg.v.string_val), c_token, c_token);

c_token++;

} else {

int_error(c_token, "invalid expression ");

}

/* The remaining operators are postfixes and can be stacked, e.g. */

/* Array[i]**2, so we may have to loop to catch all of them. */

while (TRUE) {

/* add action code for ! (factorial) operator */

if (equals(c_token, "!")) {

c_token++;

(void) add_action(FACTORIAL);

}

/* add action code for ** operator */

else if (equals(c_token, "**")) {

c_token++;

parse_unary_expression();

(void) add_action(POWER);

}

/* Parse and add actions for range specifier applying to previous entity.

* Currently the [beg:end] form is used to generate substrings, but could

* also be used to extract vector slices. The [i] form is used to index

* arrays, but could also be a shorthand for extracting a single-character

* substring.

else if (equals(c_token, "[") && !isanumber(c_token-1)) {

/* handle '*' or empty start of range */

if (equals(++c_token,"*") || equals(c_token,":")) {

union argument *empty = add_action(PUSHC);

empty->v_arg.type = INTGR;

empty->v_arg.v.int_val = 1;

if (equals(c_token,"*"))

c_token++;

} else

parse_expression();

/* handle array indexing (single value in square brackets) */

if (equals(c_token, "]")) {

c_token++;

(void) add_action(INDEX);

continue;

}

if (!equals(c_token, ":"))

int_error(c_token, "':' expected");

/* handle '*' or empty end of range */

if (equals(++c_token,"*") || equals(c_token,"]")) {

union argument *empty = add_action(PUSHC);

empty->v_arg.type = INTGR;

empty->v_arg.v.int_val = 65535; /* should be INT_MAX */

if (equals(c_token,"*"))

c_token++;

} else

parse_expression();

if (!equals(c_token, "]"))

int_error(c_token, "']' expected");

c_token++;

(void) add_action(RANGE);

/* Whatever this is, it isn't another postfix operator */

} else {

break;

}

/* HBB 20010309: Here and below: can't store pointers into the middle

* of at->actions[]. That array may be realloc()ed by add_action() or

* express() calls!. Access via index savepc1/savepc2, instead. */

static void

parse_conditional_expression()

{

/* create action code for ? : expressions */

if (equals(c_token, "?")) {

int savepc1, savepc2;

/* Fake same recursion level for alternatives

* set xlabel a>b ? 'foo' : 'bar' -1, 1

* FIXME: This won't work:

* set xlabel a-b>c ? 'foo' : 'bar' offset -1, 1

parse_recursion_level--;

c_token++;

savepc1 = at->a_count;

add_action(JTERN);

parse_expression();

if (!equals(c_token, ":"))

int_error(c_token, "expecting ':'");

c_token++;

savepc2 = at->a_count;

add_action(JUMP);

at->actions[savepc1].arg.j_arg = at->a_count - savepc1;

parse_expression();

at->actions[savepc2].arg.j_arg = at->a_count - savepc2;

add_action(NOP);

parse_recursion_level++;

}

static void

parse_logical_OR_expression()

{

/* create action codes for || operator */

while (equals(c_token, "||")) {

int savepc;

c_token++;

savepc = at->a_count;

add_action(JUMPNZ); /* short-circuit if already TRUE */

accept_logical_AND_expression();

/* offset for jump */

at->actions[savepc].arg.j_arg = at->a_count - savepc;

(void) add_action(BOOLE);

}

static void

parse_logical_AND_expression()

{

/* create action code for && operator */

while (equals(c_token, "&&")) {

int savepc;

c_token++;

savepc = at->a_count;

add_action(JUMPZ); /* short-circuit if already FALSE */

accept_inclusive_OR_expression();

at->actions[savepc].arg.j_arg = at->a_count - savepc; /* offset for jump */

(void) add_action(BOOLE);

}

static void

parse_inclusive_OR_expression()

{

/* create action code for | operator */

while (equals(c_token, "|")) {

c_token++;

accept_exclusive_OR_expression();

(void) add_action(BOR);

}

static void

parse_exclusive_OR_expression()

{

/* create action code for ^ operator */

while (equals(c_token, "^")) {

c_token++;

accept_AND_expression();

(void) add_action(XOR);

}

static void

parse_AND_expression()

{

/* create action code for & operator */

while (equals(c_token, "&")) {

c_token++;

accept_equality_expression();

(void) add_action(BAND);

}

static void

parse_equality_expression()

{

/* create action codes for == and != numeric operators

* eq and ne string operators */

while (TRUE) {

if (equals(c_token, "==")) {

c_token++;

accept_relational_expression();

(void) add_action(EQ);

} else if (equals(c_token, "!=")) {

c_token++;

accept_relational_expression();

(void) add_action(NE);

} else if (equals(c_token, "eq")) {

c_token++;

accept_relational_expression();

(void) add_action(EQS);

} else if (equals(c_token, "ne")) {

c_token++;

accept_relational_expression();

(void) add_action(NES);

} else

break;

}

static void

parse_relational_expression()

{

/* create action code for < > >= or <=

* operators */

while (TRUE) {

if (equals(c_token, ">")) {

c_token++;

accept_bitshift_expression();

(void) add_action(GT);

} else if (equals(c_token, "<")) {

/* Workaround for * in syntax of range constraints */

if (scanning_range_in_progress && equals(c_token+1, "*") ) {

break;

}

c_token++;

accept_bitshift_expression();

(void) add_action(LT);

} else if (equals(c_token, ">=")) {

c_token++;

accept_bitshift_expression();

(void) add_action(GE);

} else if (equals(c_token, "<=")) {

c_token++;

accept_bitshift_expression();

(void) add_action(LE);

} else

break;

}

static void

parse_bitshift_expression()

{

/* create action codes for << and >> operators */

while (TRUE) {

if (equals(c_token, "<<")) {

c_token++;

accept_additive_expression();

(void) add_action(LEFTSHIFT);

} else if (equals(c_token, ">>")) {

c_token++;

accept_additive_expression();

(void) add_action(RIGHTSHIFT);

} else

break;

View remainder of file in raw view

gnuplot/src/parse.c at branch-5-4-stable · gnuplot/gnuplot · GitHub

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