mirror of
https://github.com/postgres/postgres.git
synced 2025-07-23 03:21:12 +03:00
Postgres95 1.01 Distribution - Virgin Sources
This commit is contained in:
Marc G. Fournier
270
src/backend/nodes/read.c
Normal file
270
src/backend/nodes/read.c
Normal file
@ -0,0 +1,270 @@
|
||||
/*-------------------------------------------------------------------------
|
||||
*
|
||||
* read.c--
|
||||
* routines to convert a string (legal ascii representation of node) back
|
||||
* to nodes
|
||||
*
|
||||
* Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/nodes/read.c,v 1.1.1.1 1996/07/09 06:21:33 scrappy Exp $
|
||||
*
|
||||
* HISTORY
|
||||
* AUTHOR DATE MAJOR EVENT
|
||||
* Andrew Yu Nov 2, 1994 file creation
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include <ctype.h>
|
||||
#include "postgres.h"
|
||||
#include "nodes/pg_list.h"
|
||||
#include "nodes/readfuncs.h"
|
||||
#include "utils/elog.h"
|
||||
|
||||
/*
|
||||
* stringToNode -
|
||||
* returns a Node with a given legal ascii representation
|
||||
*/
|
||||
void *
|
||||
stringToNode(char *str)
|
||||
{
|
||||
void *retval;
|
||||
|
||||
(void) lsptok(str, NULL); /* set the string used in lsptok */
|
||||
retval = nodeRead(true); /* start reading */
|
||||
|
||||
return retval;
|
||||
}
|
||||
|
||||
/*****************************************************************************
|
||||
*
|
||||
* the lisp token parser
|
||||
*
|
||||
*****************************************************************************/
|
||||
|
||||
#define RIGHT_PAREN (1000000 + 1)
|
||||
#define LEFT_PAREN (1000000 + 2)
|
||||
#define PLAN_SYM (1000000 + 3)
|
||||
#define AT_SYMBOL (1000000 + 4)
|
||||
#define ATOM_TOKEN (1000000 + 5)
|
||||
|
||||
/*
|
||||
* nodeTokenType -
|
||||
* returns the type of the node token contained in token.
|
||||
* It returns one of the following valid NodeTags:
|
||||
* T_Integer, T_Float, T_String
|
||||
* and some of its own:
|
||||
* RIGHT_PAREN, LEFT_PAREN, PLAN_SYM, AT_SYMBOL, ATOM_TOKEN
|
||||
*
|
||||
* Assumption: the ascii representation is legal
|
||||
*/
|
||||
static NodeTag
|
||||
nodeTokenType(char *token, int length)
|
||||
{
|
||||
NodeTag retval;
|
||||
|
||||
/*
|
||||
* Check if the token is a number (decimal or integer,
|
||||
* positive or negative
|
||||
*/
|
||||
if (isdigit(*token) ||
|
||||
(length>=2 && *token=='-' && isdigit(*(token+1)) ))
|
||||
{
|
||||
/*
|
||||
* skip the optional '-' (i.e. negative number)
|
||||
*/
|
||||
if (*token == '-') {
|
||||
token++;
|
||||
}
|
||||
|
||||
/*
|
||||
* See if there is a decimal point
|
||||
*/
|
||||
|
||||
for (; length && *token != '.'; token++, length--);
|
||||
|
||||
/*
|
||||
* if there isn't, token's an int, otherwise it's a float.
|
||||
*/
|
||||
|
||||
retval = (*token != '.') ? T_Integer : T_Float;
|
||||
}
|
||||
else if (isalpha(*token))
|
||||
retval = ATOM_TOKEN;
|
||||
else if (*token == '(')
|
||||
retval = LEFT_PAREN;
|
||||
else if (*token == ')')
|
||||
retval = RIGHT_PAREN;
|
||||
else if (*token == '@')
|
||||
retval = AT_SYMBOL;
|
||||
else if (*token == '\"')
|
||||
retval = T_String;
|
||||
else if (*token == '{')
|
||||
retval = PLAN_SYM;
|
||||
return(retval);
|
||||
}
|
||||
|
||||
/*
|
||||
* Works kinda like strtok, except it doesn't put nulls into string.
|
||||
*
|
||||
* Returns the length in length instead. The string can be set without
|
||||
* returning a token by calling lsptok with length == NULL.
|
||||
*
|
||||
*/
|
||||
char *
|
||||
lsptok(char *string, int *length)
|
||||
{
|
||||
static char *local_str;
|
||||
char *ret_string;
|
||||
|
||||
if (string != NULL) {
|
||||
local_str = string;
|
||||
if (length == NULL) {
|
||||
return(NULL);
|
||||
}
|
||||
}
|
||||
|
||||
for (; *local_str == ' '
|
||||
|| *local_str == '\n'
|
||||
|| *local_str == '\t'; local_str++);
|
||||
|
||||
/*
|
||||
* Now pointing at next token.
|
||||
*/
|
||||
ret_string = local_str;
|
||||
if (*local_str == '\0') return(NULL);
|
||||
*length = 1;
|
||||
|
||||
if (*local_str == '\"') {
|
||||
for (local_str++; *local_str != '\"'; (*length)++, local_str++);
|
||||
(*length)++; local_str++;
|
||||
}else if (*local_str == ')' || *local_str == '(' ||
|
||||
*local_str == '}' || *local_str == '{') {
|
||||
local_str++;
|
||||
}else {
|
||||
for (; *local_str != ' '
|
||||
&& *local_str != '\n'
|
||||
&& *local_str != '\t'
|
||||
&& *local_str != '{'
|
||||
&& *local_str != '}'
|
||||
&& *local_str != '('
|
||||
&& *local_str != ')'; local_str++, (*length)++);
|
||||
(*length)--;
|
||||
}
|
||||
return(ret_string);
|
||||
}
|
||||
|
||||
/*
|
||||
* This guy does all the reading.
|
||||
*
|
||||
* Secrets: He assumes that lsptok already has the string (see below).
|
||||
* Any callers should set read_car_only to true.
|
||||
*/
|
||||
void *
|
||||
nodeRead(bool read_car_only)
|
||||
{
|
||||
char *token;
|
||||
NodeTag type;
|
||||
Node *this_value, *return_value;
|
||||
int tok_len;
|
||||
char tmp;
|
||||
bool make_dotted_pair_cell = false;
|
||||
|
||||
token = lsptok(NULL, &tok_len);
|
||||
|
||||
if (token == NULL) return(NULL);
|
||||
|
||||
type = nodeTokenType(token, tok_len);
|
||||
|
||||
switch(type) {
|
||||
case PLAN_SYM:
|
||||
this_value = parsePlanString();
|
||||
token = lsptok(NULL, &tok_len);
|
||||
if (token[0] != '}') return(NULL);
|
||||
|
||||
if (!read_car_only)
|
||||
make_dotted_pair_cell = true;
|
||||
else
|
||||
make_dotted_pair_cell = false;
|
||||
break;
|
||||
case LEFT_PAREN:
|
||||
if (!read_car_only) {
|
||||
List *l = makeNode(List);
|
||||
|
||||
lfirst(l) = nodeRead(false);
|
||||
lnext(l) = nodeRead(false);
|
||||
this_value = (Node*)l;
|
||||
}else {
|
||||
this_value = nodeRead(false);
|
||||
}
|
||||
break;
|
||||
case RIGHT_PAREN:
|
||||
this_value = NULL;
|
||||
break;
|
||||
case AT_SYMBOL:
|
||||
break;
|
||||
case ATOM_TOKEN:
|
||||
if (!strncmp(token, "nil", 3)) {
|
||||
this_value = NULL;
|
||||
/*
|
||||
* It might be "nil" but it is an atom!
|
||||
*/
|
||||
if (read_car_only) {
|
||||
make_dotted_pair_cell = false;
|
||||
} else {
|
||||
make_dotted_pair_cell = true;
|
||||
}
|
||||
}else {
|
||||
tmp = token[tok_len];
|
||||
token[tok_len] = '\0';
|
||||
this_value = (Node*)pstrdup(token); /* !attention! not a Node.
|
||||
use with caution */
|
||||
token[tok_len] = tmp;
|
||||
make_dotted_pair_cell = true;
|
||||
}
|
||||
break;
|
||||
case T_Float:
|
||||
tmp = token[tok_len];
|
||||
token[tok_len] = '\0';
|
||||
this_value = (Node*)makeFloat(atof(token));
|
||||
token[tok_len] = tmp;
|
||||
make_dotted_pair_cell = true;
|
||||
break;
|
||||
case T_Integer:
|
||||
tmp = token[tok_len];
|
||||
token[tok_len] = '\0';
|
||||
this_value = (Node*)makeInteger(atoi(token));
|
||||
token[tok_len] = tmp;
|
||||
make_dotted_pair_cell = true;
|
||||
break;
|
||||
case T_String:
|
||||
tmp = token[tok_len - 1];
|
||||
token[tok_len - 1] = '\0';
|
||||
token++;
|
||||
this_value = (Node*)makeString(token); /* !! not strdup'd */
|
||||
token[tok_len - 2] = tmp;
|
||||
make_dotted_pair_cell = true;
|
||||
break;
|
||||
default:
|
||||
elog(WARN, "nodeRead: Bad type %d", type);
|
||||
break;
|
||||
}
|
||||
if (make_dotted_pair_cell) {
|
||||
List *l = makeNode(List);
|
||||
|
||||
lfirst(l) = this_value;
|
||||
if (!read_car_only) {
|
||||
lnext(l) = nodeRead(false);
|
||||
}else {
|
||||
lnext(l) = NULL;
|
||||
}
|
||||
return_value = (Node*)l;
|
||||
}else {
|
||||
return_value = this_value;
|
||||
}
|
||||
return(return_value);
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user