414 lines
9.3 KiB
C
414 lines
9.3 KiB
C
/*
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* $Id: read.c,v 1.3 2005-02-04 16:23:34 bacon Exp $
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*/
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#include <xp/lisp/lisp.h>
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#include <xp/lisp/token.h>
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#define IS_SPACE(x) xp_isspace(x)
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#define IS_DIGIT(x) xp_isdigit(x)
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#define IS_ALPHA(x) xp_isalpha(x)
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#define IS_ALNUM(x) xp_isalnum(x)
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#define IS_IDENT(c) \
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((c) == XP_CHAR('+') || (c) == XP_CHAR('-') || \
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(c) == XP_CHAR('*') || (c) == XP_CHAR('/') || \
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(c) == XP_CHAR('%') || (c) == XP_CHAR('&') || \
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(c) == XP_CHAR('<') || (c) == XP_CHAR('>') || \
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(c) == XP_CHAR('=') || (c) == XP_CHAR('_') || \
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(c) == XP_CHAR('?'))
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#define TOKEN_CLEAR(lsp) xp_lisp_token_clear (lsp->token)
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#define TOKEN_TYPE(lsp) lsp->token->type
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#define TOKEN_IVALUE(lsp) lsp->token->ivalue
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#define TOKEN_FVALUE(lsp) lsp->token->fvalue
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#define TOKEN_SVALUE(lsp) lsp->token->buffer
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#define TOKEN_SLENGTH(lsp) lsp->token->size
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#define TOKEN_ADD_CHAR(lsp,ch) \
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do { \
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if (xp_lisp_token_addc (lsp->token, ch) == -1) { \
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lsp->error = XP_LISP_ERR_MEM; \
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return -1; \
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} \
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} while (0)
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#define TOKEN_COMPARE(lsp,str) xp_lisp_token_compare (lsp->token, str)
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#define TOKEN_END 0
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#define TOKEN_INT 1
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#define TOKEN_FLOAT 2
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#define TOKEN_STRING 3
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#define TOKEN_LPAREN 4
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#define TOKEN_RPAREN 5
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#define TOKEN_IDENT 6
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#define TOKEN_QUOTE 7
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#define TOKEN_DOT 8
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#define TOKEN_INVALID 50
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#define TOKEN_UNTERM_STRING 51
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#ifdef __cplusplus
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extern "C" {
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#endif
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static xp_lisp_obj_t* read_obj (xp_lisp_t* lsp);
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static xp_lisp_obj_t* read_list (xp_lisp_t* lsp);
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static xp_lisp_obj_t* read_quote (xp_lisp_t* lsp);
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static int read_token (xp_lisp_t* lsp);
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static int read_number (xp_lisp_t* lsp, int negative);
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static int read_ident (xp_lisp_t* lsp);
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static int read_string (xp_lisp_t* lsp);
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#ifdef __cplusplus
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}
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#endif
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#define NEXT_CHAR(lsp) \
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do { \
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if (lsp->creader (&lsp->curc, lsp->creader_extra) == -1) { \
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lsp->error = XP_LISP_ERR_READ; \
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return -1; \
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} \
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} while (0)
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#define NEXT_TOKEN(lsp) \
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do { \
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if (read_token(lsp) == -1) return XP_NULL; \
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} while (0)
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void xp_lisp_set_creader (xp_lisp_t* lsp, xp_lisp_creader_t func, void* extra)
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{
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xp_lisp_assert (lsp != XP_NULL);
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lsp->creader = func;
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lsp->creader_extra = extra;
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lsp->creader_just_set = 1;
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}
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xp_lisp_obj_t* xp_lisp_read (xp_lisp_t* lsp)
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{
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xp_lisp_assert (lsp != XP_NULL && lsp->creader != XP_NULL);
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if (lsp->creader_just_set) {
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// NEXT_CHAR (lsp);
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if (lsp->creader (&lsp->curc, lsp->creader_extra) == -1) {
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lsp->error = XP_LISP_ERR_READ;
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return XP_NULL;
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}
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lsp->creader_just_set = 0;
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}
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lsp->error = XP_LISP_ERR_NONE;
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NEXT_TOKEN (lsp);
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if (lsp->mem->locked != XP_NULL) {
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xp_lisp_unlock_all (lsp->mem->locked);
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lsp->mem->locked = XP_NULL;
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}
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lsp->mem->locked = read_obj (lsp);
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return lsp->mem->locked;
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}
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static xp_lisp_obj_t* read_obj (xp_lisp_t* lsp)
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{
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xp_lisp_obj_t* obj;
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switch (TOKEN_TYPE(lsp)) {
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case TOKEN_END:
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lsp->error = XP_LISP_ERR_END;
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return XP_NULL;
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case TOKEN_LPAREN:
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NEXT_TOKEN (lsp);
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return read_list (lsp);
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case TOKEN_QUOTE:
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NEXT_TOKEN (lsp);
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return read_quote (lsp);
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case TOKEN_INT:
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obj = xp_lisp_make_int (lsp->mem, TOKEN_IVALUE(lsp));
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if (obj == XP_NULL) lsp->error = XP_LISP_ERR_MEM;
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xp_lisp_lock (obj);
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return obj;
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case TOKEN_FLOAT:
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obj = xp_lisp_make_float (lsp->mem, TOKEN_FVALUE(lsp));
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if (obj == XP_NULL) lsp->error = XP_LISP_ERR_MEM;
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xp_lisp_lock (obj);
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return obj;
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case TOKEN_STRING:
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obj = xp_lisp_make_string (
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lsp->mem, TOKEN_SVALUE(lsp), TOKEN_SLENGTH(lsp));
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if (obj == XP_NULL) lsp->error = XP_LISP_ERR_MEM;
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xp_lisp_lock (obj);
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return obj;
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case TOKEN_IDENT:
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xp_lisp_assert (lsp->mem->nil != XP_NULL && lsp->mem->t != XP_NULL);
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if (TOKEN_COMPARE(lsp,XP_TEXT("nil")) == 0) obj = lsp->mem->nil;
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else if (TOKEN_COMPARE(lsp,XP_TEXT("t")) == 0) obj = lsp->mem->t;
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else {
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obj = xp_lisp_make_symbol (
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lsp->mem, TOKEN_SVALUE(lsp), TOKEN_SLENGTH(lsp));
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if (obj == XP_NULL) lsp->error = XP_LISP_ERR_MEM;
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xp_lisp_lock (obj);
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}
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return obj;
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}
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lsp->error = XP_LISP_ERR_SYNTAX;
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return XP_NULL;
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}
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static xp_lisp_obj_t* read_list (xp_lisp_t* lsp)
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{
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xp_lisp_obj_t* obj;
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xp_lisp_obj_cons_t* p, * first = XP_NULL, * prev = XP_NULL;
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while (TOKEN_TYPE(lsp) != TOKEN_RPAREN) {
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if (TOKEN_TYPE(lsp) == TOKEN_END) {
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lsp->error = XP_LISP_ERR_SYNTAX; // unexpected end of input
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return XP_NULL;
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}
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if (TOKEN_TYPE(lsp) == TOKEN_DOT) {
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if (prev == XP_NULL) {
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lsp->error = XP_LISP_ERR_SYNTAX; // unexpected .
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return XP_NULL;
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}
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NEXT_TOKEN (lsp);
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obj = read_obj (lsp);
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if (obj == XP_NULL) {
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if (lsp->error == XP_LISP_ERR_END) {
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//unexpected end of input
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lsp->error = XP_LISP_ERR_SYNTAX;
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}
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return XP_NULL;
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}
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prev->cdr = obj;
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NEXT_TOKEN (lsp);
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if (TOKEN_TYPE(lsp) != TOKEN_RPAREN) {
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lsp->error = XP_LISP_ERR_SYNTAX; // ) expected
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return XP_NULL;
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}
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break;
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}
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obj = read_obj (lsp);
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if (obj == XP_NULL) {
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if (lsp->error == XP_LISP_ERR_END) {
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// unexpected end of input
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lsp->error = XP_LISP_ERR_SYNTAX;
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}
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return XP_NULL;
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}
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p = (xp_lisp_obj_cons_t*)xp_lisp_make_cons (
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lsp->mem, lsp->mem->nil, lsp->mem->nil);
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if (p == XP_NULL) {
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lsp->error = XP_LISP_ERR_MEM;
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return XP_NULL;
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}
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xp_lisp_lock ((xp_lisp_obj_t*)p);
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if (first == XP_NULL) first = p;
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if (prev != XP_NULL) prev->cdr = (xp_lisp_obj_t*)p;
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p->car = obj;
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prev = p;
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NEXT_TOKEN (lsp);
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}
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return (first == XP_NULL)? lsp->mem->nil: (xp_lisp_obj_t*)first;
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}
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static xp_lisp_obj_t* read_quote (xp_lisp_t* lsp)
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{
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xp_lisp_obj_t* cons, * tmp;
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tmp = read_obj (lsp);
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if (tmp == XP_NULL) {
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if (lsp->error == XP_LISP_ERR_END) {
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// unexpected end of input
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lsp->error = XP_LISP_ERR_SYNTAX;
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}
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return XP_NULL;
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}
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cons = xp_lisp_make_cons (lsp->mem, tmp, lsp->mem->nil);
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if (cons == XP_NULL) {
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lsp->error = XP_LISP_ERR_MEM;
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return XP_NULL;
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}
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xp_lisp_lock (cons);
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cons = xp_lisp_make_cons (lsp->mem, lsp->mem->quote, cons);
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if (cons == XP_NULL) {
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lsp->error = XP_LISP_ERR_MEM;
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return XP_NULL;
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}
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xp_lisp_lock (cons);
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return cons;
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}
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static int read_token (xp_lisp_t* lsp)
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{
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xp_lisp_assert (lsp->creader != XP_NULL);
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TOKEN_CLEAR (lsp);
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for (;;) {
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// skip white spaces
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while (IS_SPACE(lsp->curc)) NEXT_CHAR (lsp);
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// skip the comments here
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if (lsp->curc == XP_CHAR(';')) {
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do {
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NEXT_CHAR (lsp);
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} while (lsp->curc != XP_CHAR('\n') && lsp->curc != XP_EOF);
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}
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else break;
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}
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if (lsp->curc == XP_EOF) {
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TOKEN_TYPE(lsp) = TOKEN_END;
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return 0;
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}
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else if (lsp->curc == XP_CHAR('(')) {
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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TOKEN_TYPE(lsp) = TOKEN_LPAREN;
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NEXT_CHAR (lsp);
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return 0;
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}
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else if (lsp->curc == XP_CHAR(')')) {
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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TOKEN_TYPE(lsp) = TOKEN_RPAREN;
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NEXT_CHAR (lsp);
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return 0;
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}
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else if (lsp->curc == XP_CHAR('\'')) {
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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TOKEN_TYPE(lsp) = TOKEN_QUOTE;
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NEXT_CHAR (lsp);
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return 0;
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}
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else if (lsp->curc == XP_CHAR('.')) {
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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TOKEN_TYPE(lsp) = TOKEN_DOT;
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NEXT_CHAR (lsp);
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return 0;
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}
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else if (lsp->curc == XP_CHAR('-')) {
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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NEXT_CHAR (lsp);
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return (IS_DIGIT(lsp->curc))?
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read_number (lsp, 1): read_ident (lsp);
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}
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else if (IS_DIGIT(lsp->curc)) {
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return read_number (lsp, 0);
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}
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else if (IS_ALPHA(lsp->curc) || IS_IDENT(lsp->curc)) {
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return read_ident (lsp);
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}
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else if (lsp->curc == XP_CHAR('\"')) {
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NEXT_CHAR (lsp);
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return read_string (lsp);
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}
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TOKEN_TYPE(lsp) = TOKEN_INVALID;
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NEXT_CHAR (lsp); // consume
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return 0;
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}
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static int read_number (xp_lisp_t* lsp, int negative)
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{
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do {
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TOKEN_IVALUE(lsp) =
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TOKEN_IVALUE(lsp) * 10 + lsp->curc - XP_CHAR('0');
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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NEXT_CHAR (lsp);
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} while (IS_DIGIT(lsp->curc));
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if (negative) TOKEN_IVALUE(lsp) *= -1;
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TOKEN_TYPE(lsp) = TOKEN_INT;
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// TODO: read floating point numbers
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return 0;
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}
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static int read_ident (xp_lisp_t* lsp)
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{
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do {
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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NEXT_CHAR (lsp);
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} while (IS_ALNUM(lsp->curc) || IS_IDENT(lsp->curc));
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TOKEN_TYPE(lsp) = TOKEN_IDENT;
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return 0;
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}
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static int read_string (xp_lisp_t* lsp)
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{
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int escaped = 0;
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xp_lisp_cint code = 0;
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do {
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if (lsp->curc == XP_EOF) {
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TOKEN_TYPE(lsp) = TOKEN_UNTERM_STRING;
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return 0;
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}
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// TODO:
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if (escaped == 3) {
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/* \xNN */
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}
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else if (escaped == 2) {
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/* \000 */
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}
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else if (escaped == 1) {
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/* backslash + character */
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if (lsp->curc == XP_CHAR('a'))
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lsp->curc = XP_CHAR('\a');
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else if (lsp->curc == XP_CHAR('b'))
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lsp->curc = XP_CHAR('\b');
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else if (lsp->curc == XP_CHAR('f'))
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lsp->curc = XP_CHAR('\f');
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else if (lsp->curc == XP_CHAR('n'))
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lsp->curc = XP_CHAR('\n');
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else if (lsp->curc == XP_CHAR('r'))
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lsp->curc = XP_CHAR('\r');
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else if (lsp->curc == XP_CHAR('t'))
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lsp->curc = XP_CHAR('\t');
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else if (lsp->curc == XP_CHAR('v'))
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lsp->curc = XP_CHAR('\v');
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else if (lsp->curc == XP_CHAR('0')) {
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escaped = 2;
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code = 0;
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NEXT_CHAR (lsp);
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continue;
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}
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else if (lsp->curc == XP_CHAR('x')) {
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escaped = 3;
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code = 0;
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NEXT_CHAR (lsp);
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continue;
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}
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}
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else if (lsp->curc == XP_CHAR('\\')) {
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escaped = 1;
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NEXT_CHAR (lsp);
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continue;
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}
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TOKEN_ADD_CHAR (lsp, lsp->curc);
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NEXT_CHAR (lsp);
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} while (lsp->curc != XP_CHAR('\"'));
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TOKEN_TYPE(lsp) = TOKEN_STRING;
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NEXT_CHAR (lsp);
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return 0;
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}
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