0,0 → 1,218 |
/* -*- c++ -*- */ |
/* |
* Copyright © 2010 Intel Corporation |
* |
* Permission is hereby granted, free of charge, to any person obtaining a |
* copy of this software and associated documentation files (the "Software"), |
* to deal in the Software without restriction, including without limitation |
* the rights to use, copy, modify, merge, publish, distribute, sublicense, |
* and/or sell copies of the Software, and to permit persons to whom the |
* Software is furnished to do so, subject to the following conditions: |
* |
* The above copyright notice and this permission notice (including the next |
* paragraph) shall be included in all copies or substantial portions of the |
* Software. |
* |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
* DEALINGS IN THE SOFTWARE. |
*/ |
|
#include <assert.h> |
#include <stdio.h> |
#include <math.h> |
#include "s_expression.h" |
|
s_symbol::s_symbol(const char *str, size_t n) |
{ |
/* Assume the given string is already nul-terminated and in memory that |
* will live as long as this node. |
*/ |
assert(str[n] == '\0'); |
this->str = str; |
} |
|
s_list::s_list() |
{ |
} |
|
static void |
skip_whitespace(const char *&src, char *&symbol_buffer) |
{ |
size_t n = strspn(src, " \v\t\r\n"); |
src += n; |
symbol_buffer += n; |
/* Also skip Scheme-style comments: semi-colon 'til end of line */ |
if (src[0] == ';') { |
n = strcspn(src, "\n"); |
src += n; |
symbol_buffer += n; |
skip_whitespace(src, symbol_buffer); |
} |
} |
|
static s_expression * |
read_atom(void *ctx, const char *&src, char *&symbol_buffer) |
{ |
s_expression *expr = NULL; |
|
skip_whitespace(src, symbol_buffer); |
|
size_t n = strcspn(src, "( \v\t\r\n);"); |
if (n == 0) |
return NULL; // no atom |
|
// Check for the special symbol '+INF', which means +Infinity. Note: C99 |
// requires strtof to parse '+INF' as +Infinity, but we still support some |
// non-C99-compliant compilers (e.g. MSVC). |
if (n == 4 && strncmp(src, "+INF", 4) == 0) { |
expr = new(ctx) s_float(INFINITY); |
} else { |
// Check if the atom is a number. |
char *float_end = NULL; |
float f = _mesa_strtof(src, &float_end); |
if (float_end != src) { |
char *int_end = NULL; |
int i = strtol(src, &int_end, 10); |
// If strtof matched more characters, it must have a decimal part |
if (float_end > int_end) |
expr = new(ctx) s_float(f); |
else |
expr = new(ctx) s_int(i); |
} else { |
// Not a number; return a symbol. |
symbol_buffer[n] = '\0'; |
expr = new(ctx) s_symbol(symbol_buffer, n); |
} |
} |
|
src += n; |
symbol_buffer += n; |
|
return expr; |
} |
|
static s_expression * |
__read_expression(void *ctx, const char *&src, char *&symbol_buffer) |
{ |
s_expression *atom = read_atom(ctx, src, symbol_buffer); |
if (atom != NULL) |
return atom; |
|
skip_whitespace(src, symbol_buffer); |
if (src[0] == '(') { |
++src; |
++symbol_buffer; |
|
s_list *list = new(ctx) s_list; |
s_expression *expr; |
|
while ((expr = __read_expression(ctx, src, symbol_buffer)) != NULL) { |
list->subexpressions.push_tail(expr); |
} |
skip_whitespace(src, symbol_buffer); |
if (src[0] != ')') { |
printf("Unclosed expression (check your parenthesis).\n"); |
return NULL; |
} |
++src; |
++symbol_buffer; |
return list; |
} |
return NULL; |
} |
|
s_expression * |
s_expression::read_expression(void *ctx, const char *&src) |
{ |
assert(src != NULL); |
|
/* When we encounter a Symbol, we need to save a nul-terminated copy of |
* the string. However, ralloc_strndup'ing every individual Symbol is |
* extremely expensive. We could avoid this by simply overwriting the |
* next character (guaranteed to be whitespace, parens, or semicolon) with |
* a nul-byte. But overwriting non-whitespace would mess up parsing. |
* |
* So, just copy the whole buffer ahead of time. Walk both, leaving the |
* original source string unmodified, and altering the copy to contain the |
* necessary nul-bytes whenever we encounter a symbol. |
*/ |
char *symbol_buffer = ralloc_strdup(ctx, src); |
return __read_expression(ctx, src, symbol_buffer); |
} |
|
void s_int::print() |
{ |
printf("%d", this->val); |
} |
|
void s_float::print() |
{ |
printf("%f", this->val); |
} |
|
void s_symbol::print() |
{ |
printf("%s", this->str); |
} |
|
void s_list::print() |
{ |
printf("("); |
foreach_in_list(s_expression, expr, &this->subexpressions) { |
expr->print(); |
if (!expr->next->is_tail_sentinel()) |
printf(" "); |
} |
printf(")"); |
} |
|
// -------------------------------------------------- |
|
bool |
s_pattern::match(s_expression *expr) |
{ |
switch (type) |
{ |
case EXPR: *p_expr = expr; break; |
case LIST: if (expr->is_list()) *p_list = (s_list *) expr; break; |
case SYMBOL: if (expr->is_symbol()) *p_symbol = (s_symbol *) expr; break; |
case NUMBER: if (expr->is_number()) *p_number = (s_number *) expr; break; |
case INT: if (expr->is_int()) *p_int = (s_int *) expr; break; |
case STRING: |
s_symbol *sym = SX_AS_SYMBOL(expr); |
if (sym != NULL && strcmp(sym->value(), literal) == 0) |
return true; |
return false; |
}; |
|
return *p_expr == expr; |
} |
|
bool |
s_match(s_expression *top, unsigned n, s_pattern *pattern, bool partial) |
{ |
s_list *list = SX_AS_LIST(top); |
if (list == NULL) |
return false; |
|
unsigned i = 0; |
foreach_in_list(s_expression, expr, &list->subexpressions) { |
if (i >= n) |
return partial; /* More actual items than the pattern expected */ |
|
if (expr == NULL || !pattern[i].match(expr)) |
return false; |
|
i++; |
} |
|
if (i < n) |
return false; /* Less actual items than the pattern expected */ |
|
return true; |
} |