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path: root/mesalib/src/glsl/s_expression.cpp
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Diffstat (limited to 'mesalib/src/glsl/s_expression.cpp')
-rw-r--r--mesalib/src/glsl/s_expression.cpp69
1 files changed, 57 insertions, 12 deletions
diff --git a/mesalib/src/glsl/s_expression.cpp b/mesalib/src/glsl/s_expression.cpp
index 0aecfa19c..36624541b 100644
--- a/mesalib/src/glsl/s_expression.cpp
+++ b/mesalib/src/glsl/s_expression.cpp
@@ -38,14 +38,15 @@ s_list::s_list()
{
}
-unsigned
-s_list::length() const
+static void
+skip_whitespace(const char *& src)
{
- unsigned i = 0;
- foreach_iter(exec_list_iterator, it, this->subexpressions) {
- i++;
+ src += strspn(src, " \v\t\r\n");
+ /* Also skip Scheme-style comments: semi-colon 'til end of line */
+ if (src[0] == ';') {
+ src += strcspn(src, "\n");
+ skip_whitespace(src);
}
- return i;
}
static s_expression *
@@ -53,10 +54,9 @@ read_atom(void *ctx, const char *& src)
{
s_expression *expr = NULL;
- // Skip leading spaces.
- src += strspn(src, " \v\t\r\n");
+ skip_whitespace(src);
- size_t n = strcspn(src, "( \v\t\r\n)");
+ size_t n = strcspn(src, "( \v\t\r\n);");
if (n == 0)
return NULL; // no atom
@@ -90,8 +90,7 @@ s_expression::read_expression(void *ctx, const char *&src)
if (atom != NULL)
return atom;
- // Skip leading spaces.
- src += strspn(src, " \v\t\r\n");
+ skip_whitespace(src);
if (src[0] == '(') {
++src;
@@ -101,7 +100,7 @@ s_expression::read_expression(void *ctx, const char *&src)
while ((expr = read_expression(ctx, src)) != NULL) {
list->subexpressions.push_tail(expr);
}
- src += strspn(src, " \v\t\r\n");
+ skip_whitespace(src);
if (src[0] != ')') {
printf("Unclosed expression (check your parenthesis).\n");
return NULL;
@@ -139,3 +138,49 @@ void s_list::print()
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_iter(exec_list_iterator, it, list->subexpressions) {
+ if (i >= n)
+ return partial; /* More actual items than the pattern expected */
+
+ s_expression *expr = (s_expression *) it.get();
+ if (expr == NULL || !pattern[i].match(expr))
+ return false;
+
+ i++;
+ }
+
+ if (i < n)
+ return false; /* Less actual items than the pattern expected */
+
+ return true;
+}