Changeset 20ac1a4 in mainline for uspace/app/bithenge/script.c

Timestamp:

2012-07-30T02:07:10Z (12 years ago)

Author:

Sean Bartell <wingedtachikoma@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

78d3a00

Parents:

10334c2e

Message:

Bithenge: add syntactic sugar for if in struct

File:

• uspace/app/bithenge/script.c (modified) (6 diffs)

uspace/app/bithenge/script.c

@@ -342 +342 @@
 
 static bithenge_transform_t *parse_transform(state_t *state);
+static bithenge_transform_t *parse_struct(state_t *state);
 
 static bithenge_expression_t *parse_expression(state_t *state)
@@ -490 +491 @@
 }
 
-static bithenge_transform_t *parse_if(state_t *state)
+static bithenge_transform_t *parse_if(state_t *state, bool in_struct)
 {
         expect(state, TOKEN_IF);
@@ -497 +498 @@
         expect(state, ')');
         expect(state, '{');
-        bithenge_transform_t *true_xform = parse_transform(state);
+        bithenge_transform_t *true_xform =
+            in_struct ? parse_struct(state) : parse_transform(state);
         expect(state, '}');
-        expect(state, TOKEN_ELSE);
-        expect(state, '{');
-        bithenge_transform_t *false_xform = parse_transform(state);
-        expect(state, '}');
+        bithenge_transform_t *false_xform = NULL;
+        if (state->token == TOKEN_ELSE) {
+                next_token(state);
+                expect(state, '{');
+                false_xform =
+                    in_struct ? parse_struct(state) : parse_transform(state);
+                expect(state, '}');
+        } else {
+                if (in_struct) {
+                        bithenge_node_t *node;
+                        int rc = bithenge_new_empty_internal_node(&node);
+                        if (rc != EOK) {
+                                error_errno(state, rc);
+                                goto error;
+                        }
+                        bithenge_expression_t *expr;
+                        rc = bithenge_const_expression(&expr, node);
+                        if (rc != EOK) {
+                                error_errno(state, rc);
+                                goto error;
+                        }
+                        rc = bithenge_expression_transform(&false_xform, expr);
+                        if (rc != EOK) {
+                                error_errno(state, rc);
+                                false_xform = NULL;
+                                goto error;
+                        }
+                } else
+                        syntax_error(state, "else expected");
+        }
         if (state->error != EOK) {
+error:
                 bithenge_expression_dec_ref(expr);
                 bithenge_transform_dec_ref(true_xform);
@@ -519 +548 @@
 }
 
+/* The TOKEN_STRUCT and '{' must already have been skipped. */
 static bithenge_transform_t *parse_struct(state_t *state)
 {
@@ -525 +555 @@
         /* We keep an extra space for the {NULL, NULL} terminator. */
         subxforms = state_malloc(state, sizeof(*subxforms));
-        expect(state, TOKEN_STRUCT);
-        expect(state, '{');
         while (state->error == EOK && state->token != '}') {
-                if (state->token == '.') {
-                        expect(state, '.');
-                        subxforms[num].name = expect_identifier(state);
+                if (state->token == TOKEN_IF) {
+                        subxforms[num].transform = parse_if(state, true);
+                        subxforms[num].name = NULL;
+                } else {
+                        if (state->token == '.') {
+                                next_token(state);
+                                subxforms[num].name = expect_identifier(state);
+                        } else {
+                                subxforms[num].name = NULL;
+                        }
                         expect(state, TOKEN_LEFT_ARROW);
-                } else {
-                        subxforms[num].name = NULL;
-                        expect(state, TOKEN_LEFT_ARROW);
-                }
-                subxforms[num].transform = parse_transform(state);
-                expect(state, ';');
+                        subxforms[num].transform = parse_transform(state);
+                        expect(state, ';');
+                }
                 num++;
                 subxforms = state_realloc(state, subxforms,
                     (num + 1)*sizeof(*subxforms));
         }
-        expect(state, '}');
 
         if (state->error != EOK) {
@@ -571 +602 @@
                 return parse_invocation(state);
         } else if (state->token == TOKEN_IF) {
-                return parse_if(state);
+                return parse_if(state, false);
         } else if (state->token == TOKEN_STRUCT) {
-                return parse_struct(state);
+                next_token(state);
+                expect(state, '{');
+                bithenge_transform_t *xform = parse_struct(state);
+                expect(state, '}');
+                return xform;
         } else {
                 syntax_error(state, "unexpected (transform expected)");