diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/compile.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/src/compile.c b/src/compile.c index 0c90e18..2eac523 100644 --- a/src/compile.c +++ b/src/compile.c @@ -134,6 +134,8 @@ typedef struct { /* Views in order; a table (no value) is followed by its columns. */ char view_names[VIEWS][NAME], view_row[VIEWS][NAME], view_list[VIEWS][NAME]; Expr *view_value[VIEWS]; + Expr *view_filter[VIEWS]; /* a table's where condition, or NULL */ + unsigned char view_byte[VIEWS]; /* a filtered table's list + 1 */ int view_table[VIEWS]; /* a column's table + 1, or 0 */ int view_line[VIEWS][2], view_column[VIEWS][2]; /* a table's row name and list name */ unsigned views; @@ -144,7 +146,7 @@ typedef struct { int row; /* the table whose column is being generated, or -1 */ /* The fold whose block is being generated: its item's name and list, and * the fn scope it began in (whose parameters its block cannot read). */ - bool folding; + bool folding, filtering; char fold_name[NAME]; int fold_list; Scope *fold_scope; @@ -1097,7 +1099,8 @@ static void state_declaration(Compiler *c) { ++c->states; } -/* view name = each row in list { column = value ... }: one row per item. */ +/* view name = each row in list [where condition] { column = value ... }: one + * row per item, or per item the condition keeps. */ static void table_declaration(Compiler *c, unsigned table) { take(c); /* each */ Token row = expect_name(c, "a name for each item"); @@ -1110,6 +1113,10 @@ static void table_declaration(Compiler *c, unsigned table) { c->view_column[table][0] = row.column; c->view_line[table][1] = list.line; c->view_column[table][1] = list.column; + if (word(c, "where")) { /* a row only for the items it keeps */ + take(c); + c->view_filter[table] = expression(c, 0, false); + } expect(c, "{", "'{' on the line of the table"); separators(c); while (!is(c, "}")) { @@ -1650,6 +1657,7 @@ static Kind value(Compiler *c, const Expr *e, bool handler, int height) { int list = state_index(c, e->member); if (list < 0 || c->state_types[list] != STATE_LIST) fail_at(c, e->line, e->column, "'%s' is not a list", e->member); if (c->folding) fail_at(c, e->line, e->column, "a count, sum, max or min cannot hold another"); + if (c->filtering) fail_at(c, e->line, e->column, "a table's where cannot hold a count, sum, max or min"); unsigned at = c->code_count, joins = c->joins; emit(c, e->line, e->column, FOLD, 0, 0); c->folding = true; @@ -1920,6 +1928,16 @@ static void generate(Compiler *c, unsigned char **module, size_t *size) { c->view_types[i] = 2; c->view_code[i][0] = (uint32_t)list; c->view_code[i][1] = 0; + if (c->view_filter[i]) { + /* The filter runs as a column of the list: it reads the table's row. */ + c->row = (int)i; + c->filtering = true; + c->view_code[i][0] = c->code_count; + number(c, c->view_filter[i], false, 0); + c->view_code[i][1] = c->code_count - c->view_code[i][0]; + c->view_byte[i] = (unsigned char)(list + 1); + c->filtering = false; + } continue; } c->row = c->view_table[i] - 1; @@ -2021,7 +2039,7 @@ static void generate(Compiler *c, unsigned char **module, size_t *size) { for (unsigned i = 0; i < c->views; ++i) { p = put32(p, view_name[i]); *p++ = (unsigned char)c->view_types[i]; - *p++ = 0; + *p++ = c->view_byte[i]; p = put16(p, (uint32_t)c->view_table[i]); p = put32(p, c->view_code[i][0]); p = put32(p, c->view_code[i][1]); |