chore: Remove Expr (#171)

This is a huge refactoring to remove the Expr type so that the AST is
now represented as the same structure as the SQL standard and types have
been moved the relevant files.

docs/v-client-library-docs.rst

@@ -351,7 +351,7 @@ struct VirtualTable
 
    pub struct VirtualTable {
    	create_table_sql  string
-   	create_table_stmt CreateTableStmt
+   	create_table_stmt TableDefinition
    	data              VirtualTableProviderFn [required]
    mut:
    	is_done bool

generate-grammar.py

@@ -314,10 +314,10 @@ def parse_grammar(grammar):
             # If there is a parsing function we replace the current rule with a
             # subrule:
             #
-            #   <term> /* Expr */ ::=
+            #   <term> /* Term */ ::=
             #       <factor>
-            #     | <term> <asterisk> <factor>   -> binary_expr
-            #     | <term> <solidus> <factor>    -> binary_expr
+            #     | <term> <asterisk> <factor>   -> term_1
+            #     | <term> <solidus> <factor>    -> term_2
             #
             # Becomes:
             #
@@ -334,7 +334,7 @@ def parse_grammar(grammar):
             # can capture all the children and invoke the parsing function.
             if '->' in rule:
                 rule, parse_function = rule.split(' -> ')
-                new_rule = name[:-1] + ': ' + str(rule_number + 1) + '>'
+                new_rule = name[:-1] + ': #' + str(rule_number + 1) + '>'
                 lines.append(new_rule + ' ::= ' + rule)
                 rules[rule_number] = new_rule
                 parse_functions[new_rule] = (parse_function.strip(), re.findall('(<.*?>|[^\s]+)', rule))
@@ -375,7 +375,7 @@ def rule_name(name):
     return name
 
 def var_name(name):
-    return "rule_" + rule_name(name).lower().replace('<', '').replace('-', '_').replace(':', '').replace('>', '_').replace(' ', '_').replace('^', '_')
+    return "rule_" + rule_name(name).lower().replace('<', '').replace('#', '_').replace('-', '_').replace(':', '').replace('>', '_').replace(' ', '_').replace('^', '_')
 
 # Generate grammar file
 grammar_file = open('vsql/grammar.v', mode='w')
@@ -459,11 +459,18 @@ def var_name(name):
 for rule in sorted(parse_functions.keys(), key=lambda s: s.lower()):
     grammar_file.write("\t\t'" + rule + "' {\n")
     function_name, terms = parse_functions[rule]
-    grammar_file.write("\t\t\treturn [EarleyValue(parse_" + function_name + "(")
+    if function_name == function_name.lower():
+        grammar_file.write("\t\t\treturn [EarleyValue(parse_" + function_name + "(")
+    else:
+        grammar_file.write("\t\t\treturn [EarleyValue(" + function_name + "(")
     grammar_file.write(', '.join([
         'children[' + str(i) + '] as ' + grammar_types[t]
         for i, t in enumerate(terms)
-        if t in grammar_types and grammar_types[t] != '']) + ") !)]\n")
+        if t in grammar_types and grammar_types[t] != '']))
+    if function_name == function_name.lower():
+        grammar_file.write(") !)]\n")
+    else:
+        grammar_file.write("))]\n")
 
     grammar_file.write("\t\t}\n")
 

tests/values.sql

@@ -28,7 +28,10 @@ EXPLAIN SELECT * FROM (VALUES ROW(1, 'foo', TRUE));
 -- EXPLAIN: EXPR ($1.COL1 NUMERIC, $1.COL2 CHARACTER VARYING(3), $1.COL3 BOOLEAN)
 
 EXPLAIN SELECT * FROM (VALUES 1, 'foo', TRUE) AS t1 (abc, col2, "f");
--- error 42601: syntax error: ROW provides the wrong number of columns for the correlation
+-- EXPLAIN: T1:
+-- EXPLAIN:   VALUES (ABC NUMERIC, COL2 NUMERIC, "f" NUMERIC) = ROW(1), ROW('foo'), ROW(TRUE)
+-- EXPLAIN: TABLE T1 (ABC NUMERIC, COL2 NUMERIC, "f" NUMERIC)
+-- EXPLAIN: EXPR (T1.ABC NUMERIC, T1.COL2 NUMERIC, T1."f" NUMERIC)
 
 EXPLAIN SELECT * FROM (VALUES ROW(1, 'foo', TRUE)) AS t1 (abc, col2, "f");
 -- EXPLAIN: T1:
@@ -37,7 +40,7 @@ EXPLAIN SELECT * FROM (VALUES ROW(1, 'foo', TRUE)) AS t1 (abc, col2, "f");
 -- EXPLAIN: EXPR (T1.ABC NUMERIC, T1.COL2 CHARACTER VARYING(3), T1."f" BOOLEAN)
 
 SELECT * FROM (VALUES 1, 'foo', TRUE) AS t1 (abc, col2, "f");
--- error 42601: syntax error: ROW provides the wrong number of columns for the correlation
+-- error 42601: syntax error: unknown column: T1.COL2
 
 SELECT * FROM (VALUES ROW(1, 'foo', TRUE)) AS t1 (abc, col2, "f");
 -- ABC: 1 COL2: foo f: TRUE
@@ -103,7 +106,7 @@ SELECT * FROM (VALUES 1, 2) AS t1 (foo);
 -- FOO: 2
 
 SELECT * FROM (VALUES 1, 2) AS t1 (foo, bar, baz);
--- error 42601: syntax error: ROW provides the wrong number of columns for the correlation
+-- error 42601: syntax error: unknown column: T1.BAR
 
 SELECT * FROM (VALUES ROW(1, 2), ROW(3, 4)) AS t1 (foo, bar);
 -- FOO: 1 BAR: 2

vsql/alter_sequence.v

@@ -5,7 +5,7 @@ module vsql
 
 import time
 
-fn execute_alter_sequence(mut c Connection, stmt AlterSequenceStmt, elapsed_parse time.Duration) !Result {
+fn execute_alter_sequence(mut c Connection, stmt AlterSequenceGeneratorStatement, elapsed_parse time.Duration) !Result {
 	t := start_timer()
 
 	c.open_write_connection()!
@@ -24,38 +24,34 @@ fn execute_alter_sequence(mut c Connection, stmt AlterSequenceStmt, elapsed_pars
 				// Not possible.
 			}
 			SequenceGeneratorRestartOption {
-				if option.restart_value is NoExpr {
-					sequence.current_value = sequence.reset() - sequence.increment_by
+				if v := option.restart_value {
+					sequence.current_value = (v.eval(mut c, Row{}, map[string]Value{})!).as_int() - sequence.increment_by
 				} else {
-					sequence.current_value = (eval_as_value(mut c, Row{}, option.restart_value,
-						map[string]Value{})!).as_int() - sequence.increment_by
+					sequence.current_value = sequence.reset() - sequence.increment_by
 				}
 			}
 			SequenceGeneratorIncrementByOption {
-				sequence.increment_by = (eval_as_value(mut c, Row{}, option.increment_by,
-					map[string]Value{})!).as_int()
+				sequence.increment_by = (option.increment_by.eval(mut c, Row{}, map[string]Value{})!).as_int()
 
 				// Since we increment the value after it's returned we need to correct
 				// for the current value that takes into account the difference of the
 				// new INCREMENT BY.
 				sequence.current_value += (sequence.increment_by - old_sequence.increment_by) - 1
 			}
 			SequenceGeneratorMinvalueOption {
-				if option.min_value is NoExpr {
-					sequence.has_min_value = false
-				} else {
-					sequence.min_value = (eval_as_value(mut c, Row{}, option.min_value,
-						map[string]Value{})!).as_int()
+				if v := option.min_value {
+					sequence.min_value = (v.eval(mut c, Row{}, map[string]Value{})!).as_int()
 					sequence.has_min_value = true
+				} else {
+					sequence.has_min_value = false
 				}
 			}
 			SequenceGeneratorMaxvalueOption {
-				if option.max_value is NoExpr {
-					sequence.has_min_value = false
-				} else {
-					sequence.max_value = (eval_as_value(mut c, Row{}, option.max_value,
-						map[string]Value{})!).as_int()
+				if v := option.max_value {
+					sequence.max_value = (v.eval(mut c, Row{}, map[string]Value{})!).as_int()
 					sequence.has_max_value = true
+				} else {
+					sequence.has_min_value = false
 				}
 			}
 			SequenceGeneratorCycleOption {