Merge pull request #1841 from ruby/then-keyword

Track the then keyword for conditionals

Author: kddnewton

config.yml

@@ -1385,6 +1385,8 @@ nodes:
  type: location?
  - name: predicate
  type: node
+ - name: then_keyword_loc
+ type: location?
  - name: statements
  type: node?
  kind: StatementsNode
@@ -2446,6 +2448,8 @@ nodes:
  type: location
  - name: predicate
  type: node
+ - name: then_keyword_loc
+ type: location?
  - name: statements
  type: node?
  kind: StatementsNode

lib/prism/desugar_compiler.rb

@@ -188,6 +188,7 @@ def desugar_or_write_defined_node(node, read_class, write_class, *arguments)
  IfNode.new(
  node.operator_loc,
  DefinedNode.new(nil, read_class.new(*arguments, node.name_loc), nil, node.operator_loc, node.name_loc),
+ node.operator_loc,
  StatementsNode.new([read_class.new(*arguments, node.name_loc)], node.location),
  ElseNode.new(
  node.operator_loc,

src/prism.c

@@ -3206,6 +3206,7 @@ static pm_if_node_t *
 pm_if_node_create(pm_parser_t *parser,
  const pm_token_t *if_keyword,
  pm_node_t *predicate,
+ const pm_token_t *then_keyword,
  pm_statements_node_t *statements,
  pm_node_t *consequent,
  const pm_token_t *end_keyword
@@ -3235,6 +3236,7 @@ pm_if_node_create(pm_parser_t *parser,
  },
  .if_keyword_loc = PM_LOCATION_TOKEN_VALUE(if_keyword),
  .predicate = predicate,
+ .then_keyword_loc = PM_OPTIONAL_LOCATION_TOKEN_VALUE(then_keyword),
  .statements = statements,
  .consequent = consequent,
  .end_keyword_loc = PM_OPTIONAL_LOCATION_TOKEN_VALUE(end_keyword)
@@ -3265,6 +3267,7 @@ pm_if_node_modifier_create(pm_parser_t *parser, pm_node_t *statement, const pm_t
  },
  .if_keyword_loc = PM_LOCATION_TOKEN_VALUE(if_keyword),
  .predicate = predicate,
+ .then_keyword_loc = PM_OPTIONAL_LOCATION_NOT_PROVIDED_VALUE,
  .statements = statements,
  .consequent = NULL,
  .end_keyword_loc = PM_OPTIONAL_LOCATION_NOT_PROVIDED_VALUE
@@ -3277,7 +3280,7 @@ pm_if_node_modifier_create(pm_parser_t *parser, pm_node_t *statement, const pm_t
  * Allocate and initialize an if node from a ternary expression.
  */
 static pm_if_node_t *
-pm_if_node_ternary_create(pm_parser_t *parser, pm_node_t *predicate, pm_node_t *true_expression, const pm_token_t *colon, pm_node_t *false_expression) {
+pm_if_node_ternary_create(pm_parser_t *parser, pm_node_t *predicate, const pm_token_t *qmark, pm_node_t *true_expression, const pm_token_t *colon, pm_node_t *false_expression) {
  pm_assert_value_expression(parser, predicate);
  pm_conditional_predicate(predicate);
 
@@ -3303,6 +3306,7 @@ pm_if_node_ternary_create(pm_parser_t *parser, pm_node_t *predicate, pm_node_t *
  },
  .if_keyword_loc = PM_OPTIONAL_LOCATION_NOT_PROVIDED_VALUE,
  .predicate = predicate,
+ .then_keyword_loc = PM_LOCATION_TOKEN_VALUE(qmark),
  .statements = if_statements,
  .consequent = (pm_node_t *)else_node,
  .end_keyword_loc = PM_OPTIONAL_LOCATION_NOT_PROVIDED_VALUE
@@ -5348,7 +5352,7 @@ pm_undef_node_append(pm_undef_node_t *node, pm_node_t *name) {
  * Allocate a new UnlessNode node.
  */
 static pm_unless_node_t *
-pm_unless_node_create(pm_parser_t *parser, const pm_token_t *keyword, pm_node_t *predicate, pm_statements_node_t *statements) {
+pm_unless_node_create(pm_parser_t *parser, const pm_token_t *keyword, pm_node_t *predicate, const pm_token_t *then_keyword, pm_statements_node_t *statements) {
  pm_conditional_predicate(predicate);
  pm_unless_node_t *node = PM_ALLOC_NODE(parser, pm_unless_node_t);
 
@@ -5370,6 +5374,7 @@ pm_unless_node_create(pm_parser_t *parser, const pm_token_t *keyword, pm_node_t
  },
  .keyword_loc = PM_LOCATION_TOKEN_VALUE(keyword),
  .predicate = predicate,
+ .then_keyword_loc = PM_OPTIONAL_LOCATION_TOKEN_VALUE(then_keyword),
  .statements = statements,
  .consequent = NULL,
  .end_keyword_loc = PM_OPTIONAL_LOCATION_NOT_PROVIDED_VALUE
@@ -5400,6 +5405,7 @@ pm_unless_node_modifier_create(pm_parser_t *parser, pm_node_t *statement, const
  },
  .keyword_loc = PM_LOCATION_TOKEN_VALUE(unless_keyword),
  .predicate = predicate,
+ .then_keyword_loc = PM_OPTIONAL_LOCATION_NOT_PROVIDED_VALUE,
  .statements = statements,
  .consequent = NULL,
  .end_keyword_loc = PM_OPTIONAL_LOCATION_NOT_PROVIDED_VALUE
@@ -11839,14 +11845,19 @@ parse_arguments_list(pm_parser_t *parser, pm_arguments_t *arguments, bool accept
 }
 
 static inline pm_node_t *
-parse_predicate(pm_parser_t *parser, pm_binding_power_t binding_power, pm_context_t context) {
+parse_predicate(pm_parser_t *parser, pm_binding_power_t binding_power, pm_context_t context, pm_token_t *then_keyword) {
  context_push(parser, PM_CONTEXT_PREDICATE);
  pm_diagnostic_id_t error_id = context == PM_CONTEXT_IF ? PM_ERR_CONDITIONAL_IF_PREDICATE : PM_ERR_CONDITIONAL_UNLESS_PREDICATE;
  pm_node_t *predicate = parse_value_expression(parser, binding_power, error_id);
 
  // Predicates are closed by a term, a "then", or a term and then a "then".
  bool predicate_closed = accept2(parser, PM_TOKEN_NEWLINE, PM_TOKEN_SEMICOLON);
- predicate_closed |= accept1(parser, PM_TOKEN_KEYWORD_THEN);
+
+ if (accept1(parser, PM_TOKEN_KEYWORD_THEN)) {
+ predicate_closed = true;
+ *then_keyword = parser->previous;
+ }
+
  if (!predicate_closed) {
  pm_parser_err_current(parser, PM_ERR_CONDITIONAL_PREDICATE_TERM);
  }
@@ -11858,7 +11869,9 @@ parse_predicate(pm_parser_t *parser, pm_binding_power_t binding_power, pm_contex
 static inline pm_node_t *
 parse_conditional(pm_parser_t *parser, pm_context_t context) {
  pm_token_t keyword = parser->previous;
- pm_node_t *predicate = parse_predicate(parser, PM_BINDING_POWER_MODIFIER, context);
+ pm_token_t then_keyword = not_provided(parser);
+
+ pm_node_t *predicate = parse_predicate(parser, PM_BINDING_POWER_MODIFIER, context, &then_keyword);
  pm_statements_node_t *statements = NULL;
 
  if (!match3(parser, PM_TOKEN_KEYWORD_ELSIF, PM_TOKEN_KEYWORD_ELSE, PM_TOKEN_KEYWORD_END)) {
@@ -11873,10 +11886,10 @@ parse_conditional(pm_parser_t *parser, pm_context_t context) {
 
  switch (context) {
  case PM_CONTEXT_IF:
- parent = (pm_node_t *) pm_if_node_create(parser, &keyword, predicate, statements, NULL, &end_keyword);
+ parent = (pm_node_t *) pm_if_node_create(parser, &keyword, predicate, &then_keyword, statements, NULL, &end_keyword);
  break;
  case PM_CONTEXT_UNLESS:
- parent = (pm_node_t *) pm_unless_node_create(parser, &keyword, predicate, statements);
+ parent = (pm_node_t *) pm_unless_node_create(parser, &keyword, predicate, &then_keyword, statements);
  break;
  default:
  assert(false && "unreachable");
@@ -11890,14 +11903,14 @@ parse_conditional(pm_parser_t *parser, pm_context_t context) {
  if (context == PM_CONTEXT_IF) {
  while (accept1(parser, PM_TOKEN_KEYWORD_ELSIF)) {
  pm_token_t elsif_keyword = parser->previous;
- pm_node_t *predicate = parse_predicate(parser, PM_BINDING_POWER_MODIFIER, PM_CONTEXT_ELSIF);
+ pm_node_t *predicate = parse_predicate(parser, PM_BINDING_POWER_MODIFIER, PM_CONTEXT_ELSIF, &then_keyword);
  pm_accepts_block_stack_push(parser, true);
  pm_statements_node_t *statements = parse_statements(parser, PM_CONTEXT_ELSIF);
  pm_accepts_block_stack_pop(parser);
 
  accept2(parser, PM_TOKEN_NEWLINE, PM_TOKEN_SEMICOLON);
 
- pm_node_t *elsif = (pm_node_t *) pm_if_node_create(parser, &elsif_keyword, predicate, statements, NULL, &end_keyword);
+ pm_node_t *elsif = (pm_node_t *) pm_if_node_create(parser, &elsif_keyword, predicate, &then_keyword, statements, NULL, &end_keyword);
  ((pm_if_node_t *) current)->consequent = elsif;
  current = elsif;
  }
@@ -16179,6 +16192,7 @@ parse_expression_infix(pm_parser_t *parser, pm_node_t *node, pm_binding_power_t
  return (pm_node_t *) pm_while_node_modifier_create(parser, &token, predicate, statements, PM_NODE_TYPE_P(node, PM_BEGIN_NODE) ? PM_LOOP_FLAGS_BEGIN_MODIFIER : 0);
  }
  case PM_TOKEN_QUESTION_MARK: {
+ pm_token_t qmark = parser->current;
  parser_lex(parser);
  pm_node_t *true_expression = parse_expression(parser, PM_BINDING_POWER_DEFINED, PM_ERR_TERNARY_EXPRESSION_TRUE);
 
@@ -16192,7 +16206,7 @@ parse_expression_infix(pm_parser_t *parser, pm_node_t *node, pm_binding_power_t
  pm_token_t colon = (pm_token_t) { .type = PM_TOKEN_MISSING, .start = parser->previous.end, .end = parser->previous.end };
  pm_node_t *false_expression = (pm_node_t *) pm_missing_node_create(parser, colon.start, colon.end);
 
- return (pm_node_t *) pm_if_node_ternary_create(parser, node, true_expression, &colon, false_expression);
+ return (pm_node_t *) pm_if_node_ternary_create(parser, node, &qmark, true_expression, &colon, false_expression);
  }
 
  accept1(parser, PM_TOKEN_NEWLINE);
@@ -16201,7 +16215,7 @@ parse_expression_infix(pm_parser_t *parser, pm_node_t *node, pm_binding_power_t
  pm_token_t colon = parser->previous;
  pm_node_t *false_expression = parse_expression(parser, PM_BINDING_POWER_DEFINED, PM_ERR_TERNARY_EXPRESSION_FALSE);
 
- return (pm_node_t *) pm_if_node_ternary_create(parser, node, true_expression, &colon, false_expression);
+ return (pm_node_t *) pm_if_node_ternary_create(parser, node, &qmark, true_expression, &colon, false_expression);
  }
  case PM_TOKEN_COLON_COLON: {
  parser_lex(parser);