From: Jean Privat <jean@pryen.org>
Date: Wed, 10 Jul 2019 13:54:14 +0000 (-0400)
Subject: syntax: add safe call syntax `x?.foo`
X-Git-Url: http://nitlanguage.org

syntax: add safe call syntax `x?.foo`

Signed-off-by: Jean Privat <jean@pryen.org>
---

diff --git a/src/parser/nit.sablecc3xx b/src/parser/nit.sablecc3xx
index 1931792..d7380c5 100644
--- a/src/parser/nit.sablecc3xx
+++ b/src/parser/nit.sablecc3xx
@@ -204,6 +204,7 @@ ge = '>=';
 gg = '>>';
 starship = '<=>';
 bang='!';
+quest='?';
 at='@';
 semi=';';
 
@@ -792,6 +793,7 @@ atid~forclass {-> atid}
 
 recv~nopar~nobra {-> expr}
 	= expr_atom~nopar~nobra dot no {-> expr_atom~nopar~nobra.expr}
+	| {safe} expr_atom~nopar~nobra quest dot no {-> New expr.safe(expr_atom~nopar~nobra.expr, quest)}
 	| {implicit} {-> New expr.implicit_self()}
 	;
 
@@ -1053,6 +1055,7 @@ expr	= {block} expr* kwend?
 	| {debug_type} kwdebug kwtype expr type
 	| {vararg} expr dotdotdot
 	| {namedarg} id assign expr
+	| {safe} expr quest
 	| {type} type
 	| {methid} expr [id]:methid
 	| {at} annotations
diff --git a/src/parser/parser_abs.nit b/src/parser/parser_abs.nit
index 2f42bfc..8c0930c 100644
--- a/src/parser/parser_abs.nit
+++ b/src/parser/parser_abs.nit
@@ -295,6 +295,9 @@ end
 class TBang
 	super Token
 end
+class TQuest
+	super Token
+end
 class TAt
 	super Token
 end
@@ -1200,6 +1203,11 @@ class ANamedargExpr
 	var n_assign: TAssign is writable, noinit
 	var n_expr: AExpr is writable, noinit
 end
+class ASafeExpr
+	super AExpr
+	var n_expr: AExpr is writable, noinit
+	var n_quest: TQuest is writable, noinit
+end
 class ATypeExpr
 	super AExpr
 	var n_type: AType is writable, noinit
diff --git a/src/parser/parser_nodes.nit b/src/parser/parser_nodes.nit
index 0c535c2..92dbea0 100644
--- a/src/parser/parser_nodes.nit
+++ b/src/parser/parser_nodes.nit
@@ -983,6 +983,11 @@ class TStarship
 	super TokenOperator
 end
 
+# The operator `?`
+class TQuest
+	super TokenOperator
+end
+
 # The operator `!`
 class TBang
 	super TokenOperator
@@ -2750,6 +2755,17 @@ class AVarargExpr
 	var n_dotdotdot: TDotdotdot is writable, noinit
 end
 
+# A receiver with a `?` suffix used in safe call operator.
+class ASafeExpr
+	super AExpr
+
+	# The expression made safe
+	var n_expr: AExpr is writable, noinit
+
+	# The `?` symbol
+	var n_quest: TQuest is writable, noinit
+end
+
 # An named notation used to pass an expression by name in a parameter
 class ANamedargExpr
 	super AExpr