Support elif.

check.sh

@@ -45,6 +45,11 @@ tests="
 10-if
 10-if-false
 10-if-word-variable
+10-if-multiple
+10-if-else
+10-else-multiple
+10-if-elif
+
 11-for
 11-for-split-sequence
 

gash/peg.scm

@@ -350,6 +350,8 @@
     (('substitution o) `(substitution ,(transform o)))
     (('if-clause expr then) `(if-clause ,(transform expr) ,(transform then)))
     (('if-clause expr then else) `(if-clause ,(transform expr) ,(transform then) ,(transform else)))
+    (('elif-part expr then) `(if-clause ,(transform expr) ,(transform then)))
+    (('elif-part expr then else) `(if-clause ,(transform expr) ,(transform then) ,(transform else)))
     (('then-part o ...) `(begin ,@(map transform o)))
     (('else-part o ...) `(begin ,@(map transform o)))
     (('word 'singlequotes) "")

test/10-else-multiple.sh

@@ -0,0 +1,6 @@
+if false; then
+    :
+else
+    echo one
+    echo two
+fi

test/10-else.multiple.stdout

@@ -0,0 +1,2 @@
+one
+two

test/10-if-elif.sh

@@ -0,0 +1,8 @@
+if false; then
+    exit 1
+elif false; then
+     exit 2
+else
+    exit 0
+fi
+exit 1

test/10-if-else.sh

@@ -0,0 +1,6 @@
+if false; then
+    exit 1
+else
+    exit 0
+fi
+exit 1

test/10-if-multiple.sh

@@ -0,0 +1,4 @@
+if true; then
+    echo one
+    echo two
+fi

test/10-if-multiple.stdout

@@ -0,0 +1,2 @@
+one
+two