fix reduce syntax to emit results for each initial value

Author: itchyny

cli/test.yaml

@@ -3379,6 +3379,22 @@
   expected: |
     4.5
 
+- name: reduce with select in update
+  args:
+    - 'reduce range(5) as $x (0; . + $x | select($x != 2))'
+  input: 'null'
+  expected: |
+    8
+
+- name: reduce with query in start
+  args:
+    - 'reduce range(5) as $x (range(3); . + $x)'
+  input: 'null'
+  expected: |
+    10
+    11
+    12
+
 - name: reduce with variable binding
   args:
     - 'reduce .[] as $x (0; . + $x) as $x | $x'
@@ -3438,6 +3454,33 @@
     0
     1
 
+- name: foreach with select in update
+  args:
+    - -c
+    - 'foreach range(5) as $i (0; . + $i | select($i != 2); [$i, .])'
+  input: 'null'
+  expected: |
+    [0,0]
+    [1,1]
+    [3,4]
+    [4,8]
+
+- name: foreach with query in start
+  args:
+    - -c
+    - 'foreach range(3) as $i (range(3); . + $i; [$i, .])'
+  input: 'null'
+  expected: |
+    [0,0]
+    [1,1]
+    [2,3]
+    [0,1]
+    [1,2]
+    [2,4]
+    [0,2]
+    [1,3]
+    [2,5]
+
 - name: foreach with unary operator
   args:
     - '[-foreach -.[] as $i (0; . + $i)]'

compiler.go

@@ -726,9 +726,6 @@ func (c *compiler) compileTry(e *Try) error {
 func (c *compiler) compileReduce(e *Reduce) error {
 	c.appendCodeInfo(e)
 	defer c.newScopeDepth()()
-	setfork := c.lazy(func() *code {
-		return &code{op: opfork, v: len(c.codes)}
-	})
 	c.append(&code{op: opdup})
 	v := c.newVariable()
 	f := c.newScopeDepth()
@@ -737,6 +734,9 @@ func (c *compiler) compileReduce(e *Reduce) error {
 	}
 	f()
 	c.append(&code{op: opstore, v: v})
+	setfork := c.lazy(func() *code {
+		return &code{op: opfork, v: len(c.codes)}
+	})
 	if err := c.compileQuery(e.Query); err != nil {
 		return err
 	}