Improve handling of import statements in GHCi (#20473)

Currently in GHCi, when given a line of user input we:

1. Attempt to parse and handle it as a statement
2. Otherwise, attempt to parse and handle a single import
3. Otherwise, check if there are imports present (and if so display an error message)
4. Otherwise, attempt to parse a module and only handle the declarations

This patch simplifies the process to:

Attempt to parse and handle it as a statement
Otherwise, attempt to parse a module and handle the imports and declarations

This means that multiple imports in a multiline are now accepted, and a multiline containing both imports and declarations is now accepted (as well as when separated by semicolons).

11 files changed, 19 insertions, 5 deletions

diff --git a/testsuite/tests/ghc-e/should_fail/T9905fail2.stderr b/testsuite/tests/ghc-e/should_fail/T9905fail2.stderr
index 2e3e2d94cc..9143eccae4 100644
--- a/testsuite/tests/ghc-e/should_fail/T9905fail2.stderr
+++ b/testsuite/tests/ghc-e/should_fail/T9905fail2.stderr
@@ -1,3 +1,3 @@
 
-<interactive>:1:19: error:
+<interactive>:0:19: error:
     Module ‘Data.List’ does not export ‘bogusIdentifier’
diff --git a/testsuite/tests/ghci/scripts/T10663.script b/testsuite/tests/ghci/scripts/T10663.script
index 10be57f52a..406d0ca7ee 100644
--- a/testsuite/tests/ghci/scripts/T10663.script
+++ b/testsuite/tests/ghci/scripts/T10663.script
@@ -1 +1,2 @@
-import Data.List; sort [2, 1]
\ No newline at end of file
+import Data.List; xs = sort [2, 1]
+xs
\ No newline at end of file
diff --git a/testsuite/tests/ghci/scripts/T10663.stderr b/testsuite/tests/ghci/scripts/T10663.stderr
deleted file mode 100644
index 7170dbf29c..0000000000
--- a/testsuite/tests/ghci/scripts/T10663.stderr
+++ /dev/null
@@ -1 +0,0 @@
-error: expecting a single import declaration
\ No newline at end of file
diff --git a/testsuite/tests/ghci/scripts/T10663.stdout b/testsuite/tests/ghci/scripts/T10663.stdout
new file mode 100644
index 0000000000..3169929f69
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T10663.stdout
@@ -0,0 +1 @@
+[1,2]
\ No newline at end of file
diff --git a/testsuite/tests/ghci/scripts/T20473a.script b/testsuite/tests/ghci/scripts/T20473a.script
new file mode 100644
index 0000000000..d84edb4129
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T20473a.script
@@ -0,0 +1,7 @@
+:{
+import Data.List
+
+xs :: [Int]
+xs = sort [2,1]
+:}
+sort xs
diff --git a/testsuite/tests/ghci/scripts/T20473a.stdout b/testsuite/tests/ghci/scripts/T20473a.stdout
new file mode 100644
index 0000000000..6ed63af507
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T20473a.stdout
@@ -0,0 +1 @@
+[1,2]
diff --git a/testsuite/tests/ghci/scripts/T20473b.script b/testsuite/tests/ghci/scripts/T20473b.script
new file mode 100644
index 0000000000..4fb53badf3
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T20473b.script
@@ -0,0 +1,2 @@
+import Data.List; import Data.Function
+on (==) sort [1,2] [2,1]
diff --git a/testsuite/tests/ghci/scripts/T20473b.stdout b/testsuite/tests/ghci/scripts/T20473b.stdout
new file mode 100644
index 0000000000..0ca95142bb
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T20473b.stdout
@@ -0,0 +1 @@
+True
diff --git a/testsuite/tests/ghci/scripts/T6007.stderr b/testsuite/tests/ghci/scripts/T6007.stderr
index aa2be4ee6d..bd5c31dd57 100644
--- a/testsuite/tests/ghci/scripts/T6007.stderr
+++ b/testsuite/tests/ghci/scripts/T6007.stderr
@@ -2,5 +2,5 @@
 <interactive>:1:19:
     Module ‘System.IO’ does not export ‘does_not_exist’
 
-<interactive>:1:20:
+<interactive>:3:20:
     Module ‘Data.Maybe’ does not export ‘does_not_exist’
diff --git a/testsuite/tests/ghci/scripts/all.T b/testsuite/tests/ghci/scripts/all.T
index d67ff95308..884df5a811 100755
--- a/testsuite/tests/ghci/scripts/all.T
+++ b/testsuite/tests/ghci/scripts/all.T
@@ -348,3 +348,5 @@ test('T20206', normal, ghci_script, ['T20206.script'])
 test('T20217', normal, ghci_script, ['T20217.script'])
 test('T7388', normal, ghci_script, ['T7388.script'])
 test('T20627', normal, ghci_script, ['T20627.script'])
+test('T20473a', normal, ghci_script, ['T20473a.script'])
+test('T20473b', normal, ghci_script, ['T20473b.script'])
diff --git a/testsuite/tests/th/T10019.stdout b/testsuite/tests/th/T10019.stdout
index 85510c1af1..413d875440 100644
--- a/testsuite/tests/th/T10019.stdout
+++ b/testsuite/tests/th/T10019.stdout
@@ -1 +1 @@
-"Constructor from Ghci1.Option: Ghci1.Some :: forall (a_0 :: *) .\n                                             a_0 %1 -> Ghci1.Option a_0"
+"Constructor from Ghci2.Option: Ghci2.Some :: forall (a_0 :: *) .\n                                             a_0 %1 -> Ghci2.Option a_0"