From f510b7d33468a179b3849f13c579d3d5d3449352 Mon Sep 17 00:00:00 2001
From: Richard Tia <richie.tia@gmail.com>
Date: Fri, 15 Jul 2022 16:14:11 -0700
Subject: [PATCH 1/6] feat: add string trimming and padding functions

---
 extensions/functions_string.yaml | 147 ++++++++++++++++++++++++++++++-
 1 file changed, 146 insertions(+), 1 deletion(-)

diff --git a/extensions/functions_string.yaml b/extensions/functions_string.yaml
index 66b389301..e78b0c52f 100644
--- a/extensions/functions_string.yaml
+++ b/extensions/functions_string.yaml
@@ -27,7 +27,9 @@ scalar_functions:
         return: "BOOLEAN"
   -
     name: substring
-    description: Extract a portion of a string from another string.
+    description: >-
+      Extract a substring of a specified length starting from position start.
+      A start value of 1 refers to the first characters of the string.
     impls:
       - args:
           - value: "varchar<L1>"
@@ -163,3 +165,146 @@ scalar_functions:
           - value: "fixedchar<L1>"
           - value: "varchar<L2>"
         return: "BOOLEAN"
+  -
+    name: ltrim
+    description: >-
+      Remove any occurrence of the characters from the left side of the string.
+      If no characters are specified, spaces are removed.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: "varchar<L2>"
+        return: "varchar<L1>"
+      - args:
+          - value: "string"
+          - value: "string"
+        return: "string"
+      - args:
+          - value: "fixedchar<L1>"
+          - value: "fixedchar<L2>"
+        return: "string"
+  -
+    name: rtrim
+    description: >-
+      Remove any occurrence of the characters from the right side of the string.
+      If no characters are specified, spaces are removed.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: "varchar<L2>"
+        return: "varchar<L1>"
+      - args:
+          - value: "string"
+          - value: "string"
+        return: "string"
+      - args:
+          - value: "fixedchar<L1>"
+          - value: "fixedchar<L2>"
+        return: "string"
+  -
+    name: trim
+    description: >-
+      Remove any occurrence of the characters from the left and right sides of
+      the string. If no characters are specified, spaces are removed.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: "varchar<L2>"
+        return: "varchar<L1>"
+      - args:
+          - value: "string"
+          - value: "string"
+        return: "string"
+      - args:
+          - value: "fixedchar<L1>"
+          - value: "fixedchar<L2>"
+        return: "string"
+  -
+    name: lpad
+    description: Left-pad the string with the characters until the specified length of the string has been reached.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: i32
+          - value: "varchar<L2>"
+        return: "string"
+      - args:
+          - value: "string"
+          - value: i32
+          - value: "string"
+        return: "string"
+      - args:
+          - value: "fixedchar<L1>"
+          - value: i32
+          - value: "fixedchar<L2>"
+        return: "string"
+  -
+    name: rpad
+    description: Right-pad the string with the characters until the specified length of the string has been reached.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: i32
+          - value: "varchar<L2>"
+        return: "string"
+      - args:
+          - value: "string"
+          - value: i32
+          - value: "string"
+        return: "string"
+      - args:
+          - value: "fixedchar<L1>"
+          - value: i32
+          - value: "fixedchar<L2>"
+        return: "string"
+  -
+    name: center
+    description: Pad the string with characters from each side until the specified length of the string has been reached.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: i32
+          - value: "varchar<L2>"
+        return: "string"
+      - args:
+          - value: "string"
+          - value: i32
+          - value: "string"
+        return: "string"
+      - args:
+          - value: "fixedchar<L1>"
+          - value: i32
+          - value: "fixedchar<L2>"
+        return: "string"
+  -
+    name: left
+    description: Extract count characters starting from the left of the string.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: i32
+        return: "varchar<L1>"
+      - args:
+          - value: "string"
+          - value: i32
+        return: "string"
+      - args:
+          - value: "fixedchar<l1>"
+          - value: i32
+        return: "string"
+  -
+    name: right
+    description: Extract count characters starting from the right of the string.
+    impls:
+      - args:
+          - value: "varchar<L1>"
+          - value: i32
+        return: "varchar<L1>"
+      - args:
+          - value: "string"
+          - value: i32
+        return: "string"
+      - args:
+          - value: "fixedchar<l1>"
+          - value: i32
+        return: "string"

From 3bfdb96591fe850d98ae585d17e0e23c8c423e62 Mon Sep 17 00:00:00 2001
From: Richard Tia <richie.tia@gmail.com>
Date: Mon, 18 Jul 2022 15:17:44 -0700
Subject: [PATCH 2/6] refactor: add names and descriptions for args

---
 extensions/functions_string.yaml | 90 ++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/extensions/functions_string.yaml b/extensions/functions_string.yaml
index e78b0c52f..f16a84c3c 100644
--- a/extensions/functions_string.yaml
+++ b/extensions/functions_string.yaml
@@ -173,15 +173,27 @@ scalar_functions:
     impls:
       - args:
           - value: "varchar<L1>"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "varchar<L2>"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "varchar<L1>"
       - args:
           - value: "string"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "string"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "string"
       - args:
           - value: "fixedchar<L1>"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "fixedchar<L2>"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "string"
   -
     name: rtrim
@@ -191,15 +203,27 @@ scalar_functions:
     impls:
       - args:
           - value: "varchar<L1>"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "varchar<L2>"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "varchar<L1>"
       - args:
           - value: "string"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "string"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "string"
       - args:
           - value: "fixedchar<L1>"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "fixedchar<L2>"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "string"
   -
     name: trim
@@ -209,15 +233,27 @@ scalar_functions:
     impls:
       - args:
           - value: "varchar<L1>"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "varchar<L2>"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "varchar<L1>"
       - args:
           - value: "string"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "string"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "string"
       - args:
           - value: "fixedchar<L1>"
+            name: "input"
+            description: "The string to remove characters from."
           - value: "fixedchar<L2>"
+            name: "characters"
+            description: "The set of characters to remove."
         return: "string"
   -
     name: lpad
@@ -225,18 +261,36 @@ scalar_functions:
     impls:
       - args:
           - value: "varchar<L1>"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "varchar<L2>"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
       - args:
           - value: "string"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "string"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
       - args:
           - value: "fixedchar<L1>"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "fixedchar<L2>"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
   -
     name: rpad
@@ -244,18 +298,36 @@ scalar_functions:
     impls:
       - args:
           - value: "varchar<L1>"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "varchar<L2>"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
       - args:
           - value: "string"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "string"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
       - args:
           - value: "fixedchar<L1>"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "fixedchar<L2>"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
   -
     name: center
@@ -263,18 +335,36 @@ scalar_functions:
     impls:
       - args:
           - value: "varchar<L1>"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "varchar<L2>"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
       - args:
           - value: "string"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "string"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
       - args:
           - value: "fixedchar<L1>"
+            name: "input"
+            description: "The string to pad."
           - value: i32
+            name: "length"
+            description: "The length of the output string."
           - value: "fixedchar<L2>"
+            name: "characters"
+            description: "The set of characters to use for padding."
         return: "string"
   -
     name: left

From 2b0e096e77ca763a0d3e69bb92d7642666d1bfa4 Mon Sep 17 00:00:00 2001
From: Richard Tia <richie.tia@gmail.com>
Date: Thu, 21 Jul 2022 12:19:12 -0700
Subject: [PATCH 3/6] refactor: remove promotions and function definitions for
 fixedchar

---
 extensions/functions_string.yaml | 91 ++++++--------------------------
 1 file changed, 16 insertions(+), 75 deletions(-)

diff --git a/extensions/functions_string.yaml b/extensions/functions_string.yaml
index f16a84c3c..dab8cb296 100644
--- a/extensions/functions_string.yaml
+++ b/extensions/functions_string.yaml
@@ -175,7 +175,7 @@ scalar_functions:
           - value: "varchar<L1>"
             name: "input"
             description: "The string to remove characters from."
-          - value: "varchar<L2>"
+          - value: "varchar<L1>"
             name: "characters"
             description: "The set of characters to remove."
         return: "varchar<L1>"
@@ -187,14 +187,6 @@ scalar_functions:
             name: "characters"
             description: "The set of characters to remove."
         return: "string"
-      - args:
-          - value: "fixedchar<L1>"
-            name: "input"
-            description: "The string to remove characters from."
-          - value: "fixedchar<L2>"
-            name: "characters"
-            description: "The set of characters to remove."
-        return: "string"
   -
     name: rtrim
     description: >-
@@ -205,7 +197,7 @@ scalar_functions:
           - value: "varchar<L1>"
             name: "input"
             description: "The string to remove characters from."
-          - value: "varchar<L2>"
+          - value: "varchar<L1>"
             name: "characters"
             description: "The set of characters to remove."
         return: "varchar<L1>"
@@ -217,14 +209,6 @@ scalar_functions:
             name: "characters"
             description: "The set of characters to remove."
         return: "string"
-      - args:
-          - value: "fixedchar<L1>"
-            name: "input"
-            description: "The string to remove characters from."
-          - value: "fixedchar<L2>"
-            name: "characters"
-            description: "The set of characters to remove."
-        return: "string"
   -
     name: trim
     description: >-
@@ -235,7 +219,7 @@ scalar_functions:
           - value: "varchar<L1>"
             name: "input"
             description: "The string to remove characters from."
-          - value: "varchar<L2>"
+          - value: "varchar<L1>"
             name: "characters"
             description: "The set of characters to remove."
         return: "varchar<L1>"
@@ -247,14 +231,6 @@ scalar_functions:
             name: "characters"
             description: "The set of characters to remove."
         return: "string"
-      - args:
-          - value: "fixedchar<L1>"
-            name: "input"
-            description: "The string to remove characters from."
-          - value: "fixedchar<L2>"
-            name: "characters"
-            description: "The set of characters to remove."
-        return: "string"
   -
     name: lpad
     description: Left-pad the string with the characters until the specified length of the string has been reached.
@@ -266,10 +242,10 @@ scalar_functions:
           - value: i32
             name: "length"
             description: "The length of the output string."
-          - value: "varchar<L2>"
+          - value: "varchar<L1>"
             name: "characters"
             description: "The set of characters to use for padding."
-        return: "string"
+        return: "varchar<L1>"
       - args:
           - value: "string"
             name: "input"
@@ -281,17 +257,6 @@ scalar_functions:
             name: "characters"
             description: "The set of characters to use for padding."
         return: "string"
-      - args:
-          - value: "fixedchar<L1>"
-            name: "input"
-            description: "The string to pad."
-          - value: i32
-            name: "length"
-            description: "The length of the output string."
-          - value: "fixedchar<L2>"
-            name: "characters"
-            description: "The set of characters to use for padding."
-        return: "string"
   -
     name: rpad
     description: Right-pad the string with the characters until the specified length of the string has been reached.
@@ -303,10 +268,10 @@ scalar_functions:
           - value: i32
             name: "length"
             description: "The length of the output string."
-          - value: "varchar<L2>"
+          - value: "varchar<L1>"
             name: "characters"
             description: "The set of characters to use for padding."
-        return: "string"
+        return: "varchar<L1>"
       - args:
           - value: "string"
             name: "input"
@@ -318,33 +283,28 @@ scalar_functions:
             name: "characters"
             description: "The set of characters to use for padding."
         return: "string"
-      - args:
-          - value: "fixedchar<L1>"
-            name: "input"
-            description: "The string to pad."
-          - value: i32
-            name: "length"
-            description: "The length of the output string."
-          - value: "fixedchar<L2>"
-            name: "characters"
-            description: "The set of characters to use for padding."
-        return: "string"
   -
     name: center
-    description: Pad the string with characters from each side until the specified length of the string has been reached.
+    description: >-
+      Pad the string with characters from each side until the specified length of the string has
+      been reached. If padding is uneven, the default option is to have extra padding on the right.
     impls:
       - args:
+          - options: [ RIGHT, LEFT ]
+            required: false
           - value: "varchar<L1>"
             name: "input"
             description: "The string to pad."
           - value: i32
             name: "length"
             description: "The length of the output string."
-          - value: "varchar<L2>"
+          - value: "varchar<L1>"
             name: "characters"
             description: "The set of characters to use for padding."
-        return: "string"
+        return: "varchar<L1>"
       - args:
+          - options: [ RIGHT, LEFT ]
+            required: false
           - value: "string"
             name: "input"
             description: "The string to pad."
@@ -355,17 +315,6 @@ scalar_functions:
             name: "characters"
             description: "The set of characters to use for padding."
         return: "string"
-      - args:
-          - value: "fixedchar<L1>"
-            name: "input"
-            description: "The string to pad."
-          - value: i32
-            name: "length"
-            description: "The length of the output string."
-          - value: "fixedchar<L2>"
-            name: "characters"
-            description: "The set of characters to use for padding."
-        return: "string"
   -
     name: left
     description: Extract count characters starting from the left of the string.
@@ -378,10 +327,6 @@ scalar_functions:
           - value: "string"
           - value: i32
         return: "string"
-      - args:
-          - value: "fixedchar<l1>"
-          - value: i32
-        return: "string"
   -
     name: right
     description: Extract count characters starting from the right of the string.
@@ -394,7 +339,3 @@ scalar_functions:
           - value: "string"
           - value: i32
         return: "string"
-      - args:
-          - value: "fixedchar<l1>"
-          - value: i32
-        return: "string"

From cf41bdf9ce47816939a99b9a0c96117e20943d69 Mon Sep 17 00:00:00 2001
From: Richard Tia <richie.tia@gmail.com>
Date: Tue, 26 Jul 2022 08:41:47 -0700
Subject: [PATCH 4/6] refactor: update arg lengths

---
 extensions/functions_string.yaml | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/extensions/functions_string.yaml b/extensions/functions_string.yaml
index b914a339d..89012e85f 100644
--- a/extensions/functions_string.yaml
+++ b/extensions/functions_string.yaml
@@ -261,7 +261,7 @@ scalar_functions:
           - value: "varchar<L1>"
             name: "input"
             description: "The string to remove characters from."
-          - value: "varchar<L1>"
+          - value: "varchar<L2>"
             name: "characters"
             description: "The set of characters to remove."
         return: "varchar<L1>"
@@ -283,7 +283,7 @@ scalar_functions:
           - value: "varchar<L1>"
             name: "input"
             description: "The string to remove characters from."
-          - value: "varchar<L1>"
+          - value: "varchar<L2>"
             name: "characters"
             description: "The set of characters to remove."
         return: "varchar<L1>"
@@ -305,7 +305,7 @@ scalar_functions:
           - value: "varchar<L1>"
             name: "input"
             description: "The string to remove characters from."
-          - value: "varchar<L1>"
+          - value: "varchar<L2>"
             name: "characters"
             description: "The set of characters to remove."
         return: "varchar<L1>"
@@ -328,7 +328,7 @@ scalar_functions:
           - value: i32
             name: "length"
             description: "The length of the output string."
-          - value: "varchar<L1>"
+          - value: "varchar<L2>"
             name: "characters"
             description: "The set of characters to use for padding."
         return: "varchar<L1>"
@@ -354,7 +354,7 @@ scalar_functions:
           - value: i32
             name: "length"
             description: "The length of the output string."
-          - value: "varchar<L1>"
+          - value: "varchar<L2>"
             name: "characters"
             description: "The set of characters to use for padding."
         return: "varchar<L1>"
@@ -384,7 +384,7 @@ scalar_functions:
           - value: i32
             name: "length"
             description: "The length of the output string."
-          - value: "varchar<L1>"
+          - value: "varchar<L2>"
             name: "characters"
             description: "The set of characters to use for padding."
         return: "varchar<L1>"

From bdcba3e80ecc252c3438bb90a64fbe5bfb26ab71 Mon Sep 17 00:00:00 2001
From: Richard Tia <richie.tia@gmail.com>
Date: Wed, 27 Jul 2022 10:59:16 -0700
Subject: [PATCH 5/6] refactor: update descriptions for lpad and rpad

---
 extensions/functions_string.yaml | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/extensions/functions_string.yaml b/extensions/functions_string.yaml
index 89012e85f..5ad26a3b0 100644
--- a/extensions/functions_string.yaml
+++ b/extensions/functions_string.yaml
@@ -319,7 +319,12 @@ scalar_functions:
         return: "string"
   -
     name: lpad
-    description: Left-pad the string with the characters until the specified length of the string has been reached.
+    description: >-
+      Left-pad the input string with the string of 'characters' until the specified length of the
+      string has been reached. If the input string is longer than 'length', remove characters from
+      the right-side to shorten it to 'length' characters. If the string of 'characters' is longer
+      than the remaining 'length' needed to be filled, only pad until 'length' has been reached.
+      If 'characters' is not specified, the default value is a single space.
     impls:
       - args:
           - value: "varchar<L1>"
@@ -330,7 +335,7 @@ scalar_functions:
             description: "The length of the output string."
           - value: "varchar<L2>"
             name: "characters"
-            description: "The set of characters to use for padding."
+            description: "The string of characters to use for padding."
         return: "varchar<L1>"
       - args:
           - value: "string"
@@ -341,11 +346,16 @@ scalar_functions:
             description: "The length of the output string."
           - value: "string"
             name: "characters"
-            description: "The set of characters to use for padding."
+            description: "The string of characters to use for padding."
         return: "string"
   -
     name: rpad
-    description: Right-pad the string with the characters until the specified length of the string has been reached.
+    description: >-
+      Right-pad the input string with the string of 'characters' until the specified length of the
+      string has been reached. If the input string is longer than 'length', remove characters from
+      the left-side to shorten it to 'length' characters. If the string of 'characters' is longer
+      than the remaining 'length' needed to be filled, only pad until 'length' has been reached.
+      If 'characters' is not specified, the default value is a single space.
     impls:
       - args:
           - value: "varchar<L1>"
@@ -356,7 +366,7 @@ scalar_functions:
             description: "The length of the output string."
           - value: "varchar<L2>"
             name: "characters"
-            description: "The set of characters to use for padding."
+            description: "The string of characters to use for padding."
         return: "varchar<L1>"
       - args:
           - value: "string"
@@ -367,7 +377,7 @@ scalar_functions:
             description: "The length of the output string."
           - value: "string"
             name: "characters"
-            description: "The set of characters to use for padding."
+            description: "The string of characters to use for padding."
         return: "string"
   -
     name: center

From 0b47bd596bf7738ff7fc8151454a4687e7712966 Mon Sep 17 00:00:00 2001
From: Richard Tia <richie.tia@gmail.com>
Date: Thu, 28 Jul 2022 08:13:04 -0700
Subject: [PATCH 6/6] refactor: remove center function

---
 extensions/functions_string.yaml | 32 --------------------------------
 1 file changed, 32 deletions(-)

diff --git a/extensions/functions_string.yaml b/extensions/functions_string.yaml
index 5ad26a3b0..9b8a84ad2 100644
--- a/extensions/functions_string.yaml
+++ b/extensions/functions_string.yaml
@@ -379,38 +379,6 @@ scalar_functions:
             name: "characters"
             description: "The string of characters to use for padding."
         return: "string"
-  -
-    name: center
-    description: >-
-      Pad the string with characters from each side until the specified length of the string has
-      been reached. If padding is uneven, the default option is to have extra padding on the right.
-    impls:
-      - args:
-          - options: [ RIGHT, LEFT ]
-            required: false
-          - value: "varchar<L1>"
-            name: "input"
-            description: "The string to pad."
-          - value: i32
-            name: "length"
-            description: "The length of the output string."
-          - value: "varchar<L2>"
-            name: "characters"
-            description: "The set of characters to use for padding."
-        return: "varchar<L1>"
-      - args:
-          - options: [ RIGHT, LEFT ]
-            required: false
-          - value: "string"
-            name: "input"
-            description: "The string to pad."
-          - value: i32
-            name: "length"
-            description: "The length of the output string."
-          - value: "string"
-            name: "characters"
-            description: "The set of characters to use for padding."
-        return: "string"
   -
     name: left
     description: Extract count characters starting from the left of the string.