[nongnu] elpa/emacsql 223db2d397 141/427: Add quote operator.

[ELPA Syncer]

branch: elpa/emacsql
commit 223db2d39789c67c15a3002516b76c9670114cb6
Author: Christopher Wellons <wellons@nullprogram.com>
Commit: Christopher Wellons <wellons@nullprogram.com>

    Add quote operator.
---
 README.md  | 11 +++++++++++
 emacsql.el |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/README.md b/README.md
index 8c554d7a9b..f680060849 100644
--- a/README.md
+++ b/README.md
@@ -117,6 +117,17 @@ With `glob` and `like` keep in mind that they're matching 
the
 *printed* representations of these values, even if the value is a
 string.
 
+Inside expressions, Emacsql cannot tell the difference between symbol
+literals and column references. If you're talking about the symbol
+itself, just quote it as you would in normal Elisp. Note that this
+does not "escape" `$n` variables: it just means the argument gets
+quoted.
+
+```el
+[... :where (= category 'hiking)]
+(emacsql db [... :where (= category '$1)] 'hiking)
+```
+
 The `||` concatenation operator is unsupported because concatenating
 printed representations breaks an important constraint: all values must
 remain readable within SQLite.
diff --git a/emacsql.el b/emacsql.el
index 158a23e439..9292a0b730 100644
--- a/emacsql.el
+++ b/emacsql.el
@@ -531,6 +531,10 @@ definitions for return from a `emacsql-defexpander'."
              (cl-ecase (length args)
                (1 (format "-(%s)" (recur 0)))
                (2 (format "%s - %s" (recur 0) (recur 1)))))
+            ;; quote special case
+            ((quote)
+             (cl-ecase (length args)
+               (1 (var (nth 0 args) :value))))
             ;; IN special case
             ((in)
              (cl-case (length args)