[2.1.0] Rewrite .to_s/.to_i/.to_f only as whole words

CHANGELOG.md

@@ -4,6 +4,15 @@ All notable changes to plx are recorded here. The format follows
 [Keep a Changelog](https://keepachangelog.com/), and plx uses the extension
 version in `plx.control` (currently `1.0`).
 
+## [Unreleased]
+
+### Fixed
+
+- `.to_s`, `.to_i` and `.to_f` were rewritten as casts wherever the text
+  appeared, so a field whose name starts with one of them broke:
+  `r.to_status` became `r::texttatus`. They are now rewritten only as whole
+  words, and `x.to_s()` with an empty argument list works too.
+
 ## [2.0.1] - 2026-08-25
 
 Packaging only. **The extension is unchanged at 2.0.0**, so there is no

src/plx_transpile.c

@@ -1379,14 +1379,24 @@ rewrite_expr_inner(Ctx *cx, const char *s, int len, bool boolctx)
 			}
 			continue;
 		}
-		/* .to_i / .to_s / .to_f casts */
-		if (c == '.' && i + 4 <= len && strncmp(s + i, ".to_", 4) == 0)
+		/*
+		 * .to_i / .to_s / .to_f casts, as whole words only: a field such as
+		 * r.to_status or r.to_s_name is left alone. An empty argument list,
+		 * x.to_s(), is dropped with the method name.
+		 */
+		if (c == '.' && i + 5 <= len && strncmp(s + i, ".to_", 4) == 0 &&
+			(s[i + 4] == 'i' || s[i + 4] == 's' || s[i + 4] == 'f') &&
+			!(i + 5 < len && (isalnum((unsigned char) s[i + 5]) || s[i + 5] == '_' ||
+							  s[i + 5] == '$' || IS_HIGHBIT_SET(s[i + 5]))))
 		{
-			char		k = (i + 4 < len) ? s[i + 4] : '?';
+			char		k = s[i + 4];
 
-			if (k == 'i') { appendStringInfoString(&out, "::integer"); i += 5; continue; }
-			if (k == 's') { appendStringInfoString(&out, "::text"); i += 5; continue; }
-			if (k == 'f') { appendStringInfoString(&out, "::double precision"); i += 5; continue; }
+			appendStringInfoString(&out, k == 'i' ? "::integer" :
+								   k == 's' ? "::text" : "::double precision");
+			i += 5;
+			if (i + 1 < len && s[i] == '(' && s[i + 1] == ')')
+				i += 2;
+			continue;
 		}
 		/* operator runs */
 		if (strchr("=!<>+-*/%&|?:~^", c))

test/expected/plx_features.out

@@ -233,3 +233,16 @@ SELECT f_strict() AS strict_no_row;
             -1
 (1 row)
 
+-- .to_s / .to_i / .to_f are rewritten as whole words only, so a field whose
+-- name starts with to_s, to_i or to_f is left alone; x.to_s() also works
+CREATE FUNCTION f_to_cast(n int) RETURNS text LANGUAGE plxruby AS $$
+r = fetch_one("select 'shipped' as to_status, 'x' as to_s_name, 2 as to_items")
+return "#{r.to_status}/#{r.to_s_name}/#{r.to_items}/#{n.to_s}/#{n.to_s()}/#{'4.5'.to_f}/#{'12'.to_i + 1}"
+$$;
+SELECT f_to_cast(3);
+       f_to_cast        
+------------------------
+ shipped/x/2/3/3/4.5/13
+(1 row)
+
+DROP FUNCTION f_to_cast(int);

test/sql/plx_features.sql

@@ -143,3 +143,12 @@ rescue => e
 end
 $$;
 SELECT f_strict() AS strict_no_row;
+
+-- .to_s / .to_i / .to_f are rewritten as whole words only, so a field whose
+-- name starts with to_s, to_i or to_f is left alone; x.to_s() also works
+CREATE FUNCTION f_to_cast(n int) RETURNS text LANGUAGE plxruby AS $$
+r = fetch_one("select 'shipped' as to_status, 'x' as to_s_name, 2 as to_items")
+return "#{r.to_status}/#{r.to_s_name}/#{r.to_items}/#{n.to_s}/#{n.to_s()}/#{'4.5'.to_f}/#{'12'.to_i + 1}"
+$$;
+SELECT f_to_cast(3);
+DROP FUNCTION f_to_cast(int);