Data update

Task/Determine-if-a-string-is-numeric/DuckDB/determine-if-a-string-is-numeric.duckdb

@@ -0,0 +1,22 @@
+CREATE OR REPLACE FUNCTION is_valid_number(s) AS
+    CASE
+        WHEN s IS NULL THEN false
+        WHEN try_cast(s AS DOUBLE) IS NOT NULL THEN true
+        ELSE false
+    END;
+
+# Illustration
+select s, is_valid_number(s) from
+   (select unnest([
+      '123.0',
+      '123.',
+       '-123',
+       '3.14159',
+       '1.2.3',
+       'abc',
+       'A440',
+       ' 12 ',
+       '0A',
+       '+1E10',
+       '1E-10'
+       ]) as s);

Task/Determine-if-a-string-is-numeric/Nom/determine-if-a-string-is-numeric.num

@@ -0,0 +1,67 @@
+#*
+
+GRAMMAR OR PARSE TOKENS
+  int* -  an unsigned integer
+  sint* - a +/- signed integer
+  .* - decimal point
+
+HISTORY
+  12 sept 2021: written, working
+
+*#
+
+ # remove leading space
+ begin { while [:space:]; clear; }
+
+ read;
+ [0-9] {
+   while [0-9]; put; clear; add "int*"; push; .reparse
+ }
+ [.+-] { put; add "*"; push; .reparse }
+ [:space:] { while [:space:]; clear; add "space*"; push; .reparse }
+ !"" {
+   put; clear;
+   add "Non-numeric char at "; lines; add ":"; chars; add "\n";
+   print; quit;
+ }
+
+parse>
+ # To visualise token reduction uncomment this:
+ #lines; add ":"; chars; add " "; print; clear;
+ #add "\n"; unstack; print; clip; stack;
+
+ pop; pop;
+
+ # -------------
+ # 2 tokens
+ "+*int*","-*int*" { clear; add "sint*"; push; .reparse }
+
+ pop;
+ # -------------
+ # 3 tokens
+ "sint*.*int*","int*.*int*" {
+   clear; add "float*"; push; .reparse
+ }
+
+ (eof) {
+   # ignore trailing space
+   stack; pop; "space*" { clear; }
+   unstack;
+   "int*","sint*","float*" {
+     replace "sint*" "signed integer,";
+     replace "int*" "integer,";
+     replace "*" ",";
+     put; clear;
+     add "It looks like a number (of type "; get; add ")\n";
+     print; quit;
+   }
+   replace "sint*" "signed integer,";
+   replace "int*" "integer,";
+   replace "*" ",";
+   put; clear;
+   add "Doesnt look like one number \n";
+   add "It was parsed as '"; get; add "'\n";
+   print; quit;
+ }
+
+ push; push; push;

Task/Determine-if-a-string-is-numeric/Pluto/determine-if-a-string-is-numeric.pluto

@@ -0,0 +1,9 @@
+function chk(a)
+    return tonumber(a) != nil
+end
+
+a = {"123", "-320",
+    "-1342.40", "abc",
+    "1,234", "a123.0"}
+
+a:map(chk); print(a:unpack())

Task/Determine-if-a-string-is-numeric/Tcl/determine-if-a-string-is-numeric-1.tcl

@@ -0,0 +1,3 @@
+proc isNumeric {str} {
+    string is double -strict $str
+}

Task/Determine-if-a-string-is-numeric/Tcl/determine-if-a-string-is-numeric-2.tcl

@@ -0,0 +1,17 @@
+# will output an error message
+# and quit
+proc fatal {msg} {
+    puts stderr "$msg"
+    exit 1
+}
+
+# a bad string
+set x  174gg.4
+
+try {
+   set n [expr {double($x)}]
+   set n [expr {int($x)}]
+   puts $x
+   } on error { error options } {
+        fatal "$::errorInfo"
+   }

Task/Determine-if-a-string-is-numeric/Tcl/determine-if-a-string-is-numeric.tcl

@@ -1 +0,0 @@
-proc isNumeric str {string is double -strict $str}