lexer: New function lex_force_string_or_id().

[pspp-builds.git] / src / language / lexer / lexer.c

diff --git a/src/language/lexer/lexer.c b/src/language/lexer/lexer.c
index a356b3821de28150b848ff6ca2131f61dfdc9b84..e72a3e47bc9637d93ad3c1f764b7099686df6d3d 100644 (file)
--- a/src/language/lexer/lexer.c
+++ b/src/language/lexer/lexer.c
@@ -337,20 +337,47 @@ lex_error_expecting (struct lexer *lexer, const char *option0, ...)
     }
 }
 
-/* Reports an error to the effect that subcommand SBC may only be
-   specified once. */
+/* Reports an error to the effect that subcommand SBC may only be specified
+   once.
+
+   This function does not take a lexer as an argument or use lex_error(),
+   because the result would ordinarily just be redundant: "Syntax error at
+   SUBCOMMAND: Subcommand SUBCOMMAND may only be specified once.", which does
+   not help the user find the error. */
 void
 lex_sbc_only_once (const char *sbc)
 {
   msg (SE, _("Subcommand %s may only be specified once."), sbc);
 }
 
-/* Reports an error to the effect that subcommand SBC is
-   missing. */
+/* Reports an error to the effect that subcommand SBC is missing.
+
+   This function does not take a lexer as an argument or use lex_error(),
+   because a missing subcommand can normally be detected only after the whole
+   command has been parsed, and so lex_error() would always report "Syntax
+   error at end of command", which does not help the user find the error. */
+void
+lex_sbc_missing (const char *sbc)
+{
+  msg (SE, _("Required subcommand %s was not specified."), sbc);
+}
+
+/* Reports an error to the effect that specification SPEC may only be specified
+   once within subcommand SBC. */
 void
-lex_sbc_missing (struct lexer *lexer, const char *sbc)
+lex_spec_only_once (struct lexer *lexer, const char *sbc, const char *spec)
 {
-  lex_error (lexer, _("missing required subcommand %s"), sbc);
+  lex_error (lexer, _("%s may only be specified once within subcommand %s"),
+             spec, sbc);
+}
+
+/* Reports an error to the effect that specification SPEC is missing within
+   subcommand SBC. */
+void
+lex_spec_missing (struct lexer *lexer, const char *sbc, const char *spec)
+{
+  lex_error (lexer, _("Required %s specification missing from %s subcommand"),
+             sbc, spec);
 }
 
 /* Prints a syntax error message containing the current token and
@@ -598,6 +625,21 @@ lex_force_string (struct lexer *lexer)
     }
 }
 
+/* If the current token is a string or an identifier, does nothing and returns
+   true.  Otherwise, reports an error and returns false.
+
+   This is meant for use in syntactic situations where we want to encourage the
+   user to supply a quoted string, but for compatibility we also accept
+   identifiers.  (One example of such a situation is file names.)  Therefore,
+   the error message issued when the current token is wrong only says that a
+   string is expected and doesn't mention that an identifier would also be
+   accepted. */
+bool
+lex_force_string_or_id (struct lexer *lexer)
+{
+  return lex_is_integer (lexer) || lex_force_string (lexer);
+}
+
 /* If the current token is an integer, does nothing and returns true.
    Otherwise, reports an error and returns false. */
 bool