aat

commit f6c426fdb32cc3ede30dc98486811f8763503d14
parent 6d5104ab82a0569523454cfd9ae88da3ce3138ab
Author: Jan Pobrislo <ccx@webprojekty.cz>
Date:   Wed, 19 Aug 2015 22:11:44 +0200

implement getting values with fallback in query.pl
Diffstat:
M
query.pl
 | 
31
+++++++++++++++++++++++++++++++
M
query_example.awk
 | 
7
+++++++

2 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/query.pl b/query.pl
@@ -14,13 +14,26 @@ query_name_next([H|T]) -->
     query_name_next(T).
 query_name_next([]) --> [].
 
+query_default_text([H|T]) --> [H], {\+memberchk(H,`'<>`)}, query_default_text(T).
+query_default_text([]) --> [].
+
 query_content([name(Name)|T]) --> query_name(Name), query_content(T).
 query_content([query(Query)|T]) --> query_exp(Query), query_content(T).
 query_content([expr(Expr)|T]) --> `'`, query_awk(Expr), `'`, query_content(T).
 query_content([]) --> [].
 
+%query_default([text(Text)|T]) --> query_default_text(Text), query_default(T).
+query_default([expr(Expr)|T]) --> `'`, query_awk(Expr), `'`, query_default(T).
+query_default([query(Query)|T]) --> query_exp(Query), query_default(T).
+query_default([query(Query, Default)|T]) -->
+    query_exp(Query, Default), query_default(T).
+query_default([]) --> [].
+
 query_exp(Content) --> `<`, query_content(Content), `>`.
 
+query_exp(Content, Default) -->
+    `<`, query_content(Content), `:`, query_default(Default), `>`.
+
 awk_string(String) --> `"`, awk_string_content(String), `"`.
 
 awk_string_content([0'\\,H|T],R) -->
@@ -61,6 +74,9 @@ awk_code([H|T],R,Prev,F) -->
 awk_code(R,R,L,L) --> [].
 % awk_code(L) --> awk_code(L,[],delim,_).
 
+query_awk([query(Query, Default)|T],delim) -->
+    query_exp(Query, Default),
+    query_awk(T, expr).
 query_awk([query(Query)|T],delim) -->
     query_exp(Query),
     query_awk(T, expr).
@@ -75,13 +91,28 @@ query_awk(L) --> query_awk(L,delim).
 
 awk_out([code(Code)|T]) --> Code, awk_out(T).
 awk_out([query(Query)|T]) --> `get(`, query_out(Query), `)`, awk_out(T).
+awk_out([query(Query, Default)|T]) -->
+    `(find(`, query_out(Query), `)?found:`, default_out(Default), `)`, awk_out(T).
 awk_out([]) --> [].
 
 query_out([name(Name)|T]) --> `"`, Name, `"`, query_out(T).
 query_out([query(Query)|T]) --> `get(`, query_out(Query), `)`, query_out(T).
+query_out([query(Query, Default)|T]) -->
+    `(find(`, query_out(Query), `)?found:`, default_out(Default), `)`, query_out(T).
 query_out([expr(Expr)|T]) --> `(`, awk_out(Expr), `)`, query_out(T).
 query_out([]) --> [].
 
+default_out([]) --> `""`.
+default_out([H|T]) --> default_out_aux([H|T]).
+%default_out_aux([text(Text)|T]) --> Text, default_out_aux(T).
+default_out_aux([query(Query)|T]) -->
+    `get(`, query_out(Query), `)`, default_out_aux(T).
+default_out_aux([query(Query, Default)|T]) -->
+    `(find(`, query_out(Query), `)?found:`, default_out(Default), `)`,
+    default_out_aux(T).
+default_out_aux([expr(Expr)|T]) --> `(`, awk_out(Expr), `)`, default_out_aux(T).
+default_out_aux([]) --> [].
+
 %%%
 
 main([InFile]) :-
diff --git a/query_example.awk b/query_example.awk
@@ -1,4 +1,11 @@
 BEGIN {
 	foo(<bar>)
 	x[<y<z>>] = <a'b()'>
+	y = ""
+	y = (y) (<c:>)
+	y = (y) (<d:'0'>)
+	y = (y) (<e:<f>>)
+	y = (y) (<g:<h:<i>>>)
+	y = (y) (<g:<h:<i:'<j> - (<k:'0'>)'>>>)
+	y = (y) (<g:<h:<i:'(<j>) - (<k:'0'>)'>>>)
 }