add ~?, gmatch

2 files changed, 42 insertions, 1 deletions

diff --git a/mew.scm b/mew.scm
index 2d29195..e72a623 100644
--- a/mew.scm
+++ b/mew.scm
@@ -1,4 +1,4 @@
-(module mew (at dec def div empty? eof esc fin final for generic-for-each get gfix giterate inc keys keyvals len loc mod nth op prn puts rep str tbl while until vals -> ->>)
+(module mew (at dec def div empty? eof esc fin final for generic-for-each get gfix giterate gmatch inc keys keyvals len loc mod nth op prn puts rep str tbl while until vals -> ->> ~?)
   (import-for-syntax matchable)
 
   (import scheme
@@ -25,6 +25,7 @@
     (rename (matchable)
       (match-lambda match-fun)
       (match-lambda* match-fun*)))
+  (reexport (chicken irregex))
 
   (reexport
     (only (chicken base)
@@ -263,4 +264,28 @@
     (syntax-rules ()
       ((_ . rest)
        (-> . rest))))
+
+  (def (~? str pat)
+    (let ((data (irregex-search pat str)))
+      (if data
+        (map (op irregex-match-substring data _)
+             (iota (inc (irregex-match-num-submatches data))))
+        #f)))
+
+  (def (gmatch pat str)
+    (let ((start 0))
+      (lambda ()
+        (if (>= start 0)
+          (let ((data (irregex-search pat str start)))
+            (if data
+              (begin
+                (set! start (irregex-match-end-index data 0))
+                (if (> (irregex-match-num-submatches data) 0)
+                  (map (op irregex-match-substring data _)
+                       (iota (inc (irregex-match-num-submatches data))))
+                  (irregex-match-substring data 0)))
+              (begin
+                (set! start -1)
+                (eof))))
+          (eof)))))
 )
diff --git a/mew.svnwiki b/mew.svnwiki
index b82d29a..979869f 100644
--- a/mew.svnwiki
+++ b/mew.svnwiki
@@ -8,6 +8,7 @@ Mew re-exports
 SRFI-1 (List library),
 SRFI-69 (Basic hash tables),
 SRFI-158 (Generators and Accumulators),
+{{(chicken irregex)}},
 and {{matchable}}.
 
 == Definitions, bindings and assignments
@@ -197,6 +198,21 @@ a value {{equal?}} to the preceding one, then stops.
 Run the generator {{<gen>}} until it stops and return its final value.
 
 
+== Regular expressions
+
+<procedure>(?~ <str> <irx>)</procedure>
+
+Matches the string {{<str>}} against the irregex (string or sexp) {{<irx>}}
+without anchoring.  Returns false on no match, else a list of all
+match data strings.
+
+<procedure>(gmatch <irx> <str>)</procedure>
+
+Returns a generator that for each match of the irregex {{<irx>}} in
+the string {{<str>}} either yields the match, or a list of all
+match data strings (if there are any).
+
+
 == Special syntax
 
 <syntax>(-> a -> b c -> d e f)</syntax>