add morphisms

- unicode
- value delimited seq
- zigzag encoding (still lacking any way to get to signed integer yet'..)

morphisms/unicode.morphism-base

@@ -0,0 +1,93 @@
+```
+```
+
+morph_string_as_ascii_to_utf8 ()
+     <Seq ~ <ValueTerminated '\0'>  Char~Ascii~x86.UInt8>
+-->  <Seq Char~Unicode>
+    ~ UTF-8
+    ~ <Seq~<ValueTerminated 0> x86.UInt8>
+```
+    while( *src ) { *dst++ = *src++; }
+    *dst = 0;
+    return 0;
+```
+
+morph_string_as_utf8_to_ascii ()
+    <Seq Char~Unicode>
+    ~ UTF-8
+    ~ <Seq~<ValueTerminated 0> x86.UInt8>
+--> <Seq ~ <ValueTerminated '\0'>  Char~Ascii~x86.UInt8>
+```
+    while( *src ) {
+        if( *src < 128 ) {
+            *dst++ = *src++;
+        } else {
+            fprintf(stderr, "(morph UTF-8 to Ascii) ignore multi-byte character\n");
+            while( *++src >= 128 );
+        }
+    }
+    *dst = 0;
+    return 0;
+```
+
+morph_string_as_ascii_to_utf32 ()
+     <Seq ~ <ValueTerminated '\0'>  Char~Ascii~x86.UInt8>
+-->  <Seq Char~Unicode>
+    ~ UTF-32LE
+    ~ <Seq~<ValueTerminated 0> x86.UInt32>
+```
+    while( *src ) { *dst++ = *src++; }
+    *dst = 0;
+    return 0;
+```
+
+morph_string_as_utf8_to_utf32 ()
+
+      <Seq Char~Unicode>
+    ~ UTF-8
+    ~ <Seq~<ValueTerminated 0> x86.UInt8>
+
+-->   <Seq Char~Unicode>
+    ~ UTF-32LE
+    ~ <Seq~<ValueTerminated 0> x86.UInt32>
+
+```
+    bool has_multibyte = false;
+    uint32_t val = 0;
+    while( *src ) {
+        uint8_t tag = (*src >> 6)&0b11;
+        switch( tag ) {
+            // single byte
+            case 0b00:
+            case 0b01:
+                if( has_multibyte ) {
+                    *dst++ = val;
+                    has_multibyte = false;
+                }
+                *dst++ = *src++;
+                break;
+
+            // start multibyte
+            case 0b11:
+                if( has_multibyte ) {
+                    *dst++ = val;
+                }
+                has_multibyte = true;
+                val = (*src++) & 0b111111;
+                break;
+
+            // continue multibyte
+            case 0b10:
+                val <<= 6;
+                val |= (*src++) & 0b111111;
+                break;
+        }
+    }
+
+    if( has_multibyte )
+        *dst++ = val;
+
+    *dst++ = 0;
+
+    return 0;
+```

morphisms/value_delim.morphism-base

@@ -0,0 +1,71 @@
+```
+#include <array/length-prefix.h>
+#include <stdlib.h>
+```
+
+morph_seqseq_valsep_uint8 (T: Type, SrcDelim: T, DstDelim: T)
+      < Seq <Seq T> >
+    ~ < ValueSep SrcDelim T >
+    ~ < Seq~<LengthPrefix x86.UInt64> T >
+
+-->   < Seq <Seq T> >
+    ~ < ValueSep DstDelim T >
+    ~ < Seq~<LengthPrefix x86.UInt64> T >
+```
+    length_prefix_uint8_array_clear( dst );
+
+    uint8_t * dst_items = dst->items;
+    for( uint64_t i = 0; i < src->len; ++i ) {
+        if( src->items[i] == SrcDelim ) {
+            length_prefix_uint8_array_push( dst, DstDelim );
+        } else if( src->items[i] == DstDelim ) {
+            if( DstDelim == '\n' ) {
+                length_prefix_uint8_array_push( dst, '\\' );
+                length_prefix_uint8_array_push( dst, 'n' );
+            }
+        } else {
+            length_prefix_uint8_array_push( dst, src->items[i] );
+        }
+    }
+
+    return 0;
+```
+
+
+morph_seqseq_as_valsep_to_lenpfx (T: Type, Delim: T, EscKey: T)
+      < Seq <Seq T> >
+    ~ < ValueSep T Delim >
+    ~ < Seq~<LengthPrefix x86.UInt64> T >
+
+--> < Seq~<LengthPrefix x86.UInt64>
+        <Seq~<LengthPrefix x86.UInt64> T >
+        ~ <RefMut < Seq~<LengthPrefix x86.UInt64> T>>
+        ~ x86.Address
+        ~ x86.UInt64
+    >
+```
+    length_prefix_uint64_array_clear( dst );
+
+    struct LengthPrefixUInt8Array * cur_item = NULL;
+
+    uint8_t const * start = &src->items[0];
+    uint8_t const * cur = start;
+    uint8_t const * end = &src->items[src->len];
+
+    while( cur < end ) {
+        if( *cur == Delim || cur+1 == end ) {
+            uint64_t len = cur - start;
+
+            cur_item = malloc( sizeof(uint64_t) + sizeof(uint8_t) * len );
+            cur_item->len = len;
+            memcpy( cur_item->items, start, len );
+
+            length_prefix_uint64_array_push( dst, (uint64_t)cur_item );
+            start = ++cur;
+        } else {
+            cur++;
+        }
+    }
+
+    return 0;
+```

morphisms/zigzag.morphism-base

@@ -0,0 +1,26 @@
+```
+```
+
+morph_i64_as_twos_complement_to_zigzag ()
+    ℤ ~ x86.Int64
+--> ℤ ~ ZigZagInt ~ ℕ ~ x86.UInt64
+```
+    if( *src >= 0 ) {
+        *dst = (2 * (uint64_t)*src)
+    } else {
+        *dst = (2 * (uint64_t)(- *src)) - 1;
+    }
+
+    return 0;
+```
+
+morph_i64_as_zigzag_to_twos_complement ()
+    ℤ ~ ZigZagInt ~ ℕ ~ x86.UInt64
+--> ℤ ~ x86.Int64
+```
+    if( *src % 2 == 0 ) {
+        *dst = *src / 2;
+    } else {
+        *dst = - ((*src+1) / 2);
+    }
+```