compiler,runtime: implement string to []rune conversion

Commit message by aykevl

4 files changed, 35 insertions, 1 deletions

diff --git a/compiler/compiler.go b/compiler/compiler.go
index 93c3f496a..00e008fbe 100644
--- a/compiler/compiler.go
+++ b/compiler/compiler.go
@@ -2458,8 +2458,10 @@ func (c *Compiler) parseConvert(typeFrom, typeTo types.Type, value llvm.Value, p
 		switch elemType.Kind() {
 		case types.Byte:
 			return c.createRuntimeCall("stringToBytes", []llvm.Value{value}, ""), nil
+		case types.Rune:
+			return c.createRuntimeCall("stringToRunes", []llvm.Value{value}, ""), nil
 		default:
-			return llvm.Value{}, c.makeError(pos, "todo: convert from string: "+elemType.String())
+			panic("unexpected type in string to slice conversion")
 		}
 
 	default:
diff --git a/src/runtime/string.go b/src/runtime/string.go
index 780c97f4b..6d9c38753 100644
--- a/src/runtime/string.go
+++ b/src/runtime/string.go
@@ -89,6 +89,21 @@ func stringToBytes(x _string) (slice struct {
 	return
 }
 
+// Convert a string to []rune slice.
+func stringToRunes(s string) []rune {
+	var n = 0
+	for range s {
+		n++
+	}
+	var r = make([]rune, n)
+	n = 0
+	for _, e := range s {
+		r[n] = e
+		n++
+	}
+	return r
+}
+
 // Create a string from a Unicode code point.
 func stringFromUnicode(x rune) _string {
 	array, length := encodeUTF8(x)
diff --git a/testdata/rangestring.go b/testdata/string.go
index 32401c2cd..f0aecd07e 100644
--- a/testdata/rangestring.go
+++ b/testdata/string.go
@@ -6,6 +6,14 @@ func testRangeString() {
 	}
 }
 
+func testStringToRunes() {
+	var s = "abcü¢€𐍈°x"
+	for i,c := range []rune(s) {
+		println(i, c)
+	}
+}
+
 func main() {
 	testRangeString()
+	testStringToRunes()
 }
diff --git a/testdata/rangestring.txt b/testdata/string.txt
index e3318b416..b5dca1981 100644
--- a/testdata/rangestring.txt
+++ b/testdata/string.txt
@@ -7,3 +7,12 @@
 10 66376
 14 176
 16 120
+0 97
+1 98
+2 99
+3 252
+4 162
+5 8364
+6 66376
+7 176
+8 120