Merge branch '201703_split_replace' of https://github.com/JonesAndrew/wren into JonesAndrew-201703_split_replace

doc/site/modules/core/string.markdown

@@ -129,6 +129,24 @@ negative to count backwards from the end of the string.
 It is a runtime error if `search` is not a string or `start` is not an integer
 index within the string's byte length.
 
+### **split**(seperator)
+
+Returns a list of one or more strings seperated by `seperator`.
+
+    :::wren
+    var string = "abc abc abc"
+    System.print(string.split(" ")) //> [abc, abc, abc]
+
+It is a runtime error if `seperator` is not a string or is an empty string.
+
+### **replace**(old, swap)
+
+Returns a new string with all occurences of `old` replaced with `swap`.
+
+    :::wren
+    var string = "abc abc abc"
+    System.print(string.replace(" ", "")) //> abcabcabc
+
 ### **iterate**(iterator), **iteratorValue**(iterator)
 
 Implements the [iterator protocol](../../control-flow.html#the-iterator-protocol)

src/vm/wren_core.wren

@@ -132,6 +132,57 @@ class String is Sequence {
   bytes { StringByteSequence.new(this) }
   codePoints { StringCodePointSequence.new(this) }
 
+  split(delim) {
+    if (!(delim is String) || delim.isEmpty) {
+      Fiber.abort("Argument must be a non-empty string.")
+    }
+
+    var result = []
+
+    var last = 0
+    var index = 0
+
+    var delimSize = delim.byteCount_
+    var size = byteCount_
+
+    while (last < size && (index = indexOf(delim, last)) != -1) {
+      result.add(this[last...index])
+      last = index + delimSize
+    }
+
+    if (last < size) {
+      result.add(this[last..-1])
+    } else {
+      result.add("")
+    }
+    return result
+  }
+
+  replace(from, to) {
+    if (!(from is String) || from.isEmpty) {
+      Fiber.abort("From must be a non-empty string.")
+    } else if (!(to is String)) {
+      Fiber.abort("To must be a string.")
+    }
+
+    var result = ""
+
+    var last = 0
+    var index = 0
+
+    var fromSize = from.byteCount_
+    var size = byteCount_
+
+    while (last < size && (index = indexOf(from, last)) != -1) {
+      result = result + this[last...index] + to
+      last = index + fromSize
+    }
+
+    if (last < size) result = result + this[last..-1]
+
+    return result
+  }
+
   *(count) {
     if (!(count is Num) || !count.isInteger || count < 0) {
       Fiber.abort("Count must be a non-negative integer.")

src/vm/wren_core.wren.inc

@@ -134,6 +134,57 @@ static const char* coreModuleSource =
 "  bytes { StringByteSequence.new(this) }\n"
 "  codePoints { StringCodePointSequence.new(this) }\n"
 "\n"
+"  split(delim) {\n"
+"    if (!(delim is String) || delim.isEmpty) {\n"
+"      Fiber.abort(\"Argument must be a non-empty string.\")\n"
+"    }\n"
+"\n"
+"    var result = []\n"
+"\n"
+"    var last = 0\n"
+"    var index = 0\n"
+"\n"
+"    var delimSize = delim.byteCount_\n"
+"    var size = byteCount_\n"
+"\n"
+"    while (last < size && (index = indexOf(delim, last)) != -1) {\n"
+"      result.add(this[last...index])\n"
+"      last = index + delimSize\n"
+"    }\n"
+"\n"
+"    if (last < size) {\n"
+"      result.add(this[last..-1])\n"
+"    } else {\n"
+"      result.add(\"\")\n"
+"    }\n"
+"    return result\n"
+"  }\n"
+"\n"
+"  replace(from, to) {\n"
+"    if (!(from is String) || from.isEmpty) {\n"
+"      Fiber.abort(\"From must be a non-empty string.\")\n"
+"    } else if (!(to is String)) {\n"
+"      Fiber.abort(\"To must be a string.\")\n"
+"    }\n"
+"\n"
+"    var result = \"\"\n"
+"\n"
+"    var last = 0\n"
+"    var index = 0\n"
+"\n"
+"    var fromSize = from.byteCount_\n"
+"    var size = byteCount_\n"
+"\n"
+"    while (last < size && (index = indexOf(from, last)) != -1) {\n"
+"      result = result + this[last...index] + to\n"
+"      last = index + fromSize\n"
+"    }\n"
+"\n"
+"    if (last < size) result = result + this[last..-1]\n"
+"\n"
+"    return result\n"
+"  }\n"
+"\n"
 "  *(count) {\n"
 "    if (!(count is Num) || !count.isInteger || count < 0) {\n"
 "      Fiber.abort(\"Count must be a non-negative integer.\")\n"

test/core/string/replace.wren

@@ -0,0 +1,17 @@
+System.print("something".replace("some", "no")) // expect: nothing
+System.print("something".replace("thing", "one")) // expect: someone
+System.print("something".replace("ometh", "umm"))  // expect: summing
+System.print("something".replace("math", "ton")) // expect: something
+
+// Multiple.
+System.print("somethingsomething".replace("some", "no")) // expect: nothingnothing
+System.print("abc abc abc".replace(" ", "")) // expect: abcabcabc
+System.print("abcabcabc".replace("abc", "")) // expect: 
+
+// Non-ASCII.
+System.print("søméthîng".replace("sømé", "nø"))  // expect: nøthîng
+System.print("søméthîng".replace("meth", "ton")) // expect: søméthîng
+
+// 8-bit clean.
+System.print("a\0b\0c".replace("\0", "")) // expect: abc
+System.print("a\0b\0c".replace("b", "") == "a\0\0c") // expect: true

test/core/string/replace_empty_old.wren

@@ -0,0 +1 @@
+"foo".replace("", "f") // expect runtime error: From must be a non-empty string.

test/core/string/replace_new_not_string.wren

@@ -0,0 +1 @@
+"foo".replace("o", 1) // expect runtime error: To must be a string.

test/core/string/replace_old_not_string.wren

@@ -0,0 +1 @@
+"foo".replace(1, "o") // expect runtime error: From must be a non-empty string.

test/core/string/split.wren

@@ -0,0 +1,16 @@
+System.print("something".split("meth")) // expect: [so, ing]
+System.print("something".split("some")) // expect: [, thing]
+System.print("something".split("ing"))  // expect: [someth, ]
+System.print("something".split("math")) // expect: [something]
+
+// Multiple.
+System.print("somethingsomething".split("meth")) // expect: [so, ingso, ing]
+System.print("abc abc abc".split(" ")) // expect: [abc, abc, abc]
+System.print("abcabcabc".split("abc")) // expect: [, , , ]
+
+// Non-ASCII.
+System.print("søméthîng".split("méth"))  // expect: [sø, îng]
+System.print("søméthîng".split("meth")) // expect: [søméthîng]
+
+// 8-bit clean.
+System.print("a\0b\0c".split("\0")) // expect: [a, b, c]

test/core/string/split_argument_not_string.wren

@@ -0,0 +1 @@
+"foo".split(1) // expect runtime error: Argument must be a non-empty string.

test/core/string/split_empty_seperator.wren

@@ -0,0 +1 @@
+"foo".split("") // expect runtime error: Argument must be a non-empty string.