Add complex str constructor (#502)

stdlib/internal/builtin.codon

@@ -402,6 +402,97 @@ class float:
 
         return result
 
+@extend
+class complex:
+    def _from_str(v: str) -> complex:
+        def parse_error():
+            raise ValueError("complex() arg is a malformed string")
+
+        buf = __array__[byte](32)
+        n = len(v)
+        need_dyn_alloc = n >= len(buf)
+
+        s = alloc_atomic(n + 1) if need_dyn_alloc else buf.ptr
+        str.memcpy(s, v.ptr, n)
+        s[n] = byte(0)
+
+        x = 0.0
+        y = 0.0
+        z = 0.0
+        got_bracket = False
+        start = s
+        end = cobj()
+
+        while str._isspace(s[0]):
+            s += 1
+
+        if s[0] == byte(40):  # '('
+            got_bracket = True
+            s += 1
+            while str._isspace(s[0]):
+                s += 1
+
+        z = _C.strtod(s, __ptr__(end))
+
+        if end != s:
+            s = end
+
+            if s[0] == byte(43) or s[0] == byte(45):  # '+' '-'
+                x = z
+                y = _C.strtod(s, __ptr__(end))
+
+                if end != s:
+                    s = end
+                else:
+                    y = 1.0 if s[0] == byte(43) else -1.0
+                    s += 1
+
+                if not (s[0] == byte(106) or s[0] == byte(74)):  # 'j' 'J'
+                    if need_dyn_alloc:
+                        free(s)
+                    parse_error()
+
+                s += 1
+            elif s[0] == byte(106) or s[0] == byte(74):  # 'j' 'J'
+                s += 1
+                y = z
+            else:
+                x = z
+        else:
+            if s[0] == byte(43) or s[0] == byte(45):  # '+' '-'
+                y = 1.0 if s[0] == byte(43) else -1.0
+                s += 1
+            else:
+                y = 1.0
+
+            if not (s[0] == byte(106) or s[0] == byte(74)):  # 'j' 'J'
+                if need_dyn_alloc:
+                    free(s)
+                parse_error()
+
+            s += 1
+
+        while str._isspace(s[0]):
+            s += 1
+
+        if got_bracket:
+            if s[0] != byte(41):  # ')'
+                if need_dyn_alloc:
+                    free(s)
+                parse_error()
+            s += 1
+            while str._isspace(s[0]):
+                s += 1
+
+        if s - start != n:
+            if need_dyn_alloc:
+                free(s)
+            parse_error()
+
+        if need_dyn_alloc:
+            free(s)
+        return complex(x, y)
+
 def _jit_display(x, s: Static[str], bundle: Set[str] = Set[str]()):
     if isinstance(x, None):
         return

stdlib/internal/types/complex.codon

@@ -13,8 +13,12 @@ class complex:
     def __new__() -> complex:
         return (0.0, 0.0)
 
-    def __new__(other):
-        return other.__complex__()
+    def __new__(what):
+        # do not overload! (needed to avoid pyobj conversion)
+        if isinstance(what, str) or isinstance(what, Optional[str]):
+            return complex._from_str(what)
+        else:
+            return what.__complex__()
 
     def __new__(real, imag) -> complex:
         return (float(real), float(imag))

test/stdlib/cmath_test.codon

@@ -865,3 +865,236 @@ def test_complex64():
 
 
 test_complex64()
+
+
+def test_complex_from_string():
+    # for tests when string is not zero-terminated
+    def f(s):
+        return complex(s[1:-1])
+
+    def g(s):
+        return complex(' ' * 50 + s[1:-1] + ' ' * 50)
+
+    assert complex("1") == 1+0j
+    assert complex("1j") == 1j
+    assert complex("-1") == -1
+    assert complex("+1") == +1
+    assert complex("(1+2j)") == 1+2j
+    assert complex("(1.3+2.2j)") == 1.3+2.2j
+    assert complex("3.14+1J") == 3.14+1j
+    assert complex(" ( +3.14-6J )") == 3.14-6j
+    assert complex(" ( +3.14-J )") == 3.14-1j
+    assert complex(" ( +3.14+j )") == 3.14+1j
+    assert complex("J") == 1j
+    assert complex("( j )") == 1j
+    assert complex("+J") == 1j
+    assert complex("( -j)") == -1j
+    assert complex('1e-500') == 0.0 + 0.0j
+    assert complex('-1e-500j') == 0.0 - 0.0j
+    assert complex('-1e-500+1e-500j') == -0.0 + 0.0j
+    assert complex('1-1j') == 1.0 - 1j
+    assert complex('1J') == 1j
+
+    assert f("x1x") == 1+0j
+    assert f("x1jx") == 1j
+    assert f("x-1x") == -1
+    assert f("x+1x") == +1
+    assert f("x(1+2j)x") == 1+2j
+    assert f("x(1.3+2.2j)x") == 1.3+2.2j
+    assert f("x3.14+1Jx") == 3.14+1j
+    assert f("x ( +3.14-6J )x") == 3.14-6j
+    assert f("x ( +3.14-J )x") == 3.14-1j
+    assert f("x ( +3.14+j )x") == 3.14+1j
+    assert f("xJx") == 1j
+    assert f("x( j )x") == 1j
+    assert f("x+Jx") == 1j
+    assert f("x( -j)x") == -1j
+    assert f('x1e-500x') == 0.0 + 0.0j
+    assert f('x-1e-500jx') == 0.0 - 0.0j
+    assert f('x-1e-500+1e-500jx') == -0.0 + 0.0j
+    assert f('x1-1jx') == 1.0 - 1j
+    assert f('x1Jx') == 1j
+
+    assert g("x1x") == 1+0j
+    assert g("x1jx") == 1j
+    assert g("x-1x") == -1
+    assert g("x+1x") == +1
+    assert g("x(1+2j)x") == 1+2j
+    assert g("x(1.3+2.2j)x") == 1.3+2.2j
+    assert g("x3.14+1Jx") == 3.14+1j
+    assert g("x ( +3.14-6J )x") == 3.14-6j
+    assert g("x ( +3.14-J )x") == 3.14-1j
+    assert g("x ( +3.14+j )x") == 3.14+1j
+    assert g("xJx") == 1j
+    assert g("x( j )x") == 1j
+    assert g("x+Jx") == 1j
+    assert g("x( -j)x") == -1j
+    assert g('x1e-500x') == 0.0 + 0.0j
+    assert g('x-1e-500jx') == 0.0 - 0.0j
+    assert g('x-1e-500+1e-500jx') == -0.0 + 0.0j
+    assert g('x1-1jx') == 1.0 - 1j
+    assert g('x1Jx') == 1j
+
+    try:
+        complex("\0")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("3\09")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("1+")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("1+1j+1j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("--")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("(1+2j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("1+2j)")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("1+(2j)")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("(1+2j)123")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("x")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("1j+2")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("1e1ej")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("1e++1ej")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex(")1+2j(")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        complex("")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        f(" 1+2j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        f("1..1j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        f("1.11.1j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        f("1e1.1j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        f("   ")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        f("   J")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        g(" 1+2j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        g("1..1j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        g("1.11.1j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        g("1e1.1j")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        g("   ")
+        assert False
+    except ValueError:
+        pass
+
+    try:
+        g("   J")
+        assert False
+    except ValueError:
+        pass
+
+test_complex_from_string()