jrsonnet-stdlib 0.3.2

jsonnet standard library packaged as crate
Documentation
{
  __intrinsic_namespace__:: 'std',

  local std = self,
  local id = std.id,

  isString(v):: std.type(v) == 'string',
  isNumber(v):: std.type(v) == 'number',
  isBoolean(v):: std.type(v) == 'boolean',
  isObject(v):: std.type(v) == 'object',
  isArray(v):: std.type(v) == 'array',
  isFunction(v):: std.type(v) == 'function',

  toString(a)::
    if std.type(a) == 'string' then a else '' + a,

  substr(str, from, len)::
    assert std.isString(str) : 'substr first parameter should be a string, got ' + std.type(str);
    assert std.isNumber(from) : 'substr second parameter should be a string, got ' + std.type(from);
    assert std.isNumber(len) : 'substr third parameter should be a string, got ' + std.type(len);
    assert len >= 0 : 'substr third parameter should be greater than zero, got ' + len;
    std.join('', std.makeArray(std.max(0, std.min(len, std.length(str) - from)), function(i) str[i + from])),

  startsWith(a, b)::
    if std.length(a) < std.length(b) then
      false
    else
      std.substr(a, 0, std.length(b)) == b,

  endsWith(a, b)::
    if std.length(a) < std.length(b) then
      false
    else
      std.substr(a, std.length(a) - std.length(b), std.length(b)) == b,

  lstripChars(str, chars)::
    if std.length(str) > 0 && std.member(chars, str[0]) then
      std.lstripChars(str[1:], chars)
    else
      str,

  rstripChars(str, chars)::
    local len = std.length(str);
    if len > 0 && std.member(chars, str[len - 1]) then
      std.rstripChars(str[:len - 1], chars)
    else
      str,

  stripChars(str, chars)::
    std.lstripChars(std.rstripChars(str, chars), chars),

  stringChars(str)::
    std.makeArray(std.length(str), function(i) str[i]),

  local parse_nat(str, base) =
    assert base > 0 && base <= 16 : 'integer base %d invalid' % base;
    // These codepoints are in ascending order:
    local zero_code = std.codepoint('0');
    local upper_a_code = std.codepoint('A');
    local lower_a_code = std.codepoint('a');
    local addDigit(aggregate, char) =
      local code = std.codepoint(char);
      local digit = if code >= lower_a_code then
        code - lower_a_code + 10
      else if code >= upper_a_code then
        code - upper_a_code + 10
      else
        code - zero_code;
      assert digit >= 0 && digit < base : '%s is not a base %d integer' % [str, base];
      base * aggregate + digit;
    std.foldl(addDigit, std.stringChars(str), 0),

  parseInt(str)::
    assert std.isString(str) : 'Expected string, got ' + std.type(str);
    assert std.length(str) > 0 && str != '-' : 'Not an integer: "%s"' % [str];
    if str[0] == '-' then
      -parse_nat(str[1:], 10)
    else
      parse_nat(str, 10),

  parseOctal(str)::
    assert std.isString(str) : 'Expected string, got ' + std.type(str);
    assert std.length(str) > 0 : 'Not an octal number: ""';
    parse_nat(str, 8),

  parseHex(str)::
    assert std.isString(str) : 'Expected string, got ' + std.type(str);
    assert std.length(str) > 0 : 'Not hexadecimal: ""';
    parse_nat(str, 16),

  split(str, c)::
    assert std.isString(str) : 'std.split first parameter should be a string, got ' + std.type(str);
    assert std.isString(c) : 'std.split second parameter should be a string, got ' + std.type(c);
    assert std.length(c) == 1 : 'std.split second parameter should have length 1, got ' + std.length(c);
    std.splitLimit(str, c, -1),

  splitLimit(str, c, maxsplits)::
    assert std.isString(str) : 'std.splitLimit first parameter should be a string, got ' + std.type(str);
    assert std.isString(c) : 'std.splitLimit second parameter should be a string, got ' + std.type(c);
    assert std.length(c) == 1 : 'std.splitLimit second parameter should have length 1, got ' + std.length(c);
    assert std.isNumber(maxsplits) : 'std.splitLimit third parameter should be a number, got ' + std.type(maxsplits);
    local aux(str, delim, i, arr, v) =
      local c = str[i];
      local i2 = i + 1;
      if i >= std.length(str) then
        arr + [v]
      else if c == delim && (maxsplits == -1 || std.length(arr) < maxsplits) then
        aux(str, delim, i2, arr + [v], '') tailstrict
      else
        aux(str, delim, i2, arr, v + c) tailstrict;
    aux(str, c, 0, [], ''),

  strReplace(str, from, to)::
    assert std.isString(str);
    assert std.isString(from);
    assert std.isString(to);
    assert from != '' : "'from' string must not be zero length.";

    // Cache for performance.
    local str_len = std.length(str);
    local from_len = std.length(from);

    // True if from is at str[i].
    local found_at(i) = str[i:i + from_len] == from;

    // Return the remainder of 'str' starting with 'start_index' where
    // all occurrences of 'from' after 'curr_index' are replaced with 'to'.
    local replace_after(start_index, curr_index, acc) =
      if curr_index > str_len then
        acc + str[start_index:curr_index]
      else if found_at(curr_index) then
        local new_index = curr_index + std.length(from);
        replace_after(new_index, new_index, acc + str[start_index:curr_index] + to) tailstrict
      else
        replace_after(start_index, curr_index + 1, acc) tailstrict;

    // if from_len==1, then we replace by splitting and rejoining the
    // string which is much faster than recursing on replace_after
    if from_len == 1 then
      std.join(to, std.split(str, from))
    else
      replace_after(0, 0, ''),

  asciiUpper(str)::
    local cp = std.codepoint;
    local up_letter(c) = if cp(c) >= 97 && cp(c) < 123 then
      std.char(cp(c) - 32)
    else
      c;
    std.join('', std.map(up_letter, std.stringChars(str))),

  asciiLower(str)::
    local cp = std.codepoint;
    local down_letter(c) = if cp(c) >= 65 && cp(c) < 91 then
      std.char(cp(c) + 32)
    else
      c;
    std.join('', std.map(down_letter, std.stringChars(str))),

  range(from, to)::
    std.makeArray(to - from + 1, function(i) i + from),

  repeat(what, count)::
    local joiner =
      if std.isString(what) then ''
      else if std.isArray(what) then []
      else error 'std.repeat first argument must be an array or a string';
    std.join(joiner, std.makeArray(count, function(i) what)),

  slice(indexable, index, end, step)::
    local invar =
      // loop invariant with defaults applied
      {
        indexable: indexable,
        index:
          if index == null then 0
          else index,
        end:
          if end == null then std.length(indexable)
          else end,
        step:
          if step == null then 1
          else step,
        length: std.length(indexable),
        type: std.type(indexable),
      };
    assert invar.index >= 0 && invar.end >= 0 && invar.step >= 0 : 'got [%s:%s:%s] but negative index, end, and steps are not supported' % [invar.index, invar.end, invar.step];
    assert step != 0 : 'got %s but step must be greater than 0' % step;
    assert std.isString(indexable) || std.isArray(indexable) : 'std.slice accepts a string or an array, but got: %s' % std.type(indexable);
    local build(slice, cur) =
      if cur >= invar.end || cur >= invar.length then
        slice
      else
        build(
          if invar.type == 'string' then
            slice + invar.indexable[cur]
          else
            slice + [invar.indexable[cur]],
          cur + invar.step
        ) tailstrict;
    build(if invar.type == 'string' then '' else [], invar.index),

  member(arr, x)::
    if std.isArray(arr) then
      std.count(arr, x) > 0
    else if std.isString(arr) then
      std.length(std.findSubstr(x, arr)) > 0
    else error 'std.member first argument must be an array or a string',

  count(arr, x):: std.length(std.filter(function(v) v == x, arr)),

  mod(a, b)::
    if std.isNumber(a) && std.isNumber(b) then
      std.modulo(a, b)
    else if std.isString(a) then
      std.format(a, b)
    else
      error 'Operator % cannot be used on types ' + std.type(a) + ' and ' + std.type(b) + '.',

  map(func, arr)::
    if !std.isFunction(func) then
      error ('std.map first param must be function, got ' + std.type(func))
    else if !std.isArray(arr) && !std.isString(arr) then
      error ('std.map second param must be array / string, got ' + std.type(arr))
    else
      std.makeArray(std.length(arr), function(i) func(arr[i])),

  mapWithIndex(func, arr)::
    if !std.isFunction(func) then
      error ('std.mapWithIndex first param must be function, got ' + std.type(func))
    else if !std.isArray(arr) && !std.isString(arr) then
      error ('std.mapWithIndex second param must be array, got ' + std.type(arr))
    else
      std.makeArray(std.length(arr), function(i) func(i, arr[i])),

  mapWithKey(func, obj)::
    if !std.isFunction(func) then
      error ('std.mapWithKey first param must be function, got ' + std.type(func))
    else if !std.isObject(obj) then
      error ('std.mapWithKey second param must be object, got ' + std.type(obj))
    else
      { [k]: func(k, obj[k]) for k in std.objectFields(obj) },

  flatMap(func, arr)::
    if !std.isFunction(func) then
      error ('std.flatMap first param must be function, got ' + std.type(func))
    else if std.isArray(arr) then
      std.flattenArrays(std.makeArray(std.length(arr), function(i) func(arr[i])))
    else if std.isString(arr) then
      std.join('', std.makeArray(std.length(arr), function(i) func(arr[i])))
    else error ('std.flatMap second param must be array / string, got ' + std.type(arr)),

  join(sep, arr)::
    local aux(arr, i, first, running) =
      if i >= std.length(arr) then
        running
      else if arr[i] == null then
        aux(arr, i + 1, first, running) tailstrict
      else if std.type(arr[i]) != std.type(sep) then
        error 'expected %s but arr[%d] was %s ' % [std.type(sep), i, std.type(arr[i])]
      else if first then
        aux(arr, i + 1, false, running + arr[i]) tailstrict
      else
        aux(arr, i + 1, false, running + sep + arr[i]) tailstrict;
    if !std.isArray(arr) then
      error 'join second parameter should be array, got ' + std.type(arr)
    else if std.isString(sep) then
      aux(arr, 0, true, '')
    else if std.isArray(sep) then
      aux(arr, 0, true, [])
    else
      error 'join first parameter should be string or array, got ' + std.type(sep),

  lines(arr)::
    std.join('\n', arr + ['']),

  deepJoin(arr)::
    if std.isString(arr) then
      arr
    else if std.isArray(arr) then
      std.join('', [std.deepJoin(x) for x in arr])
    else
      error 'Expected string or array, got %s' % std.type(arr),


  format(str, vals)::

    /////////////////////////////
    // Parse the mini-language //
    /////////////////////////////

    local try_parse_mapping_key(str, i) =
      assert i < std.length(str) : 'Truncated format code.';
      local c = str[i];
      if c == '(' then
        local consume(str, j, v) =
          if j >= std.length(str) then
            error 'Truncated format code.'
          else
            local c = str[j];
            if c != ')' then
              consume(str, j + 1, v + c)
            else
              { i: j + 1, v: v };
        consume(str, i + 1, '')
      else
        { i: i, v: null };

    local try_parse_cflags(str, i) =
      local consume(str, j, v) =
        assert j < std.length(str) : 'Truncated format code.';
        local c = str[j];
        if c == '#' then
          consume(str, j + 1, v { alt: true })
        else if c == '0' then
          consume(str, j + 1, v { zero: true })
        else if c == '-' then
          consume(str, j + 1, v { left: true })
        else if c == ' ' then
          consume(str, j + 1, v { blank: true })
        else if c == '+' then
          consume(str, j + 1, v { sign: true })
        else
          { i: j, v: v };
      consume(str, i, { alt: false, zero: false, left: false, blank: false, sign: false });

    local try_parse_field_width(str, i) =
      if i < std.length(str) && str[i] == '*' then
        { i: i + 1, v: '*' }
      else
        local consume(str, j, v) =
          assert j < std.length(str) : 'Truncated format code.';
          local c = str[j];
          if c == '0' then
            consume(str, j + 1, v * 10 + 0)
          else if c == '1' then
            consume(str, j + 1, v * 10 + 1)
          else if c == '2' then
            consume(str, j + 1, v * 10 + 2)
          else if c == '3' then
            consume(str, j + 1, v * 10 + 3)
          else if c == '4' then
            consume(str, j + 1, v * 10 + 4)
          else if c == '5' then
            consume(str, j + 1, v * 10 + 5)
          else if c == '6' then
            consume(str, j + 1, v * 10 + 6)
          else if c == '7' then
            consume(str, j + 1, v * 10 + 7)
          else if c == '8' then
            consume(str, j + 1, v * 10 + 8)
          else if c == '9' then
            consume(str, j + 1, v * 10 + 9)
          else
            { i: j, v: v };
        consume(str, i, 0);

    local try_parse_precision(str, i) =
      assert i < std.length(str) : 'Truncated format code.';
      local c = str[i];
      if c == '.' then
        try_parse_field_width(str, i + 1)
      else
        { i: i, v: null };

    // Ignored, if it exists.
    local try_parse_length_modifier(str, i) =
      assert i < std.length(str) : 'Truncated format code.';
      local c = str[i];
      if c == 'h' || c == 'l' || c == 'L' then
        i + 1
      else
        i;

    local parse_conv_type(str, i) =
      assert i < std.length(str) : 'Truncated format code.';
      local c = str[i];
      if c == 'd' || c == 'i' || c == 'u' then
        { i: i + 1, v: 'd', caps: false }
      else if c == 'o' then
        { i: i + 1, v: 'o', caps: false }
      else if c == 'x' then
        { i: i + 1, v: 'x', caps: false }
      else if c == 'X' then
        { i: i + 1, v: 'x', caps: true }
      else if c == 'e' then
        { i: i + 1, v: 'e', caps: false }
      else if c == 'E' then
        { i: i + 1, v: 'e', caps: true }
      else if c == 'f' then
        { i: i + 1, v: 'f', caps: false }
      else if c == 'F' then
        { i: i + 1, v: 'f', caps: true }
      else if c == 'g' then
        { i: i + 1, v: 'g', caps: false }
      else if c == 'G' then
        { i: i + 1, v: 'g', caps: true }
      else if c == 'c' then
        { i: i + 1, v: 'c', caps: false }
      else if c == 's' then
        { i: i + 1, v: 's', caps: false }
      else if c == '%' then
        { i: i + 1, v: '%', caps: false }
      else
        error 'Unrecognised conversion type: ' + c;


    // Parsed initial %, now the rest.
    local parse_code(str, i) =
      assert i < std.length(str) : 'Truncated format code.';
      local mkey = try_parse_mapping_key(str, i);
      local cflags = try_parse_cflags(str, mkey.i);
      local fw = try_parse_field_width(str, cflags.i);
      local prec = try_parse_precision(str, fw.i);
      local len_mod = try_parse_length_modifier(str, prec.i);
      local ctype = parse_conv_type(str, len_mod);
      {
        i: ctype.i,
        code: {
          mkey: mkey.v,
          cflags: cflags.v,
          fw: fw.v,
          prec: prec.v,
          ctype: ctype.v,
          caps: ctype.caps,
        },
      };

    // Parse a format string (containing none or more % format tags).
    local parse_codes(str, i, out, cur) =
      if i >= std.length(str) then
        out + [cur]
      else
        local c = str[i];
        if c == '%' then
          local r = parse_code(str, i + 1);
          parse_codes(str, r.i, out + [cur, r.code], '') tailstrict
        else
          parse_codes(str, i + 1, out, cur + c) tailstrict;

    local codes = parse_codes(str, 0, [], '');


    ///////////////////////
    // Format the values //
    ///////////////////////

    // Useful utilities
    local padding(w, s) =
      local aux(w, v) =
        if w <= 0 then
          v
        else
          aux(w - 1, v + s);
      aux(w, '');

    // Add s to the left of str so that its length is at least w.
    local pad_left(str, w, s) =
      padding(w - std.length(str), s) + str;

    // Add s to the right of str so that its length is at least w.
    local pad_right(str, w, s) =
      str + padding(w - std.length(str), s);

    // Render an integer (e.g., decimal or octal).
    local render_int(n__, min_chars, min_digits, blank, sign, radix, zero_prefix) =
      local n_ = std.abs(n__);
      local aux(n) =
        if n == 0 then
          zero_prefix
        else
          aux(std.floor(n / radix)) + (n % radix);
      local dec = if std.floor(n_) == 0 then '0' else aux(std.floor(n_));
      local neg = n__ < 0;
      local zp = min_chars - (if neg || blank || sign then 1 else 0);
      local zp2 = std.max(zp, min_digits);
      local dec2 = pad_left(dec, zp2, '0');
      (if neg then '-' else if sign then '+' else if blank then ' ' else '') + dec2;

    // Render an integer in hexadecimal.
    local render_hex(n__, min_chars, min_digits, blank, sign, add_zerox, capitals) =
      local numerals = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
                       + if capitals then ['A', 'B', 'C', 'D', 'E', 'F']
                       else ['a', 'b', 'c', 'd', 'e', 'f'];
      local n_ = std.abs(n__);
      local aux(n) =
        if n == 0 then
          ''
        else
          aux(std.floor(n / 16)) + numerals[n % 16];
      local hex = if std.floor(n_) == 0 then '0' else aux(std.floor(n_));
      local neg = n__ < 0;
      local zp = min_chars - (if neg || blank || sign then 1 else 0)
                 - (if add_zerox then 2 else 0);
      local zp2 = std.max(zp, min_digits);
      local hex2 = (if add_zerox then (if capitals then '0X' else '0x') else '')
                   + pad_left(hex, zp2, '0');
      (if neg then '-' else if sign then '+' else if blank then ' ' else '') + hex2;

    local strip_trailing_zero(str) =
      local aux(str, i) =
        if i < 0 then
          ''
        else
          if str[i] == '0' then
            aux(str, i - 1)
          else
            std.substr(str, 0, i + 1);
      aux(str, std.length(str) - 1);

    // Render floating point in decimal form
    local render_float_dec(n__, zero_pad, blank, sign, ensure_pt, trailing, prec) =
      local n_ = std.abs(n__);
      local whole = std.floor(n_);
      local dot_size = if prec == 0 && !ensure_pt then 0 else 1;
      local zp = zero_pad - prec - dot_size;
      local str = render_int(std.sign(n__) * whole, zp, 0, blank, sign, 10, '');
      if prec == 0 then
        str + if ensure_pt then '.' else ''
      else
        local frac = std.floor((n_ - whole) * std.pow(10, prec) + 0.5);
        if trailing || frac > 0 then
          local frac_str = render_int(frac, prec, 0, false, false, 10, '');
          str + '.' + if !trailing then strip_trailing_zero(frac_str) else frac_str
        else
          str;

    // Render floating point in scientific form
    local render_float_sci(n__, zero_pad, blank, sign, ensure_pt, trailing, caps, prec) =
      local exponent = if n__ == 0 then 0 else std.floor(std.log(std.abs(n__)) / std.log(10));
      local suff = (if caps then 'E' else 'e')
                   + render_int(exponent, 3, 0, false, true, 10, '');
      local mantissa = if exponent == -324 then
        // Avoid a rounding error where std.pow(10, -324) is 0
        // -324 is the smallest exponent possible.
        n__ * 10 / std.pow(10, exponent + 1)
      else
        n__ / std.pow(10, exponent);
      local zp2 = zero_pad - std.length(suff);
      render_float_dec(mantissa, zp2, blank, sign, ensure_pt, trailing, prec) + suff;

    // Render a value with an arbitrary format code.
    local format_code(val, code, fw, prec_or_null, i) =
      local cflags = code.cflags;
      local fpprec = if prec_or_null != null then prec_or_null else 6;
      local iprec = if prec_or_null != null then prec_or_null else 0;
      local zp = if cflags.zero && !cflags.left then fw else 0;
      if code.ctype == 's' then
        std.toString(val)
      else if code.ctype == 'd' then
        if std.type(val) != 'number' then
          error 'Format required number at '
                + i + ', got ' + std.type(val)
        else
          render_int(val, zp, iprec, cflags.blank, cflags.sign, 10, '')
      else if code.ctype == 'o' then
        if std.type(val) != 'number' then
          error 'Format required number at '
                + i + ', got ' + std.type(val)
        else
          local zero_prefix = if cflags.alt then '0' else '';
          render_int(val, zp, iprec, cflags.blank, cflags.sign, 8, zero_prefix)
      else if code.ctype == 'x' then
        if std.type(val) != 'number' then
          error 'Format required number at '
                + i + ', got ' + std.type(val)
        else
          render_hex(val,
                     zp,
                     iprec,
                     cflags.blank,
                     cflags.sign,
                     cflags.alt,
                     code.caps)
      else if code.ctype == 'f' then
        if std.type(val) != 'number' then
          error 'Format required number at '
                + i + ', got ' + std.type(val)
        else
          render_float_dec(val,
                           zp,
                           cflags.blank,
                           cflags.sign,
                           cflags.alt,
                           true,
                           fpprec)
      else if code.ctype == 'e' then
        if std.type(val) != 'number' then
          error 'Format required number at '
                + i + ', got ' + std.type(val)
        else
          render_float_sci(val,
                           zp,
                           cflags.blank,
                           cflags.sign,
                           cflags.alt,
                           true,
                           code.caps,
                           fpprec)
      else if code.ctype == 'g' then
        if std.type(val) != 'number' then
          error 'Format required number at '
                + i + ', got ' + std.type(val)
        else
          local exponent = std.floor(std.log(std.abs(val)) / std.log(10));
          if exponent < -4 || exponent >= fpprec then
            render_float_sci(val,
                             zp,
                             cflags.blank,
                             cflags.sign,
                             cflags.alt,
                             cflags.alt,
                             code.caps,
                             fpprec - 1)
          else
            local digits_before_pt = std.max(1, exponent + 1);
            render_float_dec(val,
                             zp,
                             cflags.blank,
                             cflags.sign,
                             cflags.alt,
                             cflags.alt,
                             fpprec - digits_before_pt)
      else if code.ctype == 'c' then
        if std.type(val) == 'number' then
          std.char(val)
        else if std.type(val) == 'string' then
          if std.length(val) == 1 then
            val
          else
            error '%c expected 1-sized string got: ' + std.length(val)
        else
          error '%c expected number / string, got: ' + std.type(val)
      else
        error 'Unknown code: ' + code.ctype;

    // Render a parsed format string with an array of values.
    local format_codes_arr(codes, arr, i, j, v) =
      if i >= std.length(codes) then
        if j < std.length(arr) then
          error ('Too many values to format: ' + std.length(arr) + ', expected ' + j)
        else
          v
      else
        local code = codes[i];
        if std.type(code) == 'string' then
          format_codes_arr(codes, arr, i + 1, j, v + code) tailstrict
        else
          local tmp = if code.fw == '*' then {
            j: j + 1,
            fw: if j >= std.length(arr) then
              error ('Not enough values to format: ' + std.length(arr) + ', expected at least ' + j)
            else
              arr[j],
          } else {
            j: j,
            fw: code.fw,
          };
          local tmp2 = if code.prec == '*' then {
            j: tmp.j + 1,
            prec: if tmp.j >= std.length(arr) then
              error ('Not enough values to format: ' + std.length(arr) + ', expected at least ' + tmp.j)
            else
              arr[tmp.j],
          } else {
            j: tmp.j,
            prec: code.prec,
          };
          local j2 = tmp2.j;
          local val =
            if j2 < std.length(arr) then
              arr[j2]
            else
              error ('Not enough values to format: ' + std.length(arr) + ', expected more than ' + j2);
          local s =
            if code.ctype == '%' then
              '%'
            else
              format_code(val, code, tmp.fw, tmp2.prec, j2);
          local s_padded =
            if code.cflags.left then
              pad_right(s, tmp.fw, ' ')
            else
              pad_left(s, tmp.fw, ' ');
          local j3 =
            if code.ctype == '%' then
              j2
            else
              j2 + 1;
          format_codes_arr(codes, arr, i + 1, j3, v + s_padded) tailstrict;

    // Render a parsed format string with an object of values.
    local format_codes_obj(codes, obj, i, v) =
      if i >= std.length(codes) then
        v
      else
        local code = codes[i];
        if std.type(code) == 'string' then
          format_codes_obj(codes, obj, i + 1, v + code) tailstrict
        else
          local f =
            if code.mkey == null then
              error 'Mapping keys required.'
            else
              code.mkey;
          local fw =
            if code.fw == '*' then
              error 'Cannot use * field width with object.'
            else
              code.fw;
          local prec =
            if code.prec == '*' then
              error 'Cannot use * precision with object.'
            else
              code.prec;
          local val =
            if std.objectHasAll(obj, f) then
              obj[f]
            else
              error 'No such field: ' + f;
          local s =
            if code.ctype == '%' then
              '%'
            else
              format_code(val, code, fw, prec, f);
          local s_padded =
            if code.cflags.left then
              pad_right(s, fw, ' ')
            else
              pad_left(s, fw, ' ');
          format_codes_obj(codes, obj, i + 1, v + s_padded) tailstrict;

    if std.isArray(vals) then
      format_codes_arr(codes, vals, 0, 0, '')
    else if std.isObject(vals) then
      format_codes_obj(codes, vals, 0, '')
    else
      format_codes_arr(codes, [vals], 0, 0, ''),

  foldr(func, arr, init)::
    local aux(func, arr, running, idx) =
      if idx < 0 then
        running
      else
        aux(func, arr, func(arr[idx], running), idx - 1) tailstrict;
    aux(func, arr, init, std.length(arr) - 1),

  foldl(func, arr, init)::
    local aux(func, arr, running, idx) =
      if idx >= std.length(arr) then
        running
      else
        aux(func, arr, func(running, arr[idx]), idx + 1) tailstrict;
    aux(func, arr, init, 0),


  filterMap(filter_func, map_func, arr)::
    if !std.isFunction(filter_func) then
      error ('std.filterMap first param must be function, got ' + std.type(filter_func))
    else if !std.isFunction(map_func) then
      error ('std.filterMap second param must be function, got ' + std.type(map_func))
    else if !std.isArray(arr) then
      error ('std.filterMap third param must be array, got ' + std.type(arr))
    else
      std.map(map_func, std.filter(filter_func, arr)),

  assertEqual(a, b)::
    if a == b then
      true
    else
      error 'Assertion failed. ' + a + ' != ' + b,

  abs(n)::
    if !std.isNumber(n) then
      error 'std.abs expected number, got ' + std.type(n)
    else
      if n > 0 then n else -n,

  sign(n)::
    if !std.isNumber(n) then
      error 'std.sign expected number, got ' + std.type(n)
    else
      if n > 0 then
        1
      else if n < 0 then
        -1
      else 0,

  max(a, b)::
    if !std.isNumber(a) then
      error 'std.max first param expected number, got ' + std.type(a)
    else if !std.isNumber(b) then
      error 'std.max second param expected number, got ' + std.type(b)
    else
      if a > b then a else b,

  min(a, b)::
    if !std.isNumber(a) then
      error 'std.max first param expected number, got ' + std.type(a)
    else if !std.isNumber(b) then
      error 'std.max second param expected number, got ' + std.type(b)
    else
      if a < b then a else b,

  clamp(x, minVal, maxVal)::
    if x < minVal then minVal
    else if x > maxVal then maxVal
    else x,

  flattenArrays(arrs)::
    std.foldl(function(a, b) a + b, arrs, []),

  manifestIni(ini)::
    local body_lines(body) =
      std.join([], [
        local value_or_values = body[k];
        if std.isArray(value_or_values) then
          ['%s = %s' % [k, value] for value in value_or_values]
        else
          ['%s = %s' % [k, value_or_values]]

        for k in std.objectFields(body)
      ]);

    local section_lines(sname, sbody) = ['[%s]' % [sname]] + body_lines(sbody),
          main_body = if std.objectHas(ini, 'main') then body_lines(ini.main) else [],
          all_sections = [
      section_lines(k, ini.sections[k])
      for k in std.objectFields(ini.sections)
    ];
    std.join('\n', main_body + std.flattenArrays(all_sections) + ['']),

  escapeStringJson(str_)::
    local str = std.toString(str_);
    local trans(ch) =
      if ch == '"' then
        '\\"'
      else if ch == '\\' then
        '\\\\'
      else if ch == '\b' then
        '\\b'
      else if ch == '\f' then
        '\\f'
      else if ch == '\n' then
        '\\n'
      else if ch == '\r' then
        '\\r'
      else if ch == '\t' then
        '\\t'
      else
        local cp = std.codepoint(ch);
        if cp < 32 || (cp >= 127 && cp <= 159) then
          '\\u%04x' % [cp]
        else
          ch;
    '"%s"' % std.join('', [trans(ch) for ch in std.stringChars(str)]),

  escapeStringPython(str)::
    std.escapeStringJson(str),

  escapeStringBash(str_)::
    local str = std.toString(str_);
    local trans(ch) =
      if ch == "'" then
        "'\"'\"'"
      else
        ch;
    "'%s'" % std.join('', [trans(ch) for ch in std.stringChars(str)]),

  escapeStringDollars(str_)::
    local str = std.toString(str_);
    local trans(ch) =
      if ch == '$' then
        '$$'
      else
        ch;
    std.foldl(function(a, b) a + trans(b), std.stringChars(str), ''),

  manifestJson(value):: std.manifestJsonEx(value, '    '),

  manifestJsonEx(value, indent)::
    local aux(v, path, cindent) =
      if v == true then
        'true'
      else if v == false then
        'false'
      else if v == null then
        'null'
      else if std.isNumber(v) then
        '' + v
      else if std.isString(v) then
        std.escapeStringJson(v)
      else if std.isFunction(v) then
        error 'Tried to manifest function at ' + path
      else if std.isArray(v) then
        local range = std.range(0, std.length(v) - 1);
        local new_indent = cindent + indent;
        local lines = ['[\n']
                      + std.join([',\n'],
                                 [
                                   [new_indent + aux(v[i], path + [i], new_indent)]
                                   for i in range
                                 ])
                      + ['\n' + cindent + ']'];
        std.join('', lines)
      else if std.isObject(v) then
        local lines = ['{\n']
                      + std.join([',\n'],
                                 [
                                   [cindent + indent + std.escapeStringJson(k) + ': '
                                    + aux(v[k], path + [k], cindent + indent)]
                                   for k in std.objectFields(v)
                                 ])
                      + ['\n' + cindent + '}'];
        std.join('', lines);
    aux(value, [], ''),

  manifestYamlDoc(value, indent_array_in_object=false)::
    local aux(v, path, cindent) =
      if v == true then
        'true'
      else if v == false then
        'false'
      else if v == null then
        'null'
      else if std.isNumber(v) then
        '' + v
      else if std.isString(v) then
        local len = std.length(v);
        if len == 0 then
          '""'
        else if v[len - 1] == '\n' then
          local split = std.split(v, '\n');
          std.join('\n' + cindent + '  ', ['|'] + split[0:std.length(split) - 1])
        else
          std.escapeStringJson(v)
      else if std.isFunction(v) then
        error 'Tried to manifest function at ' + path
      else if std.isArray(v) then
        if std.length(v) == 0 then
          '[]'
        else
          local params(value) =
            if std.isArray(value) && std.length(value) > 0 then {
              // While we could avoid the new line, it yields YAML that is
              // hard to read, e.g.:
              // - - - 1
              //     - 2
              //   - - 3
              //     - 4
              new_indent: cindent + '  ',
              space: '\n' + self.new_indent,
            } else if std.isObject(value) && std.length(value) > 0 then {
              new_indent: cindent + '  ',
              // In this case we can start on the same line as the - because the indentation
              // matches up then.  The converse is not true, because fields are not always
              // 1 character long.
              space: ' ',
            } else {
              // In this case, new_indent is only used in the case of multi-line strings.
              new_indent: cindent,
              space: ' ',
            };
          local range = std.range(0, std.length(v) - 1);
          local parts = [
            '-' + param.space + aux(v[i], path + [i], param.new_indent)
            for i in range
            for param in [params(v[i])]
          ];
          std.join('\n' + cindent, parts)
      else if std.isObject(v) then
        if std.length(v) == 0 then
          '{}'
        else
          local params(value) =
            if std.isArray(value) && std.length(value) > 0 then {
              // Not indenting allows e.g.
              // ports:
              // - 80
              // instead of
              // ports:
              //   - 80
              new_indent: if indent_array_in_object then cindent + '  ' else cindent,
              space: '\n' + self.new_indent,
            } else if std.isObject(value) && std.length(value) > 0 then {
              new_indent: cindent + '  ',
              space: '\n' + self.new_indent,
            } else {
              // In this case, new_indent is only used in the case of multi-line strings.
              new_indent: cindent,
              space: ' ',
            };
          local lines = [
            std.escapeStringJson(k) + ':' + param.space + aux(v[k], path + [k], param.new_indent)
            for k in std.objectFields(v)
            for param in [params(v[k])]
          ];
          std.join('\n' + cindent, lines);
    aux(value, [], ''),

  manifestYamlStream(value, indent_array_in_object=false, c_document_end=true)::
    if !std.isArray(value) then
      error 'manifestYamlStream only takes arrays, got ' + std.type(value)
    else
      '---\n' + std.join(
        '\n---\n', [std.manifestYamlDoc(e, indent_array_in_object) for e in value]
      ) + if c_document_end then '\n...\n' else '\n',


  manifestPython(v)::
    if std.isObject(v) then
      local fields = [
        '%s: %s' % [std.escapeStringPython(k), std.manifestPython(v[k])]
        for k in std.objectFields(v)
      ];
      '{%s}' % [std.join(', ', fields)]
    else if std.isArray(v) then
      '[%s]' % [std.join(', ', [std.manifestPython(v2) for v2 in v])]
    else if std.isString(v) then
      '%s' % [std.escapeStringPython(v)]
    else if std.isFunction(v) then
      error 'cannot manifest function'
    else if std.isNumber(v) then
      std.toString(v)
    else if v == true then
      'True'
    else if v == false then
      'False'
    else if v == null then
      'None',

  manifestPythonVars(conf)::
    local vars = ['%s = %s' % [k, std.manifestPython(conf[k])] for k in std.objectFields(conf)];
    std.join('\n', vars + ['']),

  manifestXmlJsonml(value)::
    if !std.isArray(value) then
      error 'Expected a JSONML value (an array), got %s' % std.type(value)
    else
      local aux(v) =
        if std.isString(v) then
          v
        else
          local tag = v[0];
          local has_attrs = std.length(v) > 1 && std.isObject(v[1]);
          local attrs = if has_attrs then v[1] else {};
          local children = if has_attrs then v[2:] else v[1:];
          local attrs_str =
            std.join('', [' %s="%s"' % [k, attrs[k]] for k in std.objectFields(attrs)]);
          std.deepJoin(['<', tag, attrs_str, '>', [aux(x) for x in children], '</', tag, '>']);

      aux(value),

  local base64_table = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
  local base64_inv = { [base64_table[i]]: i for i in std.range(0, 63) },

  base64(input)::
    local bytes =
      if std.isString(input) then
        std.map(function(c) std.codepoint(c), input)
      else
        input;

    local aux(arr, i, r) =
      if i >= std.length(arr) then
        r
      else if i + 1 >= std.length(arr) then
        local str =
          // 6 MSB of i
          base64_table[(arr[i] & 252) >> 2] +
          // 2 LSB of i
          base64_table[(arr[i] & 3) << 4] +
          '==';
        aux(arr, i + 3, r + str) tailstrict
      else if i + 2 >= std.length(arr) then
        local str =
          // 6 MSB of i
          base64_table[(arr[i] & 252) >> 2] +
          // 2 LSB of i, 4 MSB of i+1
          base64_table[(arr[i] & 3) << 4 | (arr[i + 1] & 240) >> 4] +
          // 4 LSB of i+1
          base64_table[(arr[i + 1] & 15) << 2] +
          '=';
        aux(arr, i + 3, r + str) tailstrict
      else
        local str =
          // 6 MSB of i
          base64_table[(arr[i] & 252) >> 2] +
          // 2 LSB of i, 4 MSB of i+1
          base64_table[(arr[i] & 3) << 4 | (arr[i + 1] & 240) >> 4] +
          // 4 LSB of i+1, 2 MSB of i+2
          base64_table[(arr[i + 1] & 15) << 2 | (arr[i + 2] & 192) >> 6] +
          // 6 LSB of i+2
          base64_table[(arr[i + 2] & 63)];
        aux(arr, i + 3, r + str) tailstrict;

    local sanity = std.foldl(function(r, a) r && (a < 256), bytes, true);
    if !sanity then
      error 'Can only base64 encode strings / arrays of single bytes.'
    else
      aux(bytes, 0, ''),


  base64DecodeBytes(str)::
    if std.length(str) % 4 != 0 then
      error 'Not a base64 encoded string "%s"' % str
    else
      local aux(str, i, r) =
        if i >= std.length(str) then
          r
        else
          // all 6 bits of i, 2 MSB of i+1
          local n1 = [base64_inv[str[i]] << 2 | (base64_inv[str[i + 1]] >> 4)];
          // 4 LSB of i+1, 4MSB of i+2
          local n2 =
            if str[i + 2] == '=' then []
            else [(base64_inv[str[i + 1]] & 15) << 4 | (base64_inv[str[i + 2]] >> 2)];
          // 2 LSB of i+2, all 6 bits of i+3
          local n3 =
            if str[i + 3] == '=' then []
            else [(base64_inv[str[i + 2]] & 3) << 6 | base64_inv[str[i + 3]]];
          aux(str, i + 4, r + n1 + n2 + n3) tailstrict;
      aux(str, 0, []),

  base64Decode(str)::
    local bytes = std.base64DecodeBytes(str);
    std.join('', std.map(function(b) std.char(b), bytes)),

  reverse(arr)::
    local l = std.length(arr);
    std.makeArray(l, function(i) arr[l - i - 1]),

  // Merge-sort for long arrays and naive quicksort for shorter ones
  sortImpl(arr, keyF)::
    local quickSort(arr, keyF=id) =
      local l = std.length(arr);
      if std.length(arr) <= 1 then
        arr
      else
        local pos = 0;
        local pivot = keyF(arr[pos]);
        local rest = std.makeArray(l - 1, function(i) if i < pos then arr[i] else arr[i + 1]);
        local left = std.filter(function(x) keyF(x) < pivot, rest);
        local right = std.filter(function(x) keyF(x) >= pivot, rest);
        quickSort(left, keyF) + [arr[pos]] + quickSort(right, keyF);

    local merge(a, b) =
      local la = std.length(a), lb = std.length(b);
      local aux(i, j, prefix) =
        if i == la then
          prefix + b[j:]
        else if j == lb then
          prefix + a[i:]
        else
          if keyF(a[i]) <= keyF(b[j]) then
            aux(i + 1, j, prefix + [a[i]]) tailstrict
          else
            aux(i, j + 1, prefix + [b[j]]) tailstrict;
      aux(0, 0, []);

    local l = std.length(arr);
    if std.length(arr) <= 30 then
      quickSort(arr, keyF=keyF)
    else
      local mid = std.floor(l / 2);
      local left = arr[:mid], right = arr[mid:];
      merge(std.sort(left, keyF=keyF), std.sort(right, keyF=keyF)),

  sort(arr, keyF=id)::
    std.sortImpl(arr, keyF),

  uniq(arr, keyF=id)::
    local f(a, b) =
      if std.length(a) == 0 then
        [b]
      else if keyF(a[std.length(a) - 1]) == keyF(b) then
        a
      else
        a + [b];
    std.foldl(f, arr, []),

  set(arr, keyF=id)::
    std.uniq(std.sort(arr, keyF), keyF),

  setMember(x, arr, keyF=id)::
    // TODO(dcunnin): Binary chop for O(log n) complexity
    std.length(std.setInter([x], arr, keyF)) > 0,

  setUnion(a, b, keyF=id)::
    // NOTE: order matters, values in `a` win
    local aux(a, b, i, j, acc) =
      if i >= std.length(a) then
        acc + b[j:]
      else if j >= std.length(b) then
        acc + a[i:]
      else
        local ak = keyF(a[i]);
        local bk = keyF(b[j]);
        if ak == bk then
          aux(a, b, i + 1, j + 1, acc + [a[i]]) tailstrict
        else if ak < bk then
          aux(a, b, i + 1, j, acc + [a[i]]) tailstrict
        else
          aux(a, b, i, j + 1, acc + [b[j]]) tailstrict;
    aux(a, b, 0, 0, []),

  setInter(a, b, keyF=id)::
    local aux(a, b, i, j, acc) =
      if i >= std.length(a) || j >= std.length(b) then
        acc
      else
        if keyF(a[i]) == keyF(b[j]) then
          aux(a, b, i + 1, j + 1, acc + [a[i]]) tailstrict
        else if keyF(a[i]) < keyF(b[j]) then
          aux(a, b, i + 1, j, acc) tailstrict
        else
          aux(a, b, i, j + 1, acc) tailstrict;
    aux(a, b, 0, 0, []) tailstrict,

  setDiff(a, b, keyF=id)::
    local aux(a, b, i, j, acc) =
      if i >= std.length(a) then
        acc
      else if j >= std.length(b) then
        acc + a[i:]
      else
        if keyF(a[i]) == keyF(b[j]) then
          aux(a, b, i + 1, j + 1, acc) tailstrict
        else if keyF(a[i]) < keyF(b[j]) then
          aux(a, b, i + 1, j, acc + [a[i]]) tailstrict
        else
          aux(a, b, i, j + 1, acc) tailstrict;
    aux(a, b, 0, 0, []) tailstrict,

  mergePatch(target, patch)::
    if std.isObject(patch) then
      local target_object =
        if std.isObject(target) then target else {};

      local target_fields =
        if std.isObject(target_object) then std.objectFields(target_object) else [];

      local null_fields = [k for k in std.objectFields(patch) if patch[k] == null];
      local both_fields = std.setUnion(target_fields, std.objectFields(patch));

      {
        [k]:
          if !std.objectHas(patch, k) then
            target_object[k]
          else if !std.objectHas(target_object, k) then
            std.mergePatch(null, patch[k]) tailstrict
          else
            std.mergePatch(target_object[k], patch[k]) tailstrict
        for k in std.setDiff(both_fields, null_fields)
      }
    else
      patch,

  objectFields(o)::
    std.objectFieldsEx(o, false),

  objectFieldsAll(o)::
    std.objectFieldsEx(o, true),

  objectHas(o, f)::
    std.objectHasEx(o, f, false),

  objectHasAll(o, f)::
    std.objectHasEx(o, f, true),

  equals(a, b)::
    local ta = std.type(a);
    local tb = std.type(b);
    if !std.primitiveEquals(ta, tb) then
      false
    else
      if std.primitiveEquals(ta, 'array') then
        local la = std.length(a);
        if !std.primitiveEquals(la, std.length(b)) then
          false
        else
          local aux(a, b, i) =
            if i >= la then
              true
            else if a[i] != b[i] then
              false
            else
              aux(a, b, i + 1) tailstrict;
          aux(a, b, 0)
      else if std.primitiveEquals(ta, 'object') then
        local fields = std.objectFields(a);
        local lfields = std.length(fields);
        if fields != std.objectFields(b) then
          false
        else
          local aux(a, b, i) =
            if i >= lfields then
              true
            else if local f = fields[i]; a[f] != b[f] then
              false
            else
              aux(a, b, i + 1) tailstrict;
          aux(a, b, 0)
      else
        std.primitiveEquals(a, b),


  resolvePath(f, r)::
    local arr = std.split(f, '/');
    std.join('/', std.makeArray(std.length(arr) - 1, function(i) arr[i]) + [r]),

  prune(a)::
    local isContent(b) =
      if b == null then
        false
      else if std.isArray(b) then
        std.length(b) > 0
      else if std.isObject(b) then
        std.length(b) > 0
      else
        true;
    if std.isArray(a) then
      [std.prune(x) for x in a if isContent($.prune(x))]
    else if std.isObject(a) then {
      [x]: $.prune(a[x])
      for x in std.objectFields(a)
      if isContent(std.prune(a[x]))
    } else
      a,

  findSubstr(pat, str)::
    if !std.isString(pat) then
      error 'findSubstr first parameter should be a string, got ' + std.type(pat)
    else if !std.isString(str) then
      error 'findSubstr second parameter should be a string, got ' + std.type(str)
    else
      local pat_len = std.length(pat);
      local str_len = std.length(str);
      if pat_len == 0 || str_len == 0 || pat_len > str_len then
        []
      else
        std.filter(function(i) str[i:i + pat_len] == pat, std.range(0, str_len - pat_len)),

  find(value, arr)::
    if !std.isArray(arr) then
      error 'find second parameter should be an array, got ' + std.type(arr)
    else
      std.filter(function(i) arr[i] == value, std.range(0, std.length(arr) - 1)),
}